EPA-1779 – Acute and chronic effects of neurosteroid dehydroepiandrosterone on rat behavior in the foced swim test

Abstract

Neurosteroid dehydroepiandrosterone (DHEA) has been associated to various functions in the central nervous system, including modulation of memory and behavior. It has been suggested that the effects of DHEA are mediated through several neurotransmitter systems; however its mechanisms of action are not fully understood. This study aimed to investigate the behavioral profile of DHEA in the forced swim test (FST), and also its impact on locomotor activity. FST was performed in a glass cylinder, 45 cm high, 20 cm diameter filled with water up to a height of 30 cm. On the first day, male Wistar rats were forced to swim for 15 min. Rats were re-exposed to the FST for a single 5 min session, after the acute and chronic challenge with saline or DHEA. The measurement of locomotor activity was performed in a clear Plexiglas box (40×25×35 cm) for 30 min without any habituation period. The data were analyzed by one-way ANOVA, followed by Dunnett's test. In FST, ANOVA indicated statistically significant effects of DHEA. Dunnett's analysis showed that DHEA significantly decreased the duration of immobility at the dose of 10 mg/kg, exerting acute, but also chronic antidepressant-like effects. However, DHEA did not induce significant differences in time of struggling behavior. ANOVA did not show a significant effect of treatment on locomotor activity. These data experimentally support the findings that under certain circumstances, DHEA might have triggered the antidepressantlike effects in rats. Furthermore, these effects were not confounded by change in motor function.