In rat preclinical studies utilizing a pharmacological model of HD, both CB1R mRNA and protein were decreased in the caudate putamen, basal ganglia, globus pallidus, and substantia nigra (Lastres-Becker et al., 2001, 2002), though administration of substances that increased endocannabinoid activity was found to have activated the decreased population of CB1R and improve subject motor function (Lastres-Becker et al., 2002). Here, CNR1 is linked to Huntington disease.