Effects of regional striatal lesions on motor, motivational, and executive aspects of progressive-ratio performance in rats

The striatum is implicated in response selection and performance, the dorsal striatum in sensorimotor control and habit learning, and the ventral striatum in motivation and rewarded behaviors. Ventral striatal lesions produce performance changes on food-reinforced, progressive-ratio (PR) schedules, but the effects of dorsal striatal lesions on this task are not known. In this study, neither medial nor lateral dorsal striatal lesions produced deficits on the main motivational indices of PR performance. In contrast, significant impairments were observed in motoric or "executive" aspects of performance. Motivationally related manipulations of the task (food deprivation and reward magnitude) produced some subtle lesion-specific changes in behavior on these motoric or executive aspects of performance. Findings are discussed in relation to the roles of the dorsal and ventral striatum in reward-related behaviors.