Occurrence of hedonic and lack of affective deficit in 18-month-old C57BL/6 mice implications for modeling elderly depression

Abstract

 The prevalence of depression increases with aging. We hypothesized that like humans, old animals exhibit signs of hedonic deficit, along with behavioral despair. Here, sucrose intake, forced swimming, tail suspension, anxiety, novelty exploration and locomotor activity tests were compared in naive 3- and 18-month-old male C57BL/6 mice. The behavioral profile of aged mice parallels that of humans with elderly depression, in whom the symptoms of hedonic deficits typically outweigh affective disturbances. The assessment of anhedonic traits with the sucrose preference test in 18-month-old mice will be useful in preclinical studies of elderly depression and testing new antidepressants.