The Human Brain During the Third Trimester

Medial

forebrain

bundle

Medial

forebrai n

bundle

Meyer's loop

(visual radiation)

Mey er's loop

(visual radiation)

Germinal and transitional structures in italics

Frontal

lobe

Frontal

lobe

Diagonal band of Broca (vertical limb)

Median preoptic nucleus

Interhemispheric fissure

Third ventricle

Forel's

fields

G

lo

b

us

p

al

li

du

s

(e

xt

er

na

l^ s

eg

m

en

t)

G

lo

b

us

p

al

li

du

s

(e

xt

er

na

l^

se

g

m

en

t)

G

lo

b

u

s^

p

al

li

d

u

s

(i

n

te

rn

a

l^

se

gm

en

t)

G

lo

b

u

s^

p

al

li

d

u

s

(i

n

te

rn

a

l^

se

gm

en

t)

Mammillo-

thalamic tract

Mammillo-

thalamic tract

Fimbria/fFimbria/fororninixx

Dentate gyrusDentate gyrus

Diagonal band of Broca (vertical limb)

Median preoptic nucleus

Anterio

r

commissu

r

e

Anterio

r

commissu

re

Ex

tern

al^ c

aps

ule

Ex

tern

al^ c

aps

ule

Corp

us ca

llosu

m (r

ostr

um)

Corp

us ca

llosu

m (r

ostr

um)

Para-

hippocampal

gyrus

Para-

hippocampal

gyrus

Lateral

ventricl e

Subgranular

zone

Subgranular

zone

Interhemispheric fissur e

Interhemispheric fissure

Lateral fissure

Parafascicular

nucleus

Parafascicular

nucleus

C

ne

tr

o

m

ed

ia

n

n

u

cl

e

u

s

C

ne

tr

o

m

ed

ia

n

n

u

cl

e

u

s

Ventral

postero-

lateral

nucleus

Ventral

postero-

lateral

nucleus

Ventral

lateral

nucleus

Ventral

lateral

nucleus

Ventral

posteromedial

nucleus

Ventral

posteromedial

nucleus

PulvinarPulvinar

Habenulo-

interpeduncular

tract

Habenulo-

interpeduncular

tract

R

e

t

i

c

u

la

r

n

u

c

le

u

s

R

e

t

i

c

u

la

r

n

u

c

le

u

s

Cla

ust

rum

Cla

ust

rum

Cla

ust

rum

Cla

ust

rum

Pu

ta

m

en

Pu

ta

m

en

Insular gyrusInsular gyrus

Choroid plexus

POSTERIOR

COMPLEX

POSTERIOR

COMPLEX

R

E

T

I

C U L A R B E L T

R

E

T

I

C U L A R B E L T

VENTRAL

COMPLEX

VENTRAL

COMPLEX

C

en

tr

allate

ra

l

n

u

cl

e

u

s

C

en

tr

allate

ra

l

n

u

cl

e

u

s

PERIVENTRIC

ULA

RC

OM

P

L

E

X

PERIVENTRIC

ULA

RC

OM

P

L

E

X

Third ventricle

C

E

N

T

R

A

L

(^) C
O
M
P
L
E
X
C
E
N
T
R
A
L
(^) C
O
M
P
L
E
X
Ammon's horAmmon's hornn
SubiculuSubiculumm
Zona
incerta
Zona
incerta
Forel's
fields
BBA SAL GANGLIASAL GANGLIAA
SUBTHALAMUSSUBTHALAMUS
THALAMUSTHALAMUS
TECTUMTECTUM
MIDBRAIMIDBRAINN

HYPO-

THALAMUS

HYPO-

PREOPTIC THALAMUS

AREA

PREOPTIC

AREA

Bed nucleus of

the stria

terminalis

Bed nucleus of

the stria

terminalis

Subcal

losal are

a

Subcal

losal are

a

PParaventricular nucleuaraventricular nucleuss

CerCere bral aqueducebral aqueductt

Dorso-

medial

nucleus

Dorso-

medial

nucleus

Medial

preoptic

nucleus

Medial

preoptic

nucleus

SUPERIOR

COLLICULUS

SUPERIOR

COLLICULUS

M

ed

ia

l

ge

nic

ula

te

bo

dy

M

ed

ia

l

ge

nic

ula

te

bo

dy

Supra-

geniculate

nucleusSupra-

geniculate

nucleus

Lateral

geniculate

body

Lateral

geniculate

body

FFornixornix Central

gray

Central

gray Subcommissural

organ

Subcommissural

organ

Callosal

glioepithelium

Callosal

glioepithelium

Ansa

lenticularis

Ansa

lenticularis

Inter

na

l ca

psu

le (a

nter

ior lim

b)

Inter

na

l ca

psu

le (a

nter

ior lim

b)

I

n

te

r

n

a

l^

c

a

p

su

le

(p

o

st

e

r

io

r

l

im

b

)

I

n

te

rn

a

l^

c

a

p

su

le

(p

o

st

e

r

io

r

l

im

b

)

Nu

cleu

s accu

mb

ens

Nu

cleu

s accu

mb

ens

Caudate (tail)Caudate (tail)

Stria terminalisStria terminalis

C

e

re

b

r

a

l^

p

e

d

u

n

c

le

C

e

re

b

r

a

l^

p

e

d

u

n

c

le

M

ed

u

lla

ry

la

m

in

a

M

ed

u

lla

ry

la

m

in

a

Rostral migratory stream (source area)Rostral migratory stream (source area)

Lateral migratory stream

(infiltrates the claustrum)

Frontal neuroepithelium and

subventricular zone

Fr ontal neuroepithelium and

subventricular zone

Frontal stratified

transitional field

Fr ontal stratified

transitional field

Accumbent neuroepithelium

and subventricular zone

(infiltrated by the rostral migratory stream)

Accumbent neuroepithelium

and subventricular zone

(infiltrated by the rostral migratory stream)

Fornical

glioepithelium

Fo rnical

glioepithelium

GlioepitheliuGlioepitheliumm

AlAlvve ar glioepitheliuear glioepitheliumm

Parahippocampal

neuroepithelium,

subventricular zone, and

stratified transitional field

Pa rahippocampal

neuroepithelium,

subventricular zone, and

stratified transitional field

PPo sterior striatal neuroepithelium and subvosterior striatal neuroepithelium and subventricular zoneentricular zone

Te mporal neuroepithelium and subventricular zone

Te mporal stratified transitional field

DORSAL

HIPPOCAMPUS

DORSAL

HIPPOCAMPUS

White matter

Cortical plate

Layer I

Mesencephalic glioepithelium/ependymaMesencephalic glioepithelium/ependyma

Diencephalic (hypothalamic)

glioepithelium/ependyma

Diencephalic (hypothalamic)

glioepithelium/ependyma

PLATE 86B