Research On The Effects Of Repetitive Transcranial Magnetic Stimulation On The Pentylenetetrazol(PTZ)-induced Kindling Rat Models

Objective: To investigate the effects of transcranial magnetic stimulation on epilesy of SD rats induced by pentylenetetrazol(PTZ) through the behavior changes by observing and the molecular biology changes by technologies of Western blotting,real time polymerase chain reaction and immunohistochemical.Methods: All the experiment rats were randomly divided into 4 groups,including control group,the group of pentylenetetrazol-kindling rats given low frequency(0.5Hz) transcranial magnetic stimulations,the group of pentylenetetrazol-kindling rats given high frequency(10Hz) transcranial magnetic stimulations and the group recieved sham repetitive transcranial magnetic stimulations.The pentylenetetrazol was given by intraperitoneal injection at the dose of 40mg/kg.After the injection of the pentylenetetrazol,the behavior of the rats were observed closely and made records about the epilepsy.The repetitive transcranial magnetic stimulations was applied using a Magstim Rapid2 device and a 70 mm figure-of-eight coil(The Mag Stim Company, Whitland, Dyfed, UK) and the parameter was 110% rest motor threshold,1500 pulses in total with the interval of 2min between each 300 pulses.Six hours after the injection of pentylenetetrazol,each group recieved the corresponding stimulations and all the injection and stimulation last for 2 weeks.All the rats were euthasanized and decapitated after the pentylenetetrazol injection of the last day.Western blotting,real time polymerase chain reaction and immunohistochemical were conducted in the brain tissue.Use SPSS software to analyze the statistical difference of these proteins, P<0.05 was considered significant.Results: 1. Intraperitoneal injection of pentylenetetrazol give low frequency repetitive transcranial magnetic stimulation which is given after Intraperitoneal injection of pentylenetetrazol significantly prolonged the epilepsy- inducing time and the onset latency compared with sham stimulation(P < 0.05),the time of high frequency magnetic stimulation is shorter than that of the sham stimulation(P < 0.05). 2. After the low frequency magnetic stimulation,the expression of GABAAR, GAD65 in rat hippocampus compared with sham stimulation improved significantly(P < 0.05).GABAAR expression between high frequency magnetic stimulation group and sham stimulation group had no significant difference(P > 0.05), but the expression of GAD65 in the high frequency magnetic stimulation decreased significantly compared with sham stimulation group(P < 0.05); expression level of NMDAR2 A among three epileptic groups have no obvious difference.(P > 0.05). 3.The results showed that the number of rat hippocampal neurons in the epileptic rats decreased significantly compared with the control group(P < 0.05).Low frequency transcranial magnetic stimulation of epileptic rats lower the neuron loss significantly compared with the sham stimulation rats(P < 0.05).The results of Caspase-3 and TUNEL analysis suggest that the low-frequency magnetic stimulation of inhibited the hippocampal neurons apoptosis compared with sham stimulation group(P < 0.05) and the decrease of GFAP expression after stimulation suggestted that TMS inhibit the astrocyte activation and proliferation. induced by epilepsy.Conclusion: Transcranial magnetic stimulation has effects on the PTZ induced epilepsy of rat models, The repetitive transcranial magnetic stimulation can change the epileptic seizure of the pentylenetetrazol-kindling rats.The low frequency transcranial magnetic stimulation inhibit the seizure while the high frequency facilitate the seizure.The effectiveness of the transcranial magnetic stimulaiton on the epilepsy may result from some neurotransmitter receptors or related enzymes such as NMDAR2 a,GABAAR and GAD65,which have been found significantly changed after the transcranial magnetic stimulation.Low frequency repeatitive transcranial magnetic stimulation may inhibit astrocyte activation and proliferation and the neuronal apoptosis induced by epilepsy.