The Human Brain During the Third Trimester

Medial preoptic area

Diffuse fibers of the

medial forebrain bundle

FFrroonnttaall^ lloobbee

Interhemispheric

fissure

White

matter

Cortical

plate

Layer I

Cingulate

gyrus

Cingulate

Induseum gyrus

griseum

Induseum

griseum

Lateral

ventricle

C

au

da

te

n

uc

le

us

(

bo

d

y)

C

au

da

te

n

uc

le

us

(

bo

d

y)

ExterExternal capsulnal capsulee

TTe mporal lobeemporal lobe

PutamenPutamen

Olfactory

tubercle

Olfactory

tubercle

Corpu

scallosu

m(bo

dy)

Corpu

scallosu

m(bo

dy)

Choroid

plexus

Choroid

plexus

I

n

s

u

al

r

g

y

r

u

s

I

n

s

u

al

r

g

y

r

u

s

Anterior

commissure

Anterior

commissure

Optic

chiasm

Optic

chiasm

Third ve ntricle (preoptic recess)

Bed nucleus of

the stria terminalis

Bed nucleus of

the stria terminalis

Globus pallidus

(external segment)

Globus pallidus

(external segment)

Lateral

preoptic area

Lateral

preoptic area

Nucleus

accumbens

Nucleus

accumbens

FFornixornix

FFornixornix

Endopiriform

nucleus

Endopiriform

nucleus

Endopiriform

nucleus

Endopiriform

nucleus

Ventral

striatum

Ve ntral

striatum

Pr

im

ary

olfac

toryc

or

te

x

P(

ri

ofi

mr

)

Pr

im

ary

olfac

toryc

or

te

x

P(

ri

ofi

mr

)

Cave of the septum

CingulumCingulum

Lateral olfactory tract

Larg e island of Calleja

Small islands of CallejaSmall islands of Calleja

C

la

u

st

ru

m

C

la

u

st

ru

m

LaLayer IIyer II

LaLayer yer II

Lateral olfactory tractLateral olfactory tract

Primary LaLayers III-IVyers III-IV

olfactory

cortex

Primary

olfactory

cortex

SEPTUMSEPTUM

BBA SAL GANGLIASAL GANGLIAA

PREOPTIC PREOPTIC AREAAREA

C

al

u

ts

ur

m

C

al

u

ts

ur

m

Uncinate

fasciculus

Uncinate

fasciculus

Infiltrating fibers of the

stria terminalis

Infiltrating fibers of the

stria terminalis

Olfactory part of the

anterior commissure

Olfactory part of the

anterior commissure

Diagonal

band of Broca

(vertical limb)

Diagonal

band of Broca

(vertical limb)

Ve na terminalis

SUBSTANTIA

INNOMINATA

SUBSTANTIA

INNOMINAT A

Fr ontal neuroepithelium

and subventricular zone

Fr ontal stratified transitional field

Rostral migratory

stream

Anteromedial striatal

neuroepithelium and

subventricular zone

Anterolateral striatal

neuroepithelium and

subventricular zone

Diencephalic (preoptic)

glioepithelium/ependyma

Diencephalic (preoptic)

glioepithelium/ependyma

Strionuclear glioepitheliuStrionuclear glioepitheliumm

Subpial granular layer

Callosal sling

Fo rnical

glioepithelium

Stem cells of

choroid plexus

Lateral migratory stream

(infiltrates claustrum and

endopiriform nucleus)

Lateral migratory stream

(infiltrates claustrum and

endopiriform nucleus)

Lateral migratory stream

(extends toward

olfactory tubercle)

Lateral migratory stream

(extends toward

olfactory tubercle)

Callosal glioepithelium

Lateral fissure

In

te

r

n

a

l^

ca

p

su

le

(

a

n

te

r

io

r

l

im

b

)

In

te

r

n

a

l^

ca

p

su

le

(

a

n

te

r

io

r

l

im

b

)

Superior

temporal

gyrus

Inferior

frontal

gyrus

Germinal and transitional structures in italics

Middle

temporal

gyrus

Subfornical

organ?

PLATE 32B