front matter 1

Retreating roof plate

Postulated sojourn zone of
premigratory neurons in the
dorsal neuroepithelium

Floor plateFloor plate

Ventral

white

commissure

Ventral

white

commissure

Central

canal

Dorsal

canal

Dorsal

canal

Segregating ventral horn

motoneuron columns

Segregating ventral horn

motoneuron columns

Ventral horn

interneurons

Ventral horn

interneurons

Intermediate

interneurons

Intermediate

interneurons

Dorsal

root

Dorsal root

bifurcation zone

Fasciculus cuneatus

Fasciculus gracilis?

Dorsal root

collateralization zone

Dorsal funiculus

Dorsal hornDorsal horn

axial

motoneurons

axial

motoneurons

Substantia

gelatinosa

Substantia

gelatinosa

motoneuronsmotoneuronsupper limbupper limb

EpendymaEpendyma

Central

autonomic

area

Central

autonomic

area

Lateral

cervical

nucleus

Lateral

cervical

nucleus

Lamina ILamina I

Spinal nucleus

of the trigeminal

Spinal nucleus

of the trigeminal

Central

cervical

nucleus?

Central

cervical

nucleus?

Migrating

lateral cervical

nucleus neurons?

Migrating

lateral cervical

nucleus neurons?

Dorsal neuroepithelium

Laminae

IV-V

Laminae

IV-V

Li

ss

au

er

's

tr

ac

t?

Incipient

ventral

median fissure

Ventral gray

commissure

Ventral gray

commissure

Dorsal median septum

Incipient dorsal intermediate septum

V

e

n

t

r

al

funicu

l

u

s

V

e

n

t

r

al

funicu

l

u

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

PLATE 14B