Effects of Scopolamine on Conditioning of Lever Pressing

Abstract

The aim of this work was to determine the effects of scopolamine, a cholinergic antagonist, on the conditioning of an instrumental response and the contextual conditioning of this response. Five groups of rats were trained to lever-press on a Variable Interval 30 s schedule in context A. Scopolamine was administered 15 min before each conditioning session to AB 0.01 mg/kg, AB 0.10 mg/kg and AB 1.00 mg/kg groups. The AA Saline and AB Saline groups received saline injections.Contextual conditioning of the lever-pressing response was assessed in one extinction session. The AA group received this extinction session in the conditioning context (A), while the AB groups received this session in a different context (B). Results showed that scopolamine impaired the conditioning of the lever-pressing response but no effects on contextual conditioning were found.