front matter 1

Floor plateFloor plate

Central

canal

Central

canal

Ventral horn

interneurons

Ventral horn

interneurons

Intermediate

interneurons

Dorsal

root

Dorsal root

bifurcation zone

Fasciculus gracilis?

Dorsal root

collateralization zone

Lissauer's

tract?

Dorsal funiculus

Dorsal

horn Substantia

gelatinosa

Substantia

gelatinosa

EpendymaEpendyma

Lateral horn

motoneurons

(autonomic)

Lamina ILamina I

Laminae

IV-V

Laminae

IV-V

Dorsal neuroepithelium

Intermediate
neuroepithelium

Sojourn zone of premig-

ratory neurons destined

for the dorsal horn

and intermediate gray

Neurons settling

in Clarke's column?

Central autonomic area

Dorsal

canal

Dorsal

canal

axial

motoneurons

axial

motoneurons

Retreating roof plate

Ventral white

commissure

Ventral white

commissure

Ventral

median fissure

Ventral gray

commissure

Ventral gray

commissure

Dorsal median septum

L

a

t

e

r

a

l

f

u

n

ic

u

lu

s

L

a

t

e

r

a

l

f

u

n

ic

u

lu

s

V

e

n

tr

al

funic

u

lu

s

V

e

n

tr

al

funic

u

lu

s

PLATE 17B