Membrane and Cellular Biophysics and BiochemistryActivation kinetics and single channel properties of recombinant α1δ2γ2L GABAA receptor channelsJahn, Klaus1,5; Hertle, Iris2; Bufler, Johannes1; Adelsberger, Helmuth3; Pestel, Elmar4; Zieglgänsberger, Walter4; Dudel, Josef3; Franke, Christian1Author Information 1Departments of Neurology, Technical University Munich, Möhlstr. 28, 81675 Munich 2Anesthesiology, Technical University Munich, Möhlstr. 28, 81675 Munich 3Physiology, Technical University Munich, Möhlstr. 28, 81675 Munich 4Max-PlanckInstitute for Psychiatry, Munich, Germany 5Corresponding Author: Klaus Jahn Received 20 August 1997; accepted 28 August 1997 NeuroReport: November 10th, 1997 - Volume 8 - Issue 16 - p 3443-3446 Buy Abstract RECOMBINANT α1δ2α2L GABAA receptor channels, transiently expressed in HEK 293 cells, were investigated using the patch-clamp technique in combination with a device for ultra-fast solution exchange. The dose–response relationship revealed an EC50 of 11.6 ± 0.9 μM and saturated with 3 mM GABA. The slope between 0.001 and 0.01 mM GABA was 2.2 ± 0.4, indicating at least three binding sites for GABA. The rise time decreased from about 120 ms at 0.001 mM GABA to about 0.8 ms at 10 mM GABA. Single channel openings were grouped in bursts with an average duration of 10.3 ± 3.0 ms. More than 95% of the current was represented by a single channel slope conductance of about 29 pS. © Lippincott-Raven Publishers.