Figure 2. Comparison of the duration of the active state under normal conditions (control) and a condition when GABA_A receptors were blocked by the application of bicuculline in an isolated cortical slab in vivo.

Two segments of 8 LFP recordings are displayed (6 in a cortical slab, 2 in the intact cortex) in A (control conditions) and B (after the application of bicuculline). Compared to controls, active state was much shorter when inhibition was blocked. C, mean (bar) and standard deviation (line) of the duration of the active state (left panel) and silent state (right panel) in the control conditions (open bars) and in the presence of bicuculline (filled bars) are shown. After inhibition was blocked by the application of bicuculline, both the active and silent states became shorter (P value <0.0001). Interstate interval was also significantly reduced in the presence of bicuculline (P value = 0.0064) (both statistics from an unpaired t test with Welch's correction).