The mu opioid receptor is involved in buprenorphine-induced locomotor stimulation and conditioned place preference.
Marquez P, Baliram R, Kieffer BL, Lutfy K. The mu opioid receptor is involved in buprenorphine-induced locomotor stimulation and conditioned place preference. Neuropharmacology. 2007 May; 52(6):1336-41.