Figure 5.
Spiking activity of VIP interneurons and SST interneurons in superficial layers of S1 during active whisking. (a) Image of an eGFP-positive and tdTomato-positive cell targeted for cell-attached in vivo recording in a Vip-cre tdTomato 5HT3aReGFP mouse. Arrow points to an eGFP-positive, tdTomato-negative interneuron (non-VIP interneuron) and the arrowhead points to an eGFP-positive, tdTomato-positive interneuron (VIP interneuron). Scale bars represent 50 μm. (b–d) Example recordings from a 5HT3aR-positive, VIP-positive interneuron (b), a 5HT3aR-positive, VIP-negative interneuron (c), and a SST interneuron (d). Whisking motion was computed from whisker video recordings to define whisking and non-whisking periods (top). Bottom, spikes in the corresponding interneuron type recorded under two-photon guidance in loose-patch configuration. (e–g) Spiking activity of VIP interneurons and SST interneurons in superficial layers of S1 during active whisking. Whisking onset triggered raster plots of representative VIP (e), non-VIP, 5HT3aR (f) and SST (g) interneurons. Bottom, population PSTHs of VIP, non-VIP, 5HT3aR and SST interneurons. Dotted vertical line at time 0 indicates whisking onset. Dark lines indicate smoothed PSTHs. (h) Firing rates of VIP (open circles, 11 cells, 5 mice), non-VIP (gray circles, 5 cells, 3 mice) and SST (black circles, 6 cells, 2 mice) interneurons during whisking plotted against their firing rates during non-whisking periods. Dashed line indicates unity. (i) Firing rates of VIP, non-VIP and SST interneurons during whisking (W) normalized to the firing rates during non-whisking (NW) periods. Each line indicates an individual neuron (VIP interneurons, P = 0.001; non-VIP interneurons, P = 0.94; SST interneurons, P = 0.02). *P < 0.05, **P < 0.005, Wilcoxon signed-rank test. (j) Summary of recording depths of VIP (open circle), non-VIP (gray) and SST (black) interneurons.