Furthermore, we demonstrated that the increased level of miR-199b-3p in NSCs after the occurrence of chronic pain was responsible for AHN inhibition and comorbid depression.<h4>Conclusion</h4>Chronic neuropathic pain may result in an increased level of miR-199b-3p in hippocampal NSCs, which in turn targeted the Mecp2 gene and inhibited its transcription. Here, MECP2 is linked to major depressive disorder.