FIGURE 3.

Optogenetic manipulation of auditory cortical PV+ neurons. (A) Raster plot (top) and peri-stimulus time histogram (bottom) for a single unit showing significant positive modulation by optical stimulation in a PV-Cre^c57::Ai32^cba/ca mouse. Scale bars, 50 ms and 20 Hz. (B) Average waveform for the same single unit shown in panel (A). Shaded area represents the standard deviation. Inset shows the overlay of average waveform with (blue) and without (black) optical stimulation. R represents the correlation coefficient between the two average waveforms. Scale bars, 1 ms and 0.1 mV. (C) The proportion of narrow spiking (NS) and broad spiking (BS) cells within optically activated cells in C57 (blue) and hybrid (orange) animals. (D–F) Same as A–C, but for optically suppressed cells. (G,H) Scatter and kernel density plot of trough-to-peak during and 20% width of spike waveforms across single units in C57 (996 single units from 36 PV-Cre^c57::Ai32^c57) (G) and hybrid (759 single units from 21 PV-Cre^c57::Ai32^cba/ca) (H). Distributions of NS and BS cells were shown as a density plot (light blue, NS cells; light orange, BS cells), with each density level representing 10% of the population. Green, optically activated cells. Pink, optically suppressed cells. Distribution of each spike waveform measurement for each cell class was also estimated by using a kernel function analysis.