FIGURE 1.

Experimental timeline. Timeline of the experimental design. Treatment groups consisted of mice that were administered either cortisol only, cortisol with citalopram, citalopram only, or control vehicles. All four treatment groups had an n = 6 mice. After cannulation surgery, mice were allowed to recover for 2 weeks before drug treatment was initiated (weeks 0–2). To ensure effects of cortisol treatment were sufficient to model conditions of chronic stress, a 3-week period of drug treatment was maintained prior to exposing the mice to the linear track (weeks 2–5). Following 2 weeks of training on the linear track (weeks 5–7), mice were imaged during a 2-week period of daily linear track running (weeks 7–9). Mice recovered from water restriction for 1 week (weeks 9–10) before female urine sniffing test (FUST) administration and organ harvest. Cortisol (40 μg/ml) was added into the drinking water during ad lib water consumption (weeks 2–5 and 10) or administered subcutaneously (10 mg/kg) (weeks 5–9). Likewise, citalopram (10 mg/kg) was administered daily by oral gavage (weeks 2–5 and 10) and injected subcutaneously (10 mg/kg) during weeks 5–9. Untreated mice received drinking water or subcutaneous saline injections during water restriction sessions.