针刺调节膀胱功能与新的“骶髓交感神经支配”理论关系的研究

The classic neuroanatomical knowledge that sacral outflow to the pelvic organs is parasympathetic in nature has been accepted for more than a century. This doctrine has been disputed recently by reports in top scientific journals that sacral autonomic outflow is sympathetic via neurodevelopmental verifications in mice and chicken embryos, yet evidences from adult animals or physiology studies are still unproved. This new paradigm brings challenges as well as opportunities to somatic stimulation therapy such as acupuncture which has been adopted to modulate pelvic visceral functions such as urinary bladder. The aim of the present study is to clarify the vesical autonomic innervations from vagus, thoracolumbar or sacral nerves and the transmitter– receptor mechanism by neural tracing and morphological methods in adult rats. Multichannel electrophysiology experiments will be performed to discuss acupuncture regulations and autonomic controls by recording intravesical pressure, electromyogram and autonomic nerve activities synchronously, combined with axotomy and noradrenergic or cholinergic blockers. Also effects of acupuncture will be observed on rat models of bladder overactivity and acute urinary retention. The origin of parasympathetic innervation of the urinary bladder and the explicit nature of the sacral autonomic outflow will be stated systematically by morphological and physiological methods. Based on these studies, we aim to clarify the nature of the sacral autonomic control related to acupuncture modulation of bladder function, thereby to provide solid evidence for clinic application of acupuncture.

经典解剖学认为,骶髓的传出纤维对盆腔器官产生副交感样调节作用。从胚胎发育学研究角度得出的骶髓是交感样支配的最新结论，目前尚缺乏成年动物及功能方面的证据。这种理论创新给针刺等体表刺激疗法调节膀胱等盆腔脏器功能的研究造成困惑的同时带来了机遇。本项目拟在成年大鼠以膀胱为靶器官，通过神经示踪及形态方法阐明迷走神经、脊髓胸腰或骶髓部自主神经对膀胱支配的递质-受体机制。也通过在体电生理学实验，在正常、不同部位自主神经切断动物，同步观察膀胱储尿排尿功能、膀胱逼尿肌肌电、神经放电等指标，并结合药理学方法，以阐明膀胱的自主神经支配来源和性质。在膀胱过度活动和急性尿潴留模型大鼠进一步验证针刺效应，说明不同穴位调节膀胱功能的自主神经机制。我们的研究将借助形态学和电生理学同步记录，系统阐述膀胱的副交感支配来源，明确骶髓的自主神经属性，为针刺不同穴位调节膀胱功能提供依据，进一步拓宽针刺治疗盆腔器官疾病的运用范围。

膀胱功能失调会出现排尿障碍，如尿频、尿痛、尿急、尿失禁、尿潴留等症状。针刺对膀胱功能障碍性疾病有一定的调节作用，因此探讨针刺调节膀胱功能的机制，为临床针刺治疗膀胱功能障碍性疾病提供实验依据有重要意义。研究应用神经示踪形态学方法，通过膀胱给予逆向示踪剂或跨多突触病毒，示踪了膀胱初级感觉传入及交感、副交感二级神经元的分布特征，并观察了体表会阴穴与膀胱感觉神经支配的特点，说明同节段穴位调节膀胱活动的物质基础。电生理实验部分，观察针刺不同节段穴位对等容性膀胱/等张性膀胱尿流动力学、尿道括约肌、腹下神经和盆神经的活动来探讨其调节效应及相应的神经机制。结果表明支配会阴穴和膀胱的感觉神经元分布在相同的神经节段，主要为 L6-S1 背根神经节，这可能是针刺会阴穴调节膀胱功能的神经通路，可以为临床应用会阴穴治疗泌尿系统疾病提供形态学依据。胸腰、腰骶髓段脊髓侧角中膀胱二级神经元的分布在大鼠T9-L4的脊髓侧角，观察到膀胱逆向示踪的神经元，标记的大多为大、中直径神经元。延髓迷走神经背核（DMV）中未观察到标记的神经元，说明膀胱的副交感中枢不在延髓迷走神经背核，新的“骶髓交感神经支配”没有成年大鼠的形态学实验支持。等容性膀胱和等张性膀胱中，针刺、钳夹会阴穴、阴陵泉穴对尿动力学和尿道括约肌的效应，可能通过延长盆神经和腹下神经与膀胱收缩同步的爆发性放电间隔实现的，这种效应具有神经节段性，与膀胱同节段的会阴穴效应最强。在不同刺激方式中观察到针刺效应强于钳夹和刷毛刺激，提示对膀胱运动的调节中，高强度刺激优于低强度刺激，刺激的躯体组织结构层面越多，效应越好。