[Microiontophoretic study of the effect of cholinergic substances on the activity of medullary respiratory neurons].

The responses of single inspiratory, expiratory and unspecific neurons of the medulla oblongata to microelectrophoretic applications of acetylcholine, M- and N-cholinergic-blocking agents (atropine and etpenal) were studied in anesthetized cats. A relatively small amount of cholinoreactive neurons was found. Cholinoreactive units prevailed in the group of unspecific neurons. Electrophoretic application of acetylcholine evoked mainly excitatory responses. A rather mild inhibitory action of anticholinergic drugs on neurons of bulbar respiratory centre was revealed. These reactions seem to be unspecific being evoked in acetylcholine-sensitive and nonsensitive neurons.