SLC6A3 and Parkinson disease: Accordingly, acute and chronic treatment with clinical and higher L-DOPA doses has been shown to significantly reduce radioligand binding to the DAT in PD patients with lower disease severity (Guttman et al., 2001), in healthy rats (Dresel et al., 1998; Nikolaus et al., 2011b, 2013) and in the intact striata of unilaterally 6-hydroxydopamine-lesioned animals (Sossi et al., 2010).