Inhibition of jaw-opening reflex by stimulation of the central amygdaloid nucleus in the cat.
The effect of stimulation of the amygdaloid complex on the jaw-opening reflex (JOR) was studied in the cat anesthetized with pentobarbital sodium. The conditioning stimulation of the central amygdaloid nucleus (ACE), but not the other amygdaloid nuclei, markedly inhibited the JOR induced by the tooth pulp stimulation. Ipsilateral ACE conditioning stimulation with 300 microA produced inhibition which lasted approximately 500 ms from the cessation of the stimulation. Additionally, the microinjection of monosodium glutamate into ACE elicited inhibition of the JOR that lasted about 10 min. These findings suggest that the excitation of the cell bodies in ACE exerts inhibitory action on the trigeminal nociceptive reflex.
Kowada
K
K
Department of Oral Physiology, School of Dentistry, Iwate Medical University, Morioka, Japan.
Kawarada
K
K
Matsumoto
N
N
Ooe
M
M
Suzuki
T A
TA
D000679:Amygdala / Q000502:physiology*; D000818:Animals; D002415:Cats; D003213:Conditioning, Psychological; D003782:Dental Pulp / Q000502:physiology; D004558:Electric Stimulation; D004576:Electromyography; D007568:Jaw / Q000502:physiology*; D009433:Neural Inhibition; D012018:Reflex / Q000502:physiology*