[Chemical sensitivity of the neurons of the medial vestibular nucleus to enkephalins, acetylcholine, GABA and L-glutamate].

The effect of enkephalins, morphine and some neurotransmitters on spontaneous and evoked activity of neurons of the medial vestibular nucleus was investigated. The evoked activity was produced by an adequate stimulation of the vestibular apparatus. It was shown that neurons of this nucleus were highly sensitive to enkephalins, morphine, acetyl choline, GABA and L-glutamate (approximately 80% of the nerve cells were inhibited or excited in response to the micro-iontophoretic application of these substances). It was found that activation and depression effects of opioid peptides and morphine occurred due to the stimulation of mu- and delta-opiate receptors. It can be concluded that enkephalins modulate cholinergic and glutamatergic synaptic transfer in the medial vestibular nucleus. Together with opiate receptors, they participate in the perception and processing of vestibular information at the level of neurons of this nucleus.