Zinc homeostasis and neuronal death

Abstract

Zinc is an essential trace element and crucial for the normal development of the central nervous system. Zinc is abundantly present in the brain and is secreted to synaptic clefts with neurotransmitters. However, its precise role is still under investigation. Meanwhile, excess zinc is reported to contribute to neuronal death in the global ischemia. We have investigated the effects of zinc in immortalized hypothalamic neurons (GT1-7 cells). Zinc chelator caused marked death of GT1-7 cells, while zinc itself caused degeneration of GT1-7 cells. Neurotoxicity of zinc was prevented by pyruvate and calcium. However, zinc inhibited death of GT1-7 cells induced by excessive extracellular calcium. Our results suggest that zinc homeostasis is important for neuronal survival and that calcium homeostasis is implicated in zinc-induced neurotoxicity.