Fig. 4: Purinergic signaling is involved in the microglia-node wrapping contact following axonal injury.
From: In vivo imaging in mouse spinal cord reveals that microglia prevent degeneration of injured axons
a Heatmap showing microglia-node contacts from 0.5 h before to 1 hpi in the PSB0739 group. The blank and black areas indicate that time-lapse imaging is stopped during laser injury and resumed 5 min later. A total of 21 nodes from 11 mice were recorded. b Time-lapse images showing the microglia-axon interactions after injury. Blue arrowheads indicate no microglial contact at NR. Insets, overlay of SRS (blue) and YFP images (orange). White arrowheads indicate the NR. c Contingency table of the number of axon with/without microglial wrapping contact after axotomy in the control (Ctrl), PSB0739 and NPPB groups within 1 hpi. Two-sided Chi-square test, P < 0.0001 for the whole distribution. d Distance between the proximal ends and NR of injured axons after injury in the PSB0739 group. A total of 12 nodes from 6 mice were recorded. Green and black curves represent axons with and without wrapping contact following axotomy, respectively. e Plot of degeneration length before 6 hpi in the Ctrl, PSB0739 and NPPB groups. Ctrl: 13 axons from 9 mice at 4-6 hpi, PSB0739: 9 axons from 6 mice at 1-4 hpi, NPPB: 9 axons from 4 mice at 1-3 hpi. Data were present as mean ± SD. One-way ANOVA with Dunnett’s multiple comparisons test. f Heatmap showing microglia-node contacts from 5 min before to 1 hpi in the NPPB group. The blank and black areas indicates that time-lapse imaging is stopped during laser injury and resumed 5 min later. A total of 9 nodes from 4 mice were recorded. g Time-lapse images showing the microglia-axon interactions after injury. Insets, overlay of SRS (blue) and YFP images (orange). White arrowheads indicate the NR. h Distance between the proximal ends and NR of injured axons before 3 hpi in the NPPB group. Green and black curves represent axons with and without wrapping contact following axotomy, respectively. Time post injury is presented as hr:min in (b, g). Scale bars, 20 μm in (b, g); 10 μm for all the insets. Source data are provided as a Source Data file.
