FIGURE 2.

Summary of ruthenium-bipyridine-triphenylphosphine–γ-aminobutyric acid (RG) effect on (A) spikes, (B) interictal bursts, and (C) baseline standard deviation (SD). The black bars represent the values of the parameters in the 4.5 seconds immediately preceding illumination, and the gray bars represent the values of the same parameters in the 4.5 seconds during illumination, allowing a 0.5-second window for illumination electrical artifact. Illumination (light-emitting diode [LED] current 200mA) had no effect on any of the 3 parameters in the absence of RG. However, in the presence of 10µm RG, 5 seconds of illumination (current 200mA) significantly reduced all 3 parameters (p < 0.01, paired t test). When the LED current was reduced to 100mA, the spikes and bursts were still diminished (p < 0.01, paired t test), but baseline SD was not significantly reduced (p > 0.05). At 3µM RuBi-GABA, spikes, bursts, and baseline SD were reduced, but not significantly (p > 0.05). In the presence of 10µm RG plus picrotoxin (PTX; 100µm), 5 seconds of illumination no longer reduced any of the 3 parameters (p > 0.05, paired t test or Wilcoxin signed rank) (a, p > 0.05; b, p < 0.01).