A requirement for zinc in the body could be justified with PD patients, since Zn mediates (a) downregulation of glutamate release, inhibition of NMDA/mGlu-R receptors, protection against NMDA neurotoxicity (b) renders a positive modulation on GABA release (c) stimulates endogenous antioxidant enzymes and nerve growth factors (d) inhibits nNOS, endonucleases, pro-apoptotic cascades (e) augments synaptic plasticity and (f) is known to prevent age related deterioration of learning and memory [437]. Here, NOS1 is linked to Parkinson disease.