Saturday, March 17, 2018

neuroanatomy terms

PRENATAL MOUSE BRAIN ATLAS
Uta SchambraPh.D.
Department of Anatomy and Cell Biology,
Quillen College of Medicine
East Tennessee State University
Johnson CityTN
Color images and annotated diagrams of:
Gestational Days   and
Sagittalcoronal and horizontal section
PRENATAL MOUSE BRAIN ATLAS
Illustrations by Barbara A. Connelly
Author
Department of Anatomy and Cell Biology
Quillen College of Medicine
East Tennessee State University
P.O. Box
Johnson CityTN
USA
schambra@etsu.edu
􀂤  Springer Science+Business MediaLLC
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ISBN:
Uta Sc hambra
To my children EricKirstenand Heidi
vii
CONTENTS
Preface ix
Acknowledgements xi
Introduction xiii
Methods xv
References xvii
Index xix
Gestational Day
 Sagittal Sections
Enlargements: GangliaInner Ear
Pituitary
 Coronal Sections
Enlargements: Cranial Nerve Nuclei  (IIIIVVI)
Cranial Nerve Nuclei  (VmoVsenVmesVII)
 Horizontal Sections
Enlargements: CorticalThalamic and Tectal
Neuroepithelium
Eyes
Gestational Day
 Sagittal Sections
Enlargements: GangliaInner Ear
Cerebellum
 Coronal Sections
Enlargements: Septal AreaOlfactory Bulb and
Nerve
Eyes
 Horizontal Sections
Enlargements: Cortical NeuroepitheliumLateral
Ganglionic Eminence
Internal CapsuleStria terminalisStria Medullaris
Medulla
Cervical Spinal Cord
Gestational Day
 Sagittal Sections
Enlargements: Olfactory Bulb
Cerebellum
 Coronal Sections
Enlargements: CortexLateral Ganglionic Eminence
HippocampusThalamus
 Horizontal Sections
Enlargements: Cortex
Cervical Spinal Cord
Gestational Day
 Sagittal Sections
Enlargements: HippocampusThalamus,
Midline Forebrain Structure
 Coronal Sections
Enlargements: Olfactory Bulb
Corpus CallosumSeptal Area
 Horizontal Sections
Enlargements: Cerebellum
Olfactory Bulbs
Internal Capsu le
ix
PREFACE
This atlas is designed to support research in neurosciencegene
manipulationmolecular biology and neurotoxicology. For
researchers unfamiliar with the developing mouse brainfull
sections are shown to aid in the orientation and comparison to their
own sections. This atlas provides complete sets of sagittalcoronal
and horizontal sectionsuseful when determining which plane of
sectioning may be most advantageous for a particular study. For
instancesagittal and horizontal sections are well suited for a quick
scan of a brainwhile coronal sections provide more detailed
information. In the color images the hematoxylin stain provides
excellent information on neurons at different stages of
developmenti.e.neuroblasts in ventricular zones are darkly
stained while maturing neurons in intermediate zones are lightly
stained. In contrastdeveloping pathways and their glial scaffolding
are stained deeply pink with eosin. Regions of particular
developmental interestfor example the eyecranial nerve nuclei,
or gangliaare photographed at higher power to show different
stages of development. Special attention has been given to
ventricular zonesthe origin of all brain structuresin order to assist
tracking cells carrying a specific gene. For instanceusing the
bacterial artificial chromosome vector method of producing
transgenic mice (Nature : )the development of
the neurons in a gene specific nucleus could be traced back to two
progenitor cell in a related ventricular zone.
xi
ACKNOWLEDGEMENTS
I want to acknowledge my autistic son Ericwhose continued
struggle with his developmental disabilities inspired me to study
normal and abnormal brain development in order to contribute to the
research into the puzzle of autism.
Also I want to thank my graduate advisorsDrs. Jean Lauder and
Kathy Sulik who supported and encouraged me as an adult student to
begin this work. Part of my Ph. D. dissertation resulted in the first
prenatal mouse brain atlas (Atlas of the Prenatal Mouse BrainUta
B. SchambraJean M. Lauder and Jerry SilverAcademic Press,
). That effort reflected my still growing knowledge of the
developing mouse brain. I trust that the revisions in this new brain
atlas reflect the most recent knowledge in the field of murine
developmental neuroanatomy.
I am greatly indebted and thankful to my assistantBarbara A.
Connellyfor her outstanding technical work in preparation of the
computer drawings from my tracings. She skillfully and patiently
dealt with the neverending stream of annotationsand prepared the
manuscript and DVD for publication. I particularly appreciate her
tireless and goodnatured help throughout this project.
I also wish to express my gratitude to Brunhilde ToberMeyer,
DVMMSwho out of friendship gave up golden days of retirement
to tackle the unwieldy index (,+ entries were included). Her
positive attitude towards this project and meticulous work was a
great relief to me. I am very thankful for her help.
I thank the Pathology Department at East Tennessee State
University for the permission to use their Shandon Veristain
automated hematoxylin and eosin stainer to process the large number
of slides for this project.
This work was supported by the Dean of the Quillen College of
Medicine and the Department of Anatomy and Cell Biology at East
Tennessee State University and by Springer Science + Business
MediaLLC.
Thanks for their encouragement and patience to the editorial and
production staff at SpringerJoseph BurnsAnn AvourisDeborah
Doherty and Laurin Becker.
Lastbut not leastI want to recognize the excellent works by
Altman and BayerPaxinos et al.Jacobowitz and Abbottand
Kaufman (see reference list) whose publications helped me
tremendously in my understanding of the developing rodent brain.
xiii
INTRODUCTION
This Prenatal Mouse Brain Atlas provides comprehensive
documentation of mouse brain development until shortly before birth
(gestational day (GD) . average). It follows brain development
from early discernable structures in embryonic heads on GD  and
GD  to more clearly defined structures in fetal brains on GD
and GD . For additional informationsections are presented in the
three cardinal planessagittalcoronal and horizontal. Genetic or
toxicological manipulations may result in damaged offspring which
are recognized by the mouse dams and cannibalized within the first
few days. This makes studying the effects of manipulation in
postnatal animals problematicthus giving importance to a prenatal
mouse brain atlas.
For ease of usewe only use unabbreviated annotations. Structures
are identified with terms used in adult animals even if they are only
an anlage or a precursor. Tracts are often labeled even though axons
have not grown along the brightly eosin stained glial pathway.
For conveniencea DVD is provided which contains all color
imagesmatching drawings and the drawings superimposed on the
images. This DVD provides an additional tool for the researcher who
may want to print specific pages for further use.
The web siteElectronic Prenatal Mouse Brain Atlas,
www.epmba.orgprovides expanded sets of annotated GD  and
GD  coronal imageswhich can be viewed in high magnification.
The GD  coronal set can also be viewed as D presentationand
can be virtually sectioned at different planes.
xv
METHODS
The widely used inbred mouse strainCBl/J (The Jackson
Laboratories)was chosen for preparation of this atlas. Ten to
weekold females were timemated from  to  am. The day a
copulation plug was found was considered gestational day (GD) .
At the time of sacrifice ( am) on GD  or pregnant
dams were anesthetized with an intraperitoneal injection of chloral
hydrate ( mg/kg body weight). Embryos/fetuses were removed
from the uterusand their crownrump length (CRL) recorded.
Specimen of average CRL were chosen as follows: GD  mm;
GD  mm; GD  mm; and GD  mm.
GD  embryos were immersed in Bouin’s fixative for  hrsand
then rinsed in % ethanol for  week. GD  embryos and GD
and GD  fetuses were perfused transcardially at room temperature,
first with  ml of . M phosphate buffered saline (PBS)and then
for  to  min (depending on size) with % paraformaldehyde in
PBS using a Masterflex pump (flow rate . ml/min). Following
perfusionwhole heads (GD ) or brains (GD GD ) were
immersed overnight in the same fixative at °Cand then washed for
two days in several changes of PBS.
Specimens with similar CRL were selected and dehydrated in an
ascending series of ethanols and xylenes. For embedding in
Paraplastspecimens were placed on their sides for sagittalwith
faces down for coronalon their ventral surfaces for horizontal
sectioning. Sagittalcoronal and horizontal sections were then cut at
 􀈝m with a rotary microtome. Because of sidewise rotation of the
GD  embryos and the mesencepalic and pontine flexuressections
are not always strictly parallel to the midline or coronal. The GD
coronal embryo suffered forceps damage to its right cortexwhich
resulted in hematomas in the brain. Interestinglythese show well the
still nucleated red and other developing blood cells.
Tissue sections were deparaffinized in xylenes ( x  min);
ethanols (%:  x  min%;  x  min); running tap water
( min); stained with hematoxylin (Richard Allan #Fisher
Scientific;  min); rinsed with running tap water ( min); background
staining removed with acid alcohol ( ml conc. HCl /  ml %
ethanol;  sec); rinsed in running tap water ( min); passed through a
bluing solution (ammonia water;  ml NH /  ml HO;  sec);
rinsed in running tap water ( min) and % ethanol ( x  sec);
stained with eosin Y (Richard Allan #Fisher Scientific;  min);
dehydrated with % ethanol ( x  min); % ethanol ( x  min);
and xylenes ( x  min).
Stained sections were selected by areas of interest rather than at
equal intervals. Whole sections were photographed with a Spot
Insight  ver. ... digital camera (Diagnostic Instruments) using a
Leica Wild M macroscope. High magnification images were
photographed using a Leitz Laborlux S with xx and x
objectives. Images were captured on a Mac Power PC Gand then
traced using Adobe Illustrator CS ver. .. computer graphics
systems. Structures were delineated as follows: central nervous
system structuresinner ear and eye point (pt) solid; fiber tracts,
. pt dashed; gangliaolfactory and auditory epithelium. pt
solid; peripheral nerves. pt dotted; head structures. pt solid;
vessels. pt dashed. Color of images was adjustedif necessaryin
Adobe Photoshop CS ver. ..
xvii
REFERENCES
AltmanJ.and S. A. Bayer. (). “Atlas of the prenatal rat brain
development.” CRC PressAnn Arbor.
AltmanJ.and S. A. Bayer. (). “Development of the cerebellar system
in relation to its evolutionstructureand functions.” CRC PressAnn
Arbor.
CajalS. R. Y. (). “Histology of the nervous system of man and
vertebratesVol. .” Translated by Neely Swanson and Larry
W. Swanson. Oxford University PressNew York.
CajalS. R. Y. (). “Histology of the nervous system of man and
vertebratesVol. .” Translated by Neely Swanson and Larry
W. Swanson. Oxford University PressNew York.
CarpenterM. B. (). “Human neuroanatomy,” nd Ed. Williams and
WilkinsBaltimore.
HainesD. E. (). “Neuroanatomy: an atlas of structuressectionsand
systems,” th Ed. Lippincott Williams and WilkinsPhiladelphia.
JacobowitzD. M.and L. C. Abbott. (). “Chemoarchitectonic atlas of
the developing mouse brain.” CRC PressNew York.
JonesE. G. (). “The thalamus.” Cambridge University Press,
Cambridge.
KaufmanM. H. (). “The atlas of mouse development.” Academic
PressSan Diego.
Paxinos G. (). “The rat nervous system”nd Ed. Academic PressSan
Diego.
PaxinosG.K.W. S. Ashwelland I. Törk. (). “Atlas of the
developing rat nervous system,” th Ed. Academic PressSan Diego.
PaxinosG.and K. B. J. Franklin. (). “The mouse brain in stereotaxic
coordinates,” nd Ed. Academic PressSan Diego.
PaxinosG.G. HallidayC. WatsonY. Koutcherovand H. Wang. ().
“Atlas of the developing mouse brain at E.POand P.” Academic
PressSan Diego.
ValverdeF. (). “Golgi atlas of the postnatal mouse brain.” Springer
VerlagNew York.
INDEX
A
A (Noradrenergic nuclear complex) ·

A (Locus coeruleus) · 

 
A (Substantia nigra) · 
 


A (Substantia nigracompact part) · ,

A (Substantia nigrareticular part) ·

A (Ventral tegmental area) ·  ,
  ,
 
Abducens nerve (VI) ·  ,

Abducens nucleus · 


Accessory cuneate nucleus · See External
(lateral) cuneate nucleus
Accessory nerve (XI) ·
Accessory nucleus · 
Accessory olfactory bulb ·

 
Accumbens nucleus ·  ,
 
  ,
 
 
Accumbens nucleusventricular zone,
lateral ventricle ·
Adenohypophysis (Pituitaryanterior lobe)
· 

Adrenergic nucleus (C) ·
Alveus · 

Ambiguus nucleus ·
 

Amygdala ·
 
Amygdalasubventricular zonelateral
ventricle ·
Amygdalaventricular zonelateral
ventricle ·
Amygdalohippocampal area ·
Amygdaloid neuroepithelium ·
 
