Effects of electroacupuncture on the functionality of NG2-expressing cells in perilesional brain tissue of mice following ischemic stroke

Neural/glial antigen 2(NG2)-expressing cells has multipotent stem cell activity under cerebral ischemia.Our study examined the effects of electroacupuncture(EA)therapy(2 Hz,1 or 3 mA,20 minutes)at the Sishencong acupoint on motor function after ischemic insult in the brain by investigating the rehabilitative potential of NG2-derived cells in a mouse model of ischemic stroke.EA stimulation alleviated motor deficits caused by ischemic stroke,and 1 mA EA stimulation was more efficacious than 3 mA EA stimulation or positive control treatment with edaravone,a free radical scavenger.The properties of NG2-expressing cells were altered with 1 mA EA stimulation,enhancing their survival in perilesional brain tissue via reduction of tumor necrosis factor alpha expression.EA stimulation robustly activated signaling pathways related to proliferation and survival of NG2-expressing cells and increased the expression of neurotrophic factors such as brain-derived neurotrophic factor,tumor growth factor beta,and neurotrophin 3.In the perilesional striatum,EA stimulation greatly increased the number of NG2-expressing cells double-positive for oligodendrocyte,endothelial cell,and microglia/macrophage markers(CC1,CD31,and CD68).EA therapy also greatly activated brain-derived neurotrophic factor/tropomyosin receptor kinase B and glycogen synthase kinase 3 beta signaling.Our results indicate that EA therapy may prevent functional loss at the perilesional site by enhancing survival and differentiation of NG2-expressing cells via the activation of brain-derived neurotrophic factor-induced signaling,subsequently ameliorating motor dysfunction.The animal experiments were approved by the Animal Ethics Committee of Pusan National University(approval Nos.PNU2019-2199 and PNU2019-2884)on April 8,2019 and June 19,2019.

Peri-infarct reorganization at the centrum semiovale and corona radiata A diffusion tensor tractography and functional MRI study

Peri-infarct reorganization has been reported in stroke patients with a lesion at the cerebral cortex, corona radiata, or pons, separately. However, there have been no reports describing the patients with peri-infarct reorganization at multiple levels. The present study reported a patient with a middle cerebral artery infarct who showed complete paralysis of the right extremities at stroke onset. Results showed that at 3 years after stroke onset, patient＇s motor function of the affected hand appeared to have been recovered by the motor tract, which reorganized into the anterior areas of the infarcted centrum semiovale and corona radiata, as demonstrated by diffusion tensor tractography study analyzed using functional MRI activation results. This result indicates that the human brain can show extensive brain plasticity and that saving the adjacent area or penumbra around the infarct even though the lesion from multiple levels is important for functional recovery after stroke.