Effects of ketamine and/or LAA on rats' motor performance in rotarod test. Immediately after a baseline response was obtained, saline or drugs were administered intrathecally to normal rats and rotarod test was performed at different time points thereafter (6 rats in each group). The score of each group was normalized as a percentage of the baseline value. Compared with baseline, there was no statistical difference obtained from rotarod test after drugs injection, but intrathecally administered 1000 μg/kg of ketamine caused an obvious defect on rotarod test at 10 min after injection. * P < 0.05 compared with baseline response.