Referenced in: none

Automatically associated channels: TRP , TRPV , TRPV1

Title: Central terminal sensitization of TRPV1 by descending serotonergic facilitation modulates chronic pain.

Authors: Yu Shin Kim, Yuxia Chu, Liang Han, Man Li, Zhe Li, Pamela Colleen Lavinka, Shuohao Sun, Zongxiang Tang, Kyoungsook Park, Michael J Caterina, Ke Ren, Ronald Dubner, Feng Wei, Xinzhong Dong

Journal, date & volume: Neuron, 2014 Feb 19 , 81, 873-87

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/24462040

Abstract
The peripheral terminals of primary nociceptive neurons play an essential role in pain detection mediated by membrane receptors like TRPV1, a molecular sensor of heat and capsaicin. However, the contribution of central terminal TRPV1 in the dorsal horn to chronic pain has not been investigated directly. Combining primary sensory neuron-specific GCaMP3 imaging with a trigeminal neuropathic pain model, we detected robust neuronal hyperactivity in injured and uninjured nerves in the skin, soma in trigeminal ganglion, and central terminals in the spinal trigeminal nucleus. Extensive TRPV1 hyperactivity was observed in central terminals innervating all dorsal horn laminae. The central terminal TRPV1 sensitization was maintained by descending serotonergic (5-HT) input from the brainstem. Central blockade of TRPV1 or 5-HT/5-HT3A receptors attenuated central terminal sensitization, excitatory primary afferent inputs, and mechanical hyperalgesia in the territories of injured and uninjured nerves. Our results reveal central mechanisms facilitating central terminal sensitization underlying chronic pain.