The Human Brain During the Third Trimester

Basal nucleus of MeynertBasal nucleus of Meynert

SU

BS

TA

N

T

IA

IN

N

O

M

IN

AT

A

SU

BS

TA

N

T

IA

IN

N

O

M

IN

AT

A

ChorChoroid plexusoid plexus

HIPPOCAMPUS

(DORSAL)

HIPPOCAMPUS

(DORSAL)

Fimbria/fFimbria/fororninixx

Subiculum

Dentate gyrus

Ammon's horn

Caudate? (tail)

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 fissure

Layer I

Layer II

Layer III

Layer IV

Layers V- VI

Subpial granular layer Cortical plate

White matter

Orbital gyrus

Mammillo-

thalamic tract

Mammillo-

thalamic tract

Third Third ventricleventricle

Central

nucleus

Central

nucleus

Lingula

(I-II)

Lingula

(I-II)

Centralis

(III)

Centralis

(III)

Culmen

(IV-V)

Culmen

(IV-V)

Primary

fissure

Primary

fissure

Declive

(VI)

Declive

(VI)

Folium

(VIIa)

Fo lium

(VIIa)

Tuber

(VIIb)

Tuber

(VIIb)

Sim

plex lo

bul

e

(H

Simp VI)

lex lo

bule

(H

VI)

Lateral lemniscus

Nucleus of the lateral

lemniscus (dorsal)

Brachium of the

inferior colliculus

Inferio

r

colliculu

s

Inferio

r

colliculu

s

Tenia tecta

(ventral)

Tenia tecta

(ventral)

FFornixornix

Diagonal band of BrDiagonal band of Broca (voca (vertical limb)ertical limb)

Diagonal band of BrDiagonal band of Broca (horizontal limb)oca (horizontal limb)

Median prMedian preoptic nucleuseoptic nucleus

Medial prMedial preoptic nucleuseoptic nucleus

Nucleus

accumben

s

Nucleus

accumben

s

Subcallosal arSubcallosal areaea

Paraventricular

nucleus

Paraventricular

nucleus

Central

gray

Central

gray

Ansa

lenticularis?

Ansa

lenticularis?

Cerebral

aqueduct

Cerebral

aqueduct

HYPO-

THALAMUS

HYPO-

THALAMUS

AMYGDAMYGDALAALA

CEREBELLAR CEREBELLAR VERMISVERMIS

CEREBELLAR

HEMISPHERE

CEREBELLAR

HEMISPHERE

CEREBELLAR

HEMISPHERE

CEREBELLAR

HEMISPHERE

Parahippocampal

gyrus

Parahippocampal

gyrus

S

u

bg

ra

n

ula

r^

zo

n

e

S

u

bg

ra

n

ula

r^

zo

n

e

External

germinal

layer

Internal capsule? (posterior limb)

PREOPTIC

AREA

PREOPTIC

AREA

Red

nucleus

Red

nucleus

Interpeduncular

nucleus

Interpeduncular

nucleus

Habenulo-

interpeduncular

tract

Habenulo-

interpeduncular

tract

Dorsal tegmental

nucleus?

Dorsal tegmental

nucleus?

Oculomotor

nuclear complex

Oculomotor

nuclear complex

C

er

eb

ra

lp

edu

ncle

C

er

eb

ra

lp

edu

ncle

O

pti

trac

ct

O

pti

trac

ct

Anterior commissuAnterior commissurree

EndopiriEndopirifform nucleusorm nucleus Central

nucleus

Central

nucleus

Primary olfactory cortex (piriform)

Medial longitudinal

fasciculus

Medial longitudinal

fasciculus

Oculomotor neOculomotor nerve (III)rve (III)

Baso-

lateral

complex

Baso-

lateral

complex

Corticomedial

complex

Corticomedial

complex

Intercalated

mass?

Intercalated

mass?

Amygdalo-

hippocampal

area?

Amygdalo-

hippocampal

area?

Parabrachial

nucleus

Parabrachial

nucleus

Ventral tegmental

area

Ve ntral tegmental

M area

edia

lfor

ebrain

bund

le?

Me

dia

lfor

ebrain

bund

le? A

nte

rio

r lo

be

(H

I-H

V)

An

ter

io

r lo

be

(H

I-H

V)

Substantia

nigra

Substantia

nigra

O

lf

ac

to

ry

tu

be

rc

le

O

lf

ac

to

ry

tu

be

rc

le

HI

PP

OC

AM

PU

S

(V

EN

TR

AL

)

HI

PP

OC

AM

PU

S

(V

EN

TR

AL

)

MIDBR

AIN

TE

G

M

EN

TU

M

M

ID

B

R

A

I

N

T

E

C

T

U

M

M

ID

B

R

A

I

N

T

E

C

T

U

M

Reticular

formation

Reticular

fo rmation

Islands of CallejaIslands of Calleja

Lateral preoptic and

hypothalamic areas

Lateral preoptic and

hypothalamic areas

Supra-

mammillary

area

Supra-

mammillary

area

Dorsomedial

nucleus?

Dorsomedial

Rostral migratory stream nucleus?

Amygdaloid glioepithelium/

ependyma

Frontal neuroepithelium

and subventricular zone

Fr ontal neuroepithelium

and subventricular zone

Frontal stratified

transitional field

Fr ontal stratified

transitional field

Lateral migratory streaLateral migratory streamm

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

Temporal

lobe

Te mporal

lobe

Inferior temporal gyrusInferior temporal gyrus

Germinal and transitional

structures in italics

Germinal and transitional

structures in italics

Po sterior striatal neuroepithelium

and subventricular zone

AlvAlve ar glioepitheliumear glioepithelium

Diencephalic

(hypothalamic)

glioepithelium/

ependyma

Diencephalic

(hypothalamic)

glioepithelium/

ependyma

Mesencephalic

glioepithelium/

ependyma

Mesencephalic

glioepithelium/

ependyma

FFo rnical glioepitheliuornical glioepitheliumm

Ansiform

lobule

(Crus II HVIIA)

Ansiform

lobu le

(Crus II HVIIA)

Ansiform

lobule

(Crus I HVIIA)

Ansiform

lobu le

(Crus I HVIIA)

Myelination

gliosis

Myelination

gliosis

PLATE 235B