“…It is important to reiterate that the effects of Cu, even across physiological (low micromolar) concentrations, appear to vary dramatically across brain regions and cell type (Doreulee et al., ; Shcheglovitov et al., ; Marchetti et al., ; Maureira et al., ; Hu, Ni, Duff‐Canning, & Wang, ; Kapkaeva et al., ). Moreover, while decreases in Cu levels can increase excitotoxicity as mentioned above, higher levels of exogenous Cu can also decrease cell viability through oxidative stress‐linked processes (Hua et al., ; Kapkaeva et al., ). Interestingly, SCN neurons are robustly resistant to glutamate excitotoxicity, and ERK1/2 signaling in SCN tissue has been reported to be neuroprotective against excess glutamate (Bottum, Poon, Haley, Karmarkar, & Tischkau, ; Karmarkar, Bottum, Krager, & Tischkau, ).…”