Fig. 2.

Behaviors of male and female voles during the immobilization (IMO) stress and the subsequent elevated plus maze (EPM) test. Males who had their partner in the cage during the IMO test (Partner) spent significantly more time in the open arm and entered the open arm more frequently during the EPM test, compared to males who experienced IMO alone (Alone) (A). During the IMO test, females spent significantly more time sniffing and in contact with the restrainer containing the stressed male partner (Partner) than with an empty restrainer (Empty). There were no significant differences in effort (biting/pulling the restrainer) or in the total time spent with the restrainer (sum of effort, sniff, and contact) (B). In addition, females in the Partner condition spent significantly less time rearing and in total anxiety-like behaviors (sum of rearing and self-grooming) than females in the Empty condition (C). Females showed no significant group differences in behaviors from the EPM test (D). Bars indicate mean ± SEM. * represents p < 0.05; ** represents p < 0.01.