【Animal Modeling】-Effects of Electroacupuncture on Synaptic Plasticity and Microglia Polarization in Rats with Cerebral Ischemia

  Objective To explore electroacupuncture on synaptic plasticity and microglia polarization in rats with focal cerebral ischemia, and to detect the expression of miR-21/signal transducer and activator of transcription 3 (STAT3) pathway.

  Methods The distal end of the external carotid artery was double ligated with a thin wire for 60 minutes to construct a focal cerebral ischemia rat model. The neurological deficit score was used to evaluate the model preparation. The successful model rats were divided into model group, electroacupuncture group, and nimodipine group. At the same time, the sham operation group was treated as a control. After 3 weeks of treatment, the neurological deficit score was used to evaluate the degree of brain damage in each group of rats; 2, 3, 5-triphenyltetrazolium chloride (TTC) staining to determine the cerebral infarct volume of each group of rats; electron microscope observation of cerebral cortical processes Parallel morphometric analysis of touch ultrastructure; immunofluorescence staining to observe the polarization of cerebral cortex microglia; real-time fluorescent quantitative PCR (qRT-PCR) method to determine the level of miR-21 in the cerebral cortex of rats in each group; Western blotting The levels of Janus protein tyrosine kinase 2 (JAK2), p-JAK2, STAT3, and p-STAT3 in the cerebral cortex of each group of rats were measured.

  Results Compared with the sham operation group, the neurological deficit score, infarct volume, number of M1 type microglia in the cerebral cortex, miR-21, p-STAT3, and p-JAK2 levels were significantly increased in the model group (P<0 05), the number of M2 type microglia in the cerebral cortex, the number density of synapses (Nv), the density of synaptosomes (Vv), the area density of synaptic junctions (Sv), post-synaptic dense substance (PSD) , Synaptic interface surface rate, synaptic gap width was significantly reduced (P<0.05); compared with the model group, the neurological deficit score, cerebral infarction volume, M1 type small glue in the electroacupuncture group and nimodipine group The number of plasma cells, miR-21, p-STAT3, and p-JAK2 levels were significantly reduced (P<0.05), the number of M2 type microglia, Nv, Vv, Sv, PSD, synaptic interface surface rate, synaptic The gap width increased significantly (P<0.05).

  Conclusion Electroacupuncture can promote synaptic remodeling in rats with focal cerebral ischemia, and induce microglia to polarize from M1 to M2.