The Human Brain During the Third Trimester

Intercalated

masses

Intercalated

masses

HIPPOCAMPU

S

HIPPOCAMPU

S

Subiculum

Dentate gyrus

Dentate gyrus

Ammon's horn

Lateral Lateral ventriclventriclee

Temporal

lobe

Te mporal

lobe

Frontal

lobe

Frontal

lobe

Lateral migratory stream

(infiltrating the endopiriform nucleus

and entering the piriform cortex,

temporal cortex, and amygdala)

Lateral migratory stream

(infiltrating the endopiriform nucleus

and entering the piriform cortex,

temporal cortex, and amygdala)

Rostral migratory streaRostral migratory streamm

Lateral fissure

Layer I

Layer II

Layer III

Layer IV

Layers V- VI

Subpial granular layerSubpial granular layer

Cortical plate

White matter

Orbital gyrusOrbital gyrus

Mammillo-

thalamic tract

Mammillo-

thalamic tract

Lingula

(I-II)

Lingula

(I-II)

Centralis

(III)

Centralis

(III)

Culmen

(IV-V)

Culmen

(IV-V)

Primary

fissure

Pyramis

(VIII)

Pyramis

(VIII)

CEREBELLAR DEEP

NUCLEI

CEREBELLAR DEEP

NUCLEI

De

nta

te^ n

ucle

us

De

nta

te^ n

ucle

us

Interp

ositus n

ucleus

Interp

ositus n

ucleus

Folium

(VIIa)

Fo lium

(VIIa)

Tuber

(VIIb)

Tuber

(VIIb)

Sim

ple

x lo

bu

le

(H

V

I)

Sim

ple

x lo

bu

le

(H

V

Lateral lemniscus I)

Nucleus of the lateral

lemniscus (dorsal)

FFornixornix

Subcallosal arSubcallosal areaea

VVe ntromedial nucleuentromedial nucleuss

Mammillary

body

Mammillary

body

Lateral tuberal

nucleus

Lateral tuberal

nucleus

Uncinate fasciculuUncinate fasciculuss

PPerieriventricular nucleusventricular nucleus

Sexually dimoSexually dimorphic nucleus?rphic nucleus?

Supraoptic

nucleus

Supraoptic

nucleus

Cen

tra

l

gra

Ceny

tra

l

gra

y

HYPHYPOOTHALAMUSTHALAMUS

A M Y G D A L A

A M Y G D A L A

CEREBELLAR CEREBELLAR VERMISVERMIS

CEREBELLAR

HEMISPHERE

CEREBELLAR

HEMISPHERE

Parahippocampal

gyrus

Parahippocampal

gyrus

Subgranular zone

External

germinal

layer

Inter-

peduncular

nucleus

Inter-

peduncular

nucleus

Habenulo-inteHabenulo-interpeduncular tractrpeduncular tract

Dorsal tegmental

nucleus?

Dorsal tegmental

nucleus?

Trochlear nucleus

(IV)

Trochlear nucleus

(IV)

Raphe nuclear compleRaphe nuclear complexx

Su

pe

ri

or

(^) c
er
eb
el
la
r
pe
du
nc
le
(^) (d
ec
us
sa
ti
on
)
Su
pe
ri
or
(^) c
er
eb
el
la
r
pe
du
nc
le
(^) (d
ec
us
sa
ti
on
)
Superior cerebellar
peduncle
Superior cerebellar
C peduncle
er
eb
ra
lp
edu
ncle
C
er
eb
ra
lp
edu
ncle
Op
tr tic
ac
t
Op
tr tic
ac
t
Anterior commissuAnterior commissurree
EndopiriEndopirifform nucleusorm nucleus
Central
nucleus?
Central
nucleus?
Primary olfactory cortex (pirifPrimary olfactory cortex (piriform)orm)
Medial longitudinal fasciculusMedial longitudinal fasciculus
Oc
ulom
oto
r
ner
ve^ (
III)
Oc
ulom
oto
r
ner
ve^ (
III)
Baso-
lateral
complex
Baso-
lateral
complex
Corticomedial
complex
Corticomedial
complex
Amygdalo-
hippocampal
area?
Amygdalo-
hippocampal
area?
Ventral tegmental
area
Ve ntral tegmental
area
An
te
rio
r lo
be

(H

I-

HV

)

An

te

rio

r lo

be

(H

I-

HV

)

Substantia

nigra

Substantia

Olfactory nigra

tubercle

Olfactory

tubercle

MIDBRA

IN

TE

GM

ENTU

M

Reticular

formation

Reticular

fo rmation

Paramedian

lobule?

(HVIIB)

Paramedian

lobu le?

(HVIIB)

Inferior temporal gyrusInferior temporal gyrus

Third Third ventricle (preventricle (preoptic optic recess)recess)

Cerebral

aqueduct

Cerebral

aqueduct

Frontal neuroepithelium

and subventricular zone

Fr ontal neuroepithelium

and subventricular zone

Frontal stratified

transitional field

Fr ontal stratified

transitional field

Parahippocampal neuroepithe-

lium and subventricular zone

Pa rahippocampal neuroepithe-

lium and subventricular zone

Parahippocampal

stratified transitional field

Pa rahippocampal

stratified transitional field

Te mporal stratified transitional field

Te mporal neuroepithelium and subventricular zone

Germinal and transitional

structures in italics

Germinal and transitional

structures in italics

AlAlvve ar glioepitheliuear glioepitheliumm

PREOPTI

C

AREA

PREOPTI

C

AREA

Medial prMedial preoptic nucleuseoptic nucleus

Diencephalic

(hypothalamic)

glioepithelium/

ependyma

Diencephalic

(hypothalamic)

glioepithelium/

ependyma

Mesencephalic

glioepithelium/

ependyma

Mesencephalic

glioepithelium/

ependyma

Amygdaloid

glioepithelium/ependyma

Amygdaloid

glioepithelium/ependyma

Myelination

gliosis

Myelination

gliosis

Ansiform

lobule

(Crus II HVIIA)

Ansiform

lobu le

(Crus II HVIIA)

Ansiform

lobule

(Crus I HVIIA)

Ansiform

lobu le

(Crus I HVIIA)

PLATE 236B