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.
Instituto de Fisiología, Universidad Autónoma de Puebla, México.
E
E
Soto
A
A
Flores
R
R
Vega
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