Fig. 1

Excessive mitochondrial fission and ROS accumulation induced by activated Drp1 after CIRI and ODG/R. a Speckle tomography of cerebral blood flow after CIRI. b HE staining of the cerebral cortex after CIRI (bar = 50 μm). c TEM images showing mitochondria in the cerebral cortex after CIRI (bar = 2 μm). Quantitative data detailing the mitochondrial length and cristae density of each group. d mtDNA copy number and fluorescence intensity of ROS DCFH-DA in the cerebral cortex after CIRI (n = 8/group). e Activation of Drp1-Ser616 as well as the protein expression of Drp1 in total, cytoplasmic, and mitochondrial fractions after CIRI. β-actin, COX IV, and tubulin were used as internal references for total, mitochondrial, and cytoplasmic fractions, respectively (n = 8/group). f Immunofluorescence images showing co-location of Drp1 and mitochondria (COX IV) in the cerebral cortex after CIRI. Enlarged images of Additional file 1: Fig. S1c (bar = 10 μm, n = 5/group). g Mitochondrial morphology in OGD/R-treated SH-SY5Y cells after Drp1 shRNA (bar = 25 μm). The length of mitochondria was analyzed using Image J software, with 107 mitochondria observed and measured in the normal group, 323 in the OGD/R group, 378 in the OGD/R + Scr. group, and 118 in the OGD/R + Drp1 shRNA group. h Fluorescence intensity of ROS DCFH-DA and quantitative data of DHE fluorescence intensity in OGD/R-treated SH-SY5Y cells after Drp1 shRNA (bar = 50 μm, n = 8/group). i Fluorescence images and related quantitative data detailing Mito-ROS MitoSOX fluorescence in OGD/R-treated SH-SY5Y cells after Drp1 shRNA (n = 8/group). ^*P < 0.05, compared with normal group; ^#P < 0.05, compared with OGD/R group. CIRI cerebral ischemia–reperfusion injury, DCFH-DA 2',7'-dichlorodihydrofluorescein diacetate, DHE dihydroethidium, Mito-ROS mitochondrial ROS, mtDNA mitochondrial DNA, OGD/R oxygen- glucose deprivation/reoxygenation treatment, ROI Region of interest, ROS reactive oxygen species, Scr. scramble-shRNA, TEM transmission electron microscope