The Effect of Voluntary Exercise and Prenatal Exposure to Sodium Valproate on Learning, Memory, and Anxiety of Rats' Offspring.

Background: Antiepileptic drugs, such as sodium valproate (SV), are teratogenic as their usage by the pregnant mother has been associated with an increased risk of major congenital abnormalities in the fetus. In this study, the effects of voluntary exercise and prenatal exposure to SV on learning, memory, and anxiety in rats' offspring are investigated.

Methods: In the present study, 70 female albino Wistar rats (200-240g) were used. The rats were categorized in seven groups: 1 and 2, pregnant rats with exposure to SV (10 mg/kg/day i.p) 3 and 4, pregnant rats with exposure to SV (20 mg/kg/day i.p) 5 and 6, pregnant rats with exposure to normal saline (0.4 ml/day i.p) and 7, pregnant rats with exposure to lamotrigine (20 mg/kg/day i.p). The even and odd groups were sedentary and voluntary exercise groups, respectively. Learning and memory were tested in male offspring using shuttle-box; anxiety was tested by elevated plus-maze (each group n=12). Statistical analyses were performed using the one-way ANOVA (the Tukey test) and/or two-way ANOVA on rank.

Results: The results showed that voluntary exercise in male rats caused improvement of latency and duration time in the dark box compared to sedentary groups (P=0.004). Moreover, the group administrated with 10 mg/kg SV showed better learning capability than the group administrated with 20 mg/kg SV. Voluntary exercise could also improve anxiety (P=0.001).

Conclusion: This study indicated that exercise could increase learning capacity and improve memories in rats' offspring whose mothers were exposed to SV. Voluntary exercise could improve anxiety too, and the effect was dose-dependent.