Reactions to DRL schedule change in rats with septal damage

Abstract

Normal rats and rats with septal lesions were given 45 days of DRL training on one of three different schedule sequences: DRL 10-20-10, 20-30-20, and 30-40-30, with 15 days of training on each schedule value. Interpolated training on a DRL schedule having a 10-sec longer delay requirement than the initial schedule did not result in further response suppression than that generated by the initial schedule in the case of rats with septal lesions. However, normal rats showed lower responding on the second exposure of DRL 10 and DRL 20 but not on DRL 30. In general, increasing the DRL delay requirement by 10 sec resulted in decreased responding. However, the magnitude of the decrease was a function of the relative difference in schedule requirement only in the case of rats with septal damage. Decreasing the delay by 10 sec led to increased responding in both normal and operated rats, with the magnitude of the increase being a function of the relative difference in delay requirement.