目的　观察肌梭传入对延髓呼吸相关神经元自发放电的影响 ,从呼吸中枢的途径探明肌梭传入是否对呼吸运动具有反射性调节作用。方法　在氨基甲酸乙酯麻醉、断双侧颈迷走神经、肌松、人工呼吸的家兔上 ,观察了股动脉注射琥珀胆碱 (Sch)诱发肌梭兴奋对延髓呼吸相关神经元自发放电的影响。用双极银丝电极记录膈神经传出放电 ,用玻璃微电极细胞外记录延髓呼吸相关神经元单位放电 ,根据神经元放电和膈神经放电的时相关系来确定神经元的性质。记录到的单位放电信号输入示波器显示 ,并输入计算机处理 ,绘出序列密度直方图 ,直接测量并打印图形与数据 ;同时与膈神经放电同步照像。结果　 (1 )股动脉注射 Sch可明显兴奋延髓吸气神经元而抑制呼气神经元的放电活动。在 56个吸气神经元中 ,呈兴奋反应的 37个 ,抑制反应的 1 1个 ,双相反应的 2个 ,其余 6个无明显反应。在 1 7个呼气神经元中 ,呈兴奋反应的 4个 ,抑制反应的 1 0个 ,双相反应的 1个 ,其余 2个无明显反应。(2 ) Sch对吸气神经元的兴奋作用 ,一般在给药后 1～2 min即可达高峰 ;而对呼气神经元的抑制作用则发生较晚 ,一般在给药后 2～ 3min达高峰。 (3)肌注布比卡因破坏肌梭后可明显降低 Sch对延髓呼吸相关神经元的影响。较正常侧相比 ,肌注布比卡因侧肢股 Objective To observe the effect of muscle spindle afferent on spontaneous discharge of respiratory neurons in medulla oblongata and to explore whether the muscle spindle afferent reflex regulation of respiratory motility can be achieved through the way of respiratory center. Methods The spontaneous discharges of neurons in the medulla oblongata were observed on urethane anesthesia, bilateral vagus vagus nerve, muscle relaxation and artificial respiration in rabbits. The bipolar silver electrodes were used to record the phrenic nerve outburst, and the glass microelectrode was used to extracellularly record the medullary respiration-related neuron unit discharge. The neuronal properties were determined according to the temporal relationship between neuronal discharge and phrenic nerve discharge. Recorded unit discharge signal input oscilloscope display, and enter the computer processing, drawing sequence density histogram, direct measurement and printing of graphics and data; simultaneous with phrenic nerve discharge synchronous camera. Results (1) Femoral injection of Sch’s significantly excites the medullary inspiratory neurons and inhibits the discharge activity of the exhaled neurons. Of the 56 inspiratory neurons, 37 were excited, 1 of inhibition, 2 of biphasic reactions, and the remaining 6 showed no significant response. Among the 17 expiratory neurons, there were 4 excitatory reactions, 10 inhibition reactions, 1 biphasic reaction, and the other 2 showed no significant response. (2) Sch for inspiratory neurons excitement, usually 1 to 2 min after administration to reach the peak; while the inhibitory effect on expired neurons occurs later, usually at 2 ~ 3min after administration of up to peak. (3) Muscle injection of Bupivacaine can significantly reduce the influence of Sch on the respiration-related neurons after disruption of muscle spindles. Compared with the normal side, intramuscular injection of bupivacaine lateral limbs