Decreased anxiety-like behavior and locomotor/exploratory activity, and modulation in hypothalamus, hippocampus, and frontal cortex redox profile in sexually receptive female rats after short-term exposure to male chemical cues

Chemical cues are widely used for intraspecific social communication in a vast majority of living organisms ranging from bacteria to mammals. As an example, mammals release olfactory cues with urine that promote neuroendocrine modulations with changes in behavior and physiology in the receiver. In this work, four-month-old Wistar (regular 4-day cyclic) virgin female rats were utilized in the proestrus-to-estrus phase of the reproductive cycle for experimental exposure. In an isolated room, female rats were exposed for 90 min to male-soiled bedding (MSB). Elevated plus-maze assay, open field test, and light/dark box task were performed to analyze behavioral alterations on females after exposure. For biochemical assays, female rats were killed and the hypothalamus, hippocampus, and frontal cortex were isolated for further analysis. Antioxidant enzyme activities (superoxide dismutase, catalase and glutathione peroxidase), non-enzymatic antioxidant defense measurements (TRAP and TAR), and the oxidative damage parameters (TBARS, Carbonyl and SH content) were analyzed. In behavioral analyses we observe that female rats show decreased anxiety and locomotory/exploratory activities after MSB exposure. In biochemical assays we observed an increase in both enzymatic and non-enzymatic antioxidant defenses in different central nervous system (CNS) structures analyzed 30 and 90 min after MSB exposure. Furthermore, hippocampus and frontal cortex showed diminished free radical oxidative damage at 180 and 240 min after exposure. These results provide the first evidence that oxidative profile of female CNS structures are altered by chemical cues present in the MSB, thus suggesting that pheromonal communication is able to modulate radical oxygen species production and/or clearance in the female brain.