Transtorno do estresse pós-traumático durante a gestação induz ao comportamento tipo-ansioso e desregulação do eixo hipotálamo pituitária-adrenal na prole

Abstract

Stressful events in the perinatal period may alter puppies' brain structure and function leading to lifelong permanent behavioral changes. Thus, our study aims to evaluate the influence of posttraumatic stress during pregnancy on behavioral responses in mother and offspring. The pregnant rats on the 10th day of gestation were divided into 2 groups (n = 10 per group): no shock and shock. They were exposed or not to inescapable foot shocks (2 s, 0.8 mA) and isolated in individual boxes. One day after birth (DPN1), puppies were standardized into 4 males and 4 females and lactating rats were re-exposed to the shock box to assess freezing time (s). Maternal behavior was evaluated on the 2nd to 8th day of lactation in rats, the open field test was performed on the 4th day and the recognition of objects on the 5th lactation. The offspring were evaluated in childhood in the following tests (n = 10 per group): quantification of ultrasonic vocalization (DPN5) and mother's return behavior test (DPN13). During adolescence (DPN 28-32) open field behavioral tests, elevated pluz maze, play behavior and hole plate test were performed. Statistical analyzes were performed using GraphPad software version 7.0, Student's t-test or two-wayAnova followed by Bonferroni post-test. All experimental procedure were approved by the animal experimentation ethics committee of Unifal-MG, protocol no. 50/2018. The group of dams mothers showed an increase in freezing time when re-exposed to shock box, reduced maternal behavior, reduced short-term and long-term object recognition index, and increased plasma corticosterone after exposure and re-exposure to shock when compared to the non-shock mothers group. In childhood, puppies from shocked mothers showed an increase in the number of ultrasonic vocalizations, latency to achieve mother wonder, and reduced time spent in mother wonder when compared to puppies from non-shock mothers. Already in adolescence, there was a reduction in the total time of playing behavior and an increase in the number of head immersions in the hole plate test, reduction in the time spent in the open arms and increased head dips in the elevated cross maze test. , in addition to increased expression of GR in the hippocampus and an increase in plasma corticosterone after baseline dosing and after elevated cross-maze testing. Thus, we can conclude that PTSD, besides negatively affecting the mother, provides fetal reprogramming inducing anxious behavior in the offspring.