Figure 11.

Representative spiking activity across more than 1250 channels of the probe shank, spanning approximately 7.5 mm of brain tissue. The raw data is shown. The spike-map was constructed from 1 second of data recorded in AP mode; the time series of each channel’s data is plotted as a horizontal line using brightness to encode the absolute amplitude, with darker areas being an indication of neural spiking activity. Ketamine/xylazine anesthesia induces slow wave activity (with a peak frequency of 1–1.5 Hz) or delta rhythm (1.5–4 Hz) in the neocortex and thalamus, which can be observed as a rhythmic alternation of high and low spiking activity. Notes: the first ~90 channels are not displayed as they were outside of the brain and only recorded noise; the picture requires one line per channel (~1250), therefore resolution of the provided image was scaled down. Occasionally neurons near the reference electrode may spike, causing a line to be displayed on all channels using that specific local reference. Such artefacts can be eliminated during offline processing.