Electroacupuncture alleviates orofacial allo-dynia and anxiety-like behaviors by regulating synaptic plasticity of the CA1 hippocampal region in a mouse model of trigeminal neuralgia / 中国药理学与毒理学杂志

ABSTRACT

OBJECTIVE To investigate whether electroacupuncture(EA)ameliorates abnormal trigeminal neuralgia(TN)orofacial pain and anxiety-like behavior by altering synaptic plasticity in the hippocampus CA1.METHODS A mouse infraorbital nerve transection model(pT-ION)of neuropathic pain was established,and EA or sham EA was used to treat ipsilateral acu-puncture points(GV20-Baihui and ST7-Xia-guan).Golgi-Cox staining and transmission elec-tron microscopy(TEM)were administrated to observe the changes of synaptic plasticity in the hippocampus CA1.RESULTS Stable and per-sistent orofacial allodynia and anxiety-like behav-iors induced by pT-ION were related to changes in hippocampal synaptic plasticity.Golgi stain-ings showed a decrease in the density of dendritic spines,especially mushroom-type dendritic spines,in hippocampal CA1 neurons of pT-ION mice.TEM results showed that the density of synapses,membrane thickness of the postsynap-tic density,and length of the synaptic active zone were decreased,whereas the width of the synap-tic cleft was increased in pTION mice.EA attenu-ated pT-ION-induced orofacial allodynia and anx-iety-like behaviors and effectively reversed the abnormal changes in dendritic spines and syn-apse of the hippocampal CA1 region.CONCLU-SION EA modulates synaptic plasticity of hippo-campal CA1 neurons,and reduces abnormal oro-facial pain and anxiety-like behavior,providing evidence for a TN treatment strategy.