Aim
It has been reported that acupuncture at GB34 can enhance neurogenesis in the subventricular zone (SVZ) of mice treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). However, the signaling pathway that plays a critical role in neurogenesis needs to be established. Herein, we investigated the neurogenesis-promoting pathway mediated by acupuncture, focusing on extracellular signal-regulated kinase (ERK) signaling. Experimental procedure: Male 10-week-old C57BL/6 mice were intraperitoneally injected with 30 mg/kg MPTP once daily for 5 days. Subsequently, mice were intraperitoneally injected with 50 mg/kg bromodeoxyuridine (BrdU), and electroacupuncture (EA) was performed at GB34 and BL60 for 3 weeks. The survival of dopaminergic neurons in the nigrostriatal pathway, cell proliferation in the SVZ, and expression levels of brain-derived neurotrophic factor (BDNF) and phosphorylated ERK (pERK) were evaluated.
Conclusion
MPTP induced dopaminergic neuronal death in the nigrostriatal pathway, and reduced the number of BrdU-positive and BrdU/doublecortin double-positive cells in the SVZ; these parameters were restored by EA. Moreover, EA prevented MPTP-induced reduction in striatal expression of BDNF and pERK. These results indicate that EA could prevent dopaminergic neuronal death in the nigrostriatal pathway and restore neurogenesis in the SVZ, which may be attributed to the activation of the BDNF-ERK pathway.