Publication:
Activation properties of trigeminal motoneurons in participants with and without bruxism

dc.contributor.coauthorD'Amico, Jessica M.
dc.contributor.coauthorYavuz, S. Utku
dc.contributor.coauthorSaracoglu, Ahmet
dc.contributor.coauthorAtis, Elif Sibel
dc.contributor.coauthorGorassini, Monica A.
dc.contributor.departmentSchool of Medicine
dc.contributor.kuauthorTürker, Kemal Sıtkı
dc.contributor.schoolcollegeinstituteSCHOOL OF MEDICINE
dc.date.accessioned2024-11-09T23:52:43Z
dc.date.issued2013
dc.description.abstractIn animals, sodium-and calcium-mediated persistent inward currents (PICs), which produce long-lasting periods of depolarization under conditions of low synaptic drive, can be activated in trigeminal motoneurons following the application of the monoamine serotonin. Here we examined if PICs are activated in human trigeminal motoneurons during voluntary contractions and under physiological levels of monoaminergic drive (e. g., serotonin and norepinephrine) using a paired motor unit analysis technique. We also examined if PICs activated during voluntary contractions are larger in participants who demonstrate involuntary chewing during sleep (bruxism), which is accompanied by periods of high monoaminergic drive. In control participants, during a slowly increasing and then decreasing isometric contraction, the firing rate of an earlier-recruited masseter motor unit, which served as a measure of synaptic input to a later-recruited test unit, was consistently lower during derecruitment of the test unit compared with at recruitment (Delta F = 4.6 +/- 1.5 imp/s). The Delta F, therefore, is a measure of the reduction in synaptic input needed to counteract the depolarization from the PIC to provide an indirect estimate of PIC amplitude. The range of Delta F values measured in the bruxer participants during similar voluntary contractions was the same as in controls, suggesting that abnormally high levels of monoaminergic drive are not continually present in the absence of involuntary motor activity. We also observed a consistent "onion skin effect" during the moderately sized contractions (<20% of maximal), whereby the firing rate of higher threshold motor units discharged at slower rates (by 4-7 imp/s) compared with motor units with relatively lower thresholds. The presence of lower firing rates in the more fatigue-prone, higher threshold trigeminal motoneurons, in addition to the activation of PICs, likely facilitates the activation of the masseter muscle during motor activities such as eating, nonnutritive chewing, clenching, and yawning.
dc.description.indexedbyWOS
dc.description.indexedbyScopus
dc.description.issue12
dc.description.openaccessYES
dc.description.publisherscopeInternational
dc.description.sponsoredbyTubitakEuN/A
dc.description.sponsorshipCanadian Institute of Health Research [MOP-106549]
dc.description.sponsorshipTurkish Scientific and Technological Research Organization [Tubitak-107S029- SBAG-3556]
dc.description.sponsorshipAlberta Innovates: Health Solutions
dc.description.sponsorshipAlberta Paraplegic Foundation
dc.description.sponsorshipEuropean Research Council (ERC) via the ERC Advanced Grant DEMOVE [267888] This work was supported by the Canadian Institute of Health Research (MOP-106549
dc.description.sponsorshipto M. A. Gorassini) and a Turkish Scientific and Technological Research Organization (Tubitak-107S029- SBAG-3556) grant (to K. S. Turker). Salary support was provided by Alberta Innovates: Health Solutions (to M. A. Gorassini and J. M. D'Amico) and the Alberta Paraplegic Foundation (to J. M. D'Amico), and S,.U. Yavuz was supported by the European Research Council (ERC) via the ERC Advanced Grant DEMOVE (No. 267888).
dc.description.volume110
dc.identifier.doi10.1152/jn.00536.2013
dc.identifier.eissn1522-1598
dc.identifier.issn0022-3077
dc.identifier.quartileQ2
dc.identifier.scopus2-s2.0-84890376931
dc.identifier.urihttps://doi.org/10.1152/jn.00536.2013
dc.identifier.urihttps://hdl.handle.net/20.500.14288/14882
dc.identifier.wos328889700016
dc.keywordsMotoneurons
dc.keywordsPain
dc.keywordsSleep bruxism
dc.keywordsPlateaus single motor units
dc.keywordsFiring rate modulation
dc.keywordsHuman masseter muscle
dc.keywordsChronic spinal rats
dc.keywordsSleep bruxism
dc.keywordsCalcium currents
dc.keywordsCord injury
dc.keywordsGuinea pig
dc.keywordsPhysiological properties
dc.keywordsVoluntary contraction
dc.language.isoeng
dc.publisherAmerican Physiological Society (APS)
dc.relation.ispartofJournal of Neurophysiology
dc.subjectNeurosciences
dc.subjectPhysiology
dc.titleActivation properties of trigeminal motoneurons in participants with and without bruxism
dc.typeJournal Article
dspace.entity.typePublication
local.contributor.kuauthorTürker, Kemal Sıtkı
local.publication.orgunit1SCHOOL OF MEDICINE
local.publication.orgunit2School of Medicine
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relation.isParentOrgUnitOfPublication17f2dc8e-6e54-4fa8-b5e0-d6415123a93e
relation.isParentOrgUnitOfPublication.latestForDiscovery17f2dc8e-6e54-4fa8-b5e0-d6415123a93e

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