UNDERSTANDING THE PATHOPHYSIOLOGY OF MIGRAINE: ACTIVATION AND SENSITIZATION OF DURAL AFFERENTS

Persistent Link:
http://hdl.handle.net/10150/205415
Title:
UNDERSTANDING THE PATHOPHYSIOLOGY OF MIGRAINE: ACTIVATION AND SENSITIZATION OF DURAL AFFERENTS
Author:
Yan, Jin
Issue Date:
2011
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Embargo:
Embargo: Release after 05/20/2012
Abstract:
Migraine is one of the most common neurological disorders. The pathological conditions that initiate and sensitize afferent pain signaling are poorly understood. The goal of this study is to identify the ion channels and signaling proteins underlying activation and sensitization of meningeal nociceptors.In trigeminal neurons retrogradely labeled from the cranial meninges, approximately 80% responded to a pH 6.0 application with a rapidly activating and desensitizing ASIC-like current. Pharmacological experiments and kinetics analysis demonstrated that dural afferent pH-sensitive currents were mediated via activation of ASIC3. In addition, applications of decreased pH solutions were able to excite these neurons and generate action potentials. In awake animals, application of decreased pH solutions to the dura produced dose-dependent facial and hindpaw allodynia, which was also mediated through activation of ASIC3. Accumulating evidence indicates that meningeal inflammation induced sensitization of dural afferents contributes to migraine headache. We have demonstrated here that in the presence of mast cell mediators, dural afferents showed a decreased pH threshold and increased activity in response to pH stimuli both in vivo and in vitro. These data provide a cellular mechanism by which decreased pH in the meninges directly excites afferent pain-sensing neurons potentially contributing to migraine headache. It also indicates that inflammatory events within the meninges could sensitize afferent pain signaling and result in increased sensitivity of dural afferents.Intracranial Interleukin-6 (IL-6) levels have been shown to be elevated during migraine attacks, suggesting that this cytokine may facilitate pain signaling from the meninges. Here we reported that in awake animals, direct application of IL-6 to the dura produced dose-dependent facial and hindpaw allodynia via activation of the ERK signaling pathway. IL-6 application was also able to increase neuronal excitability in a manner consistent with phosphorylation of Nav1.7. These data provide a cellular mechanism by which IL-6 in the meninges causes sensitization of dural afferents therefore contributing to the pathogenesis of migraine.These findings are discussed in relation to how activation and sensitization of primary afferent neurons might initiate migraine pain signaling and how the research included in this dissertation relates to the development of new therapeutic strategies for migraine.
Type:
text; Electronic Dissertation
Keywords:
Interleukin 6; Migraine; Nav1.7; Medical Pharmacology; acid sensing ion channels; dural afferents
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Medical Pharmacology
Degree Grantor:
University of Arizona
Advisor:
Dussor, Gregory

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleUNDERSTANDING THE PATHOPHYSIOLOGY OF MIGRAINE: ACTIVATION AND SENSITIZATION OF DURAL AFFERENTSen_US
dc.creatorYan, Jinen_US
dc.contributor.authorYan, Jinen_US
dc.date.issued2011-
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.releaseEmbargo: Release after 05/20/2012en_US
dc.description.abstractMigraine is one of the most common neurological disorders. The pathological conditions that initiate and sensitize afferent pain signaling are poorly understood. The goal of this study is to identify the ion channels and signaling proteins underlying activation and sensitization of meningeal nociceptors.In trigeminal neurons retrogradely labeled from the cranial meninges, approximately 80% responded to a pH 6.0 application with a rapidly activating and desensitizing ASIC-like current. Pharmacological experiments and kinetics analysis demonstrated that dural afferent pH-sensitive currents were mediated via activation of ASIC3. In addition, applications of decreased pH solutions were able to excite these neurons and generate action potentials. In awake animals, application of decreased pH solutions to the dura produced dose-dependent facial and hindpaw allodynia, which was also mediated through activation of ASIC3. Accumulating evidence indicates that meningeal inflammation induced sensitization of dural afferents contributes to migraine headache. We have demonstrated here that in the presence of mast cell mediators, dural afferents showed a decreased pH threshold and increased activity in response to pH stimuli both in vivo and in vitro. These data provide a cellular mechanism by which decreased pH in the meninges directly excites afferent pain-sensing neurons potentially contributing to migraine headache. It also indicates that inflammatory events within the meninges could sensitize afferent pain signaling and result in increased sensitivity of dural afferents.Intracranial Interleukin-6 (IL-6) levels have been shown to be elevated during migraine attacks, suggesting that this cytokine may facilitate pain signaling from the meninges. Here we reported that in awake animals, direct application of IL-6 to the dura produced dose-dependent facial and hindpaw allodynia via activation of the ERK signaling pathway. IL-6 application was also able to increase neuronal excitability in a manner consistent with phosphorylation of Nav1.7. These data provide a cellular mechanism by which IL-6 in the meninges causes sensitization of dural afferents therefore contributing to the pathogenesis of migraine.These findings are discussed in relation to how activation and sensitization of primary afferent neurons might initiate migraine pain signaling and how the research included in this dissertation relates to the development of new therapeutic strategies for migraine.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectInterleukin 6en_US
dc.subjectMigraineen_US
dc.subjectNav1.7en_US
dc.subjectMedical Pharmacologyen_US
dc.subjectacid sensing ion channelsen_US
dc.subjectdural afferentsen_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineMedical Pharmacologyen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorDussor, Gregoryen_US
dc.contributor.committeememberDussor, Gregoryen_US
dc.contributor.committeememberPrice, Theodore J.en_US
dc.contributor.committeememberPorreca, Franken_US
dc.contributor.committeememberVanderah, Todd W.en_US
dc.contributor.committeememberStamer, W. Danielen_US
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