[Comparative characteristics of neuronal response in the vagus and facial nerve lobes of carp medulla oblongata to chemoreceptor stimulation].

The unit activity in the vagal lobe of medulla oblongata in response to stimulation of the mouth cavity and gills chemoreceptors with solutions of hydrochloric acid and sodium chloride was studied in immobilized carps and compared with those in the facial lobe in response to skin chemoreceptors stimulation. The firing rate in the vagal lobe is lower and the latent period is longer than in the facial lobe. The level of the chemical stimuli gradations analysis is different in two parts of the chemoreception primary centre. In the vagal lobe units responding to the impulses from both receptive fields as well as those responding selectively to stimulation either of the mouth cavity or the gills were found. Activity of a firing pattern was predominant in the vagal lobe units in response to stimulation with sodium chloride solutions.