Activation of metabotropic glutamate receptors inhibits synapsin I phosphorylation in visceral sensory neurons

M. Hay, C. J. Hoang, E. M. Hasser, E. M. Price

Research output: Contribution to journalArticle

12 Scopus citations

Abstract

Activation of glutamate metabotropic receptors (mGluRs) in nodose ganglia neurons has previously been shown to inhibit voltage-gated Ca++ currents and synaptic vesicle exocytosis. The present study describes the effects of mGluRs on depolarization-induced phosphorylation of the synaptic-vesicle-associated protein synapsin I. Depolarization of cultured nodose ganglia neurons with 60 mM KCl resulted in an increase in synapsin I phosphorylation. Application of mGluR agonists 1-aminocyclopentane-1s-3r-dicarboxylic acid (t-ACPD) and L(+)-2-Amino-4-phosphonobutyric acid (L-AP4) either in combination or independently inhibited the depolarization induced phosphorylation of synapsin I. Application of the mGluR antagonist (RS)-α-Methyl-4-carboxyphenylglycine (MCPG) blocked t-ACPD-induced inhibition of synapsin phosphorylation but not the effects of L-AP4. In addition, application of either t-ACPD or L-AP4 in the absence of KCl induced depolarization had no effect on resting synapsin I phosphorylation. RT-PCR analysis of mGluR subtypes in these nodose ganglia neurons revealed that these cells only express group III mGluR subtypes 7 and 8. These results suggest that activation of mGluRs modulates depolarization-induced synapsin I phosphorylation via activation of mGluR7 and/or mGluR8 and that this process may be involved in mGluR inhibition of synaptic vesicle exocytosis in visceral sensory neurons of thenodose ganglia.

Original languageEnglish (US)
Pages (from-to)195-204
Number of pages10
JournalJournal of Membrane Biology
Volume178
Issue number3
DOIs
StatePublished - Dec 1 2000
Externally publishedYes

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Keywords

  • Baroreceptors
  • Nodose ganglia
  • Synapsin
  • Synaptic proteins
  • Synaptic transmission
  • mGluRs

ASJC Scopus subject areas

  • Biophysics
  • Physiology
  • Cell Biology

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