|RABIN, BERNARD - University Of Maryland|
|CARRHILL-KNOLL, KIRSTY - University Of Maryland|
|BARTON, KERI - University Of Maryland|
Submitted to: Society for Neuroscience Abstracts and Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 7/29/2016
Publication Date: 11/12/2016
Citation: Rabin, B.M., Shukitt Hale, B., Carrhill-Knoll, K.L., Miller, M.G., Barton, K. 2016. Age as a risk factor for the disruption of cognitive performance by exposure to the types of radiation encounted on exploratory class missions to other planets. Society for Neuroscience Abstracts and Proceedings. Program No.743.04.
Technical Abstract: Exposure to the types of radiation encountered in space (particles of high energy and charge [HZE particles]) produces changes in neurocognitive performance similar to those observed in the aged organism. As such, it is possible that there would be an interaction between the effects of exposure to HZE particles and the effects of aging. Previous research using 56Fe particles has shown an interaction between age of irradiation and the dose needed to produce a deficit in cognitive performance, such that doses of HZE particles that did not affect the performance of younger subjects affected the performance of older ones. The present experiments were designed to evaluate the generality of the relationship between age of irradiation and the dose needed to disrupt cognitive performance as a function of the characteristics of the specific particle. Male F-344 rats between 2 and 16 months of age were exposed to 48Ti, 16O, and 4He particles at the NASA Space Radiation Laboratory at Brookhaven National Lab. Cognitive performance was evaluated by testing performance on an ascending fixed-ratio operant task. In this task the subject must make an increasing number of responses in order to obtain a reward (food pellet). This task measures the motivation of the organism to work for reinforcement and the responsiveness of the organism to changes in environmental contingencies, including changes in reinforcement contingencies. Overall, the results indicated that for the higher LET (linear energy transfer) particles (56Fe and 48Ti; which produce greater tissue destruction along the particle track) a lower dose was needed to disrupt cognitive performance in the older subjects. Conversely, the available results suggest that a similar relationship may not be observed for the lower LET particles (16O and 4He) which produce less tissue destruction along the particle track). These results suggest that the effectiveness of specific particles in disrupting cognitive performance may, under some conditions, vary as a function of the age of the organism at the time of irradiation and the LET of the specific particle.