 
Anterior ampulla ·
Anterior amygdaloid area ·  ,

Anterior chamber of eye ·
Anterior commissure ·
 
  ,

Anterior commissureanterior part ·
  ,
 
  ,

Anterior commissureposterior part ·
 
  ,

Anterior diencephalic fold ·  ,

Anterior hypothalamic area ·  ,
 

Anterior hypothalamic areaintermediate
zone ·
Anterior hypothalamic areaventricular
zone ·
Anterior hypothalamic neuroepithelium ·

Anterior hypothalamic nucleus ·
 

Anterior olfactory nucleus ·  ,

xix
A (Dopaminergic nuclear complex) ·
Anterior cerebral artery ·
 
Anterior commissureintrabulbar part ·
Anterior lobe (of pituitaryAdenohypophysis)

 
xx Index
 

Anterior olfactory nucleusdorsal part ·

Anterior olfactory nucleuslateral part ·
 
Anterior olfactory nucleusmedial part ·

Anterior olfactory nucleusposterior part ·

Anterior olfactory nucleusventral part ·
 
Anterior pretectal nucleus ·
 
 
Anterior (superior) semicircular canal ·


Anterior thalamic nucleus · 
 

Anterior thalamic nucleusintermediate
zone ·
Anterior thalamic nucleusventricular zone
· 
Anterodorsal hypothalamic nucleus · ,
 
Anterodorsal preoptic nucleus ·
Anterodorsal thalamic nucleus ·

Anteromedial thalamic nucleus ·


Anteroventral hypothalamic nucleus · ,
 
Anteroventral thalamic nucleus ·
 
Aqueduct · 
 
  ,
  ,
 
Aqueductintermediate zoneinferior
Aqueductintermediate zonetegmentum ·

Aqueductsubventricular zonetectum ·

Aqueductventricular zoneinferior
colliculus ·

Aqueductventricular zoneperiaqueductal
gray ·
Aqueductventricular zonesuperior
colliculus · 
Aqueductventricular zonetectum · ,
 
Aqueductventricular zonetegmentum ·
 
Arcuate hypothalamic nucleus ·  ,
 


Area postrema ·
Atlas (C vertebra) ·
Auditory cortex · 
Auditory cortexcortical plate ·
Auditory cortexlateral ventricle,
intermediate zone ·
Auditory cortexmarginal zone ·
Auditory cortexlateral ventricle,
subventricular zone ·
Auditory cortexlateral ventricle,
ventricular zone ·
Auditory meatus ·
B
B (Raphe pallidus nucleus) ·  ,
 
B (Serotonergic nuclear complex) ·

B (Raphe obscurus nucleus) ·  ,
 
 
B (Raphe magnus nucleus) ·  ,
 


B (Median raphe nucleuspons) ·
 


B (Dorsal raphe nucleuspons) ·

B (Dorsal raphe nucleusmidbrain) · ,
 


B (Median raphe nucleusmidbrain) ·

Basal nucleus of Meynert ·
Basilar artery · 
Basioccipital bone · 
Basolateral amygdaloid nucleus ·


Basomedial amygdaloid nucleus · ,
 

Basosphenoid bone ·
Bed nucleus of accessory olfactory tract ·

Bed nucleus of stria terminalis ·

 
 

colliculus · 


Index xxi
Blood vessel ·   
Brachium of inferior colliculus ·

 
Brachium of superior colliculus ·
 
 


C
C (Adrenergic nucleus) ·
CA (Hippocampal region) ·
CA (Hippocampal region) ·
CA (Hippocampal region) · 
CA (Hippocampal region) ·
CajalRetzius cells ·
Cavernous sinus ·  ,
,
Cavity of lens vesicle · 
Cavum of septum pellucidum ·
Central amygdaloid nucleus · ,
Central canal · 

Central canalventricular zonespinal cord
·
Central gray · See Periaqueductal gray
Central lateral thalamic nucleus ·
Central medial thalamic nucleus ·
 
 
 
Central medial thalamic nucleus,
subventricular zonethird ventricle ·

Central medial thalamic nucleus,
ventricular zonethird ventricle · ,

Central tegmental tract · 
Central thalamic nucleus · See Rhomboid
thalamic nucleus
Cephalic flexure · See Mesencephalic
flexure
Cerebellar neuroepithelium ·

Cerebellar nuclear neuronsmigrating · ,

Cerebellum ·  ,

Cerebellumintermediate zonefourth
ventricle ·
Cerebellumrhombic lip ·
Cerebellumventricular zonefourth
ventricle · 

Cerebral peduncle ·  ,

 
  ,

Cervical flexure ·
Cervical spinal cord ·
Cervical spinal nerves ·
Choroid fissure ·
Choroid plexus ·
  ,

 
 


Cingulate cortex · 
 



Cingulate cortexmarginal zone ·
Cingulate cortexventricular zonelateral
ventricle · 
Cingulum · 

Claustrum ·

Cochlear duct ·
  ,

Cochlear nerve (VIII) ·
 
Cochlear neuroepithelium · 
 
 
Cochlear (spiral) ganglion · 
  ,

Commissure of inferior colliculus ·
Commissure of superior colliculus ·

 
Cornea ·
Corneal epithelium · 
Corneal stroma ·
Corpus callosum ·  ,
 
Corpus callosumanterior forceps ·
 
Corpus callosumgenu ·  ,


Caudateputamen · See also striatum · ,
  ,
  ,



 
 
xxii Index
Corpus callosumposterior forceps ·
 
Corpus callosumsplenium ·

Cortexintermediate zonelateral ventricle
·
  ,


Cortexsubventricular zonelateral
ventricle ·
 
 

 
Cortexventricular zonelateral ventricle ·
 
  ,


 
Cortical amygdaloid nucleus ·
 
 
Cortical neuroepithelium ·
 
  ,

Cortical plate · 

  ,
  ,

Crista (of anterior ampulla) ·
Crista (of posterior ampulla) ·
Cuneate fasciculus · 
 
Cuneate nucleus ·
 
D
Decussation of superior cerebellar
peduncle · 

Dentate gyrus ·

 
Dentate gyrusdorsal part ·
Dentate gyrusneuroepithelium ·
Dentate gyrusventral part ·
Dentate (lateral) nucleus ·  ,


Dentatothalamic fasciculus · 
Diagonal band of Broca ·  ,
 
Dorsal cochlear nucleus ·  ,


Dorsal diencephalic sulcus ·
Dorsal endopiriform nucleus ·


Dorsal funiculus · 
Dorsal horn ·

Dorsal lateral geniculate nucleus ·

 

Dorsal lateral olfactory tract ·
 
 
Dorsal longitudinal fasciculus ·
Dorsal motor nucleus of vagus ·  ,
 
 
Dorsal nucleus of lateral lemniscus · ,

 

Dorsal premammillary nucleus ·
Dorsal raphe nucleusmidbrain (B) · ,
 


Dorsal raphe nucleuspons (B) ·

Dorsal tegmental bundle ·
Dorsal tegmental nucleus ·
 
Dorsal thalamusneuroepithelium · ,
 
Dorsomedial hypothalamic nucleus · ,
 
 

Dorsomedial tegmental area ·
Dorsomedial thalamic nucleus · See
Mediodorsal thalamic nucleus
E
Ear canal ·
Enamel organ (lower incisor) ·
Enamel organ (lower molar) ·
Enamel organ (upper incisor) ·
Enamel organ (upper molar) ·
Endolymphatic duct · 

Entopeduncular nucleus ·  ,
 
Entorhinal cortex · 
 

Dopaminergic nuclear complex (A) ·
Dorsal root ganglion · 
Index xxiii
Ependyma ·
Epidural space ·
Epithalamic neuroepithelium ·
 
Epithalamus ·
 
Epithalamusventricular zonethird
ventricle · 
Esophagus · 
Eustachian tube ·

External auditory meatus ·  ,

External capsule · 

  ,
  ,

External granular layer (of cerebellum) ·
See External germinal layer (of
cerebellum)
External germinal layer (of cerebellum) ·

 

 

External (lateral) cuneate nucleus · ,
 
External medullary lamina ·

 
 

External plexiform layer ·  ,
 
 
Extreme capsule · 
Eye · 
Eyeouter layer ·
Eyelid · 
F
Facial nerve (VII) · 
 
 
 
 
Facial nerve (VII)genu ·  ,
 

Facial nucleus · 
  ,
 

Facial nucleuslateral part ·  ,

Facial nucleusmedial part ·  ,

Facial nucleusventricular zonefourth
ventricle · 
Fasciculus retroflexus · 

 
 
 
Fastigial (medial) nucleus ·  ,


Fimbria ·
 
 

Floor of fourth ventricle · 
Floor plate ·
Forel’s field · 

Fornix ·
 
 

 
Fornixcolumn ·

Fornixpostcommissural ·

Fornixprecommissural ·
Fourth ventricle · 

 

Fourth ventricleintermediate zone,
cerebellum ·
Fourth ventricleventricular zone · ,

Fourth ventricleventricular zone,
cerebellum · 

Fourth ventricleventricular zonemedulla
· 
Fourth ventricleventricular zonepons ·

Fourth ventricleventricular zone,
precerebellar nuclei ·
Fourth ventricleventricular zone,
vestibular nuclei ·
Frontal cortex · 
Frontal cortexmarginal zone · 
Frontal cortexventricular zonelateral
ventricle · 
Frontopolar cortex ·
Frontopolar cortexmarginal zone ·
Frontopolar cortexventricular zonelateral
ventricle ·
Fusion of palatal shelves ·

xxiv Index
G
Ganglion cell layer · 

Gasserian ganglion · See Trigeminal
(semilunar) ganglion
Geniculate ganglion ·
 
Germinal trigone ·

 

Gigantocellular reticular nucleus ·

 

Glial palisades · 
Glial wedge · 
Globus pallidus · 



Glomerular layer ·
 
 
Glossopharyngeal nerve (IX) ·  ,


Gracile fasciculus · 

Gracile nucleus · 

Granular layer (of dentate gyrus) · ,
 
Granular layer (of olfactory bulb) · See
Granule cell layer (of olfactory bulb)
Granule cell layer (of dentate gyrus) · See
Granular layer (of dentate gyrus)
Granule cell layer (of olfactory bulb) ·
 
  ,

H
Habenular commissure · 

 
Habenular neuroepithelium ·
Habenular nuclei ·
Habenular recess · 

Habenulointerpeduncular tract · See
Fasciculus retroflexus
Hair follicle ·
Hematoma · 
Hippocampal fissure · 
Hippocampal formation ·  ,
 
Hippocampal neuroepithelium ·


Hippocampal region (CA) ·
Hippocampal region (CA) ·
Hippocampal region (CA) · 
Hippocampal region (CA) ·
Hippocampus ·


 
 

Hippocampusdorsal part ·
Hippocampusintermediate zone · ,
  ,
 
Hippocampussubventricular zone · ,

Hippocampusventral part ·
Hippocampusventricular zone ·

  ,
 
Hook bundle · 
Horizontal (lateral) semicircular canal ·
 
Hyaloid artery ·
Hyaloid cavity · 
Hyaloid vascular plexus · 
 
Hypoglossal nerve (XII) · 
 
Hypoglossal nucleus · 
 
 
Hypothalamic neuroepithelium ·

Hypothalamus · 

Hypothalamusventricular zonethird
ventricle · 
I
Indusium griseum · 
Inferior alveolar nerve (V) ·
Inferior cerebellar peduncle ·  ,
 

 
 

Inferior cervical ganglion ·
Inferior colliculus · 
 

  ,
 
Index xxv
Inferior colliculusintermediate zone,
aqueduct · 
Inferior colliculusneuroepithelium · ,

Inferior colliculusventricular zone,
aqueduct ·

Inferior facial ganglion · See Geniculate
ganglion
Inferior glossopharyngeal (petrosal)
ganglion · 

Inferior medullary velum · 
 
Inferior oblique muscle ·
Inferior olive · 
 
 
Inferior rectus muscle ·

Inferior vagal (nodose) ganglion ·

Inferior vestibular nucleus · 

 
Infralimbic cortex · 
Infundibular recess · 


Infundibular stalk ·
Infundibulum ·
Insular cortex · 
  ,


Interfascicular nucleus · 
Interhemispheric fissure · See Longitudinal
cerebral fissure
Intermediate gray (of spinal cord) · ,
 
Intermediate hemisphere (of cerebellum) ·
See Paravermis
Intermediate horn ·
Intermediate lobe (of pituitary) · ,

Intermediate nerve ·
Intermediate nucleus of lateral lemniscus ·

Intermediate reticular nucleus ·
Intermediate subpallial sulcus ·  ,

Intermediate zoneanterior hypothalamus ·

Intermediate zoneanterior thalamic
nucleus ·
Intermediate zoneaqueductinferior
colliculus · 
Intermediate zoneaqueducttegmentum ·

Intermediate zonefourth ventricle,
cerebellum ·
Intermediate zonehippocampus ·
  ,

Intermediate zonelateral ventricle,
auditory cortex ·
Intermediate zonelateral ventriclecortex ·
  ,
  ,


