Sensitization and activation of intracranial meningeal nociceptors by mast cell mediators.
Intracranial headaches such as migraine are thought to result from activation of sensory trigeminal pain neurons that supply intracranial blood vessels and the meninges, also known as meningeal nociceptors. Although the mechanism underlying the triggering of such activation is not completely understood, our previous work indicates that the local activation of the inflammatory dural mast cells can provoke a persistent sensitization of meningeal nociceptors. Given the potential importance of mast cells to the pain of migraine it is important to understand which mast cell-derived mediators interact with meningeal nociceptors to promote their activation and sensitization. In the present study, we have used in vivo electrophysiological single-unit recording of meningeal nociceptors in the trigeminal ganglion of anesthetized rats to examine the effect of a number of mast cell mediators on the activity level and mechanosensitivity of meningeal nociceptors. We have found that that serotonin (5-HT), prostaglandin I(2) (PGI(2)), and to a lesser extent histamine can promote a robust sensitization and activation of meningeal nociceptors, whereas the inflammatory eicosanoids PGD(2) and leukotriene C(4) are largely ineffective. We propose that dural mast cells could promote headache by releasing 5-HT, PGI(2), and histamine.
Zhang
Xi-Chun
XC
Headache Research Laboratory, Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Institutes of Medicine, Room 856, 77 Avenue Louis Pasteur, Boston, MA 02115, USA.
Strassman
Andrew M
AM
Burstein
Rami
R
Levy
Dan
D
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004594:Electrophysiology; D011464:Epoprostenol / Q000378:metabolism / Q000494:pharmacology; D006632:Histamine / Q000378:metabolism / Q000494:pharmacology; D017997:Leukotriene C4 / Q000494:pharmacology; D008297:Male; D008407:Mast Cells / Q000378:metabolism*; D008578:Meninges / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D009619:Nociceptors / Q000187:drug effects* / Q000502:physiology; D015230:Prostaglandin D2 / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000378:metabolism / Q000494:pharmacology; D013314:Stress, Mechanical
D017997:Leukotriene C4; D012701:Serotonin; D006632:Histamine; D011464:Epoprostenol; D015230:Prostaglandin D2