a Morphometric analysis of adventitial, medial, intimal and luminal volumes following partial ligation of the left carotid artery compared to sham controls. Data are the mean ± SEM of four animals, #p < 0.05 vs sham. b–d The number of DAPI nuclei/hpf in cross sections of b adventitia, c media, and d intima following partial ligation of the left carotid artery (LCA) after 3 d compared to untouched (control) and sham. Data are the mean ± SEM of 3–5 representative images per animals, n = 3, #p < 0.05. e Verhoeff-Van Gieson stained sections and corresponding confocal fluorescence images of DAPI nuclei (blue), Sca1-eGFP (green), and immunofluorescence of α-actin (SMA) (red), anti-eGFP (green), anti-CD31 (red) and anti-eNOS (red) expression in ligated LCA vessels expression in sham-operated and ligated LCA vessels. Arrows highlight Sca1-eGFP expressing cells in the adventitia (A), media (M) and neointima (NI) and CD31 and eNOS in intima. Scale bar = 20 µm. f The fraction of Sca1 cells/high power field (hpf) in the adventitia, media, and intima of sham and ligated vessels after 3 days. Data are the mean ± SEM of 3–5 sections, #p ≤ 0.05 from a minimum of four animals per experimental group. g Representative immunofluorescence images for the pro-apoptotic marker, Bax, (red) in ligated left carotid artery (LCA) vessels and contralateral right carotid artery (RCA) after 3 d. IgG was used as a control. h The number of Bax cells/hpf in the adventitia, media, and intima of sham and ligated vessels after 3 d. Arrows highlight Bax expressing cells within the adventitia (A), media (M), and neointima (NI). Data are the mean ± SEM of 3–6 sections per experimental group from three animals. #p ≤ 0.05. Scale bar = 20 µm.