A Reinforcing Circuit Action of Extrasynaptic GABAA Receptor Modulators on Cerebellar Granule Cell Inhibition
Figure 6
Neurosteroids induce parallel increases in granule cell sIPSC frequency and tonic GABA currents.
A. Voltage clamp recordings from granule cells illustrate the relatively low frequency of synaptic events in granule cells recorded in control conditions (upper trace) and the increase in the number of synaptic events following perfusion of 10 nM THDOC (lower trace). B-C. Plots show the effect of THDOC (10 nM) on the frequency of sIPSCs (B) and amplitude of tonic GABA current (C) recorded in the same cells. Individual data points are represented by open circles connected by dotted lines. Synaptic events were completely abolished in 10 µM gabazine. Amplitude of tonic GABA currents was measured as the baseline current blocked by 10 µM gabazine. * indicates p<0.05 by paired t-test, D-E. Histogram demonstrates the lack of THDOC (10 nM) modulation of granule cell sIPSC amplitude (B) and weighted τdecay (D).