Melanocortin-4 Receptor Expression in the Rostral Ventromedial Medulla Involved in Modulation of Nociception in Transgenic Mice  

作　　者：潘旭初 宋咏堂 刘成 项红兵 卢传坚 

机构地区：[1]Medical Association of Hubei Province [2]Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology [3]Department of Dermatology, Guangdong Provincial Hospital of Traditional Chinese Medicine

出　　处：《Journal of Huazhong University of Science and Technology(Medical Sciences)》2013年第2期195-198,共4页华中科技大学学报（医学英德文版）

基　　金：supported by grants from National Natural Science Foundation of China(No.81071307,No.81271766,and No.81673964);Special Fund of Fundamental Scientific Research Business Expense for Higher School of Central Government(No.2012TS060)

摘　　要：The rostral ventromedial medulla （RVM） is a prominent component of the descending modulatory system involved in the control of spinal nociceptive transmission. In the current study, we investigated melanocortin-4 receptor （MC4R） expression in the RVM, where the neurons involved in modulation of nociception reside. Using a line of mice expressing green fluorescent protein （GFP） under the control of the MC4R promoter, we found a large number of GFP-positive neurons in the RVM [nucleus raphe magnus （NRM） and nucleus gigantocellularis pars a （NGCa）]. Fluorescence immunohisto- chemistry revealed that approximately 10% of MC4R-GFP-positive neurons coexpressed tyrosine hydroxylase, indicating that they were catecholaminergic, whereas 50%-75% of those coexpressed tryp- tophan hydroxylase, indicating that they were serotonergic. Our findings support the hypothesis that MC4R signaling in RVM may modulate the activity of serotonergic sympathetic outflow sensitive to nociceptive signals, and that MC4R signaling in RVM may contribute to the descending modulation of nociceptive transmission.The rostral ventromedial medulla （RVM） is a prominent component of the descending modulatory system involved in the control of spinal nociceptive transmission. In the current study, we investigated melanocortin-4 receptor （MC4R） expression in the RVM, where the neurons involved in modulation of nociception reside. Using a line of mice expressing green fluorescent protein （GFP） under the control of the MC4R promoter, we found a large number of GFP-positive neurons in the RVM [nucleus raphe magnus （NRM） and nucleus gigantocellularis pars a （NGCa）]. Fluorescence immunohisto- chemistry revealed that approximately 10% of MC4R-GFP-positive neurons coexpressed tyrosine hydroxylase, indicating that they were catecholaminergic, whereas 50%-75% of those coexpressed tryp- tophan hydroxylase, indicating that they were serotonergic. Our findings support the hypothesis that MC4R signaling in RVM may modulate the activity of serotonergic sympathetic outflow sensitive to nociceptive signals, and that MC4R signaling in RVM may contribute to the descending modulation of nociceptive transmission.

关 键 词：melanocortin-4 receptor NOCICEPTION rostral ventromedial medulla 

分 类 号：R338[医药卫生—人体生理学]