Stressor experiences during the juvenile period increase stressor responsivity in adulthood: transmission of stressor experiences.

Stressors experienced by rodents during the juvenile period may have repercussions on anxiety and impulsivity that extend into adulthood. In the present investigation we demonstrate that during social interactions stressed adults might transmit their responses to juveniles thereby affecting later behavioral responses in adulthood. In the present investigation adult mice exposed to a stressor, exhibited altered social exploration of a juvenile (26-28 day old) mouse that comprised reduced body contact but elevated anogenital and facial contact. The juvenile mice that encountered the stressed adult, in turn, exhibited greater impulsivity in an elevated plus maze test, as well as elevated corticosterone levels. In a second experiment, adult animals that had experienced a stressor during the juvenile period also exhibited reduced social exploration (of a juvenile), but upon exposure to a further social stressor (social defeat), social exploration was altered further. Furthermore, when tested in an elevated plus maze the juvenile mice that had encountered an adult that had itself been stressed as a juvenile, exhibited increased impulsivity. However, if they encountered an adult that had been stressed both as a juvenile and as an adult, the behavioral profile of the juveniles was altered yet again in that they exhibited greater impulsivity coupled with anxiety. It is suggested that the juvenile period represents one during which stressor sensitivity is high, so that transmission of stressor effects from adults occurs readily. Moreover, stressors experienced during the juvenile period may have persistent effects on social behaviors, thereby affecting conspecifics with which they interact.