A1 adenosine receptors inhibit multiple voltage-gated Ca2+ channel subtypes in acutely isolated rat basolateral amygdala neurons

Brian A. McCool, Jeffery S. Farroni

Research output: Contribution to journalArticle

17 Scopus citations

Abstract

1. The anticonvulsant properties of 2-chloroadenosine (CADO) in the basolateral amygdala rely on the activation of adenosine-specific heptahelical receptors. We have utilized whole-cell voltage-clamp electrophysiology to examine the modulatory effects of CADO and other adenosine receptor agonists on voltage-gated calcium channels in dissociated basolateral amygdala neurons. 2. CADO, adenosine, and the A1 subtype-selective agonists N6-(L-2-Phenylisopropyl)adenosine (R-PIA) and 2-chloro-N6-cyclopentyladenosine (CCPA) reversibly modulated whole cell Ba2+ currents in a concentration-dependent fashion. CADO inhibition of barium currents was also sensitive to the A1 antagonist 1,3-dipropyl-8-cyclopentylxanthine (DPCPX). 3. The A2A-selective agonist 4-[2-[[6-Amino-9-(N-ethyl-β-D-ribofuranuronamidosyl)-9H-purin-2-yl] amino]ethyl]benzenepropanoic acid (CGS21680) was without effect. 4. CADO inhibition was predominantly voltage-dependent and sensitive to the sulphydryl-modifying reagent N-ethylmaleimide, implicating a membrane-delimited. Gi/o-coupled signal transduction pathway in the channel regulation. 5. Using Ca2+ channel subtype-selective antagonists. CADO inhibition appeared to target multiple channel subtypes, with the inhibition of ω-conotoxin GVIA-sensitive calcium channels being more prominent. 6. Our results indicate that the anti-convulsant effects CADO in the basolateral amygdala may be mediated, in part, by the A1 receptor-dependent inhibition of voltage gated calcium channels.

Original languageEnglish (US)
Pages (from-to)879-888
Number of pages10
JournalBritish Journal of Pharmacology
Volume132
Issue number4
DOIs
StatePublished - Jan 1 2001
Externally publishedYes

Keywords

  • Basolateral amygdala
  • Calcium channel
  • N-ethylmaleimide
  • Nifedipine
  • ω-agatoxin IVA
  • ω-conotoxin GVIA

ASJC Scopus subject areas

  • Pharmacology

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