[Cyclic changes in the excitability of the cerebral cortex in alert rats under conditions of direct interference with serotonin and noradrenaline metabolism].

Excitability recovery cycles in the visual cortex before and after administration of 5-OTP, d, 1-DOPA, PCPA and L-methyl-DOPA were studied on 23 alert rats with electrodes chronically implanted in the brain. The appearance of cyclicity under the influence of the drugs was established in the trace processes elicited by a photic stimulus. Differences between the periods of cyclic changes were revealed in conditions of activity predominance of the serotoninergic system (300-400 ms) and the noradrenergic system (200 ms). Their function in the short-term memory mechanisms is discussed.