The comorbidity of depressive symptoms in chronic pain has been recognized as a key health issue. However, whether discrete circuits underlie behavioral subsets of chronic pain and comorbid depression has not been addressed. Here, we report that dopamine 2 (D2) receptor–expressing medium spiny neurons in the nucleus accumbens medial shell (mNAcSh) mediate pain hypersensitivity and depression-like behaviors in mice after nerve injury. Two separate neural pathways mediate different symptoms. The glutamatergic inputs from the anteromedial thalamic nucleus to mNAcSh D2 neurons that innervated orexin-expressing neurons in the lateral hypothalamic area contributed to pain regulation. In contrast, the lateral septum GABAergic inputs to mNAcSh D2 neurons that disinhibit the ventral pallidum glutamatergic neurons mediated depression-like behaviors. These findings indicate the functional significance of heterogeneous mNAcSh D2 neurons and their neural pathways, providing a perspective for symptom-specific treatments of chronic pain and comorbid depression.
Di Liu, Fang-Xia Xu, Zhuang Yu, Xiao-Jing Huang, Ya-Bing Zhu, Li-Juan Wang, Chen-Wei Wu, Xu Zhang, Jun-Li Cao, Jinbao Li
This file is in Adobe Acrobat (PDF) format. If you have not installed and configured the Adobe Acrobat Reader on your system.
PDFs are designed to be printed out and read, but if you prefer to read them online, you may find it easier if you increase the view size to 125%.
Many versions of the free Acrobat Reader do not allow Save. You must instead save the PDF from the JCI Online page you downloaded it from. PC users: Right-click on the Download link and choose the option that says something like "Save Link As...". Mac users should hold the mouse button down on the link to get these same options.