Iron in the Brain

Objectives

After completing this article, readers should be able to:

1. Describe the role of iron in proteins involved in neuronal and glial energy metabolism, myelin production, and monoamine neurotransmitter metabolism.

2. Indicate the neonates who are at risk for iron deficiency.

3. Explain how iron deficiency affects the biochemistry, structure, signaling molecules, and electrophysiology of the hippocampus.

4. Describe the primary causes of iron overload in the neonate.

5. Explain why the preterm infant is at particular risk for iron deficiency.

Overview

This article is designed to acquaint readers with the role of iron in early brain development. Several important principles that govern the effects of nutrients on the immature brain are discussed, followed by an explanation of the roles of iron during development. Because the developing brain is sensitive to iron overload as well as iron deficiency, both are discussed in the context of human studies and in model systems.

General Principles of Nutrition and Brain Development

The first guiding principle of nutrient-brain interactions during development is the concept of timing, dose, and duration. (1) The positive or negative effects of any nutrient depend on which brain regions or processes are developing at the time that nutrient status is altered and the requirements of those regions for the nutrient during that time of development. Generally, the more rapidly an area is developing, the more vulnerable it is. Dependence on specific nutrients during phases of rapid proliferation or differentiation results in the second principle, a regionalization of brain effects during periods of nutrient deficiency. In the case of iron deficiency, certain brain areas that are dependent on iron for proper development are more vulnerable than areas that are less dependent on iron. Additionally, these same brain areas are likely to be more vulnerable at certain time points than at others. To exert a maximal effect on regional brain development, the timing of iron …