The Human Brain During the Third Trimester

Germinal and transitional structuGerminal and transitional structurres ines in italicsitalics

Lateral ventricle

Fusiform

gyrus

Fusiform

gyrus

Occipital

gyrus

Occipital

gyrus

Cerebral

aqueduct

Cerebral

aqueduct

Nucleus of the

lateral lemniscus (dorsal)

Lateral lemniscus

Interhemispheric fissure

Orbital gyruOrbital gyruss

Choroid

plexus

Choroid

plexus

Third ventricle

(infundibular

recess)

Third ventricle

(infundibu lar

recess)

Rostral migratory streamRostral migratory stream

Medial

mammillary

nucleus

Medial

mammillary

nucleus

D

O

R

S

A

L

H

IP

P

O

C

A

M

P

U

S

D

O

R

S

A

L

H

IP

P

O

C

A

M

P

U

S

V

E

N

T

R

A

L

H

IP

PO

C

A

M

PU

S

V

E

N

T

R

A

L

H

IP

PO

C

A

M

PU

S

PParahippocampal gyrusarahippocampal gyrus

Subgranular zoneSubgranular zone

HYPHYPOOTHALAMUSTHALAMUS

Supraoptic nucleuSupraoptic nucleuss

Arcuate

nucleus

Arcuate

nucleus

C

er

eb

ra

l

p

ed

un

cl

e

C

er

eb

ra

l

p

ed

un

cl

e

Central

gray

Central

gray

Endopirirorm

nucleus

Endopirirorm

nucleus

Trochlear

nucleus (IV)

Tr ochlear

nucleus (IV)

Dorsal teg-

mental nucleus

Dorsal teg-

mental nucleus

Mesencephalic

nucleus (V)

Mesencephalic

nucleus (V)

Medial

longitudinal

fasciculus

Medial

longitudinal

fasciculus

Lateral migratory streamLateral migratory streamLateral migratory streamLateral migratory stream

Primary olfactor

y

cortex (pirif

orm)

Primary olfactor

y

cortex (pirif

orm)

Substantia

nigra

Substantia

nigra

In

fe

r

io

r

co

ll

ic

u

lu

s

In

fe

r

io

r

co

ll

ic

u

lu

s

Reticular

formation

Reticular

fo rmation

Olfactory sulcus

Olfactory

peduncle

Olfactory

peduncle

Lateral olfactory tract

Medial ol-

factory tract

AMYGDAMYGDALAALA

AMYGDAMYGDALAALA

Gyrus Gyrus rrectuectuss

C

e

r

e

b

r

a

l

p

ed

un

cle

C

e

r

e

b

r

a

l

p

ed

un

cle

Raphe nuclear complexRaphe nuclear complex

Corticomedial

complex

Corticomedial

complex

Central

nucleus

Central

nucleus

Central

nucleus

Central

nucleus

O

p

ti

c

c

h

ia

s

m

O

p

ti

c

c

h

ia

s

m

Oculomotor

nerve? (III)

Oculomotor

nerve? (III)

Medial lemniscus, spinocephalic,

and trigemino-thalamic tracts

C

ne

tr

a

l

n

u

lec

u

s

C

ne

tr

a

l

n

u

lec

u

s

Ventral

tegmental

area

Ve ntral

tegmental

area

Corticomedial

complex

Corticomedial

complex

Basolateral

complex

Basolateral

complex

Basolateral

complex

Basolateral

complex

Am

mo

n's

horn

Am

mo

n's

horn

Pars^

compa

cta

Pars^

compa

cta

Pars^ reticu

lata

Pars^ reticu

lata

Stria

terminalis

Stria

terminalis

Culmen (IVCulmen (IV-V-V ))

Intercalated

masses

Intercalated

masses

Superior

cerebellar

peduncle

Superior

cerebellar

peduncle

Anterior

olfactory

nucleus

Anterior

olfactory

nucleus

La

te

ra

lv

en

tr

ic

le

Den

ta

te

gy

ru

s

Den

ta

te

gy

ru

s

raP

ba

ar

ch

ial

nucleus

raP

ba

ar

ch

ial

nucleus

U

nc

in

at

e

fa

sc

ic

u

lu

s

U

nc

in

at

e

fa

sc

ic

u

lu

s

CEREBELLUM

VVermisermis

Alvear

glioepithelium

Alve ar

glioepithelium

Occipital stratified

transitional field

TTe mporal neuroepithelium and subvemporal neuroepithelium and subventricular zoneentricular zone

Occipital neuroepithelium

and subventricular zone

TTe mporal stratified transitional fieldemporal stratified transitional field

External

germinal layer

Parahippocampal neuroepithelium

and subventricular zone

Pa rahippocampal neuroepithelium

and subventricular zone

Parahippocampal

stratified transitional field

Pa rahippocampal

stratified transitional field

MIDBRAIMIDBRAINN

TECTU

M

TECTU

M

TEGMENTUMTEGMENTUM

Subpial

granular

layer

Subpial

granular

layer

Cortical plate

White matter

Layer I

Glioepithelium

(optic chiasm)?

Mesencephalic

glioepithelium/ependyma

Mesencephalic

glioepithelium/ependyma

Diencephalic (hypothalamic)

glioepithelium/ependyma

Amygdaloid

glioepithelium/ependyma

Amygdaloid

glioepithelium/ependyma

PLATE 142B