Effects of 1 mg kg−1 taltirelin i.v. (a, n=10), 1 mg kg−1 saline i.m. (b, n =7), and 30 μg kg−1 dexmedetomidine i.v. (c, n = 10) on normalised m. gastrocnemius EMG in awake restrained rats after 10 μg kg−1 sufentanil i.v. At t=60 min, 1 mg kg−1 naloxone i.v. was injected. Sufentanil increased EMG activity, which was not reduced by taltirelin. Dexmedetomidine reduced EMG activity to pre-sufentanil baseline values. Data are mean (standard deviation).