Electroacupuncture at GV20 and ST36 Enhances Poststroke Recovery via BDNF/TrkB-Mediated Hippocampal Protection

Background Ischemic stroke (IS) is a major cause of neurological disability. Electroacupuncture (EA) at GV20 and ST36 acupoints was investigated in a rat middle cerebral artery occlusion (MCAO) model for its effects on recovery, hippocampus neuronal injury, synaptic ultrastructure, and the brain-derived neurotrophic factor (BDNF)/TrkB pathway. Methods Forty-eight rats were randomly grouped. EA was administered daily for 28 days. Assessments included neurological deficit scores, adhesive removal test, Morris water maze, H&E and Nissl staining, transmission electron microscopy for synaptic observation, and immunohistochemistry and Western blot for BDNF/TrkB protein expression. Results EA treatment significantly improved neurological function, as indicated by reduced neurological deficit scores and shortened adhesive removal times on day 28 post-surgery ( P < 0.05). EA also ameliorated cognitive impairment, evidenced by decreased escape latency and increased target quadrant crossings in the Morris water maze test ( P < 0.05). Histological analysis revealed that EA attenuated neuronal injury and loss in the hippocampus. Furthermore, EA improved synaptic ultrastructure by increasing the number of synaptic vesicles within 50 nm of the presynaptic membrane, thickening the postsynaptic density, and narrowing the synaptic cleft ( P < 0.05). Additionally, EA reversed the MCAO-induced decrease in hippocampal BDNF and TrkB protein expression ( P < 0.05). Conclusions EA at GV20 and ST36 promotes functional recovery after IS, associated with reduced hippocampus neuronal injury, improved synaptic ultrastructure, and upregulation of the BDNF/TrkB pathway, supporting its potential application in stroke rehabilitation.