neurons in the striatum of the MPTP mouse model, it is still unknown how this nutrition affects the mitochon- drial function (25). Horvath et al. (26) reported that the mechanism of the neuroprotective effect of CoQ10 in a primate PD model was through activation of uncoupling protein 2 (UCP2), which regulates mitochondrial inner membrane potential, ATP levels and local thermogenesis. Interestingly, lack of UCP2 increased the sensitivity of dopamine neurons to MPTP, whereas UCP2 overexpres- sion decreased MPTP-induced nigral dopamine cell loss in mice (27). The authors suggested the critical importance of UCP2 in normal nigral dopamine cell metabolism and offer a novel therapeutic target, UCP2, for the prevention/treatment of PD. From a scientific point of view, we would like to know if CoQ10 improves mitochondrial function to protect dopaminergic neurons from in vivo MPTP neurotoxicity. 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