Background Recent studies show that gender may have a significant impact on brain functions. However, the reports of sex effects on spatial ability and synaptic plasticity in rodents are divergent and controversial. Here spatial learning and memory was measured in male and female rats by using Morris water maze (MWM) task. Moreover, to assess sex difference in hippocampal synaptic plasticity we examined hippocampal long-term potentiation (LTP) at perforant pathway-dentate gyrus (PP-DG) synapses. Results In MWM task, male rats outperformed female rats, as they had significantly shorter swim distance and escape latency to find the hidden platform during training days. During spatial reference memory test, female rats spent less time and traveled less distance in the target zone. Male rats also had larger LTP at PP-DG synapses, which was evident in the high magnitude of population spike (PS) potentiation and the field excitatory post synaptic potentials (fEPSP) slope. Conclusions Taken together, our results suggest that sex differences in the LTP at PP-DG synapses, possibly contribute to the observed sex difference in spatial learning and memory.

It is well established that prenatal valproic acid exposure in rats leads to autism-like behaviors and social deficits. Long-term potentiation changes in the brain have been proposed as a potential mechanism in the development of autistic behaviour. However, there are controversies regarding the effect of in utero valproic acid exposure on long-term potentiation. This study examined the social interaction, and long-term potentiation induction in perforant pathway-dentate gyrus synapses in male offspring of a rat model of autism induced by prenatal exposure to valproic acid. On embryonic day 12.5, the pregnant dams received an injection of 500 mg/kg valproic acid (intraperitoneal) to produce the autism model. The sociability test was performed between postnatal days 37 and 40. The offsprings were urethane-anesthetized and placed into a stereotaxic apparatus for surgery, electrode implantation, and field potential recording on postnatal days 45 to 55. In the dentate gyrus region, excitatory post synaptic potentials slope and population spike amplitude were measured. valproic acid-exposed offspring showed significantly impaired social interaction. The Birth weight in valproic acid-exposed rats was significantly lower than control rats. The dentate gyrus synapses’ ability to induce long-term potentiation was hampered by valproic acid exposure. The decreasing excitatory post synaptic potential slope and population spike amplitude of long-term potentiation provide evidence in favor of this notion. It is widely supposed that the hippocampus plays a central role in the process of learning and memory as well as social interaction and social memory. Therefore, deficiencies in hippocampal synaptic plasticity may be responsible, at least in part, for the social interaction deficits in valproic acid -exposed rats.

The susceptibility to cardiovascular disease in offspring could be reduced prior to birth through maternal intervention, before and during pregnancy. We evaluated whether the initiation periods of maternal exercise in preconception and pregnancy periods induce beneficial effects in the adult male offspring. Thirty-two female rats were divided into control and exercise groups. The exercise groups involve exercise before pregnancy or the preconception periods, exercise during pregnancy, and exercise before and during pregnancy. The mothers in the exercise groups were run on the treadmill in different periods. Then the birth weight and weekly weight gain of male offspring were measured, and the blood and left ventricle tissue of samples were collected for analysis of the Sirtuin 6 (Sirt6) and insulin growth factor-2 (IGF-2) gene expression, serum levels of low-density lipoprotein (LDL), high-density lipoprotein (HDL), cholesterol (Cho), and triglycerides (TG). There was no significant difference in the birth weight of offspring groups (P = 0.246) while maternal HIIT only during pregnancy leads to reduce weekly weight gain of offspring. Our data showed that Sirt6 and IGF-2 gene expression was increased (P = 0.017) and decreased (P = 0.047) by maternal exercise prior to and during pregnancy, respectively. Also, the serum level of LDL (p = 0.002) and Cho (P = 0.007) were significantly decreased and maternal exercise leads to improves the running speed of the adult male offspring (p = 0.0176). This study suggests that maternal HIIT prior to and during pregnancy have positive intergenerational consequence in the health and physical readiness of offspring.

In the current study, we first tried to determine sex differences in spatial learning and memory in the valproic acid (VPA) rat model of autism. Second, the effects of interval training (IT) and continuous training (CT) exercises were examined in male and female offsprings. To induce autism-like animal model, the pregnant rats were injected 500 mg/kg NaVPA (intraperitoneal) at the embryonic day 12.5. IT and CT aerobic exercises were started at postnatal day 56. Then, on postnatal days 84–89, a Morris water maze (MWM) test was conducted on the separate groups of offsprings. Aerobic training was performed on a rodent treadmill with 0% slope for 8 weeks, 5 days/week, and 50 min/day. Unlike control animals, VPA-exposed female offspring had a better performance than VPA-exposed male offspring in MWM acquisition. In the case of MWM reference memory, we did not observe a sex difference between VPA-exposed male and VPA-exposed female offspring. Both IT and CT exercises in both control and VPA-exposed male rats significantly improved MWM acquisition. Moreover, both IT and CT exercises significantly improved MWM acquisition in control female rats. In addition, IT exercise (but not CT) significantly improved MWM acquisition in VPA-exposed female offsprings. Both IT and CT exercises in VPA-exposed that male and female offsprings improved the MWM reference memory. In conclusion, our observation demonstrated that prenatal exposure to VPA affects the spatial learning and memory in a sex dependent manner. We have shown that both IT and CT exercises are able to improve cognitive function in healthy and autistic rat offsprings.

Considerable scientific evidence suggests that the intrauterine environment plays a crucial role in determining the long-term health of offspring. The present study aims to investigate the effects of high-intensity interval training in maternal rats before and during pregnancy on the antioxidant status, mitochondrial gene expression, and anxiety-like behavior of their offspring. A total of thirty-two female rats were assigned to four maternal groups based on the timing of exercise: before pregnancy, before and during pregnancy, during pregnancy, and sedentary. The female and male offspring were allocated to groups that matched their mothers’ exercise regimen. Anxiety-like behavior in the offspring was evaluated using the open-field and elevated plus-maze tests. Our findings indicate that maternal HIIT does not have any detrimental effect on the anxiety-related behavior of offspring. Also, maternal exercise before and during pregnancy could improve the general activity of the offspring. Furthermore, our results demonstrate that female offspring exhibit more locomotion activity than males. Besides, maternal HIIT leads to a reduction in the levels of TOS and MDA, while TAC levels increase, and significantly upregulate the gene expression of PGC1-α, NFR1, and NRF2 in both sexes in the heart. Therefore, our study suggests that maternal HIIT is a beneficial maternal behavior and serves as a cardioprotective agent to enhance the health of the next generations.