Identification of spinal circuits transmitting and gating mechanical pain.

Abstract

Pain information processing in the spinal cord has been postulated to rely on nociceptive transmission (T) neurons receiving inputs from nociceptors and Aβ mechanoreceptors, with Aβ inputs gated through feed-forward activation of spinal inhibitory neurons (INs). Here, we used intersectional genetic manipulations to identify these critical components of pain transduction. Marking and ablating six populations of spinal excitatory and inhibitory neurons, coupled with behavioral and electrophysiological analysis, showed that excitatory neurons expressing somatostatin (SOM) include T-type cells, whose ablation causes loss of mechanical pain. Inhibitory neurons marked by the expression of dynorphin (Dyn) represent INs, which are necessary to gate Aβ fibers from activating SOM(+) neurons to evoke pain. Therefore, peripheral mechanical nociceptors and Aβ mechanoreceptors, together with spinal SOM(+) excitatory and Dyn(+) inhibitory neurons, form a microcircuit that transmits and gates mechanical pain. PAPERCLIP:

• Authors: Bo Duan, Longzhen Cheng, Steeve Bourane, Olivier Britz, Christopher Padilla, Lidia Garcia-Campmany, Michael Krashes, Wendy Knowlton, Tomoko Velasquez, Xiangyu Ren, Sarah Ross, Bradford B Lowell, Yun Wang, Martyn Goulding, Qiufu Ma
• Journal: Cell (Cell) Vol. 159 Issue 6 Pg. 1417-1432 (Dec 04 2014) ISSN: 1097-4172 [Electronic] United States
• PMID: 25467445 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2014 Elsevier Inc. All rights reserved.

Chemical References

• Somatostatin
• Dynorphins

Topics

• Animals
• Dynorphins (metabolism)
• Mechanoreceptors (metabolism)
• Mice
• Neurons (physiology)
• Pain (metabolism)
• Pain Perception
• Somatostatin (metabolism)
• Spinal Cord (physiology)