Figure 6.

Timing of spiking relative to UP states. (A) Average spikes per trial per cell across all on-cell recordings. Across all on-cell experiments, almost all spikes in all layers were fired during UP states. Error bars represent standard error of the mean. Total spike count includes early and UP state spikes as well as additional spikes that did not fit either category (for example, spikes occurring after an UP state, or spikes occurring at long latency in the absence of a detected UP state). (B) Cumulative mean first-spike latency distributions relative to stimulus onset show no significant differences between layers 2/3, 4, and 5. The mean first spike latency for each cell was determined by averaging the latency to the earliest spike across trials. Layer 6 is omitted from this figure due to the relatively low number of cells recorded in layer 6. Dotted line, Layer 2/3; Dashed line, Layer 4; Solid line, Layer 5. (C) Cumulative mean first-spike latency distributions relative to UP state onset similarly show no significant differences between layers. (D) Spike latencies relative to UP states in MUA from multichannel recordings show that layer 5 is active before the other layers during UP states.