Constant and flickering light stimulations produce similar effects on RNA content in visual cells.

Adult male rats were illuminated for 2 h with a constant or flickering light of 40 Lx intensity; frequency of flickering was 2 Hz. By means of two-wave-length visible cytospectrophotometry of gallocyanin-stained sections, it was shown that the light stimulation resulted in a marked RNA accumulation in retina ganglion neurons and in the neurons of all the cell layers of visual cortex (with the only exception of the layer VI). In the cells of perineuronal glia, a decrease of the RNA content per cell was found in the retina while no changes were observed in the visual cortex. Effects of constant and flickering light stimulations were qualitatively and quantitatively similar.