Structural changes in pyramidal cell dendrites and synapses in the unaffected side of the sensorimotor cortex following transcranial magnetic stimulation and rehabilitation training in a rat model of focal cerebral infarct

摘要

Very little is known about the effects of transcranial magnetic stimulation and rehabilitation training on pyramidal cell dendrites and synapses of the contralateral,unaffected sensorimotor cortex in a rat model of focal cerebral infarct.The present study was designed to explore the mechanisms underlying improved motor function via transcranial magnetic stimulation and rehabilitation training following cerebral infarction.Results showed that rehabilitation training or transcranial magnetic stimulation alone reduced neurological impairment in rats following cerebral infarction,as well as significantly increased synaptic curvatures and post-synaptic density in the non-injured cerebral hemisphere sensorimotor cortex and narrowed the synapse cleft width.In addition,the percentage of perforated synapses increased.The combination of transcranial magnetic stimulation and rehabilitation resulted in significantly increased total dendritic length,dendritic branching points,and dendritic density in layer V pyramidal cells of the non-injured cerebral hemisphere motor cortex.These results demonstrated that transcranial magnetic stimulation and rehabilitation training altered structural parameters of pyramidal cell dendrites and synapses in the non-injured cerebral hemisphere sensorimotor cortex,thereby improving the ability to compensate for neurological functions in rats following cerebral infarction.