Adenosine modulates a voltage-dependent chloride conductance in cultured hippocampal neurons.
Whole cell currents were recorded in cultured rat hippocampal neurons using the patch-clamp method. When the cells were held near the resting membrane potential (-60 mV) the application of adenosine (1 microM) or the adenosine analogues 2CA (100 nM) and R-PIA (40 nM) induced a steady-state inward current. This response was unchanged when extra- and intracellular media were used, in which Na+ and K+ were substituted by impermeable ions in equimolar concentrations. In contrast the current was affected by lowering the extracellular Cl- concentration and thus Cl- was considered to be the ionic carrier. Additionally an almost complete block of the current was observed after applications of DIDS (50 microM), a putative Cl- channel blocker. The modulated current was voltage-dependent and was slowly activated by hyperpolarizing voltage steps. The adenosine action was theophylline- and pertussis toxin-sensitive indicating that the modulatory effect is mediated via an A1 receptor coupled to a G protein of the Gi or Go class.
Mager
R
R
Max Planck Institute for Psychiatry, Department of Neuromorphology, Martinsried, F.R.G.
Ferroni
S
S
Schubert
P
P
D015762:2-Chloroadenosine / Q000494:pharmacology; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000241:Adenosine / Q000502:physiology*; D000818:Animals; D002478:Cells, Cultured; D018118:Chloride Channels; D002712:Chlorides / Q000502:physiology*; D004553:Electric Conductivity / Q000187:drug effects / Q000502:physiology; D006624:Hippocampus / Q000187:drug effects / Q000196:embryology / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D008565:Membrane Proteins / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D010660:Phenylisopropyladenosine / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
D018118:Chloride Channels; D002712:Chlorides; D008565:Membrane Proteins; D015762:2-Chloroadenosine; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid; D010660:Phenylisopropyladenosine; D000241:Adenosine; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid