荧光逆行示踪法定位神经端侧缝合后再生来源的实验研究

目的 应用荧光逆行示踪法研究神经端.侧缝合修复臂丛神经损伤的有效性及再生神经的脊髓定位.方法 雌性SD大鼠24只,随机分为4组,造成臂丛神经上干损伤模型,分别以膈神经、同侧颈,神经根为供体神经,按照端.侧和端.端两种缝合方式修复肌皮神经.术后3个月,对大鼠肌皮神经和供体神经分别采用真蓝和双脒基黄进行逆行示踪.3、7、14 d后进行灌注固定,取颈段脊髓连续切片,荧光显微镜观察.结果 各观察点背根节及脊髓前角均出现荧光标记细胞,并逐渐增多.以同侧颈,为供体神经组,标记细胞仅出现在该节段,而以膈神经为供体神经组,标记细胞出现在颈_(3-5)节段.端一侧缝合组在相应脊髓前角或背根神经节出现,同时具有两种荧光剂的双标细胞或在同一脊髓节段同时出现分别以两种荧光剂标记的单标细胞.结论 采用不同供体神经进行端.侧缝合联合神经移植修复臂丛神经可使神经再生,荧光逆行示踪可以准确定位端.侧缝合后再生神经的来源.

Localization of the origin of regenerating axons in end-to-side neurorraphy by fluorescence retrograde tracing: an experiment study

Objective To explore the effectiveness of end-to-side neurorraphy for reconstruction of brachial plexus injuries and the spinal localization of regenerating axons using fluorescence retrograde tracing. Methods Twenty-four female SD rats were subject to brachial plexus upper trunk injury and randomized into 4 groups: phrenic nerve to musculocutaneous nerve end-to-end transfer, phrenic nerve to musculocutaneous nerve end-to-side transfer, ipsilateral C_7 to musculocutaneous nerve end-to-end transfer, and ipsilateral C_7 to musculocutaneous nerve end-to-side transfer. Three months after the surgery, the musculocutaneous nerve and the donor nerves were retrogradely traced by True Blue and Diamidino Yellow, respectively. C_2 to T_2 dorsal root ganglion (DRG) and spinal cord were harvested after perfusion fixation 3, 7 and 14 days later. 30 μm-thinkness shoes were observed under the fruromicroscope. Results Fluorescence labeled neurons were seen both in DRG and anterior horn of the spinal cord. There were more and more positively labelled neurons with the pass of time. The fluorescence labeled neurons of C_7 group were observed only in C_7-DRG and anterior horn of the corresponding spinal cord. The ones of phrenic nerve were found in C_3 to C_5 DRG and anterior horn of the corresponding spinal cord. Two kinds of single labeled neurons or double labeled neurons were observed in the same site in the groups of end-to-side neurorraphy. Conclusion Nerve regeneration is possible in an end-to- side neurorraphy brachial plexus reconstruction model. Fluorescence retrograde tracing can be used for precise neuron localization.