6 ohda hydrobromide

Mice were pre-treated subcutaneously with buprenorphine (0.05 mg/kg) for analgesia, then deeply anesthetized with isoflurane (4% induction then 1–2%) and placed in a stereotaxic frame (David Kopf instruments, Tujunga, CA, USA) on a headed pad and OcryGel was used to protect from dry eyes. Lidocaine (6 mg/kg) was injected subcutaneously before incising the scalp. Mice received 1.5 µL infusion of 6-OHDA hydrobromide (2.7 µg/µL, free base, Tocris, Bristol, UK, Table 1) either into the left or right SNc over 5 min at the following coordinates: AP: 3 mm, ML ± 1.3 mm and DV −4.7 mm, according to the atlas of Paxinos and Watson, (2001). The injection site was randomized between experimental groups. The microinjector was slowly removed 5 min after the end of the injection to minimize backflow. Control mice (Sham) received an injection of the corresponding volume of vehicle (0.02% ascorbic acid in NaCl) in the same conditions.

Animals were anesthetized by inhalation of isofluorane gas (3 % administrated at 1.5 L/min), and then mounted onto a stereotactic frame with a nose-cone for anesthesia delivery. 6-OHDA hydrobromide (10 μg) was dissolved in 2 μL of 0.9 % ice-cold saline containing 0.02 % ascorbic acid (Tocris Bioscience, Bristol, UK) and injected to the right striatum at following coordinates (in mm) relative to bregma: AP +0.24, LM +3.6, DV -3.8 (Paxmos and Watson, 1982[28 ]). Also, rats were given intraperitoneal (i.p.) injection of 25 mg/ kg desipramine (Sigma Chemical Co., USA) 30 min prior to the 6-OHDA injection to prevent noradrenergic neuronal loss at the injection site (Mahmoudi et al., 2011[21 (link)]).
In the OH+CDNF group, 2 weeks following induction of PD, 10 µg of recombinant human CDNF (PeproTech, Rocky Hill, NJ, USA) in 4 µL of PBS was injected to the right SVZ at following coordinates: AP +0.24, LM +1.8, DV -3.8 (Paxmos and Watson, 1982[28 ]). Sham model rats were only injected with 2 μL vehicle of 6-OHDA (0.9 % saline containing 0.02 % (w/v) ascorbic acid) into the striatum. Furthermore, 6-OHDA-lesioned rats in the OH+Vehicle group received 4 µL of PBS (vehicle of CDNF) into the SVZ. The protocol of our experimental design is summarized in Figure 1(Fig. 1).