Effects of Age on the Disruption of Cognitive Performance by Exposure to Space Radiation

Abstract

Exposure to low doses of heavy particles and protons, which will be encountered during long-term exploratory class missions to other planets, can cause deficits in cognitive performance. These deficits are similar to those observed in aged animals. The long-term effects of such exposures and their relationship to the short-term effects and to aging remain to be established. Two-month old rats were exposed to a variety of heavy particles and protons. Recognition memory was tested at two time points following irradiation. The results showed that exposure to doses of radiation that did not disrupt cognitive performance in the younger animals, disrupted performance when the subjects were re-tested at an older age. These results indicate that there is an interaction between the age of the organism and the effects of exposure to space radiation on cognitive performance, such that exposure to doses of heavy particles or protons that may not produce an initial effect on cognitive performance may produce an effect as the organism ages. Because of the interaction between exposure to the types of radiation encountered in space and age, it is possible that participating in exploratory class missions may have consequences for the quality of life after the conclusion of the mission.