Fig. 5: Regulation of microglia-node interaction by neuronal voltage-gated sodium channels in physiological and pathological conditions.

a Illustration of the experimental design. b Representative images of microglia (green) and axons (orange) before and 40 min after electrical stimulation. Scale bar: 20 μm. c Heatmap showing microglia-node contacts during 1-h time-lapse imaging before and after electrical stimulation. The blank area indicates the time interval for stimulation. Images were taken every 5 min. A total of 37 nodes from 3 mice were recorded. d The percentage of contacted NR by microglia in the 37 recorded nodes before and after electrical stimulation. The gray vertical dashed line indicates the start point of electrical stimulation. The purple and red dashed line indicate the mean percentage value of contacted NR before (~57%) and after (~66%) stimulation, respectively. e Time-lapse images at indicated time points showing the microglia-axon dynamics and interactions in response to axonal injury in the TTX treatment group. Scale bar, 20 μm. Insets, overlay of SRS (blue) and YFP image (orange). White arrowheads indicate the NR. Scale bar, 10 μm. The axon did not degenerate out of node within 48 hpi. Time post injury is presented as hr: min. f Heatmap showing microglia-node contacts from 5 min before to 1 hpi in the TTX group. The blank and black areas indicates that time-lapse imaging is stopped during laser injury and resumed 5 min later. A total of 16 nodes from 8 mice were recorded. g Distance between the proximal ends and NR of injured axons at the indicated time points after injury in the TTX group. Green and black curves represent the axon with and without wrapping contact following axotomy, respectively. A total of 14 nodes from 8 mice were recorded. Figure (a) created using BioRender (https://biorender.com/). Source data are provided as a Source Data file.