Materials
L-DOPA methyl ester, benserazide hydrochloride, tropicamide and VU-0152100 were purchased from Sigma-Aldrich (S. Louis MO, USA), 6-OHDA hydrobromide, telenzepine, PD-102807 and AFDX-116 from Tocris (Bristol, UK). Telenzepine, PD-102807, tropicamide, AFDX-116 and VU-0152100 were dissolved in Ringer for local perfusion through the microdialysis probe. 6-OHDA was dissolved in ascorbate-saline for intracerebral injection, whereas all the other drugs were dissolved in saline and administered systemically at the volume of 1.0 ml/Kg body weight.