Simple Ethological Models of Depression: Social-Isolation Induced “Despair” in Chicks and Mice

Abstract

Social isolation is widely considered to be one of the major vectors whieh contributes to the onset of depression. Although an isolation-induced "despair" model of depression is available for primates, neuroscience work would be faeilitated by a simplified model that could be used routinely. In the following work we analyzed the ability of social isolation to faeilitate immobility in the mouse forced swimming test and to decrease separation induced distress voealizations (DVs) in young ehieks. Isolation increased immobility only in very young mice (17-21 days of age) but not in older juveniles or adults. Chronie isolation reduced DVs in chieks and made them more susceptible to the DV reducing effects of reserpine. The ehronically isolated young ehiek appears to be an exeellent and inexpensive model for the analysis of despair/depression processes in brain.