Exploratory behavior of rats following visual cortical and subcortical lesions

Abstract

Exploratory behaviors of rats with lesions of the visual cortex or superior colliculus (SC) were examined using a traditional open field and a smaller closed field. Animals with large bilateral lesions of the SC or lesions restricted to the deep laminae of the SC exhibited excessive locomotor activity in both experimental situations. The degree of habituation of this hyperactivity and other behaviors such as investigating rearing, exploratory nose poking, and self-initiated exposure to illuminated visual stimuli in the closed field were also examined. Consideration of the complete range of exploratory responses and the effect of lesions on them lead to a proposal that the hyperactivity of rats with SC lesions is an impairment adjunct to sensory neglect and orienting behavior impairments.