6 hydroxydopamine hcl

Animals were fully anaesthetized with pentobarbital anesthesia (50 mg/kg, i.p., Vetbutal, Biowet Pulawy, Poland) and atropine sulfate (0.25 mg/kg, s.c, Polfa, Poland) and placed in a stereotactic apparatus (Kopf Instruments, USA). The skull was exposed by a midline incision of the skin and a hole was drilled above the lesion site. The neurotoxin 6-OHDA (6-hydroxydopamine HCl, Sigma–Aldrich, Poland) was injected into the right SNpc in a volume of 4 μl (3 μg/μl dissolved in 0.9% NaCl containing 0.1% ascorbic acid). The following coordinates from the rat stereotactic atlas (Paxinos and Watson 2007 ) were used (in reference to bregma): anteroposterior (AP) – 5.3, lateral (L) – 2.4, dorsoventral (DV) – 7.5. Injections were performed using a microsyringe with a 26-gauge needle (Hamilton, USA) that was attached to a microinjection unit (Model 5000, Kopf Instruments, USA). The injection rate was 0.5 μl/min and the cannula was left in place for additional 5 min after injection to allow for diffusion into the tissue. To protect noradrenergic neurons from damage, animals received an intraperitoneal injection with the noradrenaline reuptake inhibitor desipramine (25 mg/kg, Sigma-Aldrich, Poland) 30 min prior to neurotoxin injection (Fulceri et al. 2006 (link)). Sham-lesioned controls underwent the same procedure but received vehicle instead of 6-OHDA.