Impact of supplementation with omega-3 fatty acids after maternal dietary deficiency on adolescent anxiety and microglial morphology.

Dietary maternal deficiency in omega-3 polyunsaturated fatty acids (n-3 PUFA) is a potential risk factor for the development of anxiety and other mood disorders in children and adolescents. Here, we used a previously characterized maternal PUFA dietary deficiency model in rats to determine the impact of postweaning supplementation on adolescent anxiety-like behaviors. We focused on two models of anxiety: innate anxiety tested by the elevated plus maze and a novel operant model of learned anxiety where animals learn that actions may be associated with a variable probability of harm. Given that recent basic and clinical studies have associated anxiety and other adverse effects of PUFA deficiency on inflammatory processes and microglial structure and function, we also assessed the impact of our dietary deficiency model and supplementation on adolescent microglial morphology in multiple brain regions. We found that the male and female adolescent PUFA-deficient groups exhibit increased innate anxiety, but only females showed enhanced learned anxiety. Supplementation after weaning did not significantly affect innate anxiety but ameliorated learned anxiety in females. Thus, the beneficial effects of supplementation on adolescent anxiety may be sex-specific and depend on the type of anxiety. We also found that PUFA deficiency influences microglia function in adolescents in the amygdala and nigrostriatal, but not mesolimbic, brain regions. Collectively, these data suggest that while PUFA dietary supplementation may be effective in reducing adolescent anxiety, this effect is context-, sex-, and brain network-specific. (PsycInfo Database Record (c) 2024 APA, all rights reserved).