Performance in hippocampus- and PFC-dependent cognitive domains are not concomitantly impaired in rats exposed to 20cGy of 1GeV/n (56)Fe particles

Life Sci Space Res (Amst). 2016 Aug;10:17-22. doi: 10.1016/j.lssr.2016.06.005. Epub 2016 Jun 27.

Abstract

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.

MeSH terms

  • Animals
  • Behavior, Animal / radiation effects*
  • Cognition / radiation effects*
  • Cosmic Radiation*
  • Dose-Response Relationship, Radiation
  • Hippocampus / physiopathology*
  • Hippocampus / radiation effects
  • Male
  • Prefrontal Cortex / physiopathology*
  • Prefrontal Cortex / radiation effects
  • Rats
  • Rats, Wistar