Ethanol Induced Sign‐tracking in Swiss Mice

Abstract

Rationale It is thought that alcohol addiction is influenced by environmental cues. One way this relationship is built is through Pavlovian learning, in which the alcohol is repeatedly paired with an environmental cue. Sign-tracking is a type of behavior that exhibits a Pavlovian learned association. Objectives Our experiment studies induced sign-tracking using ethanol and a light visual cue (conditioned stimulus or CS). Methods In this study, one set of mice was given ethanol through intraperitoneal (IP) injections before being placed in an apparatus with a spatially isolated light visual cue. A control group was also placed in an apparatus with the light visual cue, but was not given ethanol IP injections until an hour after the trial (in the home cage). Following these conditioning trials, the mice were given a series of preference tests, where the visual cue was present (CS+) and both groups of mice received saline IP injections prior to the test. Results Throughout the conditioning trials, there was no distinction between groups for the time spent on the light side of the apparatus. However, when examining the nose poke counts per trial, the paired group poked more in the CS+ hole during preference test 2 compared to the CShole. Conclusions The paired group of mice did learn the association, and it can be argued that sign-tracking was observed because the mice showed a preference for the CS+ in the nose poke count of preference test