Male and Female Laboratory Rats Equally Acquire Running‐Based Flavor‐Aversion Learning1

Laboratory rats can be conditioned to shy away from a flavored substance consumed immediately before running in activity wheels, suggesting flavor‐aversion learning. We examined whether the factor of sex impacted running‐based flavor‐aversion learning. A differential conditioning procedure was employed in Experiment 1: The measure of learning was the degree of differentiation in the intake of a target flavor solution paired with running and an unpaired non‐target flavor solution. Flavor‐aversion learning was observed as a gradual decrease in the intake of the target solution, which was absent in that of the non‐target solution. Although females ran more than twice as fast as males, the degree of differential conditioning was similar for males and females. This was the case not only for absolute intake but also for intake per body weight and change from the initial intake (percentage decrease). The null effect of sex was replicated in Experiment 2, which employed a simple conditioning procedure. These results suggest that rats’ running‐based flavor‐aversion learning is a robust phenomenon, despite the subjects being male or female.