Posttrial Administration of Cholinergic Drugs does not Affect Consummatory Successive Negative Contrast in Rats
Abstract
Posttraining administration of cholinergic drugs modulates the consolidation of memory processes in several learning tasks. We studied the effect of the administration of atropine (cholinergic antagonist, Experiment 1) and physostigmine (acetylcholinesterase inhibitor, Experiment 2) immediately after the first session of reward downshift, and immediately after the last preshift session (Experiment 3) on a consummatory successive negative contrast procedure. Animals were given access to a high-value reward (32% sucrose solution), and surprisingly shifted to a low-value reward (4% sucrose solution) in a second phase. The results indicate that atropine and physostigmine have no effects on contrast. The role of cholinergic neurotransmission in the memory of surprising reward changes is discussed.