Acute, Low-Dose Neutron Exposures Adversely Impact Central Nervous System Function.
A recognized risk of long-duration space travel arises from the elevated exposure astronauts face from galactic cosmic radiation (GCR), which is composed of a diverse array of energetic particles. There is now abundant evidence that exposures to many different charged particle GCR components within acute time frames are sufficient to induce central nervous system deficits that span from the molecular to the whole animal behavioral scale. Enhanced spacecraft shielding can lessen exposures to charged particle GCR components, but may conversely elevate neutron radiation levels. We previously observed that space-relevant neutron radiation doses, chronically delivered at dose-rates expected during planned human exploratory missions, can disrupt hippocampal neuronal excitability, perturb network long-term potentiation and negatively impact cognitive behavior. We have now determined that acute exposures to similar low doses (18 cGy) of neutron radiation can also lead to suppressed hippocampal synaptic signaling, as well as decreased learning and memory performance in male mice. Our results demonstrate that similar nervous system hazards arise from neutron irradiation regardless of the exposure time course. While not always in an identical manner, neutron irradiation disrupts many of the same central nervous system elements as acute charged particle GCR exposures. The risks arising from neutron irradiation are therefore important to consider when determining the overall hazards astronauts will face from the space radiation environment.
['Klein|Peter M|PM|0000-0002-3232-3387', 'Alaghband|Yasaman|Y|', 'Doan|Ngoc-Lien|NL|0000-0002-4901-621X', 'Ru|Ning|N|', 'Drayson|Olivia G G|OGG|', 'Baulch|Janet E|JE|', 'Kramár|Enikö A|EA|', 'Wood|Marcelo A|MA|', 'Soltesz|Ivan|I|', 'Limoli|Charles L|CL|']
D000818:Animals D001522:Behavior, Animal D003359:Cosmic Radiation D006624:Hippocampus D008297:Male D008568:Memory D051379:Mice D009473:Neuronal Plasticity D009502:Neutrons
neutrons long-term potentiation space radiation cognitive dysfunction electrophysiology