title: Preconditioning-specific reduction of c-fos expression in hippocampal granule and pyramidal but not other forebrain neurons of ischemic brain: a quantitative immunohistochemical study.
abstract: To specify targets for an ischemic preconditioning paradigm (ischemic tolerance), c-fos expressions in ischemic (induced by 10 min bilateral carotid-occlusions subsequent to coagulation of vertebral arteries) and preconditioned rats (treated for 4 min carotid-occlusions 72 h before ischemia) were compared in 12 forebrain areas/nuclei. Fos immunostaining was applied to serial sections of the forebrain and the density (cell number/area measured) of Fos-immunopositive (Fos+) neurons, as well as their percentile changes were determined in five hippocampal and seven extrahippocampal areas/nuclei of ischemic and preconditioned rats. The ratio of counts found in ischemic over control animals showed several fold increase of Fos+ cells in the three layers (granule cell, molecular and polymorphic) of the dentate gyrus, CA3 and CA1 pyramidal neurons, as well as in thalamic and hypothalamic nuclei and limbic cortical areas. In contrast, preconditioning did not alter c-fos expressions significantly in the extrahippocampal brain areas investigated. These results strengthen the hypothesis that the hippocampal and dentate neurons are more susceptible to ischemic tolerance than cells in other brain regions. In fact stress-response and induction of ischemic tolerance in different forebrain areas can be distinguished.
authors.affiliation: Department of Neurochemistry, Chemical Research Center, HAS, Budapest, Hungary.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Nyitrai
authors.forename: László
authors.initials: L
authors.lastname: Puskás
authors.forename: Károly
authors.initials: K
authors.lastname: Antal
authors.forename: Viktor
authors.initials: V
authors.lastname: Takács
authors.forename: Miklós
authors.initials: M
authors.lastname: Sass
authors.forename: Gábor
authors.initials: G
authors.lastname: Juhász
authors.forename: Julianna
authors.initials: J
authors.lastname: Kardos
authors.forename: Miklós
authors.initials: M
authors.lastname: Palkovits
mesh_terms: D000818:Animals; D002545:Brain Ischemia / Q000378:metabolism / Q000473:pathology*; D002452:Cell Count; D006624:Hippocampus / Q000098:blood supply* / Q000378:metabolism; D007150:Immunohistochemistry; D019194:Ischemic Preconditioning; D009474:Neurons / Q000378:metabolism* / Q000473:pathology; D016548:Prosencephalon / Q000098:blood supply* / Q000378:metabolism*; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D016760:Proto-Oncogene Proteins c-fos