Beneficial effect of saturated and poly-unsaturated fat-rich diet on risky decision-making behaviour in adolescent rats exposed to early-life stress.

Previous studies suggest that early-life stress (ELS) induced by early maternal separation and isolation (MS) stress during the stress hyporesponsive period (SHRP) leads to increased curiosity-like and increased risky decision-making behaviour in adolescence. Evidence suggests that dietary interventions early in adolescence could play an important role in mitigating the detrimental effects of MS stress on risky decision-making behaviour. Hence, the present study hypothesized that nutritional supplements such as saturated fat (SFA) and/or polyunsaturated fat (PUFA) would be beneficial in ameliorating the impact of MS stress on risky decision-making behaviour when incorporated into the diet during early adolescence. NC and MS rats were subjected to the Risky Decision-Taking Task (RDTT) to assess the rats' ability to make decisions under risky conditions. The results showed that MS rats took less time to cross the risky zone to collect a large reward. However, when an SFA-rich and PUFA-rich diet was provided, the latency of the MS rats increased. Similarly, MS stress-induced reduction in risk assessment was restored to normal with the SFA and PUFA-rich diet. Risk-index (RI) values also showed a similar trend with reduced RI values in MS, but nutritional supplementation increased the RI values making it comparable to that NC. Correlation analysis has further revealed a direct correlation between the anxiety-like behaviour and the risk-taking tendency in MS rats and not in the NC group. SFA-rich diet led to a positive correlation between anxiety-like and risk-taking behaviour. These findings thus support the hypothesis that PUFA- and SFA-rich diet may be introduced at adolescence to mitigate MS-stress induced increased risky decision-making behaviour due to a deficit in risk assessment.