Js. Soblosky et al., Graded unilateral cervical spinal cord injury in the rat: evaluation of forelimb recovery and histological effects, BEH BRA RES, 119(1), 2001, pp. 1-13
The purpose of this study was to develop a model of unilateral cervical (C4
-C5) spinal cord contusion injury in the rat and to characterize the functi
onal and histological consequences following three injury levels using a ne
w weight-drop spinal cord injury device. We evaluated forepaw/forelimb and
hindlimb functions by: (1) a horizontal ladder beam measuring paw misplacem
ents and slips; and (2) the forelimb preference test which measures the for
elimb used for pushing off to rear, for support, and to land on after reari
ng. Rats with a mild spinal cord injury displayed primarily a forepaw defic
it (forepaw misplacements) for 8 weeks after injury. Paw preference also im
proved after injury. but failed to reach control levels even after 12 weeks
. These rats had damage primarily to the rubrospinal, spinocervicothalamic.
and the uncrossed lateral corticospinal tracts in the dorsolateral funicul
us a well as some loss of the lateral spinothalamic tracts in the lateral f
uniculus. Rats with a moderate injury had a prominent forepaw deficit still
evident at 12 weeks after injury as well as a mild but not significant hin
dlimb deficit. Paw preference improved slightly 12 weeks. There was a large
r lesion in the dorsolateral and lateral funiculi than in mildly injured ra
ts which extended into the ventrolateral funiculi. There was a significant
loss of gray matter compared to rats with a mild injury. Rats with a severe
injury displayed significant forelimb and hindlimb deficits throughout the
12 week testing period compared to rats with a mild or moderate injury. an
d also had a more severe paw preference bias (90%). The lesion encompassed
the entire dorsolateral, lateral and ventrolateral funiculi with some disru
ption of the ventral funiculus. There was more significant gray matter necr
osis compared to rats with either a mild or moderate injury. Thus, the spin
al cord injury device we used may be useful for studying graded cervical sp
inal cord injury in rats acid potential treatments or interventions, becaus
e both the behavioral and histological effects are reproducible and consist
ent. (C) 2001 Elsevier Science B.V. All rights reserved.