【摘要】 在豚鼠肠系膜下神经节(IMG)及其支配的结肠段联合标本上,对IMG细胞内电位与肠段纵肌或环肌舒缩活动进行了同步记录。实验结果表明:(1)肠段预置张力为零时,约50％IMG细胞有自发的快兴奋性突触后电位(EPSP)活动,切断结肠神经或以筒箭毒(50μmol/L)灌流IMG后消失;(2)筒箭毒或低钙高镁溶液阻断神经节传递时,环肌节律性收缩幅度增大,节律变慢,但对纵肌节律性收缩无明显影响,(3)串刺激节前神经,在IMG细胞引起一串快EPSP或动作电位并常跟随迟慢的EPSP,同时,纵肌在0.1-0.2s潜伏期后出现迅速的、时程基本与动作电位串一致的舒张波,后者在筒箭毒灌流IMG后消失,而环肌运动可见舒张、舒张波延长或收缩波增大。结果提示:IMG不仅中继经典的胆碱能传出功能,还参与以胆碱能传递为中介的肠-肠反射,该反射活动的传出效应主要在于抑制环肌收缩。更多还原

【Abstract】 A perfused inferior mesenteric ganglion (IMG)-colon preparation was pre-pared from the guinea-pig for intracellular recording of IMG neurons and forsimultaneously recording the muscular contraction. It was found that: (1) Atzero preloaded tension of colon, the spontaneous fast excitatory post-synaptic po-tentials (f-EPSPs) could be recorded in about 50% sampled neurons. Thesef-EPSPs were abolished by either severing the colonic nerve or superfusing IMG withdtubocurarine (d-TC, 50 μmol/L). (2) The contraction of circular but not longitu-dinal muscle was augmented and slowed down by superfusing IMG with d-TC or lowCa/high Mg solution. (3) A train stimulation of the preganglionic nerves initiateda volley of f-EPSPs or orthodromic discharges, in the IMG neurons and a quick re-laxation of the longitudinal muscle with a latency of between 0.1 s and 0.2 s. Theresponses of the neuron and the muscle could be eliminated by superfusing IMGwith d-TC. Multiple irregular responses of the circular muscle of the colon tothe train stimulation could also be found. The results suggest that the IMG neu-rons parpicipate in the cholinergic afferents and colo-colonic reflex mediated bycholinoceptors. The output of the reflex mainly inhibited the circular muscle con-traction of the colon.更多还原