The activation of 5-HT(3) receptors evokes GABA release in the spinal cord

Brain Res. 2003 Jul 18;978(1-2):250-5. doi: 10.1016/s0006-8993(03)02952-4.

Abstract

We carried out experiments using a microdialysis method to determine whether activation of 5-HT(3) receptors increases the concentration of GABA in the dorsal horn of the spinal cord. Intrathecal perfusion of a selective 5-HT(3) receptor agonist, 1-phenylbiguanide (0.3, 1.0, and 3.0 mM) dose-dependently, increased GABA concentration, while concentrations of glutamate and glycine were not changed. The concentration of aspartate was increased only by 3.0 mM of 1-phenylbiguanide. Our results have provided direct evidence that activation of 5-HT(3) receptors evokes GABA release in the spinal dorsal horn, possibly producing analgesia.

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • Aspartic Acid / metabolism
  • Biguanides / pharmacology
  • Dose-Response Relationship, Drug
  • Glutamic Acid / metabolism
  • Glycine / metabolism
  • Male
  • Microdialysis / methods
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Serotonin / metabolism*
  • Receptors, Serotonin, 5-HT3
  • Serotonin Receptor Agonists / pharmacology*
  • Spinal Cord / anatomy & histology
  • Spinal Cord / chemistry
  • Spinal Cord / drug effects
  • Spinal Cord / metabolism*
  • Time Factors
  • gamma-Aminobutyric Acid / metabolism*

Substances

  • Biguanides
  • Receptors, Serotonin
  • Receptors, Serotonin, 5-HT3
  • Serotonin Receptor Agonists
  • Aspartic Acid
  • Glutamic Acid
  • gamma-Aminobutyric Acid
  • Glycine
  • phenyl biguanide