Peripheral indoleamine 2,3-dioxygenase 1 is required for comorbid depression-like behavior but does not contribute to neuropathic pain in mice

In conclusion, our findings show for the first time that neuropathic pain is associated with an increase of Ido1 in liver, but not brain, downstream of spinal cord IL-1β signaling and that Ido1 mediates comorbid depression. Moreover, comorbidity of neuropathic pain and depression are only partially mediated by a common mechanism because mechanical hyperalgesia develops independently of Ido1.