The effects of variable interval schedule on anhedonic induction by Rats subjected to chronic mild stress

Abstract

This study has investigated the performance of rats in concurrent schedule of variable intervals (conc VI VI) and the development of anhedonia induced to chronic mild stress (CMS). The subjects were submitted to tests of consumption/preference of liquids, operant sessions (conc VI VI) and CMS. The frequency response on the bar that corresponded to sucrose liberation was greater before the CMS than during and after the stress protocol. During the CMS, the subjects showed an increase in fluid intake and weight loss. The weight loss during the CMS seems to be related to the combination of deprivation and intermittent aversive stimuli and increased consumption of liquids during the CMS in concurrent schedule exposure.Keywords: chronic mild stress, aversive stimulus, concurrent schedule, variable interval, Rattus norvegicus.