DEVELOPMENT OF ENZYMES OF ENERGY-METABOLISM IN THE NEONATAL MAMMALIANBRAIN

The metabolic capability for the complete oxidation of glucose, i.e. a erobic glycolysis, is highly developed in the brains of neurologically mature (precocial) species at birth, whereas this activity is severel y limited in the brains of neurologically immature (non-precocial) spe cies such as the rat and human. The latter utilize a mixture of glucos e and ketone bodies for synthetic and energetic activities and the adv ent of neurological competence associated with the capability for comp lete dependence on and oxidation of glucose must await the development of key enzymes such as the pyruvate dehydrogenase complex (PDHC). A s imilar relationship appears to exist with respect to the development o f neurological maturity of different brain regions in a single species , the rat. The development of the enzymes of energy metabolism of neon atal rat brain will be discussed with respect to the energy fuels avai lable to the neonatal brain. In particular mechanisms by which the PDH C develops in neonatal brain will be evaluated. Evidence suggests that this is due to a specific increase in enzyme protein in contrast to a general increase in mitochondrial activity.