Early Brain Growth

Abstract

After completing this article, readers should be able to: 1. Discuss the roles of macronutrients (protein and energy) in neuronal and glial structure and neurotransmitter synthesis and function. 2. Delineate the neonates at risk for protein-energy malnutrition. 3. Characterize the neurodevelopment handicaps that occur in infants who experience intrauterine growth restriction. 4. Describe the mechanism by which protein and energy malnutrition alter the size of the brain. 5. Explain the effects of mild-to-moderate malnutrition on brain growth. Pediatric clinicians and researchers have long understood the importance of providing adequate nutritional intake to infants and children to promote appropriate neurodevelopmental outcome. Studies describing the untoward effects of nutritional microcephaly in humans date back to the seminal work of Winick and Rosso in the 1960s, ( 1) but the concept of loss of brain growth during periods of malnutrition was well known before that time. In this review, we assess the potential mechanisms by which macronutrients interact with the developing brain, including a discussion of the molecular, biochemical, structural, and behavioral effects of protein-energy malnutrition on the brain. Further, we examine the neurodevelopmental effects of clinical conditions that result in decreased head growth velocity between 24 and 40 weeks postconception, including intrauterine growth restriction (IUGR) and failure to thrive in preterm infants. Finally, we consider nutritional and non-nutritional strategies that have the potential to preserve normal brain growth. The brain is a dynamic structure throughout the lifespan ( 2) that is constantly remodeling itself, guided by the interaction between an intrinsic, apparently experience-independent set of factors and extrinsic experiences. The former frames a basic blueprint of predictable neurobehavioral milestone development that typically developing humans follow. The latter translates into the methods by which daily positive and negative experiences mold and shape the brain, providing variability in the developmental trajectory among humans. Fundamentally, within any developmental time period, …