Perinatal and postweaning diets high in omega-3 fatty acids have age- and sex-specific effects on the fatty acid composition of the cerebellum and brainstem of C57BL/6 mice.

The sex- and age-specific effects of omega (n)-3 polyunsaturated fatty acids (PUFA) enriched diets on brainstem and cerebellar fatty acid composition, and the expression of stearoyl-CoA desaturase (SCD)-1 and myelin basic protein (MBP) were investigated in C57BL/6 mice. Female mice were fed diets (20% fat, w/w) high or low in n-3 PUFA before mating, during pregnancy and lactation; and offspring (both males and females) were weaned onto their mother's designated diet for 16 weeks. A diet high in n-3 PUFA caused an accretion of docosahexaenoic acid in the cerebellum. Monounsaturated fatty acids increased from weaning to 16 weeks in the cerebellum. The changes in the cerebellar fatty acids were more pronounced in females, with a significant effect of diet. A diet high in n-3 PUFA increased cerebellar SCD-1 and MBP mRNA expression. These findings are novel and demonstrate that the effects of n-3 PUFA are brain region, age- and sex-specific.