Приглашение к дискуссии: железодефицит и нарушения НС

[Dr.Vad]

Фрагменты тематических публикаций.

Iron Deficiency in the Brain

Iron deficiency has been proposed to have adverse effects on brain function, causing cognitive and learning impairment in infants and young children.The severity and duration of iron deficiency are important indicators in brain disorders associated with iron deficiency. It has been suggested that iron and transferrin deficiency might be responsible for degeneration of the C1 and C2 areas of the hippocampus. Unfortunately, supplementation with iron has not proven effective, especially if the iron deficiency occurred during a critical state of brain development and neural differentiation (when changes are irreversible). The alteration of neurotransmitters such as noradrenaline, serotonin, and dopamine during a state of iron deficiency might explain some of the behavioral and developmental changes observed in human infants.

Restless Legs Syndrome

Motor deterioration is suggested to be associated with iron deficiency in the brain. There is some evidence indicating that iron deficiency alters motor activity and circadian patterns of motor activity. The association of restless legs syndrome (RLS) with iron deficiency anemia that can be improved with iron consumption has been known for decades. Because RLS is seen more frequently in pregnant women (12%-20%), it has been suggested that RLS also might be associated with iron deficiency.

Из
Iron and brain disorders.
Sadrzadeh SM, Saffari Y.
Am J Clin Pathol. 2004 Jun;121 Suppl:S64-70.

----------------------------------------------------------------------
How is behavior related to brain iron and neurotransmitter biology?

Iron-deficient animals and human infants have changes in behavior that are resistant to iron therapy. We demonstrated, in animal models, that behavioral changes are robustly associated with changes to central DA and iron concentrations. Our most recent analysis of behavior, dopamine (DA) and regional brain iron, however, reveals some relevant relationships:

Multivariate regression analysis of spontaneous activity demonstrates that as much as 65% of the variability in exploration of the novel environment is associated with ventral midbrain iron, and DA D1 receptor density in midbrain and caudate putamen.

Multivariate analysis of anxiety-like behaviors demonstrates that nearly 45% of the variance in latency to move to a "safer" environment can be attributed to variation in nucleus accumbens DA transporter and D2 receptor density.

Preweaning iron deficiency and postweaning iron deficiency in rats results in decreased exploration and decreased movement. Iron repletion results in the normalization of several of these behaviors as well as normalization of most of the alterations in DA biology.

Adult iron deficiency and cognitive functioning

A limited number of studies have been conducted to determine if iron deficiency during nondevelopmental periods of life are associated with changes in behavior, cognition and brain function. Studies in adolescents who were iron deficient, but not anemic, revealed alterations in cognitive functioning that could be attributed to iron depletion but not anemia. When specific tests of attention are performed, iron-deficient anemic adolescents perform less well than iron-sufficient teens and also respond to iron therapy.

This brief article has highlighted several of the known biologic roles of brain iron on neural metabolism and functioning. Although much of the work has focused on early development as the "critical period", there is not yet certainty that that period has been exactly defined or limited to infants less than 2 y of age. The more recent evidence with adults with RLS, iron deficiency in renal disease and simple postpartum iron deficiency all suggest that neural functioning and behavioral consequences to brain iron deficits are not limited to infants.

Из Iron deficiency alters brain development and functioning.
Beard J.
J Nutr. 2003 May;133(5 Suppl 1):1468S-72S.