“…In addition to the SNc, putative DA cells have been visualized in the striatum, which is the major target site of the SNc. Neurons positive for tyrosine hydroxylase (TH), the rate-limiting enzyme in the biosynthesis of catecholamines, have been detected in the striatum of mice (Baker et al, 2003), rats (Tashiro et al, 1989;Mura et al, 1995Mura et al, , 2000Meredith et al, 1999), monkeys (Dubach et al, 1987;Betarbet et al, 1997;Palfi et al, 2002) and humans (Cossette et al, 1999(Cossette et al, , 2003Porritt et al, 2000).…”