Intermediate zonelateral ventriclelateral
ganglionic eminence · 
Intermediate zonelateral ventriclemedial
ganglionic eminence · 
Intermediate zonelateral ventricle,
pallidum ·
Intermediate zonelateral ventricle,
piriform cortex ·
Intermediate zonelateral ventricleseptal
area · 
Intermediate zoneneural retina ·

Intermediate zoneolfactory ventricle,
olfactory bulb · 
Intermediate zonethird ventriclelateral
preoptic area ·
Intermediate zonethird ventriclemedial
preoptic area ·
Intermediate zonethird ventricle,
paratenial thalamic nucleus ·
Internal arcuate fibers ·
Internal capsule · 
 
 


Internal carotid artery · 



Internal jugular vein ·

Internal medullary lamina ·
Internal plexiform layer ·  ,


Interpeduncular fossa · 
 
Interpeduncular nucleus · 
 
 
Interpeduncular nucleuscaudal part ·
Interpeduncular nucleusrostral part ·
Interposed nucleus · 
 

Interstitial nucleus · 

xxvi Index
Interventricular foramen ·  ,
 


Intraretinal (subretinalventricular) space
(of eye)· 
Intrinsic muscle ·
Isthmal canal ·
Isthmal neuroepithelium ·
Isthmal recess ·
Isthmus ·   


J
Jacob’s organ · See Vomeronasal organ
Jugular (superior vagal) ganglion · See
Superior vagal (jugular) ganglion
L
Lacunosummoleculare layer ·

Lamina terminalis ·
 
Laryngopharynx ·
Larynx ·
Lateral amygdaloid nucleus ·


Lateral cuneate nucleus · See External
(lateral) cuneate nucleus
Lateral (dentate) nucleus (of cerebellum) ·
Lateral dorsal thalamic nucleus ·
 
  ,

Lateral dorsal thalamic nucleusventricular
zonethird ventricle ·
Lateral funiculus ·

Lateral ganglionic eminence · 
 
 

 
Lateral ganglionic eminenceintermediate
zonelateral ventricle · 
Lateral ganglionic eminence,
subventricular zonelateral ventricle ·
 

Lateral ganglionic eminenceventricular
zonelateral ventricle ·
 
Lateral habenular nucleus ·  ,

 

Lateral hemisphere (of cerebellum) · ,
 
  ,

Lateral horn ·
Lateral hypothalamic area ·



Lateral hypothalamuspeduncular part ·

Lateral lemniscus · 
 
 
 
 
Lateral mammillary nucleus ·
 

Lateral migratory stream · ,
 
 

Lateral migratory streamhead · ,
 
Lateral migratory streamreservoir · ,
 
 
Lateral olfactory tract ·
  ,
 
 
Lateral orbital cortex ·
Lateral parabrachial nucleus ·

Lateral paragigantocellular nucleus ·
Lateral posterior thalamic nucleus ·

 

Lateral preoptic area · 
 
 
Lateral preoptic areaintermediate zone,
third ventricle ·
Lateral preoptic areaventricular zone,
third ventricle ·
Lateral preoptic nucleus ·
Lateral rectus muscle ·
Lateral reticular nucleus · 
Lateral septal nucleus ·  ,

 




  ,

Index xxvii
Lateral septal nucleusdorsal part ·
Lateral septal nucleusintermediate part ·

Lateral septal nucleusventral part ·
Lateral tracts ·
Lateral ventricle ·  ,
 
 
 
 
  ,

Lateral ventricleanterior horn ·
 

Lateral ventricleintermediate zone,
Lateral ventricleintermediate zonecortex
·
  ,


Lateral ventricleintermediate zonelateral
ganglionic eminence · 
Lateral ventricleintermediate zonemedial
ganglionic eminence · 
Lateral ventricleintermediate zone,
pallidum ·
Lateral ventricleintermediate zone,
piriform cortex ·
Lateral ventricleintermediate zoneseptal
area · 
Lateral ventricleposterior horn · ,
 

Lateral ventriclesubventricular zone,
amygdala ·
Lateral ventriclesubventricular zone,
auditory cortex ·
Lateral ventriclesubventricular zone,
cortex · 
 



Lateral ventriclesubventricular zone,
lateral ganglionic eminence ·


Lateral ventriclesubventricular zone,
medial ganglionic eminence ·

Lateral ventriclesubventricular zone,
pallidum ·
Lateral ventriclesubventricular zone,
septal area · 

Lateral ventriclesubventricular zone,
subiculum ·
Lateral ventricleventricular zone,
accumbens nucleus ·
Lateral ventricleventricular zone,
amygdala ·
Lateral ventricleventricular zone,
auditory cortex ·
Lateral ventricleventricular zone,
cingulate cortex · 
Lateral ventricleventricular zone,
cortex ·
  ,

 
 

Lateral ventricleventricular zonefrontal
cortex · 
Lateral ventricleventricular zone,
frontopolar cortex ·
Lateral ventricleventricular zonelateral
ganglionic eminence ·  ,
 
Lateral ventricleventricular zonemedial
ganglionic eminence · 
Lateral ventricleventricular zone,
occipital cortex ·
Lateral ventricleventricular zone,
pallidum ·
Lateral ventricleventricular zoneparietal
cortex ·
Lateral ventricleventricular zoneseptal
area · 
Lateral ventricleventricular zone,
subiculum ·
Lateral vestibular nucleus · 


 
Laterodorsal tegmental nucleus ·
Lens ·   

Lens bow region · 
Lens epithelium · 
Lenticular fasciculus · 

Lingual nerve (V) ·
Lithoid nucleus ·
Locus coeruleus (A) · 

 
Longitudinal cerebral fissure ·  ,

 
Longitudinal fasciculuspons ·
 
Longitudinal stria ·
Lower eyelid · 
Lower jaw (mandible) ·
auditory cortex ·
xxviii Index
M
Macula (of utricle) ·
Magnocellular nucleus (of lateral
hypothalamus) · 
Magnocellular nucleus of posterior
commissure ·
Magnocellular preoptic nucleus ·

Mammillary areaventricular zonethird
ventricle ·
Mammillary body · 
Mammillary neuroepithelium ·  ,
 
Mammillary peduncle ·
Mammillary recess · 
 

Mammillotegmental tract ·  ,

 
 
Mammillothalamic tract ·
 


Mandibular nerve (V) ·  ,
  ,

Mandibular process · 
 
Marginal zone · 
  ,
  ,


Marginal zoneauditory cortex ·
Marginal zonecingulate cortex ·
Marginal zonefrontal cortex · 
Marginal zonefrontopolar cortex ·
Marginal zoneparietal cortex ·
Marginal zonesomatosensory cortex ·
Masseter muscle · 
Maxilla ·
Maxillary nerve (V) ·  ,
 
 
Maxillary process · 
 
Meckel’s cartilage ·

Medial accessory oculomotor nucleus ·

Medial amygdaloid nucleus ·  ,
 
 
Medial diencephalic sulcus ·  ,

Medial (fastigial) nucleus (of cerebellum) ·

Medial forebrain bundle · 
  ,

 
Medial ganglionic eminence · ,

 
Medial ganglionic eminenceintermediate
zonelateral ventricle · 
Medial ganglionic eminence,
subventricular zonelateral ventricle ·

Medial ganglionic eminenceventricular
zonelateral ventricle ·  ,

Medial geniculate nucleus · 
 
   
 
Medial habenular nucleus · 

  ,

Medial habenular nucleusventricular
zonethird ventricle ·
Medial lemniscus ·  ,

 
 
 
  ,

Medial longitudinal fasciculus · ,

 
 
  ,

Medial mammillary nucleus · ,

 
Medial motor nucleus (of spinal cord) ·

Medial nasal prominence ·
Medial orbital cortex ·
Medial parabrachial nucleus ·

Medial paralemniscal nucleus ·
Medial preoptic area · 
 


Medial preoptic areaintermediate zone,
third ventricle ·
Medial preoptic areaventricular zone,
third ventricle ·
Medial preoptic nucleus ·  ,
 

 
Index xxix
Medial pretectal nucleus ·  ,

Medial rectus muscle ·  ,

Medial septal nucleus ·


 
Medial tuberal nucleus ·  ,
 

Medial vestibular nucleus · 
 
 
 

Median eminence · 
 

Median fibrous septum (of tongue) ·
Median preoptic nucleus ·  ,

Median raphe nucleusmidbrain (B) ·

Median raphe nucleuspons (B) · ,
 


Mediodorsal thalamic nucleus ·  ,
 



Mediodorsal thalamic nucleus,
subventricular zonethird ventricle ·

Mediodorsal thalamic nucleusventricular
zonethird ventricle ·
Medulla ·
 
Medullaventricular zonefourth ventricle
· 
Mesencephalic flexure · 
Mesencephalic trigeminal nucleus ·

 
 
 
Mesencephalic trigeminal tract (V) · ,
 
Microcellular tegmental nucleus ·


Midbrain · 
Middle cerebellar peduncle ·  ,
 
 
 

Middle cerebral artery · 
Middle cerebral vein ·
Middle diencephalic fold ·  ,

Midline ·
Midline fusion of palatal shelves ·
Midline zipper glia ·
Mitotic cells · 
Mitral cell layer · 
 


Molecular layer (of cerebellum) ·
 


Molecular layer (of hippocampus) · ,

Motor cortex · 
  ,
  ,
 

Motor neurons ·
Motor nucleus (of ventral horn) ·

N
Nasal capsule ·
Nasal cartilage ·
Nasal cavity ·  ,
 
Nasal septum · 

Nasopharynx · 
Neural retina · 

Neural retinaintermediate zone ·

Neural retinaventricular zone ·
 
Neuroepitheliumamygdaloid ·  ,
 
 
Neuroepitheliumcerebellar ·
 
Neuroepitheliumcochlear ·  ,
 
 
Neuroepitheliumcortical ·
 
  ,

Neuroepitheliumdentate gyrus ·
Neuroepitheliumdorsal thalamus · ,
 
Neuroepitheliumepithalamic ·

Neuroepitheliumhabenular ·
xxx Index
Neuroepitheliumhippocampal ·  ,
 

Neuroepitheliumhypothalamic ·
 
Neuroepitheliuminferior colliculus · ,

Neuroepitheliumisthmal ·
Neuroepitheliummammillary ·  ,
 
Neuroepitheliumolfactory ·  ,

 
Neuroepitheliumpontine ·
Neuroepitheliumposterior hypothalamic ·

Neuroepitheliumposterior precerebellar ·

Neuroepitheliumprecerebellar ·

Neuroepitheliumpreoptic · 
 
Neuroepitheliumpretectal · 
Neuroepitheliumseptal · 


 
Neuroepitheliumspinal cord · 
Neuroepitheliumstriatal ·  ,
  ,

 
 
Neuroepitheliumtectal ·  ,
 

Neuroepitheliumtegmental ·
Neuroepitheliumthalamic ·  ,

Neuroepitheliumventral thalamus · ,

Neuroepitheliumvestibular ·  ,


Neurohypophysis (Pituitaryposterior lobe)

Nigrostriatal bundle · 
Nodose ganglion · See Inferior vagal
(nodose) ganglion
Noradrenergic nuclear complex (A) ·

Nostril (external naris) · 
Nuclei of lens fibers ·

Nucleus of brachium of inferior colliculus ·
 
Nucleus of Darkschewitsch ·
 
Nucleus of horizontal limb of diagonal
band · 

 

Nucleus of inferior colliculus · ,
 
Nucleus of lateral olfactory tract · ,
 

Nucleus of optic tract · 

Nucleus of posterior commissure · ,

Nucleus of stria medullaris ·  ,

Nucleus of trapezoid body ·  ,

Nucleus of vertical limb of diagonal band ·


 
Nucleus proprius ·
O
Occipital cortex ·

Occipital cortexventricular zonelateral
ventricle·
Occipital sinus ·
Oculomotor nerve (III) ·
 

Oculomotor nucleus ·

 
Olfactory artery ·

Olfactory bulb ·
  ,



Olfactory bulbintermediate zone,
olfactory ventricle · 

Olfactory bulbsubventricular zone,
olfactory ventricle · 
 
Olfactory bulbventricular zoneolfactory
ventricle · 
 

Olfactory cortex · See Piriform cortex
Olfactory epithelium ·  ,
  ,
 
 
 
Neuroepitheliumpallidal ·
· 
Index xxxi
Olfactory nerve (I) ·  ,
 
 
 
Olfactory nerve layer · 

 
 
Olfactory neuroepithelium ·  ,

 
Olfactory tubercle · 

 


Olfactory ventricle · 
 
 
 
Olfactory ventricleintermediate zone,
olfactory bulb · 
Olfactory ventriclesubventricular zone,
olfactory bulb ·

Olfactory ventricleventricular zone,
olfactory bulb ·


Olivary pretectal nucleus ·
Ophthalmic nerve (V) ·
 
Optic chiasm ·
 
 
Optic cupinner layer ·
Optic cupouter layer ·
Optic disk ·
Optic fiber layer ·

Optic nerve (II) · 
 


Optic pit ·
Optic recess ·

 
Optic stalk ·
 
Optic tract ·
  ,


 

