Effects of w3/ w6 fatty acids on behavioral developments of rats: Relation with neurotransmitters

ABSTRACT

Docosahexaenoic acid(DHA) is a major fatty acid of the gray matter in brain, especially of the synaptic membranes. Modification of membrane fatty acids by dietary fatty acids may influence membrane characteristics and metabolism of neurotransmitters including it's release and reuptake. The effect of w3/w6 fatty acids in maternal diet on the brain neurotransmitters of the offsptings and their behavioral development were investigated in this study. Adult female rats were fed experimental diets with different contents of w3 and w6 fatty acids throughtout pregnancy and lactation and up to 16weekss of pup's age. Experimental diets consisted of 10 wt% fat cornoil (CO source of w6, LA), perilla oil (PO source of w3, a-LNA) and fish oil(FO source of lonfg chain w3, EPA & DHA). At 3,7 and 16weeks of age, frontal cortex, corpus striatum, thaltmus and cerebellum were dissected out of the whole brain, and the concentrations of 5-hydroxytryptamines(5-HT), catechoamines,and their metabolites were measured by HPLC-ECD. At 16weeks of age, fatty acid compositions of whole brain were determined by GLC. Physical development test in Y-water maze were performed at 15weeks of pup's age. The concentrations of 5-HT in thalamus & hypothalamus was found to be most significiantly correlated with learning ability(r=0.508, p<0.05). At 15weeks of age, the PO group showed higher learning ability compared to the CO or the FO group. Evemn though the DHA level stays rather constant in thhe brain tissue, the ratios of arachidoni c acid(AA,w6)/EPA+DHA(w3) vary significiantly with dietary fatty acids. DHA is known to fulfill very important structural and/or metabolic funtion in membrane system of the brain and AA and its metabolites may also act as transsynaptic messenger and/or second messenger and as the substrate for the production of many biologically active compounds, such as prostaglandins. Therefore, to accomplish full development of brain, proper supply of AA as well as DHA must be considered. Much more studies are needed to clarify th.