[Microionophoretic study of the effect of various neurotransmitters on the activity of neurons in the bulbar respiratory center].

Three putative neurotransmitters (L--glutamate--L--GL; GABA and noradrenaline--NA) were applied to bulbar respiratory neurons and for comparison, to unspecific cells. L--GL induced excitation in all tested inspiratory, expiratory and unspecific neurons of the bulbar respiratory area. GABA depressed the firing of respiratory and unspecific neurons. Stimulation of NA receptors resulted in neuronal activation or inhibition with prevailing excitatory effects for all three types of the neurons. Two types of NA-specific receptors seem to exist among the respiratory and nonrespiratory neurons of the bulbar region of dorsal and ventral respiratory areas.