Electrical activity of the visual cortex under conditions of change in the levels of monoamines in the brain of animals.

The changes in the electrograms of the visual cortex of awake animals under the influence of light stimulation in conditions of a pharmacological effect on the monoamine (MA) systems of the brain were investigated in experiments on 8 rabbits and 12 rats. The following was found following the administration of MA precursors (5-hydroxytryptophan and d,l-dihydroxyphenylalanine): a) a decrease in the amplitude of the averaged evoked potentials in response to rhythmical light stimuli (1-20 pulses/sec); b) intensification of rapid (15-25 Hz) oscillations in the spontaneous electrical activity of the cortex, as well as attenuation and modification of the effects of the blocker of MA synthesis, a-methyl-dihydroxyphenylalanine. A potentiation of the MA precursors was observed with light stimulation in the frequency spectra of the electrocorticograms. The specific characteristics of the action of the catecholamine precursor were manifested in the same conditions in the form of an intensification of the power of the 5-7 Hz rhythms, and an attenuation of the power of the 2-3 Hz rhythms.