 

Oral cavity · 
  ,

Orbital cavity ·
Orbital cortex ·


Organum vasculosum ·
Oriens layer · 

Oropharynx · 

Otic ganglion ·
Otocyst ·

Outer nuclear layer of retina ·
P
Palatal shelf · 

Pallidal neuroepithelium ·
 
 
Pallidumintermediate zonelateral
ventricle ·
Pallidumsubventricular zonelateral
ventricle ·
Pallidumventricular zonelateral ventricle
·
Parabigeminal nucleus ·
Parabrachial nucleus · 


Paracollicular tegmentum ·
Parafascicular thalamic nucleus ·
 

 
Paramedian raphe nucleus ·  ,

Parapyramidal reticular nucleus ·

Parasubthalamic nucleus ·  ,

Paratenial thalamic nucleus ·
 
Paratenial thalamic nucleusintermediate
zonethird ventricle ·
Paraventricular hypothalamic nucleus · ,

 
 
Paraventricular hypothalamic nucleus,
ventricular zonethird ventricle ·
Paraventricular thalamic nucleus ·

 
 

xxxii Index
Paraventricular thalamic nucleus,
subventricular zonethird ventricle ·
Paraventricular thalamic nucleus,
ventricular zoneventricular zone · ,

Paravermis ·

Parietal cortex · 
Parietal cortexmarginal zone ·
Parietal cortexventricular zonelateral
ventricle · 
Parvocellular reticular nucleus ·
Pedunculopontine tegmental nucleus · ,

Periaqueductal gray · 
 
Periaqueductal grayventricular zone,
aqueduct ·
Perineural mesenchyme · 
Periolivary nucleus ·
Periventricular hypothalamic nucleus · ,

Petrosal ganglion · See Inferior
glossopharyngeal (petrosal) ganglion
Pharynx ·
Philtrum ·
Piaarachnoid ·
Pia mater ·
Pineal gland · 
 
 
Pineal recess ·
 
Pinna (of ear) · 
Piriform cortex · 
 



Piriform cortexintermediate zonelateral
ventricle ·
Pituitary · 
 
Pituitaryanterior lobe (Adenohypophysis)
· 

Pituitaryintermediate lobe ·

Pituitaryposterior lobe (Neurohypophysis)
· 

Polymorph layer (of hippocampus) · ,

Pons ·
 
Ponsventricular zonefourth ventricle ·

Pontine flexure ·
Pontine neuroepithelium ·
Pontine nuclei · 

 
Pontine reticular nucleus ·
 
 

Posterior ampulla ·
Posterior cerebral artery · 

Posterior commissure ·  ,
 


Posterior communicating artery ·
Posterior diencephalic fold ·  ,

Posterior dorsal tegmental nucleus ·
Posterior hypothalamic area ·  ,
 


Posterior hypothalamic areaventricular
zoneventricular zone ·
Posterior hypothalamic neuroepithelium ·

Posterior hypothalamic nucleus ·
Posterior lobe (of pituitary,
Neurohypophysis) ·  ,

Posterior precerebellar neuroepithelium ·

Posterior pretectal nucleus ·  ,

Posterior semicircular canal ·  ,
 

Posterior thalamic nucleus · 
 
 

Posterior thalamic nucleusventricular
zoneventricular zone ·
Precerebellar (extramural) migration · ,

Precerebellar (intramural) migration · ,

Precerebellar migration ·  ,




Precerebellar nucleiventricular zone,
fourth ventricle ·
Precerebellar neuroepithelium ·


  ,
Index xxxiii
Precommissural nucleus ·  ,
 

Prelimbic cortex ·
Premammillary nucleus ·  ,

Preoptic area ·
Preoptic neuroepithelium ·  ,

Prepositus hypoglossal nucleus ·

 
Presphenoid wing · 
Pretectal neuroepithelium · 
Pretectum · 
Pretectumventricular zonethird ventricle
· 
Primary lens fibers ·
Primary palate ·
Principal mammillary tract · 
 
 

Principal (sensory) trigeminal nucleus · ,
 
  ,
  ,
 
Purkinje cell layer ·  ,
 


Purkinje cellsmigrating ·
Pyramidal cell layer (of hippocampus) ·

 
 
Pyramidal decussation · 
Pyramidal tract · 
 
  ,

R
Radiatum layer · 
Raphe magnus nucleus (B) ·  ,
 


Raphe obscurus nucleus (B) ·  ,


Raphe pallidus nucleus (B) ·  ,
 
Rathke’s pouch · 
 
Red blood cells (nucleated) ·  ,
 
Red nucleus ·

 

Reticular formationmedulla ·  ,
 

Reticular formationmidbrain ·
 

Reticular formationpons ·
 
Reticular thalamic nucleus ·
 
  ,
 

Reticulospinal tract ·
Reticulotegmental nucleus ·  ,
 
Retinal pigment epithelium · 


Retrorubral field ·
Retrosplenial cortex ·

  ,

Reuniens thalamic nucleus ·  ,



Reuniens thalamic nucleussubventricular
zonethird ventricle · 
Reuniens thalamic nucleusventricular
zonethird ventricle ·  ,

Rhinal fissure ·

Rhomboid thalamic nucleus ·

Roof of lateral ventricle ·
Roof of oral cavity ·
Roof plate · 
Rostral linear raphe nucleus ·
Rubrospinal tract ·
S
Saccule ·
 
Scarpa’s ganglion · See Vestibular
(Scarpa’s) ganglion
Sclera · 
Semilunar ganglion · See Trigeminal
(semilunar) ganglion Septal area ·
Septal areaintermediate zonelateral
ventricle · 
 
 
xxxiv Index
Septal areasubventricular zonelateral
ventricle · 
Septal areaventricular zonelateral
ventricle ·

Septal cartilage ·
Septal neuroepithelium ·


 
Septofimbrial nucleus · 

Septohippocampal nucleus ·
Serotonergic nuclear complex (B) ·

Serous gland ·
Sinusoids · 
Sling cells · 
Solitary tract · 
 

 

Solitary tract nucleus ·
 
  ,


Somatosensory cortex ·  ,
 

 

Somatosensory cortexmarginal zone ·
Spinal cord · 
 
Spinal cord neuroepithelium · 
Spinal cordventricular zonecentral canal
·
Spinal trigeminal nucleus ·  ,
  ,
  ,
  ,

Spinal trigeminal tract (V) ·  ,
  ,
  ,
 

Spinal vestibular nucleus · See Inferior
vestibular nucleus
Spinocerebellar tract ·
Spinothalamic tract ·
Spiral (cochlear) ganglion · See Cochlear
(spiral) ganglion
Stria medullaris · 
 
  ,
 
 
Striatal neuroepithelium ·  ,



Striatum· See also Caudateputamen· ,
 
Subcommissural organ ·

 
Subfornical organ · 
 
 
Subgeniculate nucleus ·
Subiculum · 
 

Subiculumsubventricular zonelateral
ventricle ·
Subiculumventricular zonelateral
ventricle ·
Submandibular gland ·  ,

Subparafascicular thalamic nucleus · ,
 

Subplate ·
  ,

Subretinal space · See Intraretinal
(subretinalventricular) space (of eye)
Substantia gelatinosa ·
Substantia innominata · 
 
Substantia nigra (A) · 
 


Substantia nigra (A)compact part · ,

Substantia nigra (A)reticular part ·

Subthalamic nucleus ·
 
 
Subventricular zoneaqueducttectum ·

Subventricular zonecentral medial
thalamic nucleus · 
Subventricular zonehippocampus · ,

Subventricular zonelateral ventricle,
amygdala ·
Stria terminalis · 
 
 
 

Index xxxv
Subventricular zonelateral ventricle,
auditory cortex ·
Subventricular zonelateral ventricle,
cortex ·
 
 


Subventricular zonelateral ventricle,
lateral ganglionic eminence ·


Subventricular zonelateral ventricle,
medial ganglionic eminence ·

Subventricular zonelateral ventricle,
pallidum ·
Subventricular zonelateral ventricle,
septal area · 

Subventricular zonelateral ventricle,
subiculum ·
Subventricular zoneolfactory ventricle,
olfactory bulb · 

Subventricular zonethird ventricle,
central medial thalamic nucleus · ,

Subventricular zonethird ventricle,
mediodorsal thalamic nucleus ·
Subventricular zonethird ventricle,
paraventricular thalamic nucleus,·
Subventricular zonethird ventricle,
reuniens thalamic nucleus ·

Sulcus limitans · 
Superior cerebellar artery · 
Superior (anterior) semicircular canal ·


Superior cerebellar peduncle ·
 


 

Superior cervical ganglion ·

Superior colliculus ·  ,
 

  ,

Superior colliculusventricular zone,
aqueduct · 
Superior glossopharyngeal ganglion · ,

Superior mammillary nucleus ·
Superior medullary velum ·  ,
 
Superior oblique muscle ·

Superior olive ·
 
 

Superior rectus muscle ·
Superior sagittal sinus ·

Superior semicircular canal · See Anterior
(superior) semicircular canal
Superior vagal (jugular) ganglion · ,


Superior vestibular nucleus ·  ,
 
 
Suprachiasmatic nucleus ·  ,
 
 
Supramammillary decussation ·

Supramammillary nucleus ·  ,
 
Supramammillary nucleuslateral part ·

Supramammillary nucleusmedial part ·

Supraoptic nucleus · 

T
Tectal neuroepithelium · 
 

Tectospinal tract ·

Tectum · 
Tectumsubventricular zoneaqueduct ·

Tectumventricular zoneaqueduct · ,
 
Tegmental neuroepithelium ·
Tegmentum ·
Tegmentumintermediate zoneaqueduct ·

Tegmentumventricular zoneaqueduct ·
 
Tela choroidea ·
Temporal cortex ·
Temporal cortexventricular zone ·
Tenia tecta · 
Terete hypothalamic nucleus ·
Thalamic fasciculus ·
Thalamic neuroepithelium ·  ,

Thalamocortical tract ·
Thalamus ·
 
xxxvi Index
Third ventricle ·  ,

 
 
 

Third ventricleintermediate zonelateral
preoptic area ·
Third ventricleintermediate zonemedial
preoptic area ·
Third ventricleintermediate zone,
paratenial thalamic nucleus ·
Third ventriclesubventricular zone,
mediodorsal thalamic nucleus ·
Third ventriclesubventricular zone,
paraventricular thalamic nucleus ·
Third ventriclesubventricular zone,
reuniens thalamic nucleus·

Third ventricleventricular zone ·,

Third ventricleventricular zoneanterior
hypothalamus ·
Third ventricleventricular zoneanterior
thalamic nucleus · 
Third ventricleventricular zonecentral
medial thalamic nucleus ·  ,

Third ventricleventricular zone,
epithalamus · 
Third ventricleventricular zone,
hypothalamus ·  ,
Third ventricleventricular zonelateral
dorsal thalamic nucleus ·
Third ventricleventricular zonelateral
preoptic area ·
Third ventricleventricular zone,
mammillary area ·
Third ventricleventricular zonemedial
habenular nucleus ·
Third ventricleventricular zonemedial
preoptic area ·
Third ventricleventricular zone,
mediodorsal thalamic nucleus ·
Third ventricleventricular zone,
paraventricular hypothalamic nucleus ·

Third ventricleventricular zone,
paraventricular thalamic nucleus · ,

Third ventricleventricular zoneposterior
hypothalamus ·
Third ventricleventricular zoneposterior
thalamic nucleus ·
Third ventricleventricular zonepretectum
· 
Third ventricleventricular zonereuniens
thalamic nucleus · 

Thyroid gland ·
Tongue · 
 

Tooth budlower molar ·
Tooth budupper incisor ·
Trachea ·
Transverse cerebral fissure ·
Transverse pontine fibers ·
Transverse sinus ·
Trapezoid body ·
Triangular septal nucleus ·

Trigeminal motor nucleus · 
 
 
 

Trigeminal nerve (V)motor root ·
 
 
Trigeminal nerve (V)sensory root · ,
 
 
 
Trigeminal (semilunar) ganglion ·
 

Trochlear nerve (IV) · 
 
Trochlear nucleus ·
 

Tuberoinfundibular tract · 
Tympanic cavity ·

U
Upper eyelid · 
Upper lip ·
Utricle · 


V
Vagus nerve (X) ·
 
Vascular organ of lamina terminalis · ,
 
Vascular plexus of choroid fissure ·
Ventral anterior thalamic nucleus · ,

Ventral cochlear nucleus ·
 
 
Ventral diencephalic sulcus ·
Ventral funiculus · 

Index xxxvii
Ventral hippocampal commissure · ,
 

Ventral horn · 
Ventral hornmotor neurons ·

Ventral lateral geniculate nucleus ·


 
Ventral lateral thalamic nucleus ·

 

Ventral medial thalamic nucleus ·
 
 
 
