front matter 1

Roof plate

Roof plate

Floor plateFloor plate

Ventral funiculus

Spinal canal with

persisting central part and

receding dorsal and ventral parts

Ventral horn

motoneurons

Ventral horn

motoneurons

Ventral horn

interneurons

Ventral horn

interneurons

Intermediate

interneurons

Ventral horn motoneurons

Ventral horn interneurons

Intermediate interneurons

Intermediate neuroepithelium

Dorsal root

bifurcation zone

Dorsal root

collateralization zone

Dorsal root

bifurcation zone

Dorsal root

collateralization zone

Lissauer's

tract?

Lissauer's

tract?

Dorsal

funiculus

Dorsal

funiculus

Dorsal

horn

Substantia

gelatinosa

Substantia

gelatinosa

Lateral funiculus

Lamina ILamina I

Laminae

IV-V

Laminae

IV-V

Dorsal

horn Substantia

gelatinosa

Substantia

gelatinosa

Lamina ILamina I

Laminae

IV-V

Laminae

IV-V

Dorsal neuroepithelium

Floor plateFloor plate

VVentral funiculusentral funiculus

Central canal

Dorsal canal

Ventral canal

Lateral funiculusLateral funiculus

Ventral neuroepithelium

Ventral neuroepithelium

Sojourn zone of premigratory neurons destined

for the dorsal horn and intermediate gray

Sojourn zone of premigratory neurons destined

for the dorsal horn and intermediate gray

Dorsal and intermediate

neuroepithelia

Central autonomic area

Central

autonomic area

Ventral

white

commissure

Ventral

white

commissure

PLATE 20B