Fig. 6.

Early ION cutting disrupts patterns of spontaneous activity. a In vivo calcium imaging of the large-barrel field of the somatosensory cortex L4 of a normal TCA-GCaMP Tg mouse at P5, which expresses GCaMP6s in TCAs. TCA termini demonstrated “patchwork”-type spontaneous activity³⁹, in which each “activated zone” corresponds to a single barrel. Representative images of activated zones at three time points and the merged image with pseudo color (top) and traces of boundaries for activated zones (bottom). See also Supplementary Movie 1. b A heat map of activated-zone boundaries in all activated events in 15 min. c Positions of circular regions of interests (ROIs). In most cases, ROIs were numbered according to the principal component analysis (PCA) scores of the correlations of the fluorescence changes. In a few ROIs (9–18), the original orders based on the PCA scores were manually rearranged to show individual barrels clearly (e). Color shades represent the positions of individual activated zones (i.e., barrels). d (Left) Representative fluorescence signals. (Right) Orange vertical lines in the raster plots (ΔF/F > 50%) demonstrate synchronized activities among ROIs, which were confined to individual barrels. e Correlation matrix constructed from the fluorescence changes of all ROI pairs. f In vivo calcium imaging of the large-barrel field of the somatosensory cortex L4 of a TCA-GCaMP Tg mouse at P5 in which ION was cut at P0 (Early-ION-cut mouse). TCA termini demonstrated spontaneous activity that lacked the patchwork pattern. Individual activated zones are largely overlapped. Representative images of activated zones at three time points and the merged image with pseudo color (top) and traces of boundaries for activated zones (bottom) are shown (see also Supplementary Movie 2). g Heat maps of activated-zone boundaries in all firing events observed in 15 min. h Positions of ROIs in the Early-ION-cut mouse. All ROIs were numbered according to the PCA scores of the correlations of the fluorescence changes. i Representative fluorescence signals and raster plots (ΔF/F > 50%). Orange vertical lines: synchronized activities among ROIs. Note that there were no specific clusters of ROIs. j Correlation matrices constructed from the fluorescence changes of all ROI pairs in the Early-ION-cut mouse. Scale bars: 150 µm