大鼠孤束核葡萄糖敏感神经元、胰岛素敏感神经元对耳甲电针的反应

Responses of glucose-sensitive neurons and insulin-sensitive neurons in nucleus tractus solitarius to electroacupuncture at auricular concha in rats

目的:初步探讨耳针降糖作用的中枢机制。方法:微电极胞外记录孤束核(NTS)神经元活动,将记录的细胞随机分为颈静脉注射葡萄糖组、胰岛素组及耳甲电针组,观察上述处理因素对各组神经元放电活动的影响。结果:NTS存在葡萄糖敏感和胰岛素敏感神经元,葡萄糖敏感神经元中抑制型占37.3%,兴奋型占10.9%;胰岛素敏感神经元中兴奋型占33.3%,抑制型占4.9%;电针耳甲,NTS神经元有49.3%(34/69)放电频率增加,4.3%(3/69)放电频率减少,34个耳针激活细胞中有18个对葡萄糖呈抑制反应,8个对胰岛素呈兴奋反应。结论:耳甲电针能兴奋NTS葡萄糖敏感神经元(抑制反应型为主)和胰岛素敏感神经元(激活反应型为主),耳针的降糖效应可能与调节上述神经元放电活动有关。

Objective To investigate the central mechanism of hypoglycemic effect induced by ear acupuncture. Methods Extracellular single-unit recordings were carried out in nucleus tractus sotitarius （NTS） of rats after infusion of glucose, insulin via jugular venous and electroacupuncture at auricular concha, observing responses of glucose-sensitive neurons and insulin-sensitive neurons in NTS to electroacupuncture stimulation at auricular concha. Results There existed glucose-sensitive neurons and insulin-sensitive neurons in NTS. Among glucose-sensitive neurons, inhibitory ones accounted for 37.3%, and excitable ones accounted for 10.9%. Among the insulin-sensitive neurons, excitable ones accounted for 33.3 %, ture was given at auricular concha, 49.3% （34/69） while 4.3% （3/69） showed decrease in firing rate. and inhibitory ones aceounted for 4.9 %. When electroacupuncof total neurons recorded in NTS showed increase in firing rate, Among the 34 exciting-responsive neurons, there were 18 neurons responding to glucose infusion with a discharge decreased in frequency, and there were 8 neurons responding to insulin infusion with a discharge increased in firing rate. Conclusion Acupuncture stimulation at auricular concha can irritate the neurons in NTS, which show largely inhibitory and excitable response to glucose and insulin infusion, respectively. The hypoglycemic effect induced neuronsr firing activities. by auricular acupuncture possibly results from regulating these