[Effect of electrocutaneous stimulation on responses of neurons in the parvocellular portion of the medial geniculate body induced by acoustic stimulation].

The effect of contralateral forepaw electrical stimulation on responses evoked by a click in neurons of the parvocellular part of the medial geniculate body was studied in cats anesthetized by thyopental sodium and immobilized with myorelaxine. Neurons in which responses to a click were inhibited by conditioning forepaw stimulation were located in areas of the parvocellular part of the medial geniculate body adjoining the ventro-posterior nucleus and the magnocellular part of the medial geniculate body. Forepaw stimulation did not affect the neurons located in lateral area of the parvocellular part of the medial geniculate body. In most neurons intracellular recording revealed EPSP-spike-IPSP or EPSP-IPSP sequence in response to a click while forepaw stimulation evoked exclusively IPSPs. Inhibition of neuronal responses to a click produced by forepaw stimulation may develop both during IPSP and without it. The mechanisms of inhibitory effect of forepaw stimulation on responses evoked by a click in neurons of the parvocellular part of the medial geniculate body are discussed.