Fourteen rats were anesthetized and 20 μg of 6-hydroxydopamine (6-OHDA; Sigma-Aldrich) were stereotaxically injected at a concentration of 4 μg/μl (in 0.2 mg/ml ascorbate in saline) at one site in the MFB (stereotaxic coordinates: anteroposterior, −4.4 mm; mediolateral, −1.2 mm; dorsoventral, −7.8 mm) using a Hamilton syringe. The toxin was injected at a rate of 1 μl/minute. To ensure complete lesion of the nigrostriatal DA pathway, the animals were screened by amphetamine-induced rotation at a dose of 2.5 mg/kg. Only animals [10] that exhibited a mean ipsilateral rotation score of seven or more complete body turns per minute were included in the study.
