Sp
in
o
c
e
p
h
a
li
c
t
r
a
c
t
s
?
Sp
in
o
c
e
p
h
a
li
c
t
r
a
c
t
s
?
VVentral funiculusentral funiculus
VVentral grayentral gray
Intermediate grayIntermediate gray
Lateral
funiculus
Lateral
funiculus
Vestibulospinal tract?
Dorsal grayDorsal gray
Dorsal funiculus
Dorsal root bifurcation zone
Superficial fasciculus cuneatus
Deep fasciculus cuneatus
Superficial fasciculus gracilis
Deep fasciculus gracilis
Dorsal root collateralization zone
Lissauer's tract
Myelinating terminals of
dorsal root collaterals
Ventral
corticospinal
tract
Ventral
corticospinal
tract
Lateral
corticospinal tract
Lateral
corticospinal tract
Dorsal root
Central canal
surrounded by ependyma
Central canal
surrounded by ependyma
Int
ra
sp
in
al
tr
a
c
ts
?
Int
ra
sp
in
al
tr
a
c
ts
?
S
p
in
o c e r e b e l
l a r t r a c t s?
S
p
in
o c e r e b e l
l a r t r a c t s?
Incipient
subgelatinosal
plexus
Incipient
subgelatinosal
plexus
Reticulated
area
Reticulated
area
Dorsal median septum
Dorsal intermediate septum
Ventral median fissure
VVentral white commissureentral white commissure
VVentral gray commissureentral gray commissure
Lateral
reticulospinal
tract?
Lateral
reticulospinal
tract?
See the matched cell body stained section in Plates 68A and B
The medial and central fi bers in the intraspinal tracts have a greater stain-
ing density than the dorsolateral parts. That same gradient is seen at the
thoracic level of the GW26 (Plate 51) and GW 31 (Plate 56) specimens.
PLATE 67B