Effects of essential fatty acid deficiency on mouse brain development.

The effect of essential fatty acid (EFA) deficiency on the activities of several membrane-bound enzymes was examined in the brains of C57BL/6J mice. Pregnant females were placed on an EFA-deficient diet during the last week of gestation and their progeny were examined at intervals up to 16 weeks after birth. Early signs of the deficiency, such as reduced body and brain weight, were noted in the mice on the experimental diet. The fatty acid ratio of 20:3w9/20:4w6, a biochemical index of EFA deficiency, rose progressively in the deficient brains from 0.17 at 4 weeks to 0.68 at 16 weeks. Only one of the membrane-bound enzymes studied, i.e. ATPase, demonstrated any consistent significant alteration in specific activity as a consequence of the deficiency. The accumulation of myelin, as measured by the levels of myelin basic protein, was reduced from the earliest age studied. These findings suggest that EFA deficiency does not exert a general, nonspecific effect on all membranes in the brain and that hypomyelination is a major effect of EFA deficiency on brain development.