Ventral nucleus of lateral lemniscus · ,
 


Ventral pallidum ·
 
 
Ventral posterior lateral thalamic nucleus ·
   
 
  ,

Ventral posterior medial thalamic nucleus ·
   
 


Ventral premammillary nucleus ·
Ventricular space (of eye) · See Intraretinal
(subretinal) space (of eye)
Ventral spinocerebellar tract ·
Ventral tegmental area (A) ·  ,

 
 

Ventral tegmental decussation ·
Ventral tegmental nucleus ·
Ventral thalamusneuroepithelium · ,

Ventricular zoneaqueductinferior
colliculus ·

Ventricular zoneaqueductperiaqueductal
gray ·
Ventricular zoneaqueductsuperior
colliculus · 
Ventricular zoneaqueducttectum · ,
   
Ventricular zoneaqueducttegmentum ·
 
Ventricular zonecentral canalspinal cord
·
Ventricular zonefourth ventricle · ,

Ventricular zonefourth ventricle,
cerebellum · 

Ventricular zonefourth ventriclemedulla
· 
Ventricular zonefourth ventriclepons ·

Ventricular zonefourth ventricle,
precerebellar nuclei ·
Ventricular zonefourth ventricle,
vestibular nuclei ·
Ventricular zonehippocampus ·

  ,
 
Ventricular zonelateral ventricle,
accumbens nucleus ·
Ventricular zonelateral ventricle,
amygdala ·
Ventricular zonelateral ventricleauditory
cortex ·
Ventricular zonelateral ventricle,
cingulate cortex · 
Ventricular zonelateral ventriclecortex ·
 
Ventricular zonelateral ventriclefrontal
cortex · 
Ventricular zonelateral ventricle,
frontopolar cortex ·
Ventricular zonelateral ventriclelateral
ganglionic eminence · 
 
Ventricular zonelateral ventriclemedial
ganglionic eminence ·  ,

Ventricular zonelateral ventricleoccipital
cortex ·
Ventricular zonelateral ventricle,
pallidum ·
Ventricular zonelateral ventricleparietal
cortex ·
Ventricular zonelateral ventricleseptal
area ·

Ventricular zonelateral ventricle,
subiculum ·
Ventricular zoneneural retina ·
 



 

 
Ventricular zonelateral ventricle,
temporal cortex ·
Ventricular zoneolfactory ventricle,
olfactory bulb ·


Ventricular zonethird ventricle ·

Ventricular zonethird ventricleanterior
hypothalamus ·
Ventricular zonethird ventricleanterior
thalamic nucleus · 
Ventricular zonethird ventriclecentral
Ventricular zonethird ventricle,
epithalamus · 
Ventricular zonethird ventricle,
hypothalamus · 
Ventricular zonethird ventriclelateral
dorsal thalamic nucleus ·
Ventricular zonethird ventriclelateral
preoptic area ·
Ventricular zonethird ventricle,
mammillary area ·
Ventricular zonethird ventriclemedial
habenular nucleus ·
Ventricular zonethird ventriclemedial
preoptic area ·
Ventricular zonethird ventricle,
mediodorsal thalamic nucleus ·
Ventricular zonethird ventricle,
Ventricular zonethird ventricle,
paraventricular thalamic nucleus · ,

Ventricular zonethird ventricleposterior
hypothalamus ·
Ventricular zonethird ventricleposterior
thalamic nucleus ·
Ventricular zonethird ventriclepretectum

Ventricular zonethird ventriclereuniens
thalamic nucleus · 

Ventromedial hypothalamic nucleus · ,
 

  ,

Vermis · 
 
Vertebral artery ·
Vestibular nerve (VIII) · 

Vestibular neuroepithelium ·  ,


Vestibular nucleiventricular zonefourth
ventricle ·
Vestibular (Scarpa’s) ganglion · ,


Vestibulocochlear nerve (VIII) ·  ,

 
Visual cortex · 
 
 
Vitreous space ·
Vomer · 
Vomeronasal nerve ·  ,
Vomeronasal organ ·  ,

W
Whisker (vibrissa) follicle · ,
 

White layer of superior colliculus · ,

White matter (of cortex) ·


Z
Zona incerta · 

 



How was super woman born

 If everyone on her Island is a Woman, How was superwoman born?

some random ideas on Parthenogenesis and  unisexual reproduction
using laser-assisted  microdissection to dissect ova /polar bodies and sperm to achieve this;

Ultrastructure of Human Sperm

The Sperm Cell: Production, Maturation, Fertilization, Regeneration 2nd Edition pdf

This revised and updated second edition provides a comprehensive account of the human male gamete. Detailed overviews of human sperm production, maturation, and function - and how these processes affect and influence fertility, infertility, and assisted reproduction - are given. A wide range of new developments including proteomics, spermatogenesis, sperm-specific WW domain-binding proteins, Ca2+ signalling, DNA packaging, epididymis are explored, whilst a new chapter presents information gained from mouse genetics, highlighting how it informs male fertility research. The impact of environmental factors during pre-pubertal and pubertal stages of life is also investigated. Featuring engaging prose with chapters organized topographically, The Sperm Cell remains an essential resource for andrologists, clinical scientists, and laboratory personnel.
Ultrastructure of Human ovum


Ultrastructure of Human polar bodies

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Physiological and Pathological Aspects of Sperm Metabolism


