front matter 1

Floor plateFloor plate

Central

canal

Ventral horn

interneurons

Ventral horn

interneurons

Intermediate

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

Lamina ILamina I

Laminae

IV-V

Laminae

IV-V

Intermediate

neuroepithelium Sojourn zone of

premigratory neurons

destined for the dorsal

horn and intermediate

gray

Dorsal neuroepithelium

Lateral horn

motoneurons?

(autonomic)

Central autonomic

area

Migratory stream of

lateral horn motoneurons?

Dorsal

canal

Dorsal

canal

axial

motoneurons

axial

motoneurons

Retreating roof plate

Ventral white

commissure

Ventral white

commissure

Ventral

median fissure

Dorsal median septum

V

e

n

tr

a

l

funiculu

s

V

e

n

tr

a

l

funiculu

s

L a t e r a l f u n i c u l

u

s

L a t e r a l f u n i c u l

u

s

PLATE18B