Dietary omega‐3 polyunsaturated fatty acid deprivation lowers seizure threshold in rats

Abstract

Several candidate genes that play a role in seizure etiology have been identified. Yet, the impact of environmental influences such as dietary omega‐3 polyunsaturated fatty acids (n‐3 PUFA) is not known. We therefore tested the impact of chronic dietary n‐3 PUFA deprivation on seizure threshold in the cortex and amygdala. Rats were surgically implanted with electrodes in the cortex or amygdala, and subsequently randomized to the AIN‐93G diet containing n‐3 PUFA derived from soybean oil, or a modified n‐3 PUFA‐deficient version derived from coconut and safflower oil. The rats were maintained on the diets for 33 weeks. Seizure thresholds were measured monthly by electrically stimulating the cortex and amygdala. At the end of 33 weeks, seizure threshold was assessed following a bolus subcutaneous injection of oleic (OA) or docosahexaenoic acids (DHA). Dietary n‐3 PUFA deprivation resulted in a statistically significant decrease in cortical and amygdaloid thresholds by week 16, relative to baseline (P<0.05). The decrease in thresholds was not observed in rats on the control, soybean oil diet. Compared to a bolus injection of OA, acute injection of DHA raised seizure threshold in rats on the control diet but not the n‐3 PUFA deficient diet (P<0.05). These findings demonstrate for the first time that dietary n‐3 PUFA deficiency increases seizure susceptibility in rats.Grant Funding SourceCanadian Institutes of Health research