豚鼠肠系膜下神经节及其结肠段离体标本的反射活动

Reflex Activities in An in Vitro Preparation of Inferior Mesenteric Ganglia and Distal Colon of the Guinea-Pig

By using the preparation of inferior mesenteric ganglia (IMG) associated with distal colon of guinea-pig, the relationship between synaptic transmission in ganglion cell and movement of longitudinal and circular muscles of colon was investigated. It was found that when the preload tention of both muscles was set 0, the spontaneous synaptic potentials were recorded in IMG cells. Cutting colonic nerve irreversibly eliminated the potentials. Radialy distending the colon induced a slow depolarization lasting for about 70-190s in IMG neurones, This slow potential was resistant to d-TC and atropine. In addition, the summation of the slow potential induced by distending colon and ls-EPSP evoked by stimulating hypogastric nerve could, be observed. A train stimulation of pre-ganglionic nerve caused the relaxation of the longitudinal muscle, but irregulation in the motion of the circular muscle. The results suggest that cholinergic and non-cholinergic activities were included in the colon-IMG-colon reflex in which they control the movements of the intestines coofdinately.