WIN 55,212-5 (1 μM), AM251 (3 μM) and Picrotoxin (50 or 100 μM) were dissolved in dimethyl sulfoxide (DMSO) and prepared from stock solutions. All drugs were diluted in ACSF (1:1000) to achieve final concentrations. Final DMSO concentrations in extracellular saline did not exceed 0.1%. All drugs were purchased from Tocris Cookson Inc. (St. Louis, Mo.)
