title: Behavioral consequences of radiation exposure to simulated space radiation in the C57BL/6 mouse: open field, rotorod, and acoustic startle.
abstract: Two experiments were carried out to investigate the consequences of exposure to proton radiation, such as might occur for astronauts during space flight. C57BL/6 mice were exposed, either with or without 15-g/cm2 aluminum shielding, to 0-, 3-, or 4-Gy proton irradiation mimicking features of a solar particle event. Irradiation produced transient direct deficits in open-field exploratory behavior and acoustic startle habituation. Rotorod performance at 18 rpm was impaired by exposure to proton radiation and was impaired at 26 rpm, but only for mice irradiated with shielding and at the 4-Gy dose. Long-term (>2 weeks) indirect deficits in open-field activity appeared as a result of impaired experiential encoding immediately following exposure. A 2-week recovery prior to testing decreased most of the direct effects of exposure, with only rotorod performance at 26 rpm being impaired. These results suggest that the performance deficits may have been mediated by radiation damage to hippocampal, cerebellar, and possibly, forebrain dopaminergic function.
authors.affiliation: Department of Radiation Medicine, Loma Linda University, Loma Linda, California 92350, USA. mpecaut@dominion.llumc.edu
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Pecaut
authors.forename: Paul
authors.initials: P
authors.lastname: Haerich
authors.forename: Cara N
authors.initials: CN
authors.lastname: Zuccarelli
authors.forename: Anna L
authors.initials: AL
authors.lastname: Smith
authors.forename: Eric D
authors.initials: ED
authors.lastname: Zendejas
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Nelson
mesh_terms: D000818:Animals; D001306:Auditory Pathways / Q000528:radiation effects; D001522:Behavior, Animal / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005106:Exploratory Behavior / Q000528:radiation effects*; D005260:Female; D051379:Mice; D008810:Mice, Inbred C57BL; D008954:Models, Biological; D009048:Motor Skills / Q000528:radiation effects; D011522:Protons; D011597:Psychomotor Performance / Q000528:radiation effects*; D011897:Random Allocation; D013216:Reflex, Startle / Q000528:radiation effects*; D013026:Space Flight; D013997:Time Factors
chemical_list: D011522:Protons