[Effects of different neuromediators and regulatory peptides on the impulse activity of neurons in vestibular zone-I of the cerebral cortex].

Microelectrodes and micro-iontophoresis of physiologically active substances in experiments with cats immobilized by muscle relaxants made it apparent that different classical neuromediators (acetylcholine, norepinephrine, GABA and others) and regulatory peptides (enkephalins, thyrotropin-releasing hormone, vasoactive intestinal peptide (VIP), somatostatin (SS) and others) are capable to influence directly 68 to 100% of neurons in vestibular zone-I of the cerebral cortex. In the presence of L-glutamate, the inhibiting effect of enkephalins, VIP and SS on the neurons impulse activity was essentially unaltered. Also it was shown that enkephalins, VIP and SS are potent to augment the inhibiting effect of GABA and glycine. Therefore, these substances may have the neuromediator and/or neuromodulator role in this cortical zone.