Effects of running before pregnancy on long-term memory and hippocampal alterations induced by prenatal stress

Abstract

Studies have shown that an adverse environment in utero influences fetal growth and development, leading to several neuroendocrine and behavioral changes in adult life. Nevertheless, the mechanisms involved in the long-term benefits of pregestational exercise are still poorly understood. Thus, this study aimed to evaluate the effects of physical exercise before the gestational period on memory behavior and gene expression in the hippocampus of adult mice submitted to prenatal stress. Female Balb/c mice were divided into three groups: control (CON), prenatal restraint stress (PNS), and exercise before the gestational period plus PNS (EX + PNS). When adults, male and female offspring were submitted to the object recognition test followed by the hippocampal evaluation of BDNF exons I and IV mRNA expression, as well as hypothalamic-pituitary-adrenal axis related genes. Pregestational exercise did not prevent the decreased recognition index, as well as GR and CRHR1 gene expression observed in PNS males. Conversely, prenatal stress did not influence female memory behavior. Moreover, exercise attenuated the effects of prenatal stress on female BDNF IV gene expression. The results indicate that pregestational exercise was able to prevent the effects of maternal stress on hippocampal BDNF IV gene expression in females, although no effects were seen on the stress-induced memory impairment in males.

Keywords: BDNF; Early-life stress; Exercise; HPA axis; Hippocampus; Memory.