In each mouse, the DA lesion was also assessed using an infrared imaging system (Odyssey CLx; LI-COR Biosciences, Lincoln, NE, USA) from a 50 μm-thick section taken at the pre-commissural level of the striatum (1.34 mm from bregma). Sections were immunostained for TH and DAT, using secondary antibodies coupled to infrared fluorescent dyes. The primary antibody against TH was the same as above (1/1000, overnight at 4 oC). The monoclonal antibody against DAT (1/1000, overnight at 4 oC, catalog no. MAB369; EMD Millipore Corporation, Billerica, USA) was raised in rat. Donkey anti-rabbit 680 (1/1000, 2 h at RT, catalog no. 926-68073; LI-COR Biosciences) and goat anti-rat 800 (1/1000, 2 h at RT, catalog no. 926-32219; LI-COR Biosciences) were used as secondary antibodies. Two solid-state diode lasers (685 nm and 785 nm) were used to excite secondary antibodies coupled to infrared fluorescent dyes. Intensity values of TH and DAT immunoreactivity were taken from six 0.16 mm2 squares randomly placed over the striatum and from one 0.16 mm2 square placed over the Acb.
