Effects of intrathecal ketamine or LAA on SNL-induced mechanical allodynia, respectively. Intrathecal ketamine elevated paw withdrawal thresholds (PWTs) in a dose-dependent manner (A). *, # P < 0.05 compared with that of Saline or 100 μg/kg of ketamine, respectively. Intrathecal LAA attenuated SNL-induced mechanical allodynia individually in a dose-dependent manner (B). *, # P < 0.05 compared with that of Saline or 50 nmol of LAA, respectively.