title: Preconditioning crush increases the survival rate of motor neurons after spinal root avulsion.
abstract: In a previous study, heat shock protein 27 was persistently upregulated in ventral motor neurons following nerve root avulsion or crush. Here, we examined whether the upregulation of heat shock protein 27 would increase the survival rate of motor neurons. Rats were divided into two groups: an avulsion-only group (avulsion of the L4 lumbar nerve root only) and a crush-avulsion group (the L4 lumbar nerve root was crushed 1 week prior to the avulsion). Immunofluorescent staining revealed that the survival rate of motor neurons was significantly greater in the crush-avulsion group than in the avulsion-only group, and this difference remained for at least 5 weeks after avulsion. The higher neuronal survival rate may be explained by the upregulation of heat shock protein 27 expression in motor neurons in the crush-avulsion group. Furthermore, preconditioning crush greatly attenuated the expression of nitric oxide synthase in the motor neurons. Our findings indicate that the neuroprotective action of preconditioning crush is mediated through the upregulation of heat shock protein 27 expression and the attenuation of neuronal nitric oxide synthase upregulation following avulsion.
authors.affiliation: Department of Human Anatomy, Nanjing Medical University, Nanjing, Jiangsu Province, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Human Anatomy, Nanjing Medical University, Nanjing, Jiangsu Province, China.
authors.forename: Yizhi
authors.initials: Y
authors.lastname: Zuo
authors.affiliation: Department of Human Anatomy, Nanjing Medical University, Nanjing, Jiangsu Province, China.
authors.forename: Jianwen
authors.initials: J
authors.lastname: He
keywords: Excellent Discipline of Jiangsu Province; a grant from Education Ministry of Jiangsu Province; choline acetyltransferase; fluorescent antibody technique; heat shock protein 27; motor neurons; nerve regeneration; nerve root avulsion; neural regeneration; nitric oxide synthase; spinal nerve root