Fig. 1: Synchronous population events in the auditory cortex in wakefulness and anesthesia.
From: Awake perception is associated with dedicated neuronal assemblies in the cerebral cortex
a, Two-photon Ca2+ imaging at a 30-Hz sampling rate of up to 1,200 layer 2/3 neurons expressing GCaMP6s in the awake head-fixed mouse. Upper: imaging field of view with labeled neurons in the awake state showing the s.d. of fluorescence pixels over a 15-min sound stimulation session flanked by two 10-min-long stimulation-free periods. Scale bar, 100 μm. b, The same recording protocol and field of view as in a, but under light isoflurane anesthesia (1.3%). Most neurons are visible in both conditions, demonstrating full stability of the field of view. Weaker or absent labeling in anesthesia reflects neurons that have decreased their activity. Arrows indicate sample neurons. Scale bar, 100 μm. Bottom right: spike time estimates (red) were extracted from calcium fluorescence traces (black) using the MLSpike algorithm. c, Population raster plots and population firing rate (30-ms bins) during no stimulation (left) and stimulation (right) periods. Vertical transparent bars highlight spontaneous (blue) and evoked (pink) population events detected as described in Extended Data Fig. 1d. d, Same as in c but for anesthesia. e, The size of ongoing population events slightly increases under anesthesia (P = 0.036, n = 11 for awake and n = 6 for anesthesia, P = 0.18 for evoked events' Wilcoxon’s rank-sum test). In the box-and-whisker plots, the red mark indicates the median and the bottom and top edges of the box indicate the 25th and 75th percentiles, respectively. The whiskers extend to the extreme data points. f, Probability of sounds evoking population events in the awake state (green trace) and under anesthesia (black trace). The shaded areas indicate the s.d. around the mean. Most of the complex sounds significantly decrease their ability to drive population events (P < 0.05) when passing from wakefulness to anesthesia (Wilcoxon’s rank-sum test for e and f). AM, amplitude modulated; Spont., spontaneous; *P < 0.05; NS, not significant. All tests are two sided.
