The effect of high-frequency repetitive transcranial magnetic stimulation（r TMS） on potassium-chloride cotransporter-2（KCC2） protein expression following spinal cord injury（SCI） and the action mechanism were investigated. SCI models were established in SD rats. Five groups were set up randomly： normal control group, SCI 7-day（7 D） model group, SCI 14-day（14 D） model group, SCI-7 DrTMS group and SCI-14 DrTMS group（n=5 each）. The rats in SCI rTMS groups were treated with 10 Hz rTMS from 8 th day and 15 th day after SCI respectively, once every day, 5 days every week, a total of 4 weeks. After the model establishment, motor recovery and spasticity alleviation were evaluated with BBB scale once a week till the end of treatment. Finally, different parts of tissues were dissected out for detection of variations of KCC2 protein using Western blotting and polymerase chain reaction（PCR） technique. The results showed that the BBS scores after treatment were significantly higher in SCI-7 DrTMS group than in SCI-14 DrTMS group（P〈0.05）. As compared with normal control groups, The KCC2 protein in SCI model groups was down-regulated after SCI, and the decrease was much more significant in SCI-14 D model group than in SCI-7 D group（P〈0.05）. As compared with SCI model groups, KCC2 protein in rTMS groups was up-regulated after the treatment（P〈0.05）. The up-regulation of KCC2 protein content and expression was more obvious in SCI-7 DrTMS group than in SCI-14 DrTMS group（P〈0.05）. It was concluded that 10 Hz rTMS can alleviate spasticity in rats with SCI, which might be attributed to the up-regulation of KCC2 protein. It was also suggested that the high-frequency rTMS treatment after SCI at early stage might achieve more satisfactory curative effectiveness.
The effect of high-frequency repetitive transcranial magnetic stimulation（r TMS） on spasticity following spinal cord injury（SCI） and the action mechanism were investigated. SCI models were established in Sprague-Dawley rats. Five groups were set up： normal control group, SCI-7 day（7D） model group, SCI-14 D model group, SCI-7D r TMS group and SCI-14 D r TMS group（n=10 each）. The rats in SCI r TMS groups were treated with 10 Hz r TMS at 8th day and 15 th day after SCI respectively. Motor recovery and spasticity alleviation were evaluated by BBB scale once a week till the end of treatment. Finally, different parts of tissues were dissected out for detection of GABA receptors using Western blotting and polymerase chain reaction（PCR） technique. The results showed that the BBB scores after treatment were significantly higher in SCI-7D r TMS group than in SCI-14 D r TMS group（P〈0.05）. The GABA receptors were down-regulated more significantly in SCI-14 D model group than in SCI-7D model group（P〈0.05）. At different time points, r TMS treatment could affect the up-regulation of GABA receptors： The up-regulation of GABA receptors was more obvious in SCI-7D r TMS group than in SCI-14 D r TMS treatment group（P〈0.05）. It was concluded that 10-Hz r TMS could alleviate spasticity following SCI and promote the motor recovery in rats, which might be attributed to the up-regulation of GABA receptors. It was also suggested that early high-frequency r TMS treatment after SCI may achieve more satisfactory curative effectiveness.
