front matter 1

Roof plateRoof plate

Floor plateFloor plate

VVentral funiculusentral funiculus

Ventral

corticospinal

tract

Ventral

corticospinal

tract

Central canalCentral canal

Ventral horn

motoneurons

Ventral horn

motoneurons

Ventral horn

interneurons

Ventral horn

interneurons

Intermediate

interneurons

Intermediate

interneurons

Dorsal root bifurcation zone

Deep fasciculus cuneatus

Superficial fasciculus cuneatus

Deep fasciculus gracilis

Superficial fasciculus gracilis

Examples of

proliferating

glial densities

Dorsal root collateralization zone

Lissauer's tract

Rubrospinal

tract?

Dorsal funiculus

Dorsal

horn

Substantia

gelatinosa

Substantia

gelatinosa

Lateral

funiculus

Lateral

funiculus

EpendymaEpendyma

Central

autonomic

area

Central

autonomic

Lateral area

cervical

nucleus

Lateral

cervical

nucleus

Lamina ILamina I

Laminae

IV-V

Laminae

IV-V

Central

cervical

nucleus?

Central

cervical

nucleus?

corticospinalLateral

tract

corticospinalLateral

tract

Tectospinal tract?

Medial longitudinal fasciculus?

Vestibulospinal tract?

shoulder girdle?shoulder girdle?

arm and forearm?arm and forearm?

Dense

Sparse

Very sparse

Very dense

VVentral white commissureentral white commissure

VVentral gray commissureentral gray commissure

Dorsal median septum

Dorsal intermediate septum

D

or

sa

ls

pi

no

cer

eb

el

la

r

tr

ac

t

D

or

sa

ls

pi

no

cer

eb

el

la

r

tr

ac

t

V

en

tr

al

sp

in

o

ce

re

b

e

ll

ar

tr

ac

t

V

en

tr

al

sp

in

o

ce

re

b

e

ll

ar

tr

ac

t

Intraspin

a

l

t

r

a

c

t

s

Intraspin

a

l

t

r

a

c

t

s

Spin

oc

ep

ha

lic

tr

a

ct

s

Spin

oc

ep

ha

lic

tr

a

ct

s

skull

motoneurons?

skull

motoneurons?

Ventral

median

fissure

See Table III B-1 for the list of glial densities in each fi ber tract.

Examples of glial densities in each category are labeled in the lower

left corner of this plate.

The fi ne lines in the lateral and ventral funiculi segregate regions of differing densities of proliferating glia, not the borders

of fi ber tracts. These lines may correspond to the borders of some fi ber tracts, such as the spinocerebellar and the lateral

corticospinal tracts. Other lines run across fi ber tracts, such as the very dense region adjacent to the ventral corticospinal

tract that includes the medial longitudinal fasciculus, the tectospinal tract, and the medial part of the intraspinal tracts.

Many of the fi ber tracts in the ventral and lateral funiculi overlap and do not have distinct borders.

PLATE 39B