Substrate utilization and brain development.

Since the realization over a decade ago (Owen et aI., 1967) that the brain of the human adult can function, apparently normally, when up to two­ thirds of the substrates supplied are ketone bodies rather than glucose, consideration of substrate utili­ zation has to take into account which substrates are being used, as well as how much of each is being used. These questions have particular relevance throughout the period of brain development, both preand postnatally, since circumstances may arise under which an adequate supply of blood-borne glucose is compromised. Previous reviews on energy metabolism in the developing brain have emphasized the human baby and possible problems of adequate nutrition (Schwartz and Kalhan, 1975; Jones, 1979; Pratt, 1979; Wasterlain et aI., 1980; Cremer, 1981). In the present review, the aim has been to detail quantita­ tive data for several animal species without neces­ sarily implying that all such data are directly rele­ vant to man. Fortunately, information available on young babies and children is sufficiently com­ prehensive to allow a direct comparison with other species.