Zinc is essential for brain development and function

Abstract

Zinc's roles in brain function are poorly understood. Zinc is essential pre-and postnatally for growth, maturation, and function. In early pregnancy, zinc is essential for cell multiplication and implantation of the embryo and for cell differentiation and organ formation. Deficiency causes teratology in all tissues. Zn deficiency in later pregnancy impairs neuronal replication and migration (as observed in cerebellar external granular cells). Synaptogenesis is impaired (as observed in Purkinje cells). It has been proposed that zinc deficiency impairs calcium channels causing a decrease in intracellular calcium that suppresses gene expression of growth factors and synthesis of nucleic acids and proteins. Whatever the mechanism, effects in experimental animals include poorly reversible impairments in learning and memory later in life, which appears associated with decreased neuronal survival. It is unknown if similar phenomena occur in humans. It is known however that low fetal growth, a process caused by maternal zinc deficiency, is risk factor for coronary heart disease, type 2 diabetes mellitus, chronic lung disease, and obesity. One wonders if fetal growth is related to later neuronal health and function.

Zinc requirements and the risks and benefits of zinc supplementation

“…Patients may display poor healing of cutaneous wounds [75][76][77][78][79] without other obvious signs of zinc deficiency; hair may be easily plucked and alopecia evident; black hair may be changed to a reddish brown. Effects on the nervous system may include decreased nerve conduction [80], ataxia, disorientation [81], and impaired neuropsychological performance [82]. Initial manifestations of zinc deficiency are non-specific and unlikely to suggest zinc deficiency unless the history of the patient alerts the caregiver to the possibility.…”

Regulation and function of Zip4, the acrodermatitis enteropathica gene

“…These types of abnormalities have been associated with zinc deficiency in the rat [4,6,29,30]. Zinc is essential for brain development and function in monkeys as well [31]. Diminished DNA and RNA synthesis in neurons during zinc deficiency may cause abnormal neurogenesis [32,33].…”

A deficit in zinc availability can cause alterations in tubulin thiol redox status in cultured neurons and in the developing fetal rat brain

“…Deficits of this nutrient result in adverse effects on brain structure and function [8-10]. In humans, developmental Zn deficiency can affect infant behavior, cognitive and motor performance [11-13], and it has been associated with attention-deficit/hyperactivity disorders [14].…”

“…In rats, postnatal Zn deficiency impairs the normal development of the cerebellum, affecting the number and differentiation of Purkinje, basket, stellate, and granule cells [10]. Zn deficiency in adult rats decreases proliferation of neural precursor cells in the subgranular zone and granular cell layer of the dentate gyrus [20].…”