Membrane channels activated by taurine in cultured mouse spinal cord neurons.
Patch-clamp methods were used to compare biophysical properties of anion channels activated by taurine and gamma-aminobutyric acid in the membrane of cultured mouse spinal neurons. Outside-out patches were voltage clamped at -80 mV at a temperature of 21-23 degrees C. Bath application of GABA (1.5-2 microM) or taurine (5-40 microM) induced chloride-dependent single-channel currents in 14/20 patches tested. Amplitude distributions of these currents showed peaks corresponding to conductance levels of 8, 16, 27 and 46 pS. Only a few percent of GABA-induced events reached the 46 pS level, while 30% of taurine-induced currents were of this size. The average lifetime of taurine-activated channels in the open state was 1.0 +/- 0.07 ms, significantly shorter than the corresponding value for GABA (1.6 +/- 0.08 ms). Taurine-induced currents were abolished by 10 microM strychnine, but persisted in the presence of 50 microM bicuculline.
Mathers
D A
DA
Department of Physiology, Faculty of Medicine, University of British Columbia, Vancouver, Canada.
Grewal
A
A
Wang
Y H
YH
D000818:Animals; D002478:Cells, Cultured; D002712:Chlorides / Q000502:physiology; D007473:Ion Channels / Q000187:drug effects / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D013116:Spinal Cord / Q000187:drug effects / Q000502:physiology*; D013654:Taurine / Q000494:pharmacology*; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
D002712:Chlorides; D007473:Ion Channels; D013654:Taurine; D005680:gamma-Aminobutyric Acid