Figure 2.

MK-801, but not propranolol, impaired subsequent Pavlovian-instrumental transfer. The ratio of instrumental lever press responding during the CS relative to the previous ISI period was compared for the CS+ and the neutral CS−. (A) While rats administered saline or propranolol prior to memory reactivation showed greater responding to the CS+ than the CS−, the administration of MK-801 eliminated such selective responding (n = 8 for each group). (B) The effects of MK-801 were critically dependent upon memory reactivation, as omission of the reactivation session resulted in MK-801 having no effect on subsequent discriminative responding (MK-801: n = 7; saline: n = 9). Data presented as mean + SEM.