Fig. 2.
Concentration-related responses of GABA on extrasynaptic δGABAA receptor–mediated tonic inhibition. (A) Representative whole-cell, voltage-clamp recordings of tonic current in DGGCs in response to GABA. After recording, gabazine was applied to measure total tonic shift. (B) GABA concentration-response curves for normalized tonic current shift (pA/pF) in WT and δKO DGGCs. (C) Percent tonic current contribution of δ-subunit–containing and non–δ-containing receptors relative to the 3 μM GABA response. Percentage values were determined from the mean values of WT and δKO cells in (B). GABA concentrations less than 10 μM did not elicit significant responses in δKO DGGCs, thereby denoting majority tonic current contribution by δ-containing GABAA receptors. Recordings in whole-cell mode, voltage clamped at −65 mV. n = 6–10 cells per group and concentration. * p < 0.05.