Dissociation of stress and food-deprivation effects on spatial performance

Abstract

Food deprivation and exposure to a stressor both influence spatial performance. These effects may not be independent, because stress changes eating and body weight. The present study dissociated stress from eating and body weight to determine whether stress alters spatial performance indirectly via ingestive processes. Some rats experienced inescapable tailshock accompanied by reduced eating and body weight (STRESS+DEP), while others experienced only stress (STRESS) or only reduced eating and body weight (DEP). Eight-arm radial maze exploration was assessed in all groups. Exploration quality was similar across groups, and amount of exploration differed most between the groups that differed least with respect to deprivation: DEP rats explored more than did STRESS+DEP rats. Thus, stress apparently does not alter exploration by virtue of a change in ingestion. However, stressed rats that were spared reduced caloric intake and body weight (STRESS) explored more than did STRESS+DEP rats, suggesting that food can attenuate stress-induced reductions in exploration.