title: Effects of chewing and swallowing behavior on jaw opening reflex responses in freely feeding rabbits.
abstract: It has been reported that the jaw opening reflex (JOR) evoked by intra-oral innocuous stimulation was suppressed during a reflex swallow in anesthetized animals only. However, the mechanism of JOR inhibition during swallowing has not yet been elucidated. The aim of the present study was to investigate the effects of peripheral nerve stimulation on masticatory behaviors, as well as the modulation of low threshold afferent evoked JOR responses during chewing and swallowing in freely feeding animals. The JOR in the digastric muscle was evoked by low threshold electrical stimulation of the inferior alveolar nerve (IAN). Changes in the peak-to-peak amplitude of digastric electromyographic responses were compared among the phases of chewing and swallowing. IAN stimulation did not produce any differences in cycle duration, gape of the jaw in one cycle, or swallowing interval, suggesting a minimal effect on feeding behaviors. The JOR amplitude during the fast-closing, slow-closing, and slow-opening phases of chewing was significantly smaller than that of the control (recorded when the animal was at rest) and fast-opening phase. During swallowing, the JOR amplitude was significantly less than the control. Inhibition of the JOR during swallowing is assumed to prevent unnecessary opposing jaw opening motion.
authors: Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
authors: Aki
authors: A
authors: Yamada
authors: Yuka
authors: Y
authors: Kajii
authors: Shogo
authors: S
authors: Sakai
authors: Takanori
authors: T
authors: Tsujimura
authors: Yuki
authors: Y
authors: Nakamura
authors: Sajjiv
authors: S
authors: Ariyasinghe
authors: Jin
authors: J
authors: Magara
authors: Makoto
authors: M
authors: Inoue
mesh_terms: D000818:Animals; D003679:Deglutition; D004558:Electric Stimulation; D004576:Electromyography; D005247:Feeding Behavior; D007568:Jaw / Q000502:physiology*; D008297:Male; D008340:Mandibular Nerve / Q000502:physiology; D008409:Mastication; D011817:Rabbits; D012018:Reflex