Dietary modulation of the effects of exposure to HZE particles on cognitive performance

Authors: RABIN, BERNARD - University Of Maryland; ROTTMAN, VICTORIA - University Of Maryland; JIANG, VIVIAN - University Of Maryland; HULL, MORGAN - University Of Maryland; INGRAM, IVAN - University Of Maryland; Shukitt-Hale, Barbara

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 10/27/2019
Publication Date: 1/30/2020
Citation: Rabin, B.M., Rottman, V., Jiang, V., Hull, M.T., Ingram, I., Shukitt Hale, B. 2020. Dietary modulation of the effects of exposure to HZE particles on cognitive performance [abstract]. 2020 NASA Human Research Program Investigators Workshop, Program #20188.

Interpretive Summary:

Technical Abstract: INTRODUCTION: On exploratory class missions astronauts will be exposed to doses of HZE particles that have the potential to affect cognitive performance which may affect their ability to successfully achieve mission requirements. Physical shielding will not be totally effective in providing protection against deleterious effects of exposure to cosmic rays. Therefore other types of countermeasures must be developed and tested. Because exposure to HZE particles causes oxidative stress and neuroinflammation, dietary countermeasures that target these effects of irradiation may prove efficacious in preventing alterations in cognitive performance. Previous research with male rats has shown that antioxidant diets containing blueberry or strawberry extract prevent the cognitive deficits produced by exposure to HZE particles. Because female rats do not respond to exposure to HZE particles in a similar way to male rats, the present experiment was designed to evaluate the effectiveness of a diet containing blueberry extract in preventing the alteration of cognitive performance following exposure to 4He particles in female rats. METHODS: The animals were 120 female rats obtained from Taconic Farms; half were ovariectomized (OVX) by the supplier and half were intact. At the University of Maryland Baltimore County (UMBC) the rats were placed on a control diet or a diet containing 2% blueberry extract (n = 60/diet). Four weeks after starting the diet the rats were shipped to Brookhaven National Lab (BNL). At BNL the OVX rats were given implants containing either estradiol or vehicle prior to exposure to 4He particles (0 or 0.05 cGy, 300 MeV/n). Following irradiation the rats were returned to UMBC where they were placed on a standard Purina rat chow diet and tested for radiation-induced alterations in cognitive performance using novel object recognition performance, novel spatial location performance and operant responding on an ascending fixed-ratio task. RESULTS: Two months following irradiation there was no loss of recognition memory in any of the OVX rats on either control or blueberry diet. The blueberry diet was not effective in preventing the loss of spatial memory in the intact rats but did prevent the disruption of performance in OVX rats given estradiol implants. The use of an antioxidant diet did not prevent the disruption of operant responding in intact rats. However, there was an interaction between hormonal status at the time of irradiation and the effects of the antioxidant diet on operant responding. CONCLUSIONS: The present results using female rats contrast with the prior results using male rats; intact female rats maintained on the blueberry diet continued to show decreased performance following exposure to 4He particles. Although more research is needed, the present results suggest that the radiation protection requirements on exploratory class missions may differ for male and female astronauts.