TY - JOUR
T1 - Whole-Body Oxygen (16O) Ion-Exposure-Induced Impairments in Social Odor Recognition Memory in Rats are Dose and Time Dependent
AU - Mange, Ami
AU - Cao, Yuqing
AU - Zhang, Siyuan
AU - Hienz, Robert D.
AU - Davis, Catherine M.
N1 - Funding Information:
This research was supported by NASA grant no. NNX15AC71G and a NASA cooperative agreement, no. NCC 9-58, with the National Space Biomedical Research Institute supported through NASA nos. NCC 9-58-PF02602 and NCC 9-58-NBPF02802.
Funding Information:
This research was supported by NASA grant no. NNX15AC71G and a NASA cooperative agreement, no. NCC 9-58, with the National Space Biomedical Research Institute supported through NASA nos. NCC 9-58- PF02602 and NCC 9-58-NBPF02802.
Publisher Copyright:
© 2018 by Radiation Research Society.
PY - 2018/3
Y1 - 2018/3
N2 - Future long-duration space missions will involve travel outside of the Earth's magnetosphere, which will result in increased radiation exposure for astronauts. Exposure could permanently damage multiple tissues, including the central nervous system (CNS), and result in deleterious effects on cognition and behavior during and beyond the mission. Here, we assessed the effects of whole-body oxygen ion (16O; 1,000 MeV/n) exposure (5 or 25 cGy) on social odor recognition memory in male Long-Evans rats at one and six months after exposure. At one month postirradiation, all rats displayed a preference for a novel 1 (N1) social odor experienced during the habituation phase. When assessed for recognition memory 24 h later, only sham-irradiated rats spent more time exploring a second novel social odor (novel 2, N2), whereas rats irradiated with 5 or 25 cGy 16O ions did not show a preference for the N2 odor compared to the N1 odor experienced 24 h earlier, thus displaying a memory deficit for recall of the social odor encountered 24 h prior. At six months postirradiation, rats exposed to 25 cGy showed persistent deficits in 24 h recognition memory, while the 5 cGy-exposed rats did not. Thus, 24 h recognition memory was apparently recovered at six months postirradiation for the low, but not the higher, dose of 16O ions. Both irradiated groups displayed similar numbers of Ki67+ cells, a marker of cell proliferation, in the subventricular zone. These results further demonstrate that space-relevant 16O ion exposure has deleterious effects on the CNS, which are related to both radiation dose and time after exposure.
AB - Future long-duration space missions will involve travel outside of the Earth's magnetosphere, which will result in increased radiation exposure for astronauts. Exposure could permanently damage multiple tissues, including the central nervous system (CNS), and result in deleterious effects on cognition and behavior during and beyond the mission. Here, we assessed the effects of whole-body oxygen ion (16O; 1,000 MeV/n) exposure (5 or 25 cGy) on social odor recognition memory in male Long-Evans rats at one and six months after exposure. At one month postirradiation, all rats displayed a preference for a novel 1 (N1) social odor experienced during the habituation phase. When assessed for recognition memory 24 h later, only sham-irradiated rats spent more time exploring a second novel social odor (novel 2, N2), whereas rats irradiated with 5 or 25 cGy 16O ions did not show a preference for the N2 odor compared to the N1 odor experienced 24 h earlier, thus displaying a memory deficit for recall of the social odor encountered 24 h prior. At six months postirradiation, rats exposed to 25 cGy showed persistent deficits in 24 h recognition memory, while the 5 cGy-exposed rats did not. Thus, 24 h recognition memory was apparently recovered at six months postirradiation for the low, but not the higher, dose of 16O ions. Both irradiated groups displayed similar numbers of Ki67+ cells, a marker of cell proliferation, in the subventricular zone. These results further demonstrate that space-relevant 16O ion exposure has deleterious effects on the CNS, which are related to both radiation dose and time after exposure.
UR - http://www.scopus.com/inward/record.url?scp=85042904498&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85042904498&partnerID=8YFLogxK
U2 - 10.1667/RR14849.1
DO - 10.1667/RR14849.1
M3 - Article
C2 - 29332539
AN - SCOPUS:85042904498
SN - 0033-7587
VL - 189
SP - 292
EP - 299
JO - Radiation research
JF - Radiation research
IS - 3
ER -