Role of estrogen in mediating the effects of exposure to space radiation on cognitive performance in female rats

Authors: RABIN, BERNARD - University Of Maryland; MILLER, MARSHALL - Duke University; HAWKINS, ELIZABETH - University Of Maryland; LARSEN, ALISON - University Of Maryland; SPADAFORA, CHRISTINA - University Of Maryland; ZOLNEROWICH, NICHOLAS - University Of Maryland; DELL'ACQUA, LORRAINE - University Of Maryland; PAGDEN, WILLIAM - University Of Maryland; ROTTMAN, VICTORIA - University Of Maryland; Shukitt-Hale, Barbara

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 6/21/2018
Publication Date: 11/3/2018
Citation: Rabin, B.M., Miller, M.G., Hawkins, E.M., Larsen, A., Spadafora, C., Zolnerowich, N.N., Dell'Acqua, L.A., Pagden, W., Rottman, V., Shukitt Hale, B. 2018. Role of estrogen in mediating the effects of exposure to space radiation on cognitive performance in female rats [abstract]. 2018 Society for Neuroscience Annual Meeting Program # 593.03.

Interpretive Summary:

Technical Abstract: During exploratory class missions to other planets, astronauts will be exposed to types and doses of radiation not experienced in low earth orbit, where the space shuttle and International Space Station operate. While it is likely that both male and female astronauts will comprise the crew on these missions, the majority of the research using animal models has utilized only male subjects. The subjects were ovariectomized (OVX) and intact female rats, approximately two months of age at the time of irradiation. The OVX subjects were given implants of estradiol or vehicle. Following head-only exposure to 12C or 4He particles at Brookhaven National Lab, the rats were shipped to UMBC and tested on novel object recognition and operant responding on an ascending fixed-ratio schedule. All behavioral tests were conducted at least 2 months after irradiation, such that the hormonal status of all OVX rats was the same. Results indicate that the effects of exposure to these particles on the cognitive performance of female rats varied as a function of the specific particle, hormonal status at the time of irradiation, and the specific task. Exposure to either 12C or 4He did not cause a reliable disruption of performance on the novel object task. Estradiol provided partial protection against the deleterious effects of exposure on novel object performance. The presence of estradiol at the time of exposure did not prevent the disruption of operant performance by exposure to either particle. In the intact rats, exposure to both particles increased the responsiveness of the subject to the changes in reinforcement contingencies. These results suggest that the effects of exposure to space radiation on cognitive performance among female subjects are more variable than they are for males. While hormonal status at the time of irradiation may be a factor influencing the effects of exposure on cognitive performance, the mediating effect of female hormones are not uniform, and vary as a function of the specific particle and task.