Disruption of running activity rhythm following restricted feeding in female mice: Preventive effects of antidepressants

Biological rhythms are critical in the etiology of mood disorders; therefore,effective mood disorder treatments should address rhythm disturbances. among the variables synchronized with the light-dark cycle,spontaneous activity in rodents is useful for investigating circadian rhythms. however,previous studies have focused only on the increase of wheel-running activity under restricted feeding conditions,while little information is available on circadian rhythm of running activity. in this study,chronometrical analysis was used to assess whether circadian rhythms during wheel-running are altered by restricted feeding and affected by antidepressant drugs. wheel revolutions were automatically recorded and analyzed using cosinor-rhythmometry in 8-week old icr albino mice. when feeding was restricted to 1 h per day (21:00-22:00),wheel-running rhythms were reliably disrupted. female mice exhibited marked alterations in the pattern and extent of wheel-running beginning on day 1. subchronic treatment with imipramine or paroxetine,as well as tandospirone and (-)-doi,prevented wheel-running rhythm disruption. thus,altering the circadian activity rhythms of female mice on a 1-h feeding schedule may be useful for investigating disturbances in biological rhythms.