5-HT in the dorsal raphe nucleus is involved in the effects of 100-Hz electro-acupuncture on the pain-depression dyad in rats.

Abstract

The pain-depression dyad is becoming widespread in the clinic and is attracting increasing attention. A previous study by our group found that 100-Hz electro-acupuncture (EA), but not 2-, 50- and 2/100-Hz EA, was effective against the reserpine-induced pain-depression dyad. This finding is in contrast to the fact that low-frequency EA is commonly used to treat supraspinal-originating diseases. The present study aimed to investigate the mechanism underlying the effects of 100-Hz EA on the pain-depression dyad. Repeated reserpine injection was found to induce allodynia and depressive behaviors in rats. It decreased 5-hydroxytryptamine (5-HT) levels and immunoreactive expressions in the dorsal raphe nucleus (DRN). 100-Hz EA alleviated the pain-depression dyad and upregulated 5-HT in the DRN of reserpine-injected rats. Intracerebroventricular injection of para-chlorophenylalanine, an inhibitor of 5-HT resynthesis, suppressed the upregulation of 5-HT in the DRN by 100-Hz EA and partially counteracted the analgesic and anti-depressive effects of 100-Hz EA. The present study was the first to demonstrate that 5-HT in the DRN is involved in mediating the analgesic and anti-depressive effects of 100-Hz EA on the pain-depression dyad. This finding provided a scientific basis for high-frequency EA as a potential treatment for the pain-depression dyad.

• Authors: Yuan-Yuan Wu, Yong-Liang Jiang, Xiao-Fen He, Xiao-Yun Zhao, Xiao-Mei Shao, Jing Sun, Zui Shen, Shen-Yun Shou, Jun-Jun Wei, Jia-Yu Ye, Si-Si Yan, Jian-Qiao Fang
• Journal: Experimental and therapeutic medicine (Exp Ther Med) Vol. 14 Issue 1 Pg. 107-114 (Jul 2017) ISSN: 1792-0981 [Print] Greece
• PMID: 28672900 (Publication Type: Journal Article)