Experience with activity based anorexia enhances conditioned taste aversion learning in rats

Activity based anorexia (ABA) is a model that mimics the self-starvation and hyperactivity features of anorexia nervosa (AN). This study investigated whether a history of ABA will enhance food avoidance learning and retard its extinction in female rats. We compared the acquisition and extinction of a conditioned taste aversion (CTA) in naive (ad lib with no access to RW), ABA, and pair-fed to the food intake of ABA (with access to a locked RW) female Sprague–Dawley rats. The CTA conditioning was conducted after the ABA and pair-fed rats had recovered to their pre-food restriction body weights. For the CTA learning, 0.3 M sucrose consumption was followed by low doses LiCl (0.009 M or 0.018 M at 1.33 ml/100 g of body weight, IP) injection. The results revealed that the ABA rats acquired an aversion to sucrose significantly sooner than the naive controls. Furthermore, they completely avoided sucrose while the naive and pair-fed controls still sampled it by the end of 10 conditioning trials. When extinction was assessed by 1-bottle and 2-bottle tests, the ABA rats extinguished more slowly than the controls. However, the differences in sucrose aversion extinction between the ABA and control rats were only significant in the 1-bottle test. These data suggest that experience with AN-like behaviors results in an acquired aversion to a preferred food sooner and a longer retention of the negative food associations. These findings have implications for understanding the persistence of aberrant eating behaviors in eating disorders.

Research Highlights
► Activity based anorexia rats show increased activity but reduced food intake.
► Activity based anorexic rats dramatically reduced 25% of initial body weight.
► These anorexic rats learned a conditioned taste aversion sooner than the controls.
► The same anorexic rats extinguished the aversion more slowly than the controls.