Figure 1|. Anesthesia enhances microglial surveillance of the parenchyma.

(a) Individual microglia from awake and anesthetized mice. (b) Sholl profile of microglia in awake (black and anesthetized (blue) mice; note reduced arborization in awake mice (n=16 mice, 3–5 microglia per mouse). (c) Microglia have a greater area under the curve (AUC) in anesthetized vs. awake mice (n=16 mice, two-sided paired t-test, p=8.9×10⁻⁵, t(15)=5.30). (d) Microglia have a greater number of maximum intersections in anesthetized mice (n=16 mice, two-sided paired t-test, p=0.00051, t(15)=4.40). (e) 2D max-projection of microglial processes at the first time point (t=0) and over one hour of imaging (t=0–55) to quantify process surveillance. (f) Microglia in anesthetized animals cover more of the CNS parenchyma (n=16 mice, two-sided paired t-test, p=8.2×10⁻⁶, t(15)=6.62). (g) Microglia in an awake or anesthetized mouse surrounding a focal laser ablation injury at t=0 and t=55 minutes post-ablation. (h) Graph of microglial process recruitment from 10 minutes post-injury to 55 minutes post-injury (velocity magnitude of responding vectors/total ROI pixels; n=8 mice). (i) Response AUC of microglial process recruitment from 10–55min post-injury (n=8 mice, two-sided paired t-test, P=0.025, t(7)=2.84). (j) Microglia trend towards a greater maximum magnitude of injury response in anesthetized conditions (n=8 mice, two-sided paired t-test, p=0.077, t(7)=2.08). (k) Example local field potential (LFP) traces in anesthetized and awake conditions. (l) Normalized delta-power from LFP recordings demonstrating decreased delta-power (~54%) in the awake state relative to the anesthetized state (n=3 mice). Scale bars = 20μm. Graphs show mean±SEM; *p<0.05, **p<0.01, ***p<0.005, ****p<0.0001. Points represent individual animals. See Supplementary Table 1 for the number of females and males used in these experiments.