Fig 1: Multihistopathological findings and altered circulating immunological features of CIRI mice. A) Representative images from laser speckle contrast imaging (LSCI). B) Quantification of perfusion volumes on the ischemic vs non‐ischemic sides using LSCI (n = 10 per group). C) Neurological Deficit Score for each group (n = 10 per group). D) Flow cytometry analysis of Ly6g expression in peripheral blood cells. E) Flow cytometry analysis of Tspan4 expression in peripheral blood cells. F) Quantification of Ly6g+, Tspan4+, and double‐positive Ly6g+Tspan4+ cells by flow cytometry. Samples from five animals per group. Fluorescent channels used: Tspan4 (PE), Ly6g (PerCP). G) Dragonfly microscope images showing migrasomes in peripheral blood. Scale bar: 2 µm. The non‐exposure of phosphatidylserine on the migrasomal surface was confirmed by the absence of Apotracker staining, thereby excluding contamination by non‐migrasomal microvesicles, exosomes, or cellular debris of other origins. Fluorescent channels used: CD45 (green), Ly6g (red), Apotracker (blue). H) Quantification of plasma CD45+ and Ly6g+ migrasomes (n=3 per group). I,J) Left panels: Representative multiplex immunohistochemistry images of Tspan4 (red), Iba1 (green), and DAPI (blue) in brain tissue. Right panels: Quantification of Tspan4+ Iba1+ cells. Scale bar: 100 µm (n = 5 per group). K,L) Left panels: Representative multiplex immunohistochemistry images of Tspan4 (red), CD31 (green), and DAPI (blue) in brain tissue. Right panels: Quantification of Tspan4+ CD31+ cells. Scale bar: 100 µm (n = 5 per group). M) Representative scanning electron microscopy (SEM) images of HMC3 cells subjected to 3 h oxygen‐glucose deprivation followed by 21 h reperfusion compared with untreated controls. Scale bar: 5 µm. N) Representative SEM images of bEnd.3 cells treated similarly to HMC3 cells. Scale bar: 25 µm. All data are expressed as means ± standard deviation (SD). Statistical significance: * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001 by one‐way ANOVA followed by Tukey's multiple comparison tests. Abbreviation: CIRI, cerebral ischemia‐reperfusion injury.