Long-Term Effects of {sup 56}Fe Irradiation on Spatial Memory of Mice: Role of Sex and Apolipoprotein E Isoform

Journal Article · Wed Jun 01 00:00:00 EDT 2011 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/j.ijrobp.2010.12.034· OSTI ID:21491783

Villasana, Laura E; Benice, Theodore S ^[1]; Raber, Jacob ^[1]

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1. Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, Oregon (United States)

Purpose: To assess whether the effects of cranial {sup 56}Fe irradiation on the spatial memory of mice in the water maze are sex and apolipoprotein E (apoE) isoform dependent and whether radiation-induced changes in spatial memory are associated with changes in the dendritic marker microtubule-associated protein 2 (MAP-2) and the presynaptic marker synaptophysin. Methods and Materials: Two-month-old male and female mice expressing human apoE3 or apoE4 received either a 3-Gy dose of cranial {sup 56}Fe irradiation (600 MeV/amu) or sham irradiation. Mice were tested in a water maze task 13 months later to assess effects of irradiation on spatial memory retention. After behavioral testing, the brain tissues of these mice were analyzed for synaptophysin and MAP-2 immunoreactivity. Results: After irradiation, spatial memory retention of apoE3 female, but not male, mice was impaired. A general genotype deficit in spatial memory was observed in sham-irradiated apoE4 mice. Strikingly, irradiation prevented this genotype deficit in apoE4 male mice. A similar but nonsignificant trend was observed in apoE4 female mice. Although there was no change in MAP-2 immunoreactivity after irradiation, synaptophysin immunoreactivity was increased in irradiated female mice, independent of genotype. Conclusions: The effects of {sup 56}Fe irradiation on the spatial memory retention of mice are critically influenced by sex, and the direction of these effects is influenced by apoE isoform. Although in female mice synaptophysin immunoreactivity provides a sensitive marker for effects of irradiation, it cannot explain the apoE genotype-dependent effects of irradiation on the spatial memory retention of the mice.

• OSTI ID: 21491783
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Vol. 80, Issue 2; Other Information: DOI: 10.1016/j.ijrobp.2010.12.034; PII: S0360-3016(11)00022-8; Copyright (c) 2011 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRONMENTAL POLLUTANT EFFECTS ON LIVING ORGANISMS AND BIOLOGICAL MATERIALS
62 RADIOLOGY AND NUCLEAR MEDICINE
BRAIN
IRON 56
IRRADIATION
MICE
PROTEINS
RADIATION INJURIES
RETENTION
SEX
ANIMALS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BODY
CENTRAL NERVOUS SYSTEM
DISEASES
EVEN-EVEN NUCLEI
INJURIES
INTERMEDIATE MASS NUCLEI
IRON ISOTOPES
ISOTOPES
MAMMALS
NERVOUS SYSTEM
NUCLEI
ORGANIC COMPOUNDS
ORGANS
RADIATION EFFECTS
RODENTS
STABLE ISOTOPES
VERTEBRATES