Physiological and Pathological Aspects of   Sperm Metabolism

   Zamira Gibb and Robert John Aitken

  Physiological Aspects of Sperm   Metabolism   Spermatozoa are highly specialized cells, playing the   vital roles of paternal DNA delivery and activation of   the oocyte following fertilization. The site of sperm   deposition (in the vagina or uterus in the mammal) is   physically removed from the site of fertilization (the   oviduct), and while a proportion of sperm transport   is facilitated by uterine contractions (in mammals),   the spermatozoa must in themselves be sufficiently   motile to traverse the uterotubal junction and ultimately   locate a single cell, the oocyte. In addition, during   their sojourn within the female tract, spermatozoa   must undergo a maturation process called capacitation   in order to attain the competence to recognize the egg   and then engage in a complex cascade of cell–cell interactions   in order to achieve union of the gametes at fertilization.   This process involves extensive remodelling   of the sperm plasma membrane as well as the induction   of hyperactivated motility and, as such, is a highly   energy-dependent process          .   The process of spermatogenesis requires extensive   remodelling of a conventional spherical cell to become   one of the most highly specialized and morphologically   differentiated cells in the body. During this transformation,   the DNA in the sperm nucleus reaches   the physical limits of compaction to achieve a quasicrystalline   state          . This extreme compaction requires   the removal or resorption of most of the cytoplasm, at   the same time removing the majority of the organelles   (such as the endoplasmic reticulum, ribosomes and   Golgi apparatus) that are intimately involved in the   regulation of metabolism in somatic cells. The result   of this extensive remodelling is that spermatozoa are   left translationally and transcriptionally silent, as well   as relatively depleted of intracellular enzymes and   energy reserves such as fat droplets, yolk granules and   glycogen          . For this reason, spermatozoa are heavily   dependent on their immediate extracellular environment   for the energy substrates that drive metabolism,   as well as a variety of specialized enzymatic activities   that would normally be conducted intracellularly          .   For example, in somatic cells, the array of enzymes and   low-molecular-mass scavengers involved in mediating   protection against oxidative stress is housed intracellularly,   largely within the cytoplasmic space. Spermatozoa,   on the other hand, largely depend upon the epididymal   and seminal plasmas to provide the richest   and most diverse combination of antioxidants in the   body, including several that are unique to the male   reproductive tract       ,       .   In much the same way that economies trade using   a currency rather than a barter system, biological systems   have all evolved their own unique ‘currencies’ for   the exchange of energy. The most important of these   currencies is adenosine    ’-triphosphate (ATP), which   provides the metabolic energy to drive activities in all   living cells.   Cellular Respiration   The generation of ATP may be achieved either in the   presence (aerobic) or in the absence (anaerobic) of   oxygen. At the advent of life on Earth, the atmosphere   was almost if not entirely devoid of oxygen, and at this   time anaerobic glycolysis presented the only metabolic   pathway by which organic molecules might be broken   down with the release of energy. However, as glycolysis   typically requires large quantities of carbohydrates   such as sugars, which would not have been available   to the earliest life forms, it has been suggested that   The Sperm Cell, Second Edition, ed. Christopher J. De Jonge and Christopher L. R. Barratt. Published by Cambridge   University Press. [1]C Cambridge University Press    0      .      0      https:/www.cambridge.org/core/terms. https://doi.org/   0.   0      /                                       .00      Downloaded from https:/www.cambridge.org/core. Boston University Theology Library, on        May    0       at       :      :0   , subject to the Cambridge Core terms of use, available at   Chapter    : Physiological and Pathological Aspects of Sperm Metabolism   during this period of substrate famine, the phosphorylation   of adenosine diphosphate (ADP) to produce   ATP was driven by the energy released during the   cleavage of the carbon–nitrogen bonds of amino acids   such as glycine          .   Following the emergence of eukaryotic plant cells   as a result of the association between glycolytic and   photosynthetic prokaryotes, the levels of atmospheric   oxygen began to increase, giving rise to oxidative   metabolism and the endosymbiosis of the mitochondrion   to form the first animal cells. The ability to   exploit the highly reactive oxygen molecule as the   driving force behind ATP production results in an   extremely effective pathway for energy generation   which, while significantly more efficient than utilizing   glucose, produces significant quantities of reactive   oxygen species (ROS) as a by-product          .   As with somatic cells, the predominant metabolic   pathways that spermatozoa use to produce ATP are   glycolysis and oxidative phosphorylation (OXPHOS),   with the preferential pathway utilized by spermatozoa   of various species depending on a number of factors,   including oxygen and hexose availability          .The   enzymes necessary for glycolysis are primarily associated   with the fibrous sheath located in the principal   piece of the tail          . In contrast, OXPHOS occurs   in the mitochondrial gyres located in the midpiece.   OXPHOS is a significantly more efficient method of   ATP production than glycolysis. Despite this, spermatozoa   from most heavily researched species, including   humans and laboratory rodents, depend predominantly   on glycolysis for ATP production          . During   spermatogenesis, DNA is condensed to a crystalline   structure which not only provides mechanical protection   from ROS damage, but also allows the spermatozoa   to become streamlined for ease of movement            . During this process, the majority of the cytoplasm   is removed from the cell, and as a result, spermatozoa   have limited intracellular space to store energy   reserves in the form of glycogen, lipid droplets or yolk   granules and are almost entirely dependent on external   substrates such as fructose for glycolysis and lactate,   citrate or succinate for OXPHOS.   Glycolysis   The role of glycolysis in driving the production of ATP   for motility has been well researched due to its relative   importance in humans and laboratory species.   Large polar molecules such as glucose cannot diffuse   across membranes, and their transport is facilitated   by membrane-bound proteins, which were first   described by Kasahara and Hinkle in                    0   .These   proteins may be broadly divided into two groups,   the ATP-dependent sodium-coupled glucose transporters   (SGLTs) and the facilitative glucose transporters   (GLUTs),which allow passive transport of sugars   across the membrane       0,          . Of these, GLUTs   are significantly more abundant and have received a   great deal more attention than SGLTs. GLUTs are categorized   according to their relative ability to transport   hexoses (such as glucose, mannitol and fructose),   amino sugars and vitamins             . Since the discovery   of the glucose transporter GLUT   , a great many additional   GLUTs have been characterized          ,          .While   GLUTs    ,    ,     and     appear to be the most abundant   GLUTs expressed by spermatozoa (Table    .   )            ,                  , GLUTs    ,    a and    b have also been   described          ,    0   . The pattern of GLUT distribution,   which is largely confined to the acrosome and   principal piece of the sperm cell, suggests that glycolytic   processes are involved in generating energy for   the membrane modifications required for hyperactivation   and the acrosome reaction. Should this be the   case, the distribution of GLUTs would be expected   to change with the functional status of the cell (i.e.   between noncapacitated and capacitated states), a phenomenon   which has been reported in the dog, but   has not been observed in other species             . At this   stage, the significance of active glycolytic pathways   in OXPHOS-dependent spermatozoa (e.g. equine) for   the production of ATP for either motility or capacitation   and the acrosome reaction remains poorly   understood.   Despite the fact that spermatozoa are able to take   up sugars and utilize them as energy sources, the   extracellular glycolytic substrate availability in vivo is   scarce. The concentration of glucose and other reducing   hexoses in epididymal fluid is in trace or nondetectable   amounts          ,          , and in the oviduct is   generally in micromolar concentrations             . However,   in the dog at least, the ability of spermatozoa to   engage in gluconeogenesis by utilizing stored glycogen   may be sufficient to provide the glucose necessary   for glycolysis          ,          . Interestingly, in the presence   of a sufficient concentration of glucose, dog spermatozoa   actively store glycogen             , providing a buffer   against periods of hexose starvation. Seminal plasma   contains a relative abundance of fructose and glucose               , and the ability to store energy efficiently       Physical distribution of glucose transporters in mammalian spermatozoa   during the brief exposure that spermatozoa have to   this nutrient-rich fluid following ejaculation may provide   the energy required to ascend the female reproductive   tract and fertilize the oocyte. Although glycogen,   glycogen synthetase and glycogen phosphorylase   have also been described in spermatozoa of the ram,   boar and horse             , gluconeogenesis mechanisms are   yet to be demonstrated in any species other than the   dog. However, the ubiquitous distribution of GLUT   and the presence of enzymes associated with gluconeogenesis   and glycogen synthesis suggest that the utilization   of stored glycogen is likely to play a role, at least in   the mammal, in the maintenance of energy homeostasis   and sperm survival in vivo.   Although mitochondrial inhibition studies have   highlighted the contribution of OXPHOS to energy   production by spermatozoa             , deciphering the   relative importance of glycolysis to sperm function   is somewhat more problematic. Many studies have   attempted to quantify the relative contribution of glycolysis   by inhibiting this process using the biologically   unavailable isomer    -deoxy-D-glucose. While   this method does indeed result in a decrease in ATP,   it is a somewhat blunt instrument in that the depletion   of ATP is due to both the absence of usable hexoses and   ATP exhaustion through the futile phosphorylation of   the unusable    -deoxy-D-glucose by hexokinases    a   highly energy-dependent activity             . A more direct               https:/www.cambridge.org/core/terms. https://doi.org/   0.   0      /                                       .00      Downloaded from https:/www.cambridge.org/core. Boston University Theology Library, on        May    0       at       :      :0   , subject to the Cambridge Core terms of use, available at   Chapter    : Physiological and Pathological Aspects of Sperm Metabolism   approach to the quantification of glycolytic processes   would be to perform flux and product distribution   measurements using       C-labelled glucose and evaluating   the production of       C-labelled pyruvate and   lactate in the presence and absence of mitochondrial   inhibition. 
 Oxidative Phosphorylation 
 An excellent example of a species with OXPHOS dependent   spermatozoa is the horse. Despite the well characterized   presence of GLUTs on stallion sperm, it   has become abundantly evident that these spermatozoa   differ from those of other well-studied mammalian   species, in that their energy demands are met not by   glycolytic pathways, but by using OXPHOS          ,       ,      0   ; in the presence of mitochondrial inhibitors, they   suffer a rapid loss of velocity and a dramatic decline in   ATP content, while glycolytic human spermatozoa display   no significant decrease in motility parameters or   ATP levels             . This dependence results in an unconventional   positive relationship between reactive oxygen   species (ROS) production and fertility in the stallion            ,       ,    0   , with the source of ROS being the   mitochondrial electron transport chain, within which   about         % of O    reduced in the mitochondria during   OXPHOS forms superoxide          .   While human clinical data consistently report negative   correlations between male fertility and sperm   oxidative stress          ,          , a recent study has revealed a   paradoxical inverse relationship between fertility and   the percentage of live cells without oxidative damage   in the OXPHOS-dependent spermatozoa of the   stallion             . In addition, spermatozoa from matings   which resulted in a conception (therefore considered   to be more fertile) had lower vitality and a higher percentage   of cells displaying ROS-induced damage than   spermatozoa from matings which did not result in a   conception upon arrival at the laboratory. During in   vitro storage and transport of the samples, the more   metabolically active spermatozoa from the more fertile   stallions were becoming exhausted at a higher rate,   so that by the time that the assays were performed   in the laboratory, the cells had suffered an accelerated   demise due to the accumulation of metabolic byproducts,   such as ROS and cytotoxic lipid aldehydes. Essentially,   OXPHOS-dependent spermatozoa ‘live fast and   die young’.   To avoid the introduction of artefacts following   glycolytic inhibition             , a relatively simple method   of elucidating the mode of ATP generation by spermatozoa   may be achieved through the inhibition of   OXPHOS using mitochondrial uncouplers such as carbonyl   cyanide m-chlorophenyl hydrazone, Antimycin   A, rotenone or diphenylene iodonium. In the stallion,   OXPHOS inhibition results in over a    0% reduction in   sperm velocity and a       % reduction in sperm ATP levels,   while human sperm velocity and ATP remain unaffected.   In addition, the greater efficiency of OXPHOS mediated   ATP production supports a higher velocity,   and indeed stallion sperm velocity parameters are   around    0% faster than those of glycolysis-dependent   human spermatozoa             .   Ultimately, high ROS production by OXPHOS dependent   spermatozoa appears to be a physiologically   normal scenario brought about by superoxide   leakage from the mitochondrial electron transport   chain during OXPHOS             , with a positive relationship   between mitochondrial ROS production and   sperm velocity, leading to increased rates of lipid peroxidation                and, following prolonged storage, a   loss of motility and vitality             . This phenomenon   has a number of implications for the in vitro storage   of OXPHOS-dependent spermatozoa, since the prolonged   generation of ROS in the absence of extracellular   free radical and lipid aldehyde scavengers will   lead to irreversible oxidative damage, impairing DNA   integrity and sperm functionality.   The Translocation of ATP around the   Sperm Cell   In the majority of somatic cells, the mitochondria are   located within the cytoplasm and are therefore able   to deliver ATP from the site of production to the   sites of utilization in an effective and efficient manner.   This system is rather more problematic for cells   such as spermatozoa, in which compartmentalization   has resulted in mitochondria being physically disconnected   from the fibrous sheath of the tail where ATP   is most heavily required for motility. This anatomical   anomaly has led to an unwillingness on the part   of many researchers to acknowledge that for many   species mitochondrial ATP production plays a vital   role in the energy homeostasis of spermatozoa. While   several plausible simple ATP diffusion models have   been postulated                     , these models do not account   for the need to remove and recycle ATPase byproducts   such as ADP, Pi and H+.               https:/www.cambridge.org/core/terms. https://doi.org/   0.   0      /                                       .00      Downloaded from https:/www.cambridge.org/core. Boston University Theology Library, on        May    0       at       :      :0   , subject to the Cambridge Core terms of use, available at   Chapter    : Physiological and Pathological Aspects of Sperm Metabolism   It has been suggested that in spermatozoa the   movement of ATP and ADP between the sites of production   (the mitochondria and the cytoplasm) and the   sites of utilization occurs through flux transfer chains               .These depend upon the rapid transfer of the displacement   from equilibrium of an enzyme reaction   down a chain of adjacent enzymes, such that an ATP   added at one end could effectively be removed at the   other end. Such enzymatic shuttle systems not only   facilitate the delivery of ATP to the sites of utilization,   but also remove and recycle ATPase byproducts                        . This equilibrium displacement process may proceed   with either creatine kinase or glycolytic reactions,   and is far more rapid and efficient than the diffusion of   reactants                     , a feature of particular importance to   species with extremely long sperm flagella, such as the   rat             .   Modulation of Metabolism: In vitro Storage   of Spermatozoa   In vitro sperm storage is often necessary for a number   of reasons associated with assisted reproductive   technologies such as artificial insemination (AI)   and in vitro fertilization (IVF). During the final   phases of spermatogenesis, spermatozoa lose the ability   to biosynthesize, repair, grow and divide, becoming   remarkably simple in their metabolic functions               . Typically, sperm ageing and the inevitable senescence   that follows can be delayed or even arrested   through the implementation of temperature-induced   metabolic restriction by chilling or cryopreservation.   The phenomenon of cold-induced sperm preservation   was first discovered by Spallanzani in                          .   He observed that cooling of frog, stallion and human   semen in snow did not kill all the ‘spermatic vermicules’,   but rendered them temporarily immotile and   induced a state of lethargy from which they could   recover when returned to higher temperatures. By   restricting the metabolic rate of cells, the production   of toxic metabolic byproducts, such as hydrogen   peroxide, lipid aldehydes and carbon dioxide, is   reduced and the depletion of ATP associated with   the maintenance of homeostasis          ,       ,           is minimized.   This temperature-induced metabolic restriction   reduces the rates of both ROS production and   acidification of the storage medium through the accumulation   of lactic acid and CO    from glycolysis and   OXPHOS, respectively. However, the spermatozoa of   many stallions, human male patients and other species   do not tolerate the stresses associated with chilling or   cryopreservation particularly well                     .Therefore,   there has recently been a concerted effort to develop   media that will extend the longevity of spermatozoa   without the need to chill or cryopreserve                     .   The major advantage of chilling semen is a reduction   in sperm metabolic rate that results in improved   longevity during transport and storage and limits   the growth of harmful bacteria. Temperature-induced   reduction of sperm metabolism is of particular importance   in the case of OXPHOS-dependent spermatozoa               . If metabolism is not curtailed in these cells   by temperature reduction, OXPHOS will produce significant   quantities of ROS          , which invariably compromise   sperm function       ,          . Second, depletion of   ATP is known to compromise a wide range of ATP dependent   functions in spermatozoa that are necessary   to maintain homeostasis and prevent premature   cell death             .Therefore, it is clear that in an ambient temperature   storage medium, mitochondrial energy   production must be supported while unnecessary ATP   depletion is minimized, as a result of pressure placed   on ATP–dependent pathways such as the regulation of   ionic or osmotic flux          ,          .   