Responses of single units in the inferior olive nucleus to stimulation of the splanchnic afferents in the cat.

The activity of olivary neurons in the caudal parts of the medial accessory olive (MAO) and dorsal accessory olive (DAO) was recorded with extracellular microelectrodes in anesthetized cats. The responses were obtained by electrical stimulation of the contralateral splanchnic nerve and mechanical stimulations of gastro-intestinal and peritoneal receptors. The stimulated mechanoreceptors were slowly adapting muscular receptors of the stomach (connected with C fibers) and slowly adapting peritoneal movement receptors (connected with A gamma delta or B fibers). Splanchno-visceral, splanchno-somatic and splanchno-cortical convergences were observed, as in the cerebellum (lobule V and VI). So, the inferior olive must be considered as an integrating structure not only for central and somatic messages, but also for visceral ones.