Non-NMDA glutamatergic excitatory transmission in the descending limb of the spinobulbospinal micturition reflex pathway of the rat

Brain Res. 1995 Sep 25;693(1-2):246-50. doi: 10.1016/0006-8993(95)00738-c.

Abstract

I.v. administration of GYKI-52466, a non-competitive AMPA/kainate glutamatergic receptor antagonist, inhibited bladder contractions elicited by electrical stimulation in the pontine micturition center (PMC) in urethane-anesthetized rats. The mean threshold dose of GYKI-52466 was 2 mg/kg i.v. (range = 1-4 mg/kg). Maximum inhibition (mean = 57.7 +/- 8.2%, range = 24-83.3% of control) occurred at a dose of 8 mg/kg. CNQX, a competitive AMPA/kainate glutamatergic receptor antagonist, did not significantly alter the evoked contractions. These results indicate that AMPA/kainate receptors are involved in bulbospinal excitatory pathway from the PMC to the parasympathetic nucleus in the lumbosacral spinal cord in the rat.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Anti-Anxiety Agents*
  • Benzodiazepines / pharmacology
  • Dizocilpine Maleate / pharmacology
  • Dose-Response Relationship, Drug
  • Excitatory Amino Acid Antagonists / pharmacology
  • Female
  • Injections, Intravenous
  • Neural Pathways / physiology
  • Parasympathetic Nervous System / cytology
  • Parasympathetic Nervous System / physiology
  • Pons / physiology*
  • Rats
  • Rats, Wistar
  • Receptors, AMPA / physiology*
  • Receptors, Kainic Acid / physiology*
  • Receptors, N-Methyl-D-Aspartate / physiology
  • Spinal Cord / physiology*
  • Synaptic Transmission / physiology
  • Time Factors
  • Urinary Bladder / drug effects
  • Urinary Bladder / innervation
  • Urination / physiology*

Substances

  • Anti-Anxiety Agents
  • Excitatory Amino Acid Antagonists
  • Receptors, AMPA
  • Receptors, Kainic Acid
  • Receptors, N-Methyl-D-Aspartate
  • GYKI 52466
  • Benzodiazepines
  • Dizocilpine Maleate