大鼠脊髓全横断后TrkA和NGF在运动皮质的免疫组化研究

目的 探讨脊髓全横断后神经营养因子及相应受体在运动皮质内的分布规律，为临床应用神经生长因子治疗脊髓损伤提供实验依据。方法 用免疫组化方法和图像分析技术检测脊髓全横断后不同时相运动皮质内，神经生长因子(NGF)及其高亲和性受体TrkA的表达和分布。结果 各组运动皮质中TrkA和NGF阳性神经元主要分布在第5层；脊髓全横断3d后，运动皮质内TrkA表达上调，损伤后7d到达高峰，21d回到正常水平；NGF表达在损伤后7d上调，峰值出现在损伤后7d，21d回到正常水平。结论 NGF表达增高迟于TrkA，提示在损伤早期给予外源性NGF可能有利于受损的皮质脊髓束神经元的存活与再生．

The Immunohistochemical Study of TrkA and NGF in Adult Rat Motor Cortex Following Spinal Cord Complete Transection

Objective To study the pattern of the distribution of neurotrophin receptors tyrosine kinase A(TrkA) and nerve growth factor (NGF) in adult rat motor cortex following complete spinal cord transection (SCT). Methods With immunohistochemistry and quantitative analysis, the expression and distribution of neurotrophin receptors TrkA and NGF were detected in motor cortex following complete SCT. Results TrkA and NGF immunoreactive positive cells are mainly localized in motor cortex layer V in both control and experimental groups. The expression of TrkA in adult rat motor cortex was up-regulated after transection in day 3 and reached the peak in day 7; While the expression of NGF in motor cortex was up-regulated and reached the peak in day 7 after transection. Conclusion The up-regulation of NGF occurred earlier than that of NGF, the results suggest that administration of exogenous NGF may be beneficial for the survival and regeneration of the injured corticospinal neurons in the early period after injury.