NFE2L2 and osteogenesis imperfecta: To verify this, we first tested Nrf2 expression levels in hippocampal neurons in the POCD model through both in vivo and in vitro experiments and found that Nrf2 expression was downregulated in hippocampal neurons 9 days after anesthesia and surgery (0.5696 ± 0.1073 vs 0.9822 ± 0.1362, P = 0.0011), and Nrf2 expression was increased in hippocampal neurons after OI treatment (0.8618 ± 0.06596 vs 0.5696 ± 0.1073, P = 0.0097) (Fig. 6a, b).