|RABIN, BERNARD - University Of Maryland|
|POULOSE, SHIBU - Jean Mayer Human Nutrition Research Center On Aging At Tufts University|
|BIELINSKI, DONNA - Jean Mayer Human Nutrition Research Center On Aging At Tufts University|
|CARRIHILL-KNOLL, KIRSTY - University Of Maryland|
|HAWKINS, ELIZABETH - University Of Maryland|
|HENG, RANDY - University Of Maryland|
|LARSEN, ALISON - University Of Maryland|
|SPADAFORA, CHRISTINA - University Of Maryland|
|ZOLNEROWICH, NICHOLAS - University Of Maryland|
|PATEL, RISHIT - University Of Maryland|
Submitted to: Society for Neuroscience Abstracts and Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 6/22/2017
Publication Date: 11/11/2017
Citation: Rabin, B.M., Poulose, S.M., Miller, M.G., Bielinski, D.F., Carrihill-Knoll, K.L., Hawkins, E.M., Heng, R.C., Larsen, A., Spadafora, C., Zolnerowich, N.N., Patel, R., Shukitt Hale, B. 2017. Exposure to low doses of helium particles disrupts neuronal function and cognitive performance. Society for Neuroscience Abstracts and Proceedings. Program #396.08.
Technical Abstract: On exploratory class missions, such as a mission to Mars, astronauts will be exposed to types of radiation (cosmic rays) that are not experienced in low earth orbit where the space shuttle and International Space Station operate. A significant portion of this radiation will be composed of low linear energy transfer (LET) helium (4He) particles, which produce less damage to neuronal tissue as they pass through the brain. As such, it is important to establish the degree to which these particles might produce a disruption of neuronal function and cognitive performance. Sprague-Dawley rats weighing between 200-225 g were given either head-only or whole-body exposures to 4He particles (1000 MeV/n) at doses ranging from 0.01 to 0.5 cGy. Following exposure, the brains were removed from a subset of the rats (n = 5/dose) for analysis of oxidative stress by measuring NADPH oxidase (NOX2) expression. Measurements were also made of phosphorylated-cyclic AMP (cAMP)-responsive element-binding protein (CREB) and nuclear factor E2-related factor 2 (Nrf2). The remaining rats (n = 10/dose) underwent behavioral testing. Behavioral tests included: elevated plus maze (baseline anxiety); novel object and novel spatial recognition (learning and memory); and operant responding on an ascending fixed-ratio schedule (motivation to work for reward and responsiveness to environmental contingencies). The results indicated that changes in behavioral endpoints could be observed following exposures to 4He particles at doses as low as 0.01 to 0.025 cGy. Differences in neurochemical endpoints were observed following exposure to doses as low as 0.05 cGy (the lowest dose tested). There were no significant differences between head-only and whole-body exposures on behavioral performance. Preliminary analyses of the neurochemical data suggest that whole body exposures may not have been as effective in producing changes in neuronal functioning as were head-only exposures. Because 4He particles will constitute a significant fraction of the radiation dose to which astronauts will be exposed, the present results suggest the possibility that astronauts on exploratory class missions may be at a greater risk for HZE-induced cognitive deficits than anticipated.