Effect of early locomotor training on evoked potentials and structural organization of visual cortex dendrites of rats during ontogeny.

The effect of early locomotor training (running in a squirrel cage from an age of 1 month for 3-6 months) on evoked potentials of the rat visual cortex during ontogeny was investigated. It was established that intensified proprioceptive afferentation causes a statistically significant reduction of both the latent periods and the recovery cycles of excitability of primary responses of the visual cortex to paired light flashes, whereupon the increase in functional activity is more pronounced with respect to the indices of the excitability recovery cycle than with respect to the latent periods or primary responses. The indicated functional changes correlate with the quantitative increase in the density of dendritic spines on neurons of the visual cortex of both layer V, which are primarily the integrative-triggering apparatus of the cortex, and of the complex of layers II + III, which are primarily associative with respect to their functional significance.