Upregulation of tumor necrosis factor-alpha in the anterior cingulate cortex contributes to neuropathic pain and pain-associated aversion

Neurobiology of Disease

Wen-Jun Xin¹  Pei-Wen Yao²  Xian-Guo Liu²  Ying Zang²  Shao-Kun Wang²  Shao-Xia Chen² 

[1] Department of Anesthesiology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, 651 Dongfeng Road East, Guangzhou 510060, PR China;Pain Research Center and Department of Physiology, Zhongshan Medical School, Sun Yat-Sen University, 74 Zhongshan Rd. 2, Guangzhou 510080, PR China;

关键词: Tumor necrosis factor-alpha;    Neuropathic pain;    Pain-associated aversion;    Anterior cingulate cortex;   

DOI  :  

来源: DOAJ

【 摘 要 】

Injury associated pain involves subjective perception and emotional experience. The anterior cingulate cortex (ACC) is a key area involved in the affective component of pain processing. However, the neuroimmune mechanisms underlying enhanced ACC excitability following peripheral nerve injury are still not fully understood. Our previous work has shown that tumor necrosis factor-alpha (TNF-α) overexpression leads to peripheral afferent hyperexcitability and synaptic transmission potentiation in spinal cord. Here, we aimed to reveal the potential role of ACC TNF-α in ACC hyperexcitability and neuropathic pain. c-Fos, a widely used neuronal activity marker, was induced especially in contralateral ACC early [postoperative (PO) 1 h] and later (PO day 7 and 10) during the development of neuropathic pain. Spared nerve injury (SNI) elevated TNF-α level in contralateral ACC from PO day 5 to 14, delayed relative to decreased ipsilateral paw withdrawal threshold apparent from PO day 1 to 14. Microinjection of anti-TNF-α antibody into the ACC completely eliminated c-Fos overexpression and greatly attenuated pain aversion and mechanical allodynia induced by SNI, suggesting an important role of ACC TNF-α in the pain aversiveness and pain maintenance. Furthermore, modulating ACC pyramidal neurons via a Gi-coupled human M4 muscarinic receptor (hM4Di) or a Gq-coupled human M3 muscarinic receptor (hM3Dq), a type of designer receptors exclusively activated by designer drugs (DREADD), greatly changed the ACC TNF-α level and the mechanical paw withdrawal threshold. The positive interactions between TNF-α and ACC neurons might modulate the cytokine microenvironment thus contribute to the neuropathic pain.

【 授权许可】

Unknown