Potential mechanisms of HBOT and HIF-1α. In hypoxia, HIF-1α activates EPO and VEGF to promote neurogenesis. The accumulation of HIF-1α further induces the expression of p53 protein and BNIP3, leading to cell death. HBOT stabilizes HIF-1α, preventing it from overexpression and further, activates the Wnt pathway. Abbreviation: PHDs, prolyl hydroxylase; HIF-1α, hypoxia-inducible factor 1α; EPO, e rythropoietin; VEGF, vascular endothelial growth factor; NGN1, Neurogenin1; TCF, T-cell factor.