[Sensory after-discharges of the rat visual cortex during elaboration and extinction of a temporary connection]

Sensory after-discharges (SAD) in the rat's visual cortex became more intense at the background of an unconditioned drinking reaction. During the elaboration of a conditioned reflex to light (ten successive flashes of which the last five were reinforced) the SAD enhancement proceeded in two stages; the first coincided with the reinforcement, the second was developing in the phase of a stable conditioned reflex to the second or third flash of the rhythmic series. When reinforcement was omitted in a test with acute extinction. SAD was depressed, and was replaced by an increased number of after-effect waves, related to the appearance of "substituting" movements of the hygienic routine. It is assumed that the enhanced synchronized activity on the EEG at this moment plays an adaptive part, eliminating desynchronization and reducing the destructive action of the emotional stress.