front matter 1

Myelinated fibers

in Clarke's column

Myelinated fibers

in Clarke's column

Spin

oc

ep

ha

li

c

tr

a

c

ts

Spin

oc

ep

ha

li

c

tr

a

c

ts

VVentral funiculusentral funiculus

Ventral

gray

Ventral

gray

Intermediate

gray

Intermediate

gray

Lateral

funiculus

Lateral

funiculus

Vestibulospinal tract?

Dorsal

gray

Dorsal

gray

Lateral corticospinal tract

(sparse reactive glia)

(dense reactive glia)

Myelinated terminals of

dorsal root collaterals

Dorsal funiculus

Dorsal root

bifurcation zone

Fasciculus gracilis

Dorsal root

collateralization zone

Lissauer's

tract

Lissauer's

tract

I

ntraspina

l tracts

I

ntraspina

l tracts

Subgelatinosal pleSubgelatinosal plexusxus

myelination Reticulated areaReticulated area
gradient

myelination
gradient

Ventral median fissure

Dorsal median septum

VVentral gray commissureentral gray commissure

VVentral white commissureentral white commissure

Central canal

surrounded by ependyma

Central canal

surrounded by ependyma

Lateral

reticulospinal

tract?

Lateral

reticulospinal

tract?

See the matched cell body stained section in Plates 115A and B

Compare the low staining density of the lateral corticospinal tract in this caudal sec-

tion with the intense staining in more rostral sections, for instance, Plate 104. The

progressively decreasing staining intensity indicates a rostral to caudal gradient of

myelination in the lateral corticospinal tract.

PLATE 114B