Diverse, region-specific effects of addition of arachidonic and docosahexanoic acids to formula with low or adequate linoleic and alpha-linolenic acids on piglet brain monoaminergic neurotransmitters

Differences in visual, auditory, and learning tasks have been reported for infants and animals given diets varying in omega-3 fatty acids, but the neu robiochemical basis for these changes is unclear. This study investigated t he effect of feeding formula with 0.8% energy C18:2 omega-6 + 0.05% C18:3 o mega-3 (low), or 8.3% C18:2 omega-6 + 0.8% C18:3 omega-3 (adequate), with a nd without 0.2% energy arachidonic acid (C20:4 omega-6) and 0.16% docosahex anoic acid (C22:6 omega-3), on monoaminergic neurotransmitters in different brain regions of piglets fed formula from birth to 18 d. The amount of C18 :2 omega-6 + C18:3 omega-3 fed in formula had a significant effect on front al cortex dopamine, 3,4-dihydroxyphenylacetic acid, homovanillic acid, sero tonin, and 5-hydroxyindolacetic acid; striatum serotonin and inferior colli culus serotonin, resulting in lower concentrations in piglets fed the low c ompared with adequate C18:2 omega-6 + C18:3 omega-3 formula. Inclusion of a rachidonic acid and docosahexanoic acid in the low, but not in the adequate , C18:2 omega-6 + C18:3 omega-3 formula resulted in increased concentration s of all monoamines in the frontal cortex, and in striatum and inferior col liculus serotonin. Feeding arachidonic acid and docosahexanoic acid in the formulas increased dopamine and 5-hydroxyindolacetic acid in superior and i nferior colliculus, areas related to processing and integration of visual a nd auditory information. Higher dopamine and 5-hydroxyindolacetic acid were found in these regions even when arachidonic acid and docosahexanoic acid were added to the C18:2 omega-6 + C18:3 omega-3 adequate formula. This stud y suggests that functional changes among animals and infants fed diets vary ing in omega-6 and omega-3 fatty acids may involve altered neurotransmitter metabolism.