“Addition into the culture medium … the antioxidant N-acetylcysteine NAC , 1 mM) in the presence of Cu2+ (0.0005-0.001 mM) induced intensive death of cultured rat cerebellar granule neurons, which was significantly decreased by the zinc ion chelator TPEN (N,N,N′,N′-tetrakis(2-pyridylmethyl)ethylenediamine).”