title: Periodontal anaesthetisation decreases rhythmic synchrony between masseteric motor units at the frequency of jaw tremor.
abstract: This study links the reduction in jaw physiological tremor around 8 Hz following periodontal mechanoreceptor (PMR) anaesthetisation to changes in coherence between masseteric motor unit discharges. We have recorded single motor unit activity from two separate sites in the right masseter muscle during a low level tonic contraction, both prior to and during anaesthetisation of the peri-incisal PMRs. Anaesthetisation of PMRs decreased coherent activity between motor units circa 8 Hz, and decreased synchrony between the same motor unit pairs. It is proposed that tremor-generating inputs that cause rhythmic synchronisation of masseteric motor units arise from, or are amplified by the PMRs.
authors.affiliation: Research Centre for Human Movement Control, Discipline of Physiology, School of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA 5005, Australia.
authors.forename: Paul F
authors.initials: PF
authors.lastname: Sowman
authors.forename: Kirstin M
authors.initials: KM
authors.lastname: Ogston
authors.forename: Kemal S
authors.initials: KS
authors.lastname: Türker
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000328:Adult; D000344:Afferent Pathways / Q000187:drug effects / Q000502:physiology; D000779:Anesthetics, Local / Q000494:pharmacology*; D001732:Bite Force; D004576:Electromyography; D005260:Female; D005881:Gingiva / Q000187:drug effects / Q000294:innervation; D006801:Humans; D008012:Lidocaine / Q000494:pharmacology; D008297:Male; D008406:Masseter Muscle / Q000294:innervation / Q000502:physiology*; D008465:Mechanoreceptors / Q000187:drug effects / Q000502:physiology*; D009046:Motor Neurons / Q000502:physiology*; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology; D009469:Neuromuscular Junction / Q000187:drug effects; D010507:Periodicity; D014202:Tremor / Q000188:drug therapy*; D014276:Trigeminal Nerve / Q000187:drug effects / Q000502:physiology
chemical_list: D000779:Anesthetics, Local; D008012:Lidocaine