Iron deficiency on neuronal function

Abstract

Because of the intrinsic ability of iron to catalyze the formation of reactive oxygen species, it has been associated with oxidative stress and neurodegenerative diseases. However, iron deficiency (ID) also negatively impacts various functions of the brain, suggesting that iron plays an important physiological role in neuronal processes such as myelination, synaptogenesis, behavior and synaptic plasticity (SP). ID not only produces changes in the hippocampus, striatum, amygdale or prefrontal cortex, it also affects the interaction among these systems. In both humans and rodents, the perturbations of these structures are associated to cognitive deficits. These cognitive alterations have been well correlated with changes in neural plasticity, the possible cellular substrate of memory and learning. Given that SP is strongly affected by early ID and the lasting-neurological consequences remain even after ID has been corrected, it is important to prevent ID as well as to seek effective therapeutic interventions that reduce or reverse the long-term effects of the ID in the nervous system. This review will give an overview of the literature on the effects of iron deficit in neuronal functions such as behavior, neurotransmission and SP. We also discuss our recent data about the possible oxidative effect of iron on the mechanisms involved in neural plasticity.

Physiology of Iron Metabolism

“…The physiology of iron trafficking and metabolism has been well evaluated over the last 20 years, and several comprehensive reviews have been published on the subject [16,17,18,19,20,21,22]. Many proteins have been identified playing roles in iron metabolism.…”

An explanation of the pathophysiology of adverse neurodevelopmental outcomes in iron deficiency

“…Certain studies support that ID reduces the size of the hippocampus and has a negative impact on the levels of taurine and creatine ( Rao et al, 2011 ;Munoz and Humeres, 2012 ). Other animal studies on ID have also demonstrated that glutamine and glutamate status between neurons and glia is altered (glutamine increase and glutamate decrease), suggesting that the hippocampal glutamine/glutamate cycle is influenced and may induce further taurine reduction ( Rothman et al, 2003 ).…”

“…The glutamatergic system is also affected by ID, especially in the PFC and the hippocampus, and may be responsible for the aforementioned dopaminergic impairments ( Sesack et al, 2003 ). Iron has a possible oxidative effect, which may trigger calcium release and regulate NMDAR expression, a glutamatergic receptor that is indispensable for the synaptic plasticity ( Munoz et al, 2011 ;Munoz and Humeres, 2012 ). Further studies suggest a decrease in glutamate decarboxylase, glutamate dehydrogenase, and GABA transaminase levels, which have an additional impact on GABAergic system ( Taneja et al, 1986 ;Li, 1998 ).…”

“…Further studies suggest a decrease in glutamate decarboxylase, glutamate dehydrogenase, and GABA transaminase levels, which have an additional impact on GABAergic system ( Taneja et al, 1986 ;Li, 1998 ). Thus, neurochemical alterations of the hippocampus may have negative effects on the synaptic plasticity of the hippocampal neurons, leading to a wide range of cognitive Brought to you by | Bibliotheque de l'Universite Laval Authenticated Download Date | 7/13/15 9:57 AM deficits, including memory/learning function and intelligence ( Munoz and Humeres, 2012 ;Chen et al, 2013 ).…”

Efecto de la anemia en el desarrollo infantil: consecuencias a largo plazo

“…Todos estos procesos se llevan a cabo en el hipocampo, que es la región cerebral en la que se procesa el aprendizaje y la memoria (16) , así como comportamientos afectivos como la depresión y ansiedad (14) . La anemia y la deficiencia de hierro, en especial, en periodos de rápido crecimiento como la etapa fetal y la infancia, afecta el desarrollo del hipocampo (16) y la corteza frontal, alterando el sistema de neurotransmisión dopaminérgico. Es por ello que las etapas fetal y neonatal son consideradas cada vez más importantes en el desarrollo de la persona (7,14) .…”