front matter 1

VVentral funiculusentral funiculus

Ventral corticospinal tract?

Central canal

surrounded

by ependyma

Central canal

surrounded

by ependyma

Ventral horn

motoneurons

Ventral horn

motoneurons

Lateral horn

motoneurons

Lateral horn

motoneurons

Ventral horn

interneurons

Ventral horn

interneurons

Intermediate

interneurons

Intermediate

interneurons

Dorsal root

bifurcation zone

Superficial fasciculus gracilis

Deep fasciculus gracilis

Dorsal root

collateralization zone

Lissauer's

tract

Dorsal funiculus

Dorsal

horn

Dorsal

horn Substantia

gelatinosa

Substantia

gelatinosa

Lateral

funiculus

Lateral

funiculus

Central

autonomic

area

Central

autonomic

area

Lamina ILamina I

Laminae

IV-V

Laminae

IV-V

Clarke's

column

Clarke's

column

Lateral

corticospinal

tract

Lateral

corticospinal

tract

S

p

in

o

c

e

re

b

e

ll

a

r

tr

a

c

ts

S

p

in

o

c

e

re

b

e

ll

a

r

tr

a

c

ts

trunk

motoneurons

trunk

motoneurons

Examples of concentrations

of proliferating glia

Very dense

Sparse

Very sparse

Dense

Dorsal median septum

Ventral median fissure

Ventral gray

commissure

Ventral gray

commissure

Ventral white

commissure

Ventral white

commissure

Only the corticospinal and spinocerebellar tracts can be clearly delineated in the ventral and lateral funiculi. The cortico-

spinal tracts stand out as clear areas with very sparse proliferating glia. The spinocerebellar tracts have a slightly more

dense concentration of proliferating glia. A sparse population of proliferating glia fi lls the remaining ventral and lateral

funiculi and contains several fi ber tracts (unlabeled in this section). Refer to the matching myelin stained section for the

approximate locations of the rubrospinal, lateral reticulospinal, vestibulospinal, intraspinal, and spinocephalic tracts.

PLATE 55B

See the matched myelin stained section in Plates 54A and B