NMDA-mediated potentiation of the afferent synapse in the inner ear

Neuroreport. 1994 Oct 3;5(15):1963-5. doi: 10.1097/00001756-199410000-00031.

Abstract

In an isolated vestibular organ preparation from the axolotl (Ambystoma tigrinum), glycine (10-0.01 microM) perfusion had no effect in the resting control condition, but significantly modified the response of afferent fibres to mechanical stimuli, producing a slowly increasing discharge rate during sinusoidal mechanical stimulation periods. This action was dependent upon the stimulus duration and was antagonized by 7-chloro-kynurenic acid (7-ClKyn), 2-amino-5-phosphonopentanoic acid (AP5), N-allyl-nor-metazocina (MK-801) and extracellular magnesium. These results indicate that glycine modulates the afferent synapse in the vestibular organ, and that, NMDA receptors codify long lasting mechanical stimuli.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 2-Amino-5-phosphonovalerate / pharmacology
  • Ambystoma
  • Amplifiers, Electronic
  • Animals
  • Dizocilpine Maleate / pharmacology
  • Electrophysiology
  • Glycine / pharmacology
  • In Vitro Techniques
  • Kynurenic Acid / analogs & derivatives
  • Kynurenic Acid / pharmacology
  • N-Methylaspartate / antagonists & inhibitors
  • N-Methylaspartate / physiology*
  • Neurons, Afferent / drug effects
  • Neurons, Afferent / physiology*
  • Physical Stimulation
  • Receptors, Glycine / antagonists & inhibitors
  • Receptors, Glycine / drug effects
  • Receptors, Glycine / physiology
  • Receptors, N-Methyl-D-Aspartate / antagonists & inhibitors
  • Synapses / drug effects
  • Synapses / physiology*
  • Vestibule, Labyrinth / drug effects
  • Vestibule, Labyrinth / innervation
  • Vestibule, Labyrinth / physiology*

Substances

  • Receptors, Glycine
  • Receptors, N-Methyl-D-Aspartate
  • N-Methylaspartate
  • Dizocilpine Maleate
  • 2-Amino-5-phosphonovalerate
  • Kynurenic Acid
  • 7-chlorokynurenic acid
  • Glycine