Role of the amygdala in modulating the stress response strategies in adult rats exposed to postnatal stress.

GRILLO BALBOA J; COLAPIETRO A; CANTARELLI VI; PONZIO MF; ANTONELLI MC; PALLARES ME

Encuentro; XXVII Reunión Anual de la Sociedad Argentina de Investigación en Neurociencias (SAN); 2022

Early-life stress is a well-established risk factor for the development of behavioral disorderslater in life (e.g., depression, anxiety and post-traumatic stress disorder). Although themechanisms underlying this vulnerability are not fully elucidated, they have been linked todysregulations in the Stress System and the cortico-limbic structures that modulate its activity.Among them, the amygdala (Amy) plays a critical role in the emotional processing of threat.During early life the Amy is extremely plastic, rendering it vulnerable to environmental factorsthat could lead to atypical shaping of behavior in the long term. Among the protocols thatinduce infant maltreatment in rats, the “Scarcity-adversity model” (SAM) −by which thenesting resources provided to a lactating dam are limited− is particularly interesting, as it is themother who induces stress in her pups. The SAM is applied from postnatal day 8 to 12, acritical moment in the maturation of the Amy. We hypothesize that SAM will induce stress inthe mothers, modifying their behavior towards pups. This will, in turn, modify the structureand functioning of the Amy in their pups, leading to variations in the way the offspringresponds to stress and threat, and enhancing their vulnerability to develop behavioralalterations. Our preliminary data shows that SAM dams display greater anxiety-like traits thancontrol mothers, evidenced by a lower frequency of entry to the open arms of the ElevatedPlus Maze.