Tooth-pulp-evoked rostral spinal trigeminal neuronal excitation is attenuated by the activation of 5-HT3 receptors via GABAergic interneurons in the rat.
The effect of iontophoretic application of the 5-HT3 receptor agonist, phenylbiguanide (PBG), on the excitation of the trigeminal spinal nucleus oralis (TSNO) neurons to tooth-pulp (TP) stimulation was examined. The PBG application inhibited the TP-evoked TSNO neuronal excitation, and this inhibition was completely blocked by co-application of a GABAA receptor antagonist, bicuculline. The results suggest that the activation of 5-HT3 receptors elicits GABA release in the TSNO.
Oshima
Katsuo
K
General Dentistry of Univ. Hospital, The Nippon Dental University, School of Dentistry at Tokyo, 2-3-16, Fujimi, Chiyoda-ku, Tokyo 102-8158, Japan. oshima-k@tky.ndu.ac.jp
Takeda
Mamoru
M
Tanimoto
Takeshi
T
Katsuumi
Ichiroh
I
Matsumoto
Shigeji
S
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000818:Animals; D001640:Bicuculline / Q000494:pharmacology; D001645:Biguanides / Q000494:pharmacology; D003782:Dental Pulp / Q000294:innervation*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D018756:GABA Antagonists / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology; D007395:Interneurons / Q000187:drug effects / Q000502:physiology*; D007478:Iontophoresis / Q000379:methods; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D044406:Receptors, Serotonin, 5-HT3 / Q000502:physiology*; D012702:Serotonin Antagonists / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D014279:Trigeminal Nucleus, Spinal / Q000166:cytology*; D000077526:Tropisetron; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D001645:Biguanides; D018756:GABA Antagonists; D007211:Indoles; D044406:Receptors, Serotonin, 5-HT3; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; D005680:gamma-Aminobutyric Acid; D000077526:Tropisetron; C008846:phenyl biguanide; D001640:Bicuculline