NOS2 and Parkinson disease: In animal models, inhibition of nNOS prevents MPTP-induced Parkinsonism in both baboons and mice (Hantraye et al. 1996; Schulz et al. 1995), and MPTP-induced neuronal damage is diminished in mice lacking either the NOS1 or the NOS2A gene (Liberatore et al. 1999; Przedborski et al. 1996).