title: Neurogenic Effects of Low-Dose Whole-Body HZE (Fe) Ion and Gamma Irradiation.
abstract: Understanding the dose-toxicity profile of radiation is critical when evaluating potential health risks associated with natural and man-made sources in our environment. The purpose of this study was to evaluate the effects of low-dose whole-body high-energy charged (HZE) iron (Fe) ions and low-energy gamma exposure on proliferation and differentiation of adult-born neurons within the dentate gyrus of the hippocampus, cells deemed to play a critical role in memory regulation. To determine the dose-response characteristics of the brain to whole-body Fe-ion vs. gamma-radiation exposure, C57BL/6J mice were irradiated with 1 GeV/n Fe ions or a static137Cs source (0.662 MeV) at doses ranging from 0 to 300 cGy. The neurogenesis was analyzed at 48 h and one month postirradiation. These experiments revealed that whole-body exposure to either Fe ions or gamma radiation leads to: 1. An acute decrease in cell division within the dentate gyrus of the hippocampus, detected at doses as low as 30 and 100 cGy for Fe ions and gamma radiation, respectively; and 2. A reduction in newly differentiated neurons (DCX immunoreactivity) at one month postirradiation, with significant decreases detected at doses as low as 100 cGy for both Fe ions and gamma rays. The data presented here contribute to our understanding of brain responses to whole-body Fe ions and gamma rays and may help inform health-risk evaluations related to systemic exposure during a medical or radiologic/nuclear event or as a result of prolonged space travel.
authors.affiliation:   aDepartment of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642.
authors.forename: Tara B
authors.initials: TB
authors.lastname: Sweet
authors.affiliation:   aDepartment of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642.
authors.forename: Sean D
authors.initials: SD
authors.lastname: Hurley
authors.affiliation:   aDepartment of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Wu
authors.affiliation:   aDepartment of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642.
authors.forename: John A
authors.initials: JA
authors.lastname: Olschowka
authors.affiliation: b   Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642.|c   Department of Radiation Oncology, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642.
authors.forename: Jacqueline P
authors.initials: JP
authors.lastname: Williams
authors.affiliation:   aDepartment of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642.|d   Neurology, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642.
authors.forename: M Kerry
authors.initials: MK
authors.lastname: O'Banion
mesh_terms: D000818:Animals; D004307:Dose-Response Relationship, Radiation; D000089662:Doublecortin Protein; D005720:Gamma Rays / Q000009:adverse effects*; D007501:Iron / Q000009:adverse effects*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D055495:Neurogenesis / Q000528:radiation effects*; D013997:Time Factors; D014916:Whole-Body Irradiation / Q000009:adverse effects*
chemical_list: C000714847:Dcx protein, mouse; D000089662:Doublecortin Protein; D007501:Iron