NMDA-mediated potentiation of the afferent synapse in the inner ear.
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.
Soto
E
E
Instituto de Fisiología, Universidad Autónoma de Puebla, México.
Flores
A
A
Vega
R
R
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000557:Ambystoma; D000669:Amplifiers, Electronic; D000818:Animals; D016291:Dizocilpine Maleate / Q000494:pharmacology; D004594:Electrophysiology; D005998:Glycine / Q000494:pharmacology; D066298:In Vitro Techniques; D007736:Kynurenic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D016202:N-Methylaspartate / Q000037:antagonists & inhibitors / Q000502:physiology*; D009475:Neurons, Afferent / Q000187:drug effects / Q000502:physiology*; D010812:Physical Stimulation; D018009:Receptors, Glycine / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000502:physiology; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors; D013569:Synapses / Q000187:drug effects / Q000502:physiology*; D014722:Vestibule, Labyrinth / Q000187:drug effects / Q000294:innervation / Q000502:physiology*
D018009:Receptors, Glycine; D016194:Receptors, N-Methyl-D-Aspartate; D016202:N-Methylaspartate; D016291:Dizocilpine Maleate; D015763:2-Amino-5-phosphonovalerate; D007736:Kynurenic Acid; C057013:7-chlorokynurenic acid; D005998:Glycine