Expression of the 5-HT1B receptor by subtypes of rat trigeminal ganglion cells.
The type of trigeminal ganglion cells that express 5-HT1B receptors has not been well characterized, despite the fact that these receptors are important targets for anti-migraine drugs. We have therefore used combined in situ hybridization and immunofluorescence to examine the expression of 5-HT1B receptor messenger RNA in identified subpopulations of rat trigeminal ganglion cells. 5-HT1B-expressing cells accounted for 15% of all trigeminal ganglion cells, were medium sized, and showed immunoreactivity for either 200,000 mol. wt neurofilament, calcitonin gene-related peptide, or nerve growth factor receptor (trkA). In contrast few 5-HT1B cells showed immunoreactivity for substance P or binding of the lectin Griffonia simplicifolia IB4. Our results are consistent with 5-HT1B receptors acting to control the release of calcitonin gene-related peptide from trigeminal neurons with finely myelinated axons. 5-HT1B receptor agonists may reduce neurogenic vasodilation by activating such receptors. However many nociceptive trigeminal neurons, including the substance P and IB4-binding populations, do not express the 5-HT1B receptor.
Wotherspoon
G
G
Division of Biomedical Sciences, St Bartholomew's and Royal London School of Medicine and Dentistry, Queen Mary and Westfield College, UK.
Priestley
J V
JV
D000818:Animals; D015415:Biomarkers; D015740:Calcitonin Gene-Related Peptide / Q000032:analysis / Q000235:genetics; D004396:Coloring Agents; D015870:Gene Expression / Q000502:physiology; D017403:In Situ Hybridization; D037102:Lectins; D008297:Male; D008881:Migraine Disorders / Q000503:physiopathology; D009413:Nerve Fibers, Myelinated / Q000737:chemistry; D016900:Neurofilament Proteins / Q000032:analysis; D009475:Neurons, Afferent / Q000737:chemistry / Q000502:physiology* / Q000648:ultrastructure; D009619:Nociceptors / Q000502:physiology; D037121:Plant Lectins; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D044302:Receptor, Serotonin, 5-HT1B; D020917:Receptor, trkA / Q000235:genetics; D011985:Receptors, Serotonin / Q000032:analysis / Q000235:genetics*; D013373:Substance P / Q000032:analysis / Q000235:genetics; D014048:Tolonium Chloride; D012668:Trigeminal Ganglion / Q000737:chemistry / Q000502:physiology*; D014664:Vasodilation / Q000502:physiology
D015415:Biomarkers; D004396:Coloring Agents; C045475:Griffonia simplicifolia lectins; D037102:Lectins; D016900:Neurofilament Proteins; D037121:Plant Lectins; D012333:RNA, Messenger; D044302:Receptor, Serotonin, 5-HT1B; D011985:Receptors, Serotonin; C051774:neurofilament protein H; D014048:Tolonium Chloride; D013373:Substance P; D020917:Receptor, trkA; D015740:Calcitonin Gene-Related Peptide