Effects of paired associative stimulation on synaptic ultrastructure, neuron apoptosis and BDNF in rats with cerebral infarct / 中华物理医学与康复杂志

ABSTRACT

Objective@#To observe the effects of paired associative stimulation (PAS) on synaptic ultrastructure, neuron apoptosis and BDNF in rats with cerebral infarct, and explore the possible underlying mechanisms.@*Methods@#Forty-five male Sprague-Dawley rats were randomly divided into three groups a sham operation group, a model group and a PAS group, with 15 rats in each. All the rats underwent a surgical operation for transient middle cerebral artery occlusion (MCAO) on the right side to model focal cerebral ischemia, with those in the sham operation group left without real occlusion. PAS treatment was given to rats in the PAS group 24h after MCAO model was successfully established, while no special intervention was given to those in the sham operation group and model group. After 28 days of treatment, transmission electron microscopy was used to investigate the ultrastructure of the ischemic penumbra, TUNEL was used to observe the apoptosis of cortex neurons, and real time-PCR to investigate BDNF mRNA expression.@*Results@#It was found that after 28 days treatment ①The synaptic curvature, the synapse length and the post-synaptic density (PSD) decreased significantly in the rats of model group in contrast to those of the sham control group (P<0.05). And compare to model group, the synaptic curvature, the synapse length and the PSD increased significantly in the rats of PAS group (P<0.05). ②Compare to sham control group, the apoptosis rate of model group and PAS group increased significantly (P<0.05). And the apoptosis rate of PAS group decreased significantly in contrast to those of model group (P<0.05). ③Compare to sham control group, BDNF mRNA expression of the PAS group increased significantly(P<0.05), while BDNF mRNA expression of the model group decreased significantly(P<0.05). BDNF mRNA expression of the PAS group increased significantly in contrast to those of model group (P<0.05).@*Conclusion@#PAS promotes neural plasticity and inhibits apoptosis of cortex neurons of the ischemic penumbra in rats with ischemic cerebral infarction. One of the underlying mechanisms might be related to the up-regulation of BDNF mRNA expression.