Effects of ketamine on motor performance of rats in the rotarod test. After recording baseline response, ketamine (30, 100 or 300 μg kg-1) was administered intrathecally and rotarod test was performed 30 min later once a day for 3 days, respectively. Compared with the baseline response, no statistical differences were obtained from rotarod test after intrathecal ketamine. There were six rats in each group. KTM: ketamine.