Preconditioning selective ventral root injury promotes plasticity of ascending sensory neurons in the injured spinal cord of adult rats – possible roles of brain‐derived neurotrophic factor, TrkB and p75 neurotrophin receptor

摘要: Preconditioning sciatic nerve injury enhances axonal regeneration of ascending sensory neurons after spinal cord injury. A key question is whether direct nerves necessary for the enhanced regeneration. The lumbar 5 ventral root transection (L5 VRT) model, a model selective motor injury, provides useful tool to address this question. Here we examined effects preconditioning L5 VRT on subsequent dorsal column (DCT) in adult Sprague-Dawley rats. We found that 1 week before DCT increased number Fast Blue (FB)-labeled ganglia (DRG) and promoted sprouting/regenerating axons grow into glial scar. also induced dramatic upregulation expression brain-derived neurotrophic factor (BDNF) preconditioned DRG injured cord. Moreover, almost all FB-labeled expressed BDNF, approximately 55% these were surrounded by p75 neurotrophin receptor-positive cells. This combined led an increase BDNF- TrkB-immunoreactive fibers caudal lesion site. Taken together, findings demonstrate promotes sprouting/regeneration neurons, indicating axotomy may not be essential plasticity axons. Thus, could preprimed regenerative milieu Wallerian degeneration neuroinflammation, which might alter factors their receptors, facilitating neurons.