Early prolonged light-deprivation in hooded rats: deficits in two visual discrimination paradigms

Two types of experimental paradigms were used to study the effects of prolonged postnatal light-deprivation in hooded rats. The first experiment tested the effect of dark rearing on the acquisition of a light-flux discrimination using positive reinforcement discrimination; while the second experiment tested the effect of dark rearing on the acquisition and extinction of a conditioned emotional response (CER) using light-flux onset as a conditioning stimulus. Both positive discrimination and CER paradigms proved successful in revealing a deficit resulting from prolonged light-deprivation in hooded rats. These paradigms could differentiate a specific effect of light-deprivation on light-flux discrimination from general discrimination performance.