Rat sciatic nerve blockade by 2% lidocaine combined with 0%, 1.25%, 2.5%, or 5% MgSO4 (n = 8/group). Time courses of proprioceptive, motor, and nociceptive blockade by lidocaine combined with MgSO4 at various concentrations are shown in (A), (C), and (E), respectively. A score of 0 indicates no block or baseline, and a score of 3 indicates complete blockade. The complete blockade time (CBT) and complete recovery time (CRT) in minutes for proprioceptive, motor, and nociceptive function are shown in (B), (D), and (F). Data are presented as mean ± SEM. * P < 0.004 (lidocaine alone vs. lidocaine with MgSO4 added).