Figure 8. LSO principal neurons possess extrasynaptic δ‐GABA_ARs.

Aa, averaged current traces (n = 40) of a P4 and a P11 LSO neuron, evoked by GABA application (100 μM; 100 ms puffs for 2 min at 0.2 Hz). Black traces represent control conditions, and grey traces represent recordings after 15 min wash‐in of 10 μM GBZ. Ab, amplitude distribution of GABA‐evoked currents at P4 and P11. Ac, Sensitivity to GBZ at P4 and P11. Ba, current traces during puff application of the δ‐GABA_AR agonist THIP (1 μM), demonstrating a long‐lasting inward current that was partially blocked with GBZ. Significance levels were Šidák corrected in case of two comparisons. Bb, same cell as in Ba. The holding current (I _hold) was determined from Gaussian fits (dashed lines) to all‐point histograms (solid lines) of the different pharmacological conditions. Due to the high internal chloride concentration, both inhibitory and excitatory spontaneous synaptic current events are inward directed. To exclude those inward‐directed events, Gaussian fitting was done at the right side of the all‐point histograms. Bc, statistics of THIP‐evoked currents and sensitivity to GBZ (n = 10 cells). Asterisks above dashed line depict differences from control. Significance levels were Šidák corrected in case of two comparisons.