Comparison of jaw-opening reflex response elicited by anterior and posterior tooth tapping in the cat.
The response elicited by various levels of controlled mechanical stimuli to maxillary teeth was studied in 8 adult cats anaesthetized with alpha-chloralose. When an anterior tooth was tapped, short (4-6 ms) and long (16-20 ms) latency responses were recorded from the mylohyoid nerve. On the other hand, when a posterior tooth was tap-stimulated, only the long-latency response was induced. The effects of ether narcosis on the responses were studied. As the short-latency response was induced only by anterior tooth tapping and its amplitude increased according to increases in stimulus intensity, the response may be related to the protection of the mouth from entrance of harmful materials. The long-latency response was induced by light tapping on both anterior and posterior teeth and its amplitude increased according to increases in stimulus intensity to the posterior teeth rather than the anterior teeth. As it was readily inhibited by ether, the long-latency response may have a reflex centre in an area like the brain stem reticular formation which is particularly sensitive to ether and may be related to the regulation of jaw movement in mastication.
Munakata
Y
Y
Department of Oral Physiology, Tohoku Dental University, Koriyama, Japan.
Kasai
S
S
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001641:Bicuspid / Q000502:physiology; D002415:Cats; D003481:Cuspid / Q000502:physiology; D004986:Ether / Q000494:pharmacology; D007180:Incisor / Q000502:physiology; D007568:Jaw / Q000502:physiology*; D008410:Masticatory Muscles / Q000294:innervation*; D008437:Maxilla; D010812:Physical Stimulation; D011930:Reaction Time / Q000187:drug effects; D012018:Reflex / Q000187:drug effects / Q000502:physiology; D012154:Reticular Formation / Q000502:physiology; D014070:Tooth / Q000502:physiology*
D004986:Ether