Dept. of Psychiatry and Psychotherapy, Central Institute of Mental Health, University of Heidelberg, 68159 Mannheim, Germany.
Behav Brain Res. 2010 May 1;209(1):183-6. doi: 10.1016/j.bbr.2010.01.042. Epub 2010 Feb 1.
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.
先天性无助（cLH）大鼠是一种被广泛接受的抑郁模型，仅在独居条件下表现出对甜味溶液消耗减少，表明在应激下出现快感缺失。我们研究了群居大鼠是否可以通过电足底电击应激挑战引起类似快感缺失的行为，通过减少加糖炼乳（SCM）的摄入和减弱的惊吓反应（PAS）来衡量。与非无助（cNLH）大鼠相比，在足底电击应激后，cLH 大鼠的 SCM 摄入量减少。此外，cLH 大鼠还表现出 PAS 降低，表明奖赏感知能力不足。总之，我们证明了习得性无助的倾向与应激相互作用，导致 cLH 大鼠出现类似快感缺失的行为。这些发现进一步增加了先天性习得性无助作为抑郁动物模型的有效性，因为基因-环境相互作用被认为在这种疾病的发病机制中起作用。
