Sex-specific effects of adolescence social isolation

Adolescence is a critical period for the maturation of brain circuits regulating social behavior, including the mesocorticolimbic dopamine system. Social experiences have long-lasting consequences in the development of individuals. However, the impact of social isolation during adolescence is still unclear. A study in Behavioral Brain Research examines how social instability stress (SS) during adolescence affects social reward motivation and dopamine receptor expression in rats. Using an operant conditioning task and mRNA analysis, researchers found that SS reduces social reward motivation in female rats—but only in adulthood—while male rats showed no such effect when compared to non-isolated rats. Interestingly, SS increased D2 dopamine receptor expression—a key protein in the dopamine signaling system—in important brain regions connected to reward and motivation compared to control rats. Overall, these results show clear evidence that social stress during adolescence has lasting effects, changing how dopamine works and affecting social behavior in adult males and females differently.

Original reference: Leonetti, A. M. et al. Behav. Brain Res. 493, 115702 (2025)