人工体神经-内脏神经反射弧传出通路神经追踪研究

目的：研究大鼠人工体神经－内脏神经反射弧传出神经元胞体及其纤维末梢的分布。方法：将建立了人工体神经－内脏神经反射弧的11只模型大鼠随机分为3组（n＝4、4、3），分别用荧光金（FG）结合快蓝（FB）、辣根过氧化物酶（HRP），麦芽凝集素－辣根过氧化物酶（WGA－HRP）逆行顺行神经追踪。结果：左侧盆神经节（MPG）注射FG，尿道外括约肌（EUS）左侧注射FB后，可见FG、FB单标神经元及FG和FB双标神经元主要分布于脊髓L3尾部至L5头侧左侧前角。膀胱肌层注射HRP后，在左侧MPG可见HRP阳性神经元，WGA－HRP注射入脊髓L4左侧前角顺行追踪显示，左侧MPG4和EUS内有HRP阳性神经末梢。结论：躯体运动神经（L4VR）可以再生替代内脏传出和躯体运动混合神经，再生的神经纤维部分直接支配EUS，部分终止于MPG，在MPG内换元，由节后神经元支配膀胱，躯体运动神经元同时支配MPG和EUS可能是人工体神经－内脏神经反射弧控制排尿的主要神经解剖学基础。

Neural tracing study of efferent pathway of the artificial somatic-autonomic reflex arc

Objective To study the localization of efferent neuron and its terminals of artificial somatic-autonomic reflex arc.Methods The artificial somatic-autonomic reflex pathway was established in rat by intra-dural microanastomosis of the left L4 ventral root to L6 ventral root.The 11 model rats were divided into three groups (n=4,4,3 respectively).Retrograde tracing technique with fluorogold (FG),fast blue (FB) and horseradish peroxidase (HRP) and antegrade tracing with malt agglutinator binding horseradish Peroxidase (WGA-HRP) were applied.Results After FG was injected into the left major pelvic ganglia (MPG) and FB was injected into the external urethral sphincter (EUS),FG or FB single labeled neurons and FG-Fbdual labeled neurons were observed in locus of the left ventral horn from L3 caudal to L5 rostral.HRP positive neurons were observed in the left MPG but not in spinal cord after HRP was injected into the bladder detrusor.After WGA-HRP was injected into L4 left ventral horn,HRP positive axon terminals were observed in the left MPG and EUS,not in the detrusor.Conclusion Somatic motor axons(L4VR)can regenerate into peripheral autonomic and somatic motor nerve fibers.Some of regenerate nerve fibers directly terminated EUS,and others terminated the MPG.Postganglionic neurons that project to the bladder were distributed in the MPG;Simultaneous reinnervation of MPG and EUS by one group of somatic motor neurons may be the major neural anatomy infrastructure for controllable voiding via the somatic-autonomic reflex arc.