Immunocytochemical and pharmacological characterization of metabotropic glutamate receptors of the vestibular end organs in the frog.

Détails

ID Serval
serval:BIB_51150EFC8E9B
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Immunocytochemical and pharmacological characterization of metabotropic glutamate receptors of the vestibular end organs in the frog.
Périodique
Hearing research
Auteur(s)
Andrianov G.N., Puyal J., Raymond J., Ventéo S., Demêmes D., Ryzhova I.V.
ISSN
0378-5955
Statut éditorial
Publié
Date de publication
2005
Peer-reviewed
Oui
Volume
204
Numéro
1-2
Pages
200-209
Langue
anglais
Résumé
Using immunocytochemistry and multiunit recording of afferent activity of the whole vestibular nerve, we investigated the role of metabotropic glutamate receptors (mGluR) in the afferent neurotransmission in the frog semicircular canals (SCC). Group I (mGluR1alpha) and group II (mGluR2/3) mGluR immunoreactivities were distributed to the vestibular ganglion neurons, and this can be attributed to a postsynaptic locus of metabotropic regulation of rapid excitatory transmission. The effects of group I/II mGluR agonist (1S,3R)-1-aminocyclopentane-trans-1,3-dicarboxylic acid (ACPD) and antagonist (R,S)-alpha-methyl-4-carboxyphenylglycine (MCPG) on resting and chemically induced afferent activity were studied. ACPD (10-100 microM) enhanced the resting discharge frequency. MCPG (5-100 microM) led to a concentration-dependent decrease of both resting activity and ACPD-induced responses. If the discharge frequency had previously been restored by L-glutamate (L-Glu) in high-Mg2+ solution, ACPD elicited a transient increase in the firing rate in the afferent nerve suggesting that ACPD acts on postsynaptic receptors. The L-Glu agonists, alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) and N-methyl-D-aspartate (NMDA), were tested during application of ACPD. AMPA- and NMDA-induced responses were higher in the presence than absence of ACPD, implicating mGluR in the modulation of ionotropic glutamate receptors. These results indicate that activation of mGluR potentiates AMPA and NMDA responses through a postsynaptic interaction. We conclude that ACPD may exert modulating postsynaptic effects on vestibular afferents and that this process is activity-dependent.
Mots-clé
Animals, Blotting, Western, Brain/metabolism, Cycloleucine/analogs & derivatives, Cycloleucine/pharmacology, Electrophysiology, Glutamic Acid/metabolism, Glycine/analogs & derivatives, Glycine/pharmacology, Hair Cells, Auditory/drug effects, Hair Cells, Auditory/metabolism, Immunohistochemistry, Neurons, Afferent/drug effects, Neurons, Afferent/metabolism, Neuroprotective Agents/pharmacology, Neurotransmitter Agents/metabolism, Rana temporaria, Rats, Receptors, Metabotropic Glutamate/drug effects, Receptors, Metabotropic Glutamate/immunology, Semicircular Canals/innervation, Semicircular Canals/metabolism, Vestibular Nerve/metabolism
Pubmed
Web of science
Création de la notice
17/09/2009 11:45
Dernière modification de la notice
03/03/2018 17:10
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