跨突触病毒示踪法研究大鼠C7神经根中枢神经系统支配回路组成

目的 研究假狂犬病病毒减毒株C7神经根注射后标记神经元在脑和脊髓的分布,为健侧C7神经根移位术后的脑功能重塑研究提供实验方法.方法 取SD大鼠20只,根据脊髓和脑组织取材时间随机分为4组:6 h、12 h、24 h和36 h,每组5只动物.在右侧C7神经根注射假狂犬病病毒液2 μl.动物存活6～36 h后,使用抗病毒的多克隆抗体,通过免疫组织化学方法检测相应脊髓节段(C1～C7)和脑中感染的阳性神经元.结果 病毒注射后6～36 h,脊髓和脑中的一些结构及区域可见阳性标记细胞,主要分布在C1～C7节段脊髓灰质、外侧类巨细胞网状核、A5细胞、红核,第一、二运动皮质,第一、二感觉皮质等.随着动物存活时间的延长,脊髓和脑中被标记神经元的数目也明显增多.结论 本跨突触病毒示踪研究发现上述标记的脊髓和脑组织结构与C7神经根存在直接或(和)间接突触联系,可能直接或间接参与对C7神经根的神经支配和调节.

Identification of centrum neural circuitry involved in innervation of the C7 nerve root: a viral transsynapfic tracing study

Objective The distribution of positively labeled neurons in the brain and spinal cord was studied after injecting the attenuated strain of pseudorabies virus(PRV)into the C7nerve root so as to provide a baseline for further studying of brain functional reorganization after contrallateral C7 transfer. Methods Twenty adult Sprague Dawley rats were randomly divided into 4 groups according to the time of being sacrificed:6 hours,12 hours,24 houm and 36 hours groups.2ul of the virus was slowly injected into the risht C7 nerve root.After survival times of 6 to 36 hours,the spinal cord(C1-C7)and brain were processed immunocytochemically using a polyelonal antibody against the PRV.The positively labeled neurons were observed. Results PRV positively labeled neurons were found in some spinal cord and brain regions from 6 hours to 36 hours post injection,such as the gray matter in the C1-C7 spinal cord,the lateral paragigantoceUular nuclei,and the A5 cells,red nucleus,primary and secondary motor cortex,primary and secondary somatosensory cortex etc.The longer the survival time the more numher of positively labeled cells from the spinal cord to brain regions. Conclusion The spinal cord and brain structures labelled from the C7 nerve root by the transsynaptic tracing technique are synaptically connected with C7 and presumably are involved in the neural regulation of C7.