CNGA3: A Target of Spinal Nitric Oxide/cGMP Signaling and Modulator of Inflammatory Pain Hypersensitivity
03-Aug-2011
The Journal of Neuroscience, 2011, doi: 10.1523/JNEUROSCI.6159-10.2011, 11184-11192; published on 03.08.2011
The Journal of Neuroscience, online article
The Journal of Neuroscience, online article
A large body of evidence indicates that nitric oxide (NO) and cGMP contribute to central sensitization of pain pathways during inflammatory pain. Here, we investigated the distribution of cyclic nucleotide-gated (CNG) channels in the spinal cord, and identified the CNG channel subunit CNGA3 as a putative cGMP target in nociceptive processing. In situ hybridization revealed that CNGA3 is localized to nhibitory neurons of the dorsal horn of the spinal cord, whereas its distribution in dorsal root ganglia is restricted to non-neuronal cells. CNGA3 expression is upregulated in the superficial dorsal horn of the mouse spinal cord and in dorsal root ganglia following hindpaw inflammation evoked by zymosan. Mice lacking CNGA3 (CNGA3 -/- mice) exhibited an increased nociceptive behavior in models of inflammatory pain, whereas their behavior in models of acute or neuropathic pain was normal. Moreover, CNGA3 -/- mice developed an exaggerated pain hypersensitivity induced by intrathecal administration of cGMP analogs or NO donors. Ourm results provide evidence that CNGA3 contributes in an inhibitory manner to the central sensitization of pain pathways during inflammatory pain as a target of NO/cGMP signaling.