Cocaine hydrochloride was obtained from The Research Triangle Institute (Research Triangle Park, NC) under the National Institute on Drug Abuse Drug Supply Program. Cocaine was dissolved in physiological saline and adjusted for pH with NaOH solution to pH 7.0. Oxotremorine sesquifumarate (OxoSQ) was purchased from Sigma (St. Louis, MO) and dissolved in an artificial cerebrospinal fluid (aCSF) consisting of the following (in mM): 120 NaCl, 3.3 KCl, 1.2 CaCl2, 1.0 MgCl2, 25 NaHCO3, 1.2 KH2 PO4, 10 glucose; pH 7.3. OxoSQ solutions were aliquoted in 0.2 ml and stored at -20°C until used.
