The Effects of Single Prolonged Stress, an Animal Model of PTDS, on Novelty-Seeking Behaviours and Alterations in the Dopaminergic System in Male and Female Rats

A common underlying behavioural trait of post-traumatic stress disorder (PTSD) involves novelty-seeking behaviours, which have been related to impairments in the dopaminergic system. We therefore investigated novelty-seeking behaviours and extracellular dopamine (DA) release in response to single prolonged stress (SPS), a rodent model of PTSD. Rats were exposed to SPS and then received either saline or 0.5 mg/kg, i.p. d-amphetamine (AMP) injection one week later, before being placed in a modified novel object exploration test (Experiment 1) or being subjected to in vivo microdialysis to detect extracellular DA release in the nucleus accumbens (Experiment 2). SPS exposure significantly increased novelty-seeking behaviours in males and females. Basal accumbal DA levels in males were elevated by SPS, but not in females. These data suggest that exposure to SPS results in an increase in DA-mediated behaviours in male and female rats, and enhances accumbal DA release in males.