S raclopride tartrate

MPD (Mallinckrodt, St Louis, MO, USA) and DA D1 and D2 receptor antagonists, R(+) SCH-23390 hydrochloride and S(−)-raclopride (+)-tartrate (Sigma-Aldrich Corp, St Louis, MO, USA), respectively, were used. All injections were made fresh, dissolving the drug in 0.9% isotonic saline, equalized to 0.8 mL, and injected, via intraperitoneal (IP) route, in the morning. In previous MPD dose–response behavioral experiments ranging from 0.1 to 40.0 mg/kg, it was observed that 2.5 mg/kg of MPD elicited behavioral sensitization when given in the morning;36 (link),41 (link)–45 (link) therefore, this dosage (2.5 mg/kg) was selected. Previous studies used a range of 0.2–0.5 mg/kg SCH-23390 selective D1 DA antagonist and 0.3–0.4 mg/kg raclopride selective D2 DA antagonist, which were effective in modulating the psychostimulant effect on animal behavior and on the prefrontal cortex.19 (link),46 (link) Therefore, we chose SCH-23390, 0.4 mg/kg, and D2 DA antagonist raclopride, 0.3 mg/kg, to study the role of the D1 and D2 DA receptors in the effects of acute and chronic MPD exposure on animal behaviors.

All the following drugs, except CNO, were purchased from Sigma-Aldrich, St. Louis, MO. Working drug concentrations are as follow: LPS (O55:B5, L2880, Sigma-Aldrich; 5 mg/ml dissolved in PBS, 1 μl), oxotremorine sesquifumarate (Oxo-S, #O9126, Sigma-Aldrich; 1 μM dissolved in PBS), selegiline [R(−)-deprenyl HCl, #M003, Sigma-Aldrich; 1 mg/kg, ip, and 1 mM, 1 μl infused in the pDMS), CNO (RTI International, custom synthesis batch no. 13626-76; 7 mg/kg, ip). Drugs for electrophysiology are as follows: selegiline (100 μM), R(+)-SCH23390 HCl (D054, 10 μM), S(−)-raclopride (+)-tartrate (#R121, Sigma-Aldrich; 10 μM), ouabain octahydrate (#O3125, Sigma-Aldrich; 100 μM), pargyline HCl (#P8013, Sigma-Aldrich; 100 μM), and CNO (#13626-76, RTI International; 10 μM).