Efeitos do exercício realizado antes e/ou durante a gestação na memória da prole submetida à privação maternal

Abstract

The aim of this thesis was to study the impact of the physical exercise before and/or during pregnancy in different types of memories of Wistar offspring submitted to a maternal separation protocol in their first days of life. To assigned this, 24 females (n = 4/group) and 12 male Wistar rats were used to mate. Females dams (n = 4 per group) were submitted to 4 weeks of aerobic physical exercise before and 3 weeks during pregnancy or only 3 weeks of exercise during pregnancy (EM) using a treadmill for rodents. After delivery, pups were divided into control or maternal separated group (submitted to maternal separation protocol from postnatal day 1 to 10; PND 1-10); memory testing started PND 22 (females; n = 8-11/group) or PND 60 (males; n = 7-13/group). Maternal separation caused object and social recognition memory deficits in pre-pubertal females and young adult males. Physical exercise performed during pregnancy showed positive results, being able to prevent those deficits and enhance spatial learning in pre- pubertal females. On the other hand, when exercise was performed before and through pregnancy, we observed no significant neuroprotective effects. Those results elicit neuroprotective effects of aerobic exercise performed during pregnancy, protecting against memory deficits caused by maternal separation, however, when initiated before pregnancy reducing intensity during it, the positive effects where not observed. This may be due to epigenetic factors, such as histone H3 acetylation, which can enhance BDNF levels and elicit neuroprotective effects; in the group that started the exercise before the pregnancy such changes may not occur due to the considerable reduction in training intensity or even by an adaptation of transcriptional machinery, aspects that will be investigated in future research.