DRD2 and Parkinson disease: These results are different from, but consistent with the previous findings that PD patients off-medication (Rutledge et al., 2009) and rats with dorsal striatal lesions (Skelin et al., 2014) tended to repeat the same choice, raising the possibility that D1R-KO and D2R-KO effects on WS found in the present study might be mediated by dorsal striatum.