Supplementation of ambient-temperature semen   extenders with various antioxidants          ,          , nutrient   substrates and osmolytes              has gone a long   way toward ameliorating the detrimental effects of   ROS production and ATP depletion in spermatozoa   during storage at ambient temperatures. A   temperature-independent mechanism for inhibiting   sperm metabolism would provide the ideal solution   for ART systems, avoiding the irreversible membrane   damage induced by cooling and freezing, while avoiding   the accumulation of toxic metabolic byproducts   and the depletion of ATP. The clue to such a strategy   may be found by taking a closer look at the in vivo   environments that are conducive to sperm longevity,   namely the epididymis and the oviductal isthmus,   where spermatozoa are stored in a quiescent state for   considerable periods of time.   Pathological Aspects of Sperm   Metabolism   In parallel with recent advances in our understanding   of the metabolic pathways that drive normal sperm   function, we have seen significant advances in our   understanding of the metabolic mechanisms responsible   for defective sperm function. In this context there               https:/www.cambridge.org/core/terms. https://doi.org/   0.   0      /                                       .00      Downloaded from https:/www.cambridge.org/core. Boston University Theology Library, on        May    0       at       :      :0   , subject to the Cambridge Core terms of use, available at   Chapter    : Physiological and Pathological Aspects of Sperm Metabolism   is a general consensus that one of the major mechanisms   responsible for loss of sperm motility, fertilizing   potential and DNA integrity is oxidative stress. In   many ways ROS are a two-edged sword when it comes   to the regulation of normal sperm function. They are   required in small quantities to promote cellular processes   such as capacitation             , but when generated in   excess, they can become extremely damaging because   of their promiscuous reactivity. In the remainder of   this chapter we shall examine both aspects of these biologically   important molecules in the context of sperm   cell biology. However, in order to set the scene, we shall   first overview the fundamental chemistry of ROS and   consider the difficulties encountered in detecting these   short-lived but highly reactive molecules.   What Are Reactive Oxygen Species?   The term ‘reactive oxygen species’ covers a range of   metabolites that are derived from the reduction of oxygen,   including free radicals, such as the superoxide   anion (O   − •) or the hydroxyl radical (OH•), as well as   powerful oxidants such as hydrogen peroxide (H   O   ).   The term also covers molecular species derived from   the reaction of carbon-centred radicals with molecular   oxygen, including peroxyl radicals (ROO•), alkoxyl   radicals (RO•) and organic hydroperoxides (ROOH).   The term ‘ROS’ may also refer to other powerful oxidants   such as peroxynitrite (ONOO-) or hypochlorous   acid (HOCl) as well as the highly biologically active   nitrogen free radical nitric oxide (•NO).   The specific term ‘free radical’ refers to any atom   or molecule containing one or more unpaired electrons.   As unpaired electrons are highly energetic, and   seek out other electrons with which to pair, they confer   considerable reactivity upon such radicals. Thus, free   radicals and related ‘reactive species’ have the ability   to react with, and modify, the structure of many different   kinds of biomolecules including proteins, lipids   and nucleic acids. The wide range of targets that can   be attacked by ROS is a critical facet of their chemistry   that contributes significantly to the pathological   importance of these molecules. As most chemical   species in biological systems have only paired electrons,   free radicals are also likely to be involved in   chain reactions, whereby new free radical products are   formed. A classic example of such a chain reaction is   the peroxidation of lipids in biological membranes. In   this process, a ROS-mediated attack on unsaturated   fatty acids in the plasma membrane generates peroxyl   (ROO•) and alkoxyl (RO•) radicals that, in order to   stabilize, abstract a hydrogen atom from an adjacent   carbon, generating the corresponding acid (ROOH) or   alcohol (ROH). The abstraction of a hydrogen atom   from an adjacent lipid creates a carbon-centred radical   that combines with molecular oxygen to create another   lipid peroxide. In order to stabilize, the latter must   abstract a hydrogen atom from a nearby lipid, creating   yet another carbon radical that on reaction with   molecular oxygen will generate more lipid peroxides.   In this manner, a chain reaction is created that propagates   the peroxidative damage throughout the plasma   membrane.   Since the hydrogen abstraction process referred to   above is facilitated by the double bonds present in   unsaturated fatty acids, membranes that are rich in the   latter will be particularly vulnerable to oxidative stress.   In this context, spermatozoa are especially susceptible   because their plasma membranes are extremely rich   in unsaturated fatty acids, notably       :          0   . Such an   abundance of unsaturated lipids is necessary to create   the membrane fluidity required by the membrane   fusion events associated with fertilization (acrosomal   exocytosis and sperm–oocyte fusion); however, their   presence leaves these cells open to peroxidative attack.   Termination of such lipid peroxidation chain reactions   can be achieved with chain-breaking antioxidants such   as vitamin E (-tocopherol). The latter is extremely   effective in terminating lipid peroxidation cascades in   human spermatozoa in vitro              and has also been   shown to improve the fertility of males selected on the   basis of high levels of lipid peroxidation in their spermatozoa,   in vivo             .   The most commonly encountered ROS are O   − •   and H   O   . These molecules are capable of a range   of rapid chemical reactions yielding a correspondingly   broad range of reaction products. When in aqueous   solution, O   − • has a short half-life (    ms) and is   relatively inert. The radical is more stable and reactive   in the hydrophobic environment provided by cellular   membranes. The charge associated with O   − •   means that this molecule is generally incapable of   passing across biological membranes, although there   are reports of this molecule passing through voltage dependent   anion channels             .As a result of its lack of   membrane permeability, O   − • may be more damaging   if produced inside biological membranes than at other   sites. It is also important to note that whileO   −• can act   as either a reducing agent or a weak oxidizing agent in   aqueous solution, under the reducing conditions that               https:/www.cambridge.org/core/terms. https://doi.org/   0.   0      /                                       .00      Downloaded from https:/www.cambridge.org/core. Boston University Theology Library, on        May    0       at       :      :0   , subject to the Cambridge Core terms of use, available at   Chapter    : Physiological and Pathological Aspects of Sperm Metabolism   characterize the intracellular environment, O   − • acts   primarily as an oxidant. Many of the effects of O   − • are   believed to arise from its conversion to more reactive   oxidizing species       ,          . For example, protonation of   O   − • forms the hydroperoxyl radical (HO   •), a much   stronger oxidant:   HO   [1] H+ + O   − •.             The pH at which this reaction reaches equilibrium   (pKa) is    .   , with the result that at physiological pH,   HO   • represents less than    % of the O   − • present in   a cell. However, given the considerable reactivity and   membrane permeability of HO   •, this radical is still   believed to be a significant contributor to oxidative   damage in biological systems, with the potential to initiate   lipid peroxidation cascades          ,          .   Conversion of O   − • to other ROS also occurs. An   important means by which this takes place is the dismutation   reaction, wherein O   − • reacts with itself (i.e.   superoxide is both oxidized and reduced). In this situation,   one molecule of O   − • is oxidized to molecular   oxygen, while the other is reduced to H   O   :   O   − • + O   − • +    H+ → H   O    + O   .             Superoxide dismutase (SOD) catalyzes this conversion.   SODs are metalloenzymes thought to be present   in all oxygen-metabolizing cells             .The reaction can   occur spontaneously without SOD; however, in its   absence, dismutation will proceed much more slowly   due to the electrostatic repulsion of the anions (rate   constant of about    ×   0   M−   s−    at physiological pH).   SOD is an efficient catalyst that will drive the above   reaction at a rate constant of about    .    ×   0   M−   s−      over a wide pH range (   .        .   ). In the human spermatozoon,   there is sufficient SOD activity to account for   all of the H   O    produced by these cells             .   Superoxide formation can also lead to the generation   of other types of highly reactive species apart from   H   O   . Many transition metal ions are able to participate   in these processes, as they possess variable oxidation   numbers, permitting them to change their redox   status by either gaining or losing an electron. Consequently,   transition metals act as very effective promoters   of free radical reactions. For example, in the Fenton   reaction, H   O    undergoes decomposition in the presence   of ferrous ions to produce the pernicious hydroxyl   radical (OH•):   H   O    + Fe   + → Fe   + + OH− + OH•,   Fe   + + O   − • → Fe   + + O   .               The sum of these two reactions represents the iron catalyzed   Haber–Weiss reaction:   H   O    + O   − • → O    + OH− + OH•.             Thus, O   − • also has a key role to play in the above   reaction by serving as a reductant and facilitating the   regeneration of reduced metal ions in the extracellular   space. It is also well recognized that other transition   metals may participate in these reactions. Thus,   while iron is the major player             , copper is the other   major candidate and cobalt, aluminium, chromium,   nickel and titanium may also participate in such reactions         0   .Moreover, in seminal plasma, both iron and   copper are available in a free state and hence able to   take part in OH• production and the consequent promotion   of oxidative stress in the ejaculate             .   Detection of ROS in the Male Germ Line   Given the importance of ROS and the apparent vulnerability   of spermatozoa to oxidative stress, it might   be anticipated that sophisticated methods would have   been developed to detect these intermediate oxygen   metabolites for diagnostic purposes. In fact, this area   has been severely compromised by the absence of sensitive,   accurate analytical methods capable of confirming   the presence of specific ROS in biological systems.   The most commonly used method for detecting   ROS in an andrological context is chemiluminescence,   using the probe lucigenin or luminol          ,            . Lucigenin (N,N’-dimethyl-   ,   ’-biacridiniumdinitrate)   carries a positive ionic charge; it is generally   thought to be relatively membrane-impermeant and to   respond to O   − • in the extracellular space. However,   the positive charge associated with this molecule may   also favour its partition into mitochondria, as a consequence   of the electronegative mitochondrial membrane   potential. Indeed, studies using rat spermatozoa   as a model indicate that the lucigenin signal generated   by these cells can reflect O   − • produced by the sperm   mitochondria             . However, there are no data to suggest   that the lucigenin signals generated by human   spermatozoa are of mitochondrial origin, even though   such signals are inversely correlated with sperm quality                and significantly elevated in cases of male infertility            ,          .   One of the key features of lucigenin is that this   probe must undergo a one-electron reduction to the   radical species, LH+•, before it becomes sensitized   to the presence of O   − • (Figure    .   ). In the case of               https:/www.cambridge.org/core/terms. https://doi.org/   0.   0      /                                       .00      Downloaded from https:/www.cambridge.org/core. Boston University Theology Library, on        May    0       at       :      :0   , subject to the Cambridge Core terms of use, available at   Chapter    : Physiological and Pathological Aspects of Sperm Metabolism   NAD(P)H   Cellular O      -•   LucH+•   Dioxetane formation   Chemiluminescence   LucH+•   + = +   +   e-   -   e-   +   LucH+• LucH      O      _•   O      O    -•   HO      -   SOD   Lucigenin reduction   e.g., Cytochrome P      0   reductase   Cytochrome b    reductase   H   O      Luc   +   LucH+• Luc   +   Figure    .    Schematic representation of the chemistry for lucigenin chemiluminescence; Luc   +: lucigenin; LH+•: a lucigenin radical created   by the one–electron reduction of Luc   +. The reaction of LH+• with oxygen generates O   − •. The latter then participates in an oxygenation   reaction with LH+•, generating a dioxetane that decomposes with the generation of chemiluminescence. Any entity that can effect the   one-electron reduction of lucigenin can potentially create a redox cycle in the presence of oxygen that produces high levels of O   − • and   chemiluminescence. It is impossible to distinguish the relative contribution of such probe-dependent and cell-dependent   chemiluminescence. Hence data obtained with this probe should be interpreted with caution.   mitochondrialO   − • production, this reductive process   is accomplished by the organelle’s electron transport   chain. However, outside of the mitochondria, lucigenin   reduction can be induced by reductases such as   cytochrome P      0 reductase or cytochrome b    reductase               .This is particularly the case when exogenous   NAD(P)H is used to drive redox activity in populations   of human spermatozoa             .The LH+• generated   on reduction then combines with O   − • to produce the   dioxetane that, in turn, decomposes with the generation   of light (chemiluminescence):   Although this chemistry seems straightforward,   complications may arise due to redox cycling reactions   whereby LH+• combines with ground state oxygen   (O   ) to create O   − • and regenerate the parent lucigenin   molecule (Figure    .   ).The O   − • artificially created   in this manner will then combine with LH+• to   generate additional dioxetane and further the chemiluminescence   response (Figure    .   ). If such redox   cycling does occur, the particularly intense NADPHdependent   lucigenin signals seen in defective human   spermatozoa may be as much an indication of excessive   reductase activity as evidence for the overabundance   of O   − •             .This explanation would provide a   link between the high levels of redox activity detected   in defective spermatozoa by lucigenin chemiluminescence   and enhanced reductase activity due to the presence   of excess residual cytoplasm. There is certainly a   great deal of data to link cytoplasmic retention with   defective sperm function       0           , so such an explanation would   be fully compatible with our understanding   of the etiology of male infertility.   It has also been argued that the reaction of LH+•   with O    is thermodynamically unlikely              and that   redox cycling of this probe does not occur in biological   systems. However, given the high dose of lucigenin   typically used to detect redox activity in human sperm   samples ([1]      0 μM), the possibility of spurious results   generated by continuous cycling of the probe cannot   be excluded. As a consequence, we currently do not   know the extent to which the elevated lucigenin signals   detected in defective human spermatozoa reflect   primary O   − • production or the superabundance of   reductases due to the presence of excess cytoplasm.   What we do know is that the activity of this probe correlates   well with defective sperm function whether the   activity is promoted by treatment with NAD(P)H or   phorbol ester          ,       ,       ,          .   A similar argument may apply to luminol. This   probe has to undergo a one-electron oxidation before   it becomes sensitized to the presence of ROS. In a   common form of this assay, horseradish peroxidase is   used to promote luminol oxidation in the extracellular   space. In this form, the luminol assay largely reflects   the presence ofH   O    released to the outside of the cell.   In the absence of exogenous horseradish peroxidase,               https:/www.cambridge.org/core/terms. https://doi.org/   0.   0      /                                       .00      Downloaded from https:/www.cambridge.org/core. Boston University Theology Library, on        May    0       at       :      :0   , subject to the Cambridge Core terms of use, available at   Chapter    : Physiological and Pathological Aspects of Sperm Metabolism   e.g., Cytochrome P      0   reductase   LucH+. LucH+. LucH    Luc   +.   LucH+.   O    H   O      HO         O      −.   SOD   Luc   +.   +   e−      e−   LucH+. O      −.   Dioxetane formation   Chemiluminescence   +   +   = +   Lucigenin reduction   NAD(P)H   Cellular O   −.   Cytochrome b    reductase   Figure    .    Schematic representation of the underlying chemistry for luminol-dependent chemiluminescence. L: luminol; L•: a luminol   radical created by the one-electron oxidation of L; L+: azaquinone formed by the further one-electron oxidation of L• by oxygen, generating   O   − • as a byproduct. The reaction of L• with O   − • or L+ with H   O    generates an unstable endoperoxide whose decomposition leads to   production of the chemiluminescent species, an electronically excited aminophthalate. Redox cycling of the probe could result if human   spermatozoa possessed an appropriate reductase to convert L+ back to the parent L. Any reactant that can achieve the univalent oxidation of   luminol will generate chemiluminescence in this assay, including H   O    and ONOO_.   the assay is dependent on the presence of intracellular   peroxidases to activate the probe             . The oneelectron   oxidation of luminol leads to the creation of   a radical species (L•). The latter then interacts with   ground state oxygen to produce O   − •, which induces   the oxygenation of L• to create an unstable endoperoxide,   which ultimately breaks down with the release   of light (Figure    .   ). According to this scheme, O   − •   is an essential intermediate in the creation of luminol dependent   chemiluminescence and it is for this reason   that SOD is such an effective inhibitor of this reaction   cascade.However, the activity of this scavenger should   never be taken to indicate the primary production of   O   − • by human spermatozoa; O   − • is simply an artificially   created intermediate that is essential for luminol dependent   chemiluminescence. Indeed, any univalent   oxidant has the potential to generate O   − •, and   hence chemiluminescence, in the presence of luminol,   including ferricyanide, persulphate, hypochlorite,   ONOO   and xanthine oxidase (Figure    .   ). Hydrogen   peroxide lies upstream of O   − • in the reaction scheme   depicted in Figure    .    and its involvement in the initial   oxidation of luminol accounts for the inhibitory   effects of catalase on this form of chemiluminescence.   In addition, H   O    will also react directly with azaquinone   (L+) and thereby contribute to the formation   of excited aminophthalic acid, the chemiluminescent   species             .   Fundamentally, luminol-based assays are measuring   redox activity characterized by the cellular   generation of oxidizing species capable of creating   L•. Notwithstanding the reservations that might   be expressed concerning the specificity of this probe,   the luminol assay is robust and generates results that   are strongly correlated with sperm function          ,          .   The clinical significance of this assay has also been   emphasized in a long-term prospective study of             couples characterized by a lack of detectable pathology   in the female partners. In this cohort of patients,   a negative association was observed between luminol dependent   chemiluminescence and the incidence of   spontaneous pregnancy             . Furthermore, within this   data set, the conventional criteria of semen quality   were of no diagnostic value whatsoever             .   A recent detailed analysis of these chemiluminescent   probes confirmed that lucigenin is not a particularly   useful probe for measuring ROS generation   by human spermatozoa       0   . Furthermore, while the   combination of luminol and peroxidase was found   to be a sensitive means of detecting ROS in

