NOS1 and Huntington disease: Moreover, decreases in hippocampal and striatal neuronal nNOS mRNA and protein, and cGMP levels are observed in the R6/1 and R6/2 HD models (Deckel et al., 2001, 2002; Perez-Severiano et al., 2002; Zucker et al., 2005; Cipriani et al., 2008; Padovan-Neto et al., 2019) as well as in post-mortem tissue from patients with HD (Morton et al., 1993; Norris et al., 1996; Saavedra et al., 2013).