Age changes in electrophysiological measures of the superior colliculus and occipital cortex

Locomotor activity and electrophysiological recordings of the superior colliculus and the occipital cortex were measured for two age groups of rats (100-105 and 230-235 days old) tested in ambient light and dark sensory conditions. Age differences in response to ambient illumination were observed in both behavioral and electrophysiological data. While no age differences were found for the superior colliculus data, cortical activity of the older rats differed from that found in the younger rats. These results are interpreted in terms of potential cortical development and arousal functions.