Learning Behavior and Brain Lipid Composition in Rats Subjected to Essential Fatty Acid Deficiency during Gestation, Lactation and Growth

Abstract

Female Wistar rats, fed a purified diet containing 10% corn oil for approximately 2 weeks prior to mating and during the first 14 days of gestation, were fed the same diet or one containing 10% hydrogenated coconut oil (EFA ³-deficient) in place of corn oil, until parturition. After parturition, the females were fed the same diet or transferred to the alternate diet and progeny were weaned to the corn oil or coconut oil diet at 21 days of age. Brain lipids of the progeny were analyzed at 0, 21 and 225 days of age and the maze learning ability of adult progeny assessed. Brain weight was independent of dietary fat at all ages; total brain lipids were lower in 225 day old progeny fed the EFA-deficient diet from weaning. Brain total phospholipid and distribution of phospholipids were independent of dietary fat. Lack of EFA in the maternal diet during gestation depressed polyunsaturated fatty acids in the glycerophosphatides of the newborn progeny and elevated saturated and monoenoic acids. At weaning, brain fatty acid patterns were substantially independent of the maternal dietary fat. In adult progeny weaned to the EFA-deficient diet, ω6 and ω3 fatty acids were lower and oleic, 20:3ω9 and 22:3ω9 higher than in rats fed the control diet. The diet of the dam during gestation and lactation was without effect on the brain fatty acid profiles of adult progeny. Gestational lack of EFA irreversibly impaired learning behavior of the progeny; lactational deprivation tended to impair learning but differences from controls were not significant; post-weaning EFA deficiency was without effect on learning performance. A relationship exists between prenatal exposure to EFA deficiency and learning potential of the progeny. Whether this is a direct result of the observed changes in brain fatty acid profiles in the newborn has still to be determined.