Reactivity of primary astrocytes after exposure to ionizing radiation

Abstract

The progress of humankinds crewed missions into space and to planets or moons of our solar system is strongly increasing and will become a fundamental headstone of any space-related research. Astronauts will encounter different types of space radiation during their operations, which might cause cognitive deficits, such as negative effects on learning, attention, elevated anxiety and depression. Astrocytes have supporting function in the brain, for example in immune response to any insult to the central nervous system (CNS) and play an important role in sustaining neurons’ function. Aim of this work was to investigate the effects of ionizing radiation on the reactivity of astrocytes, since activated astrocytes can have beneficial or detrimental effects in the radioresponse of the CNS and might serve as therapeutical target to prevent radiation-caused cognitive decline. This was conducted by immunostaining of X-, or heavy-ion (12C) irradiated astrocytes to measure the expression of glial fibrillary acidic protein (GFAP), an astrocyte marker for reactivity. No significant changes in expression of GFAP, neither dose- nor time-dependent, were observed after X-irradiation. Irradiation with heavy ions (12C), seems to result in effects on astrocyte reactivity, depending on time, but not dose-dependent. In conclusion, astrocyte reactivity is a complex mechanism that could not be proven to be activated by ionizing radiation in this work, and needs to be further investigated in different experimental set-ups to be fully understood and to be potentially applied as target to prevent cognitive decline in astronauts during space missions.