Immunofluorescence and histochemistry
Samples embedded in OCT compound on a cork wrapped in aluminum foil from each participant at PRE, DAY1, POST, and REC were removed from the cork at −25°C in a Leica CM1860 cryostat (Leica Biosystems) and sectioned at 10 μm. Sections were air‐dried at room temperature overnight and then stored in a slide box at −20°C until stained. Full details of all immunofluorescent and histochemical methods and reagents can be found in the Supplemental Methods.