Effects of Omega-3 Fatty Acids on Maternal Behavior in the Perinatal Mice

Dr. Akiko Harauma, Toru Moriguchi

harauma@azabu-u.ac.jp

 

Omega-3 fatty acid, especially docosahexaenoic acid (DHA, 22:6n-3), plays an important role in both the structure and function of the nervous system.  The purpose of this study is to measure maternal behavior in the perinatal period using omega-3 fatty acid deficient pregnant mice.  Female mice were fed either an omega-3 fatty acid deficient (ω3 Def) or adequate (ω3 Adq) diet for two generations.  Their nest building was assessed in the prenatal and postpartum conditions.  The nest score and volume of ω3 Def dams were lower than those of the ω3 Adq dams during the perinatal period.  The condition after delivery was observed on the first postpartum day (PD-1) where it was observed that 30% of the ω3 Def dams attacked or ignored their newborns without nursing.  On PD-3 parental behavior was measured using the pup retrieval test.  The ω3 Def Dam showed a delayed latency time for pup retrieval behaviors relative to that of the ω3 Adq Dams.  The DHA concentration of hippocampus in ω3 Def Dams was markedly decreased compared to ω3 Adq Dams.  Moreover, the DHA level of the ω3 Def Dams who killed their pups was lower than that of the other ω3 Def Dams.  In the hippocampus, a positive correlation was observed between the DHA and serotonin, and a negative correlation was observed between the DHA and dopamine.  These results suggest that deficiency in brain DHA leads to aberrant maternal behavior and that such a deficiency could be in part responsible for postpartum depression.