Demonstration of Cl^–-channel functions of cell-derived GABA receptors in the membrane-sandwich sensor set-up.

OWLS recordings were made in Cl^–-free ACSF as running buffer with injection of Cl^–-containing ACSF (ACSF) with or without GABA and the channel blocker bicuculline (ACSF+GABA and ACSF+GABA+Bic, respectively). (A) Changes of the effective refractive index (NTM) values in a representative OWLS assay. (B) Changes in the refractive index (n_cTM) in response to the GABA-channel blocker bicuculline are shown from a representative experiment. (C) Summary of refractive index (nc_TM) changes (Δnc_TM) in response to transfusion with Cl^–-containing buffer (ACSF), in the presence of the agonist GABA (ACSF+GABA) or in the presence of both GABA and the channel-blocker bicucullin (ACSF+GABA+bicucullin). Δnc_TM values were calculated from data of 4 independent series of experiments (n≥4); averages and standard deviations are presented.