Performance in hippocampus- and PFC-dependent cognitive domains are not concomitantly impaired in rats exposed to 20cGy of 1GeV/n (56)Fe particles.
NASA is currently conducting ground based experiments to determine whether the radiation environment that astronauts will encounter on deep space missions will have an impact on their long-term health and their ability to complete the various tasks during the mission. Emerging data suggest that exposure of rodents to mission-relevant HZE radiation doses does result in the impairment of various neurocognitive processes. An essential part of mission planning is a probabilistic risk assessment process that takes into account the likely incidence and severity of a problem. To date few studies have reported the impact of space radiation in a format that is amenable to PRA, and those that have only reported data for a single cognitive process. This study has established the ability of individual male Wistar rats to conduct a hippocampus-dependent (spatial memory) task and a cortex-dependent (attentional set shifting task) 90 days after exposure to 20cGy 1GeV/n (56)Fe particles. Radiation-induced impairment of performance in one cognitive domain was not consistently associated with impaired performance in the other domain. Thus sole reliance upon a single measure of cognitive performance may substantially under-estimate the risk of cognitive impairment, and ultimately it may be necessary to establish the likelihood that mission-relevant HZE doses will impair performance in the three or four cognitive domains that NASA considers to be most critical for mission success, and build a PRA using the composite data from such studies.
Department of Radiation Oncology, Eastern Virginia Medical School, 700 W. Olney Rd., Lewis Hall, Norfolk, VA 23507, United States ; Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, Norfolk, VA 23507, United States ; Leroy T Canoles Jr. Cancer Center; Eastern Virginia Medical School, Norfolk, VA 23507, United States . Electronic address: brittera@evms.edu.
Richard A
RA
Britten
Department of Radiation Oncology, Eastern Virginia Medical School, 700 W. Olney Rd., Lewis Hall, Norfolk, VA 23507, United States.
Vania D
VD
Miller
Department of Radiation Oncology, Eastern Virginia Medical School, 700 W. Olney Rd., Lewis Hall, Norfolk, VA 23507, United States.
Melissa M
MM
Hadley
Department of Radiation Oncology, Eastern Virginia Medical School, 700 W. Olney Rd., Lewis Hall, Norfolk, VA 23507, United States.
Jessica S
JS
Jewell
Department of Radiation Oncology, Eastern Virginia Medical School, 700 W. Olney Rd., Lewis Hall, Norfolk, VA 23507, United States.
Evangeline
E
Macadat
D000818:Animals; D001522:Behavior, Animal / Q000528:radiation effects*; D003071:Cognition / Q000528:radiation effects*; D003359:Cosmic Radiation; D004307:Dose-Response Relationship, Radiation; D006624:Hippocampus / Q000503:physiopathology* / Q000528:radiation effects; D008297:Male; D017397:Prefrontal Cortex / Q000503:physiopathology* / Q000528:radiation effects; D051381:Rats; D017208:Rats, Wistar