Intrastriatal viral injections

ChAT-IRES-Cre mice or double transgenic, CalDAG-GEFI-EGFP-BAC;ChAT-IRES-Cre mice and CalDAG-GEFI-EGFP-BAC;ChAT-ChR2-EYFP BAC mice were maintained in deep anesthesia with a continuous flow of 2% isoflurane (Southmedic Inc.) in an oxygen mixture, delivered by a nose-cone attached to a stereotaxic frame. Mice were given bilateral intrastriatal injections, via NanoFil microsyringe (World Precision Instruments), of AAV5 encoding EF1αDIO hChR2(H134R)-mCherry (University of N. Carolina vector core), 0.75 μl per site, at the following stereotactic coordinates (AP = 0.9 mm, ML = −1.9 mm and +1.9 mm, DV = 2.0 mm and 2.7 mm, relative to bregma). Mice were allowed to fully recover from surgery for 2 weeks prior to the initiation of saline or D-amphetamine injections.