title: Fluoro-Jade B staining following zymosan microinjection into the spinal cord white matter.
abstract: 1. The fluorescein derivate Fluoro-Jade B (FJB), which primarily labels dead or dying neurons, was used to study the acute focal inflammation in the spinal cord white matter. Inflammation was induced by microinjection of the yeast particulate zymosan to evaluate the biological effects of intraspinal macrophages activation without the confounding effects of physical trauma. 2. A single bolus of zymosan (Sigma, 75 nL) was stereotaxically injected at the thoracic level into the lateral white matter of rat spinal cord. A standard Fluoro-Jade B staining protocol was applied to spinal cord sections at 6, 12, 24 h and 2, 4 days postinjection. Neutral Red, NADPH-diaphorase, Iba1-IR, and DAPI staining protocols accomplished examination of the cells participating in the acute inflammatory response. 3. Zymosan caused formation of clearly delineated inflammation lesions localized in the lateral white matter of the spinal cord. Fluoro-Jade B stained cells in the area of inflammation were not observed at 12 h postinjection while mild FJB staining appeared at 24 h and intense staining was observed at 2 and 4 days postinjection. 4. This study shows that the acute response to zymosan-induced inflammation in the rat spinal cord white matter causes a gradual appearance of phagocytic microglia/macrophages and delayed FJB staining of the inflammatory cells. 5. FJB, a reliable marker of dying neurons, is a more universal agent than formerly believed. One possible explanation for the gradual appearance of FJB-stained cells in the area of inflammation is that specific time is required for sufficient levels of proteins and/or myelin debris of axonal origin to appear in the cytoplasm of phagocytic microglia/macrophages.
authors.affiliation: Center of Excellence, Institute of Neurobiology, Slovak Academy of Sciences, Kosice, Slovak Republic. sagan@saske.sk
authors.forename: Kamila
authors.initials: K
authors.lastname: Saganová
authors.forename: Jozef
authors.initials: J
authors.lastname: Burda
authors.forename: Judita
authors.initials: J
authors.lastname: Orendácová
authors.forename: Dása
authors.initials: D
authors.lastname: Cízková
authors.forename: Ivo
authors.initials: I
authors.lastname: Vanický
mesh_terms: D000818:Animals; D002135:Calcium-Binding Proteins / Q000032:analysis; D005452:Fluoresceins; D005456:Fluorescent Dyes; D007211:Indoles; D008264:Macrophages / Q000502:physiology; D008297:Male; D008840:Microfilament Proteins; D008845:Microinjections; D009187:Myelitis / Q000139:chemically induced / Q000276:immunology / Q000473:pathology*; D009252:NADPH Dehydrogenase / Q000032:analysis; D009499:Neutral Red; D009930:Organic Chemicals; D010587:Phagocytosis; D051381:Rats; D013116:Spinal Cord / Q000187:drug effects*; D015054:Zymosan
chemical_list: C100745:Aif1 protein, rat; D002135:Calcium-Binding Proteins; D005452:Fluoresceins; D005456:Fluorescent Dyes; D007211:Indoles; D008840:Microfilament Proteins; D009930:Organic Chemicals; C435731:fluoro jade; D009499:Neutral Red; C007293:DAPI; D015054:Zymosan; D009252:NADPH Dehydrogenase