Further, the centrality of striatal regulation by histaminergic TMN neurons is reported to be responsible for the production of pathological grooming and the H3R expression in the striatum of HDC−/− mice is markedly up-regulated, suggesting the H3R in the striatum is a contributor to the pathology and emerges as a novel treatment of tic disorders [128,129]. The gene discussed is HRH3; the disease is tic disorder.