Stress triggers anhedonia in rats bred for learned helplessness

Behav Brain Res. 2010 May 1;209(1):183-6. doi: 10.1016/j.bbr.2010.01.042. Epub 2010 Feb 1.

Abstract

Congenitally helpless (cLH) rats, a well-accepted model for depression, show reduced consumption of sweet solutions only under single-housing conditions, indicating anhedonia under stress. We investigated if anhedonic-like behaviour, measured by a reduction of sweetened-condensed milk (SCM) intake and the pleasure-attenuated startle response (PAS), could be induced by an electric foot-shock stress challenge in group-housed rats. After foot-shock stress, reduced SCM intake was observed in cLH rats compared to non-helpless (cNLH) rats. Furthermore, cLH rats also showed a decreased PAS, indicating deficient reward perception. In summary, we demonstrate that a predisposition for learned helplessness interacts with stress to trigger anhedonic-like behaviour in cLH rats. These findings further add to the validity of congenitally learned helplessness as an animal model of depression, since gene-environment interactions are considered to play a role in the etiology of this disorder.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acoustic Stimulation / adverse effects
  • Analysis of Variance
  • Animals
  • Depression / diagnosis
  • Depression / etiology*
  • Disease Models, Animal
  • Electroshock / adverse effects
  • Food Preferences / physiology
  • Helplessness, Learned*
  • Rats
  • Reflex, Startle / physiology
  • Reward*
  • Stress, Psychological / complications*
  • Stress, Psychological / etiology