Inactivation of the Lateral But Not Medial Dorsal Striatum Eliminates the Excitatory Impact of Pavlovian Stimuli on Instrumental Responding

Effects of inactivation of the DLS and the DMS on lever-press responding during a pavlovian stimulus within the pavlovian-instrumental transfer procedure. For all figures, “pre” represents the baseline instrumental responding in the absence of any stimuli, “same” represents responding during presentation of the stimulus paired with the same outcome as the available lever, and “different” represents responding during the stimulus that was paired with the outcome earned by the alternate, currently unavailable lever. A, Mean (±SEM) lever press responding after inactivation of the DLS. After saline infusions, responding was elevated during the Same and Different stimuli relative to baseline and the impact of the same stimulus was greater than that of the Different stimulus. After BAC/MUS infusion, the enhancement of responding by presentation of the Same stimulus was greatly reduced. B, Mean (±SEM) lever press responding after inactivation of the DMS. After saline infusions, responding was elevated during the Same and Different stimuli relative to baseline and the impact of the Same stimulus was greater than that of the Different stimulus. After BAC/MUS infusion, responding was elevated during both the Same and Different stimuli compared with baseline and responding during these stimuli did not differ. n = 8 per group. Please refer to the text for complete statistical analyses. *Difference between a stimulus and baseline (p < 0.05); ^#difference between the Same and Different stimuli; ^☆difference between saline and inactivation conditions (p < 0.05).