title: Radiation-induced long-term alterations in hippocampus under experimental conditions.
abstract: BACKGROUND
  The aim of the present study was to investigate the effect of ionizing radiation on the cell population that co-forms hippocampal formation in an adult rat brain.
  
  
  METHODS
  Adult male Wistar rats were exposed to whole-body irradiation with fractionated doses of gamma rays (the total dose of 4 Gy). Thirty, 60 and 90 days after irradiation the cell-specific types housed in the CA1, CA3 subregions and adjacent layers were labelled using immunohistochemistry for specific cell phenotypes; Ki-67 marker was used for proliferating cells and GFAP for detection of astrocytes.
  
  
  RESULTS
  During the 30th day post-exposure, a considerable increase in the numbers of Ki-67-positive cells was seen. Moreover, significant decline in the density of neurons, mostly in the CA1 subregion, was observed on the 60th day. Slight overaccumulation of Ki-67-positive cells was seen in CA1 area 90 days after radiation treatment. Temporary decrease of GFAP-positive astrocytes was seen thirty days after irradiation, followed by their subsequent increase 60 days after exposure. Secondary decrease of GFAP-positive cells in both of regions was found in the group surviving 90 days post-irradiation.
  
  
  CONCLUSIONS
  Results showed that radiation response of neurons and astrocytes that form the adult hippocampus may play contributory role in the development of prognostically unfavourable adverse radiation-induced late effect.
authors.affiliation: Institute of Histology and Embryology, Jessenius Faculty of Medicine, Comenius University, Martin, Slovak Republic. balentova@jfmed.uniba.sk
authors.forename: S
authors.initials: S
authors.lastname: Bálentová
authors.forename: E
authors.initials: E
authors.lastname: Hajtmanová
authors.forename: I
authors.initials: I
authors.lastname: Kinclová
authors.forename: J
authors.initials: J
authors.lastname: Lehotský
authors.forename: D
authors.initials: D
authors.lastname: Dobrota
authors.forename: M
authors.initials: M
authors.lastname: Adamkov
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000473:pathology; D005720:Gamma Rays; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis; D006624:Hippocampus / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects*; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000032:analysis; D008297:Male; D011829:Radiation Dosage; D051381:Rats; D017208:Rats, Wistar
chemical_list: D005904:Glial Fibrillary Acidic Protein; D019394:Ki-67 Antigen