PURPOSE: A major issue in analysis of experimental results after spinal cord injury is spontaneous functional recovery induced by remaining nerve fibers. The authors investigated the relationship between the degree of locomotor recovery and the percentage and location of the fibers that spared spinal cord transection. METHODS: The spinal cords of 12 adult rats were transected at T9 with a razor blade, which often resulted in sparing of nerve fibers in the ventral spinal cord. The incompletely-transected animals were used to study the degree of spontaneous recovery of hindlimb locomotion, evaluated with the BBB rating scale, in correlation to the extent and location of the remaining fibers. RESULTS: Incomplete transection was found in the ventral spinal cord in 42% of the animals. The degree of locomotor recovery was highly correlated with the percentage of the remaining fibers in the ventral and ventrolateral funiculi. In one of the rats, 4.82% of remaining fibers in unilateral ventrolateral funiculus were able to sustain a certain recovery of locomotion. CONCLUSIONS: Less than 5% of remaining ventrolateral white matter is sufficient for an unequivocal motor recovery after incomplete spinal cord injury. Therefore, for studies with spinal cord transection, the completeness of sectioning should be carefully checked before any conclusion can be reached. The fact that the degree of locomotor recovery is correlated with the percentage of remaining fibers in the ventrolateral spinal cord, exclusive of most of the descending motor tracts, may imply an essential role of propriospinal connections in the initiation of spontaneous locomotor recovery.
PURPOSE: A major issue in analysis of experimental results after spinal cord injury is spontaneous functional recovery induced by remaining nerve fibers. The authors investigated the relationship between the degree of locomotor recovery and the percentage and location of the fibers that spared spinal cord transection. METHODS: The spinal cords of 12 adult rats were transected at T9 with a razor blade, which often resulted in sparing of nerve fibers in the ventral spinal cord. The incompletely-transected animals were used to study the degree of spontaneous recovery of hindlimb locomotion, evaluated with the BBB rating scale, in correlation to the extent and location of the remaining fibers. RESULTS: Incomplete transection was found in the ventral spinal cord in 42% of the animals. The degree of locomotor recovery was highly correlated with the percentage of the remaining fibers in the ventral and ventrolateral funiculi. In one of the rats, 4.82% of remaining fibers in unilateral ventrolateral funiculus were able to sustain a certain recovery of locomotion. CONCLUSIONS: Less than 5% of remaining ventrolateral white matter is sufficient for an unequivocal motor recovery after incomplete spinal cord injury. Therefore, for studies with spinal cord transection, the completeness of sectioning should be carefully checked before any conclusion can be reached. The fact that the degree of locomotor recovery is correlated with the percentage of remaining fibers in the ventrolateral spinal cord, exclusive of most of the descending motor tracts, may imply an essential role of propriospinal connections in the initiation of spontaneous locomotor recovery.
Authors: Guillermo García-Alías; Hayk A Petrosyan; Lisa Schnell; Philip J Horner; William J Bowers; Lorne M Mendell; James W Fawcett; Victor L Arvanian Journal: J Neurosci Date: 2011-12-07 Impact factor: 6.167
Authors: Albert C Shaw; Adam W Jackson; Tamra Holmes; Suzie Thurman; G R Davis; Andrew D McClellan Journal: Exp Neurol Date: 2010-05-25 Impact factor: 5.330
Authors: Joong H Kim; David N Loy; Qing Wang; Matthew D Budde; Robert E Schmidt; Kathryn Trinkaus; Sheng-Kwei Song Journal: J Neurotrauma Date: 2010-03 Impact factor: 5.269
Authors: Victor L Arvanian; Lisa Schnell; Li Lou; Roozbeh Golshani; Arsen Hunanyan; Arko Ghosh; Damien D Pearse; John K Robinson; Martin E Schwab; James W Fawcett; Lorne M Mendell Journal: Exp Neurol Date: 2009-04 Impact factor: 5.330