title: Automated and quantitative image analysis of ischemic dendritic blebbing using in vivo 2-photon microscopy data.
abstract: Ischemia induces a 'blebbing' of dendrites, a structural alteration where dendrites take on a 'beads on a string' appearance. We developed a toolkit program, BlebQuant, for quantitative automated bleb analysis to chart the morphology of dendrites labeled with GFP/YFP under normal conditions and after ischemia-induced damage. In vivo 2-photon data from mouse layer 5 neurons with apical dendritic tufts extending to the cortical surface were examined before, during, and after global ischemia. To quantify changes in dendritic structure, we used morphometric tools that exploit characteristic features of blebbing, distinguished as localized regions of spherical or ellipsoid swellings. By comparing acquired images during ischemia and reperfusion to a pre-ischemia reference image, our automated approach detected blebs based on defined eccentricity and area thresholds and quantified the percentage of blebbed dendrites based on a block-selection method. Our results indicate that the automated morphometric indices we employ yield results that correlate with manual assessment. The automated approach permits rapid and effective analysis of dendritic structure and may facilitate the study of ischemic dendritic damage.
authors.affiliation: Department of Psychiatry, Brain Research Centre, University of British Columbia, Vancouver, BC V6T1Z3, Canada.
authors.forename: Shangbin
authors.initials: S
authors.lastname: Chen
authors.forename: Sherri
authors.initials: S
authors.lastname: Tran
authors.forename: Albrecht
authors.initials: A
authors.lastname: Sigler
authors.forename: Timothy H
authors.initials: TH
authors.lastname: Murphy
mesh_terms: D000818:Animals; D003712:Dendrites / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D001330:Electronic Data Processing / Q000379:methods*; D049452:Green Fluorescent Proteins / Q000235:genetics; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007511:Ischemia / Q000473:pathology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D017785:Photons; D015203:Reproducibility of Results; D013003:Somatosensory Cortex / Q000378:metabolism / Q000473:pathology*; D013223:Statistics as Topic; D013997:Time Factors; D014584:User-Computer Interface
chemical_list: D049452:Green Fluorescent Proteins