Movement of zinc and its functional significance in the brain.
Zinc, an essential nutrient, is supplied to the brain via both the blood-brain and blood-cerebrospinal fluid barriers. Zinc is most concentrated in the limbic system, i.e. the hippocampus and amygdala, zinc-containing glutaminergic neuron-rich areas. A large portion of zinc serves the function of zinc metalloproteins in neurons and glial cells. In zinc-containing glutaminergic neurons, vesicular zinc, probably ionic zinc, may serve as an endogenous neuromodulator in synaptic neurotransmission. Vesicular zinc is dynamically coupled to the electrophysiological activity of zinc-containing glutaminergic neurons. Dietary zinc deprivation may influence zinc homeostasis in the brain, resulting in brain dysfunction such as learning impairment. Excessive excitation of zinc-containing glutaminergic neurons causes a decrease in vesicular zinc, and the decrease might be associated with the susceptibility to seizure. Alteration of zinc levels released into the synaptic cleft may influence neurotransmission in zinc-containing glutaminergic synapses. Therefore, zinc homeostasis in the presynaptic vesicle is important for the function of zinc-containing glutaminergic neurons.
Takeda
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Department of Radiobiochemistry, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Shizuoka 422-8526, Japan. takedaa@u-shizuoka-ken.ac.jp@
D000818:Animals; D001812:Blood-Brain Barrier; D001921:Brain / Q000098:blood supply / Q000502:physiology*; D002199:Capillary Permeability; D006801:Humans; D008032:Limbic System / Q000502:physiology; D008955:Models, Cardiovascular; D008959:Models, Neurological; D009457:Neuroglia / Q000502:physiology; D009474:Neurons / Q000502:physiology; D009435:Synaptic Transmission; D015032:Zinc / Q000502:physiology* / Q000633:toxicity
D015032:Zinc