Adolescent social isolation and food restriction impairs feeding in female mice

Preclinical animal models of eating disorders show a clear relationship between stress in the adolescent period and the development of dysfunctional coping strategies, including disordered eating. Much of this work, however, has focused on male mice despite the fact that eating disorders are predominantly observed in women. To this end, we assessed the impact of social isolation and food deprivation in adolescent female mice upon feeding and other coping behaviors. We found that social isolation, together with food restriction, caused alterations in activity levels and feeding consistent with impulsive binging behaviour in adolescent female mice. Indeed, socially isolated mice that were food restricted (FR) exhibited signs of elevated feeding following exposure to a palatable food and upon reinstatement of ad libitum (AL) food chow. FR mice also showed elevated home-cage activity and together with social isolation, altered Y-maze performance. Finally, the adolescent stress regimen appeared to cause long lasting brain atrophy, as occurs in eating disorders, as reflected by reduced gross brain weight. Hence, social isolation, when combined with restricted feeding during adolescence in female mice results in a behavioral phenotype reminiscent of symptoms associated with some eating disorders, such as binge eating.