Use of DHE as a flow cytometry probe for detecting the generation of O   − • by populations of spermatozoa. A, this probe can be   non-specifically oxidized to generate the parent ethidium (Eth); however, reaction with O   − • generates a ROS–specific DNA-sensitive   fluorochrome,    -hydroxyethidium (   OH Eth). B, hplc analysis of the fluorochromes generated by human spermatozoa has demonstrated the   presence of both Eth and    -OH Eth, confirming the generation of O   − • by these cells. C, the combination of DHE and Sytox green (green or   yellow where cells are nonviable) provides an extremely efficient means of demonstrating ROS generation by viable cells (nuclei stained red   with no trace of yellow or green staining). (A black and white version of this figure will appear in some formats. For the colour version, please   refer to the plate section.)   extracellular space, it was also found to be very   susceptible to interference by free-radical-generating   leukocytes       0   . Differentiation of the luminol signal   generated by human sperm suspensions into the component   generated by leukocyte contamination and the   component generated by defective spermatozoa still   confounds the interpretation of studies employing this   probe.   The problem of cellular contamination has been   solved by the use of flow cytometry to focus on the   cellular generation of ROS by spermatozoa while gating   out any contribution made by other cell types.The   most commonly used flow cytometry probes are dihydroethidium   and mitoSox red (MSR). These probes   are both reduction products of ethidium bromide,   but MSR has been chemically modified to give the   molecule a positive charge that results in its concentration   in the mitochondrial matrix. When run in   conjunction with a vitality stain such as Sytox green   (Figure    .   ), these probes provide a sensitive, effective   and accurate means of assessing ROS generation   by spermatozoa       0   . A potential problem with   DHE and MSR is that they can be non-specifically   oxidized to generate the parent ethidium molecule   and a positive signal in the assay. In order to be certain   that the activity probes are reflecting intracellular   ROS generation, it is important to establish that    -   hydroxyethidiumis being generated in the presence of   spermatozoa, since this reaction product is only produced   when these probes are oxidized by O   − •. Fractionation   of the fluorochromes generated by human   spermatozoa, followed by mass spectroscopy, has               https:/www.cambridge.org/core/terms. https://doi.org/   0.   0      /                                       .00      Downloaded from https:/www.cambridge.org/core. Boston University Theology Library, on        May    0       at       :      :0   , subject to the Cambridge Core terms of use, available at   Chapter    : Physiological and Pathological Aspects of Sperm Metabolism   0      0      0      0      0      00         0   0 .           .           .          y = −      .         x +    0.         , r = 0 .   0   MDA +   HA (μmol)   A        hour incubation in vitro   0      0      0      0      0      00         0   0 .    .    .    .           .       .      MDA +   HA (μmol)   y = −      .         x +       0.0      , r = 0.         B Xanthine oxidase system   Figure    .    Sperm motility is negatively impacted by lipid peroxidation. Using an assay that records the generation of malondialdehyde and      -hydroxyalkenals (MDA+   HA), it is possible to demonstrate a clear negative correlation between sperm motility and A, the generation of   lipid peroxides by spermatozoa following an overnight incubation at       °C and B, the enzymatic creation of oxidative stress using xanthine   oxidase             .   confirmed the generation of    -hydroxyethidium and   thus O   − • by these cells              (Figure    .   ).With MSR as   a probe to assess the ability of human spermmitochondria   to generateO   − •, electron leakage frombothcomplex   I and complex III has been demonstrated             .   When the generation ofO   − • occurs on thematrix side   of the innermitochondrialmembrane at complex I, the   result is the induction of lipid peroxidation and motility   loss, whereas ROS generation at complex III leads   to the rapid formation of hydrogen peroxide, which   rapidly exits the cell and enters the extracellular space               . MSR and DHE are excellent probes for mitochondrial   andtotal cellular ROS respectively, responding   readily to stimulants of ROS generation such   as lipid aldehydes, menadione and catechol oestrogens         0   . Recently, novel boronate probes have been   reported for human spermatozoa that are more sensitive   for the detection of ROS than DHE, MSR   and    ’,   ’-dichlorohydrofluorescein diacetate (DCFH).   These reagents may well have clinical utility for the   diagnosis of oxidative stress inthemale germline             .   Impact of Oxidative Stress on Spermatozoa   The clinical significance of oxidative stress in the etiology   of defective sperm function was first indicated   by Thaddeus Mann and colleagues at the University of   Cambridge,        years ago       0   .These authors observed   a correlation between the lipid peroxide content of   human spermatozoa and severemotility loss.This relationship   between motility loss and oxidative stress   is striking and has been repeatedly demonstrated in   independent studies .Thus exposure   of human spermatozoa to extracellularly generated   ROS induces a loss of motility that is directly   correlated with the level of lipid peroxidation experienced   by the spermatozoa              (Figure    .   ). Similarly,   the loss of motility observed when spermatozoa are   subjected to overnight incubation is highly correlated   with the lipid peroxidation status of the spermatozoa   at the end of the incubation period              (Figure    .   ).   The prognostic value of stress tests based on the loss   of motility observed when spermatozoa are incubated   for defined periods of time in the presence of transition   metals              is probably another reflection of the   importance of lipid peroxidation in the modulation of   sperm function. The ability of antioxidants to preserve   sperm motility in vivo and in vitro is yet more evidence   that lipid peroxidation is a major cause of motility   loss in populations of human spermatozoa             .   Recently, studies have been conducted using animal   models exhibiting infertility associated with oxidative   stress, such as the GPx    knock-out mouse and testicular   heating, that have clearly demonstrated the therapeutic   potential of antioxidants in vivo Physiological and Pathological Aspects of Sperm Metabolism   The mechanisms by which lipid peroxidation leads   to motility loss probably involve changes in the fluidity   and integrity of the plasma membrane and a   subsequent failure to maintain membrane functions   critical to flagellar movement. Disruption of membrane   Ca   +/Mg   + ATPase activity as a consequence of   decreased membrane fluidity would, for example, lead   to motility loss secondary to an increase in intracellular   calcium. In addition, the electrophilic lipid aldehydes   generated as a consequence of lipid peroxidation   are known to form adducts with the nucleophilic centres   of proteins involved in the orchestration of sperm   movement, such as the dynein heavy chain       00   . Of   course, lipid peroxidation will also disrupt all sperm   functions dependent on membrane activity, including   sperm–oocyte fusion and the ability to undergo a   physiological acrosome reaction             .   Oxidative stress is also amajor cause of DNA damage   in human spermatozoa. Using quantitative PCR to   calculate lesion frequency, the mitochondrial genome   has been shown to be much more susceptible to DNA   damage than the nuclear genome       0      . As a consequence,   the integrity of the sperm mitochondrial   genome is an excellent marker of oxidative stress, even   though this genome is of no biological significance   in its own right because sperm mitochondria do not   generally replicate after fertilization. When quantitative   PCR was used to compare the lesion frequencies   induced in spermatozoa and a variety of other cell   types following exposure toH   O   , the nuclear genome   of the male gamete was shown to be particularly resistant   to oxidative damage. This resistance is thought to   mirror the unique manner in which nuclear chromatin   is packaged in spermatozoa, as reflected in the high   levels of irradiation required to damage sperm DNA   compared with somatic cells       0      .   Adequate compaction and stabilization of sperm   nuclear DNA is therefore critical for protecting this   material from oxidative stress. Amongst Eutheria,   spermatozoa of human origin appear to be more susceptible   to DNA damage than those of most other   species. This is largely because the P    protamine, characteristic   of human spermatozoa, has a limited number   of thiol groups for disulphide bonding       0      . Furthermore,   the protamination of human spermatozoa   is notably inefficient, with around       % of the genome   remaining histone-rich, even in normal fertile men         0      . Failures in either the ability of the testes to adequately   protaminate human sperm chromatin or the   ability of the epididymis to support subsequent protamine   cross-linkage lead to imperfections in the state   of chromatin stabilization. Such deficiencies in chromatin   packaging have, in turn, been associated with   an increased risk of DNA damage       0      . The particular   vulnerability of poorly compacted sperm DNA to   oxidative attack results in high levels of the oxidative   base adduct,    -hydroxy-   ’-deoxyguanosine (   OHdG),   being present in human spermatozoa       0   ,    0      . The   spermatozoon has a limited capacity to deal with this   damage, possessing a truncated base excision repair   pathway characterized by only the first enzyme in this   process,    -oxoguanine DNA glycosylase     (OGG   ),   but none of the other downstream elements of this   DNA repair pathway       0      . As a result, spermatozoa   are capable of responding to oxidative DNA damage   by creating an abasic site at the oxidized base position,   but cannot progress the DNA repair any further   (Figure    .   ). In contrast, the oocyte possesses   very low levels of OGG    but does possess the downstream   components of the base excision repair pathway         0      . The male and female germ lines therefore   collaborate in resolving any oxidative DNA damage   brought into the egg by the fertilizing spermatozoon.   However, if the fertilizing spermatozoon has particularly   high levels of    OHdG, as is often the case in   the subfertile population       0      , then these residues   will remain associated with the chromatin of the   sperm following fertilization and, because the oocyte   is so poorly endowed with OGG   , the residues will   persist into the S-phase of the first mitotic division   (Figure    .   ). At this point the high mutagenic potential   of    OHdG, particularly its ability to create GC     AT transversions, will have a major impact on the   mutagenic load carried by the embryo          0   . Some   measure of protection against such an eventuality has   been recently indicated in a study       0       reporting an   increase in oocyte OGG    activity following fertilization   as a consequence of post-translational modifications   to oocyte enzymes involved in the base excision   repair pathway, causing nuclear localization and   accelerated    OHdG excision. Notwithstanding such   changes within the fertilized egg, the low levels of   OGG    characteristic of the oocyte emphasize the vulnerability   of embryonic development to high levels   of    OHdG carried into the oocyte by the spermatozoon   (Figure    .   ). This phenomenon has major implications   for the assisted conception industry, where   potentially damaged spermatozoa are being used to   create embryos through the increasingly popular practice   of ICSI.         0   https:/www.cambridge.org/core/terms. https://doi.org/   0.   0      /                                       .00      Downloaded from https:/www.cambridge.org/core. Boston University Theology Library, on        May    0       at       :      :0   , subject to the Cambridge Core terms of use, available at   Chapter    : Physiological and Pathological Aspects of Sperm Metabolism   Damaged base   Oxidatively   damaged base   Base excision pathway   AP endonuclease   OGG    glycosylase   APE   /XRCC         ’ OH    ’ dRP   Spermatozoa possess OGG       but none of the other enzymes   in the base excision repair   pathway Oocytes possess very little OGG     but do express   abundant APE    and XRCC   , the downstream   contributors to the base excision repair pathway   OGG    APE    XRCC      Abasic site   A   OGG      B   Figure    .    Vulnerability of embryonic development to oxidative DNA damage in the sperm nucleus. A, spermatozoa possess only the   first enzyme in the base excision repair pathway, OGG   , but none of the other downstream elements of this repair process. As a result,   spermatozoa are capable of responding to oxidative DNA damage only by the generation of an abasic site. B, oocytes possess the   downstream elements of the base excision repair pathway, APE    and XRCC   , in abundance. Thus under ideal conditions, male and female   gametes collaborate to repair oxidative DNA damage brought into the egg by the fertilizing spermatozoon. However, the lack of OGG    in   oocytes means that any    OHdG residues that have not been dealt with in the spermatozoon will persist into the S-phase of the first mitotic   division, with potential mutagenic consequences for the embryo. (A black and white version of this figure will appear in some formats. For the   colour version, please refer to the plate section.)   Conclusions   Patterns of sperm metabolism exhibit considerable   variation between species, even within the Eutheria.   While glycolysis is clearly preferred by some species,   such as the human and mouse, as the major means   of generating the ATP needed to support motility,   other species depend heavily upon OXPHOS. While   the latter is more efficient from an ATP-generation perspective,   heavy dependence on mitochondrial function   brings with it risks associated with the attendant   generation of ROS. The latter are particularly pernicious   as far as spermatozoa are concerned, damaging   the DNA in the sperm nucleus and mitochondria while   simultaneously triggering lipid peroxidation cascades   that compromise the fertilizing potential of these   cells. Understanding the origins of the oxidative stress   that plagues mammalian spermatozoa and developing   methods of alleviating this stress are major tasks for future research in this area.