| First Author | Cai YQ | Year | 2014 |
| Journal | Mol Pain | Volume | 10 |
| Pages | 70 | PubMed ID | 25410898 |
| Mgi Jnum | J:322909 | Mgi Id | MGI:6851785 |
| Doi | 10.1186/1744-8069-10-70 | Citation | Cai YQ, et al. (2014) Optogenetic activation of brainstem serotonergic neurons induces persistent pain sensitization. Mol Pain 10:70 |
| abstractText | BACKGROUND: The rostral ventromedial medulla (RVM) is a key brainstem structure that conveys powerful descending influence of the central pain-modulating system on spinal pain transmission and processing. Serotonergic (5-HT) neurons are a major component in the heterogeneous populations of RVM neurons and in the descending pathways from RVM. However, the descending influence of RVM 5-HT neurons on pain behaviors remains unclear. RESULTS: In this study using optogenetic stimulation in tryptophan hydroxylase 2 (TPH2)- Channelrhodopsin 2 (ChR2) transgenic mice, we determined the behavioral effects of selective activation of RVM 5-HT neurons on mechanical and thermal pain behaviors in vivo. We found that ChR2-EYFP-positive neurons strongly co-localized with TPH2-positive (5-HT) neurons in RVM. Optogenetic stimulation significantly increased c-fos expression in 5-HT cells in the RVM of TPH2-ChR2 mice, but not in wild type mice. Behaviorally, the optogenetic stimulation decreased both mechanical and thermal pain threshold in an intensity-dependent manner, with repeated stimulation producing sensitized pain behavior for up to two weeks. CONCLUSIONS: These results suggest that selective activation of RVM 5-HT neurons exerts a predominant effect of pain facilitation under control conditions. |
