Brightness discrimination loss after lesions of the corpus striatum in the white rat

Multiple bilateral electrolytic lesions destroying the posterior regions of the corpus striatum (including the globus pallidus) in the rat produced a marked deficit in retention of a brightness discrimination habit. Lesions placed more anteriorly within the corpus striatum had little effect. No effect on retention followed bilateral lesions of either the nucleus accumbens septi, infralimbic area, or frontal cortex. It would appear that the posterior division of the corpus striatum must be included within the “general memory system” (along with the brainstem reticular formation) by virtue of its contribution to the expression of a wide variety of learned responses.