Tooth-pulp-evoked rostral spinal trigeminal neuronal excitation is attenuated by the activation of 5-HT3 receptors via GABAergic interneurons in the rat

Brain Res. 2006 Sep 13;1109(1):70-3. doi: 10.1016/j.brainres.2006.06.036. Epub 2006 Jul 11.

Abstract

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.

Publication types

  • Comparative Study

MeSH terms

  • Action Potentials / drug effects
  • Action Potentials / physiology
  • Animals
  • Bicuculline / pharmacology
  • Biguanides / pharmacology
  • Dental Pulp / innervation*
  • Dose-Response Relationship, Drug
  • Drug Interactions
  • GABA Antagonists / pharmacology
  • Indoles / pharmacology
  • Interneurons / drug effects
  • Interneurons / physiology*
  • Iontophoresis / methods
  • Male
  • Rats
  • Rats, Wistar
  • Receptors, Serotonin, 5-HT3 / physiology*
  • Serotonin Antagonists / pharmacology
  • Serotonin Receptor Agonists / pharmacology
  • Trigeminal Nucleus, Spinal / cytology*
  • Tropisetron
  • gamma-Aminobutyric Acid / metabolism*

Substances

  • Biguanides
  • GABA Antagonists
  • Indoles
  • Receptors, Serotonin, 5-HT3
  • Serotonin Antagonists
  • Serotonin Receptor Agonists
  • gamma-Aminobutyric Acid
  • Tropisetron
  • phenyl biguanide
  • Bicuculline