Effect of inhibitors of catecholamine synthesis (α-methyltyrosine and disulfiram) on spontaneous unit activity of the sensomotor cortex and responses to afferent, caudate, and reticular stimulation

Abstract

Spontaneous activity of single units of the sensomotor cortex and their responses to flashes, clicks, electrical stimulation of the skin, and stimulation of the caudate nucleus and mesencephalic reticular formation were recorded in unanesthetized, curarized cats. α-Methyltyrosine (150 mg/kg) and disulfiram (400 mg/kg), injected 6 h before the experiment, caused an increase in the grouping of the spontaneous activity, an increase in the number of spontaneously active units, and an increase in the amplitude of the afferent short-latency responses. Phasic and tonic inhibition of the neurons during low-frequency stimulation of the caudate nucleus was potentiated by α-methyltyrosine, but weakened by disulfiram. Against the background of the action of the first of these agents, amphetamine did not exhibit its blocking action on caudate inhibition. Both substances weakened facilitatory and inhibitory reticular influences, and disulfiram was more effective in this respect.