Activation of ephrinb1/EPHB2/MAP-2/NMDAR Mediates Hippocampal Neurogenesis Promoted by Transcranial Direct Current Stimulation in Cerebral-Ischemic Mice.

tDCS, a new, safe, non-invasive physical therapy method, is often used in motor dysfunction rehabilitation. However, the effects and underlying mechanisms of tDCS on hippocampal neurogenesis after cerebral ischemia (CI) are still unclear. This study aimed to investigate the promotive effect and mechanism of repetitive anodal-tDCS on hippocampal neurogenesis after CI in mice. The CI model in mice was established using bilateral common carotid artery occlusion (BCCAO). The pathological changes in the hippocampal CA1 region and cognitive function were assessed by hematoxylin and eosin staining and Morris water maze test, respectively. Hippocampal neurogenesis was observed by immunofluorescence staining. The levels of expression of ephrinb1, EPHB2, MAP-2, and NMDAR in the hippocampi were analyzed by qRT-PCR and Western blotting. Compared with the sham mice, the model mice showed significant neuronal damage in the hippocampal CA1 region (P < 0.01), cognitive dysfunction (P < 0.01), and endogenous hippocampal neurogenesis (P < 0.01). These results suggested that the CI model was successfully established, and that CI could promote endogenous hippocampal neurogenesis, but this hippocampal neurogenesis was unable to recover cognitive dysfunction. Compared with the model mice, the tDCS mice had ameliorated pathological damage in the CA1 region (P < 0.01), improved cognitive function (P < 0.01), increased hippocampal neurogenesis (P < 0.01), and increased mRNA and protein expression of ephrinb1, EPHB2, MAP-2, and NMDAR (P < 0.05). Repetitive anodal-tDCS can promote hippocampal neurogenesis and improve cognitive function in CI mice. The effect may be related to the activation of the ephrinb1/EPHB2/MAP-2/NMDAR signaling pathway.