Figure 3. Multi-electrode array (MEA) recordings show that optogenetic stimulation restores spiking activity in cultures treated with CNQX.
(A) Spontaneously occurring bursts of spiking are identified (synchronous spikes/red dots). Expanded version of raster plot highlighting two bursts is shown below. (B) Same as in A, but after CNQX was added to the bath and bursts were now triggered by optogenetic stimulation (blue line shows duration of optogenetic stimulation). (C) Average burst rate is compared for CNQX-treated cultures with optogenetic stimulation (n=5 cultures) and control unstimulated cultures (n=3 cultures) at 1 hr, 3 hr, 6 hr (p=0.056), and 24 hr (p=0.379) after addition of CNQX or vehicle (same control data presented in Figure 1). (D) Average overall spike frequency is compared for CNQX-treated cultures with optogenetic stimulation and control unstimulated cultures at 1 hr (p=0.612), 3 hr (p=0.489), 6 hr (p=0.449), and 24 hr (p=0.22) after addition of CNQX or vehicle. Control data is same as presented in Figure 1. The mean differences at different time points are compared to control and displayed in Cumming estimation plots. Significant differences denoted by *p≤0.05, ***p≤0.001. Recordings from single cultures (filled circles), where mean values (represented by the gap in the vertical bar) and SD (vertical bars) are plotted on the upper panels. Mean differences between control and treated groups are plotted on the bottom panel, as a bootstrap sampling distribution (mean difference is represented by a filled circles and the 95% CIs are depicted by vertical error bars).
Figure 3—figure supplement 1. Multi-electrode array (MEA) recordings show optostim + CNQX increases burst frequency and spike frequency compared to CNQX alone.
