S bayk8644

Mice were anesthetized using isofluorane and then decapitated. Brains were removed, cut into left and right hemispheres, and then 300 μm coronal slices were made at 1-4°C in oxygenated (95% v/v O₂, 5% v/v CO₂) dissecting solution (208 mM sucrose, 2.5 mM KCl, 1 mM CaCl₂, 4 mM MgCl₂, 4 mM MgSO₄, 1.6 mM NaH₂PO₄, 26 mM NaHCO₃, 10 mM glucose, and 3 mM Na-pyruvate) using a Vibratome 3000 (The Vibratome Company). Typically, a total of 5-7 striatal hemi-slices (left/right hemisphere combined) were obtained from each mouse brain (1.1 to 0.14 mm from Bregma). Slices were allowed to recover on a nylon mesh for 1 h at 30°C in oxygenated ACSF (113 mM NaCl, 2.5-5 mM KCl, 2.5 mM CaCl₂, 1.2 mM MgSO₄, 1 mM NaH₂PO₄, 26 mM NaHCO₃, 20 mM glucose, and 3 mM Na-pyruvate) followed by addition of picrotoxin (50 μM) for 30 min. Slices were then transferred to oxygenated 30°C ACSF solutions supplemented with vehicle or drug for 1-30 min, as defined in the figure legends. The following drugs were used and dissolved in water or DMSO based on manufacturer's instructions: BAPTA (Sigma), (S)-BayK8644 (Tocris), FPL64176 (Tocris), isradipine (National Institute of Mental Health Chemical Synthesis and Drug Supply Program), KCl (Sigma), mibefradil (Tocris), Nickel Chloride (Sigma), nimodipine (MP Biomedicals), SNX-482 (Peptides International), and TTX (Tocris).