Caroline Peres Klein

Behavioral benefits of maternal swimming are counteracted by neonatal hypoxia-ischemia in the offspring

Hypoxia-ischemia (HI) represents one of the most common causes of neonatal encephalopathy. The central nervous system injury comprises several mechanisms, including inflammatory, excitotoxicity, and redox homeostasis unbalance leading to cell death and cognitive impairment. Exercise during pregnancy is a potential therapeutic tool due to benefits offered to mother and fetus. Swimming during pregnancy elicits a strong metabolic programming in the offsprings brain, evidenced by increased antioxidant enzymes, mitochondrial biogenesis, and neurogenesis. This article aims to evaluate whether the benefits of maternal exercise are able to prevent behavioral brain injury caused by neonatal HI. Female adult Wistar rats swam before and during pregnancy (30min/day, 5 days/week, 4 weeks). At 7(th) day after birth, the offspring was submitted to HI protocol and, in adulthood (60(th) day), it performed the behavioral tests. It was observed an increase in motor activity in the open field test in HI-rats, which was not prevented by maternal exercise. The rats subjected to maternal swimming presented an improved long-term memory in the object recognition task, which was totally reversed by neonatal HI encephalopathy. BDNF brain levels were not altered; suggesting that HI or maternal exercise effects were BDNF-independent. In summary, our data suggest a beneficial long-term effect of maternal swimming, despite not being robust enough to protect from HI injury.

Swimming exercise before and during pregnancy: Promising preventive approach to impact offspring´s health

Several environmental factors affect child development, such as the intrauterine environment during the embryonic and fetal development and early postnatal environment provided by maternal behavior. Although mechanistic effects of maternal exercise on offspring health improvement are not yet completely understood, the number of reports published demonstrating the positive influence of maternal exercise have increase. Herein, we addressed issues related to early postnatal environment provided by maternal behavior and early developmental physical landmarks, sensorimotor reflexes, and motor movements ontogeny. In brief, adult female rats underwent involuntary swimming exercise, in a moderated intensity, one week before mating and throughout pregnancy, 30 min a day, 5 days a week. Maternal exercised dams have unchanged gestational outcomes compared to sedentary dams. We found no differences concerning the frequency of pup‐directed behavior displayed by dams. However, sedentary dams displayed a poorer pattern of maternal care quality during dark cycle than exercised dams. Physical landmarks and sensorimotor reflexes development of female and male littermates did not differ between maternal groups. Developmental motor parameters such as immobility, lateral head movements, head elevation, pivoting, rearing with forelimb support and crawling frequencies did not differ between groups. Pups born to exercised dams presented higher frequency of walking and rearing on the hind legs. These data suggest that female and male littermates of exercised group present a high frequency of exploratory behavior over sedentary littermates. Taken together, the present findings reinforce that maternal exercise throughout pregnancy represent a window of opportunity to improve offsprings postnatal health.

Effect of maternal antioxidant supplementation and/or exercise practice during pregnancy on postnatal overnutrition induced by litter size reduction: Brain redox homeostasis at weaning

Prenatal and early postnatal environments can permanently influence health throughout life. Early overnutrition increases the risk to develop chronic diseases. Conversely, the intake of flavonoids and exercise practice during pregnancy seem to promote long‐term benefits to offspring. We hypothesized that benefic interventions during pregnancy could protect against possible postnatal neurochemical alterations caused by overnutrition induced by reduced litter size. Female Wistar rats were divided into four groups: (1) sedentary + vehicle, (2) sedentary + naringenin, (3) swimming exercise + vehicle, and (4) swimming exercise + naringenin. One day after birth, the litter was culled to 8 pups (control) or 3 pups (overfed) per dam, yielding control and overfed subgroups for each maternal group. Serum of 21‐days‐old pups was collected, also the cerebellum, hippocampus, and hypothalamus were dissected. Litter size reduction increased fat mass and enhanced body weight. Maternal interventions, when isolated, caused reduced glucose serum levels in offspring nurtured in control litters. In the cerebellum, reducing the litter size decreased the activity of thioredoxin reductase, which was prevented by maternal supplementation with naringenin. Hippocampus and hypothalamus have shown altered antioxidant enzymes activities in response to litter size reduction. Interestingly, when maternal exercise and naringenin supplementation were allied, the effect disappeared, suggesting a concurrent effect of the two maternal interventions. In conclusion, exercise or naringenin supplementation during pregnancy can be important interventions for combating the increasing rates of overweight during the infancy and its related neurochemical changes, especially when applied isolated.