[Effect of early deprivation of visual evoked potentials of rabbit cerebral cortex under conditions of dark and light adaptation].

Rabbits raised in the dark revealed a significant decrease in amplitude and an increase in temporal parameters of the main components of evoked potentials (EP) to diffuse flashes under dark adaptation, as well as a facilitation of the postprimary components and intensification of the sensory after-discharge. In contradistinction to normal, the deprived animals exhibited no augmentation of the amplitude of the EP primary positive phase at higher intensity of the flahses or any significant decrease in the EP amplitude under light adaptation conditions. It is suggested that early deprivation brings about a decrease in the number of elements reacting to a specific stimulation, especially of elements working in photopic conditions; the decrease in the number of activated afferent inputs in the visual cortex due to deprivation reduces the effectiveness of the processes of successive inhibition; at the same time there is an increase of synchronic influences of the thalamic inhibitory mechanisms of the cortex.