Polyunsaturated fatty-acids diet increases fear discrimination in rats and IGF-2 receptors signaling in the auditory cortex

Recent studies suggest that diet influences brain functions, though its effects on emotional processes remain unclear. Here we explored how two high-fat diets affect innate and learned fear behaviors in rats. One group was fed a polyunsaturated fatty acids-enriched diet, another received a polyunsaturated fatty acids-deficient high-fat diet, and a control group consumed standard chow. Both high-fat diet groups showed significant weight gain compared to controls. However, no differences in anxiety-like behavior, auditory fear memory, or responses to painful stimuli were observed among the three groups. Notably, rats on the polyunsaturated fatty acids -enriched diet exhibited improved discrimination between harmful and neutral auditory stimuli. This improvement was accompanied by increased insulin-like growth factor 2 receptor signaling in the excitatory neurons of the auditory cortex. These findings suggest that specific dietary components, such as polyunsaturated fatty acids, enhanced threat discrimination. Considering the connection between fear discrimination and the onset of fear-related disorders, our data may offer new insights into the factors influencing fear disorders.