Li Ai-Jun, Liu Jing-Zhang, Liu Chuan-Yong
Department of Physiology, School of Medicine, Shandong University, Jinan, PR China.
Chin J Physiol. 2002 Mar 31;45(1):19-24.
The present study was to investigate the localization of preganglionic parasympathetic neurons of gallbladder in brain stem by anatomical and functional approaches. Male or female rabbits (n = 11) were anesthetized with sodium pentobarbital (30 mg/kg, i.v.). Cholera toxin B conjugated to horseradish peroxidase (CB-HRP) was injected into the gallbladder wall. Four days later, animals were re-anesthetized and perfused transcardially with paraformaldehyde solution in a 0.1 M phosphate buffer. The rabbit brain was then frozenly sectioned. The sections were processed for HRP label and stained with neutral red. Another group of rabbits (n = 54) were anesthetized by urethane (1 g/kg) after fasting for 18-24 hours, Gallbladder pressure (GP) was measured by inserting a frog bladder filled with normal saline into the gallbladder. Myoelectrical activity of the sphincter of Oddi (SO) was induced by a pair of copper electrodes. A glass tube (30 microm tip diameter) connected with a microsyringe was directed to the dorsal vagal complex (DVC) for microinjection. Majority of retrogradely labeled cells was found bilaterally in dorsal motor nucleus of the vagus nerve (DMV) throughout the length, except the rostral and caudal part. These cells were distributed in subnuclei parvicellularis or mediocellularis of DMV. Some labeled perikarya located in the medial subnucleus of the solitary tract (mNTS). Thyrotropin-releasing hormone (TRH, 1.3 mmol/L, 0.2 microl) microinjected into the rostral portion of the DVC (including DMV and NTS) enhanced the motility of gallbladder and SO. Microinjection of TRH at the middle part of DVC seldom induces excitatory effects on the gallbladder or SO. TRH microinjected into the caudal portion of the DVC elicited weaker response of gallbladder and SO than rostral portion. Our results indicated that DMV is one of the most important original nuclei of gallbladder's vagus nerves and mNTS may be also involved in the control of gallbladder's parasympathetic activity. Neurons that innervate the gallbladder distribute at most part of DVC, and are relatively dense at rostral and caudal position of DMV.
本研究旨在通过解剖学和功能学方法研究脑干中胆囊节前副交感神经元的定位。选用雄性或雌性家兔（n = 11），用戊巴比妥钠（30 mg/kg，静脉注射）麻醉。将与辣根过氧化物酶结合的霍乱毒素B（CB-HRP）注入胆囊壁。4天后，再次麻醉动物，经心脏用0.1 M磷酸盐缓冲液中的多聚甲醛溶液进行灌注。然后将兔脑冷冻切片。对切片进行HRP标记处理并用中性红染色。另一组家兔（n = 54）在禁食18 - 24小时后用乌拉坦（1 g/kg）麻醉，通过将充满生理盐水的蛙膀胱插入胆囊来测量胆囊压力（GP）。用一对铜电极诱发Oddi括约肌（SO）的肌电活动。将连接微注射器的玻璃管（尖端直径30微米）对准迷走神经背核复合体（DVC）进行微量注射。在整个长度的迷走神经背核（DMV）双侧发现了大部分逆行标记细胞，但在头端和尾端部分除外。这些细胞分布在DMV的小细胞亚核或中细胞亚核中。一些标记的核周体位于孤束内侧亚核（mNTS）。向DVC的头端部分（包括DMV和NTS）微量注射促甲状腺激素释放激素（TRH，1.3 mmol/L，0.2微升）可增强胆囊和SO的运动性。在DVC中部微量注射TRH很少对胆囊或SO产生兴奋作用。向DVC尾端部分微量注射TRH引起的胆囊和SO反应比头端部分弱。我们的结果表明，DMV是胆囊迷走神经最重要的起始核之一，mNTS可能也参与胆囊副交感活动的控制。支配胆囊的神经元分布在DVC的大部分区域，在DMV的头端和尾端位置相对密集。
