[Photo- and phonoreactivity of visual cortex neurons following light deprivation of rabbits during ontogeny].

The study was concerned with neuronal responses of the visual cortex to diffuse flashes and sound stimuli (tones and rhythmic clicks) in 21--25 days old rabbits reared in darkness, and in control animals. It is shown that the number of neurones responding to flashes in the deprived animals is considerably smaller as compared to the control ones. The comparison of the experimental data with the data obtained previously on 2.5--5 months old rabbits permits a suggestion that an early photic deprivation for 3--3.5 weeks, while having no qualitative effect on photoreactivity of cortical neurones, slows down the rate of its formation. The subsequent development under deprivation leads to replenishment of the group of photoreactive neurones up to the normal level, presumably owing to reactive cells, and to an increase in the number of bimodal neurones, as compared to the control, owing to monomodal phonoreactive elements.