Problems of Radiation Medicine and Radiobiology

K. Loganovsky, K. Kuts

State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», Melnykova str., 53, Kyiv, 04050, Ukraine

Evoked bioelectrical brain activity following exposure to ionizing radiation

The article provides an overview of modern physiological evidence to support the hypothesis on corticolimbic system dysfunction due to the hippocampal neurogenesis impairment as a basis of the brain interhemispheric asymmetry and neurocognitive deficit after radiation exposure. The importance of the research of both evoked potentials and fields as a highly sensitive and informative method is emphasized.
Particular attention is paid to cerebral sensor systems dysfunction as a typical effect of ionizing radiation. Changes in functioning of the central parts of sensory analyzers of different modalities as well as the violation of brain integrative information processes under the influence of small doses of ionizing radiation can be critical when determining the radiation risks of space flight. The possible longterm prospects for manned flights into space, including to Mars, given the effects identified are discussed. Potential risks to the central nervous system during space travel comprise cognitive functions impairment, including the volume of short-term memory shortening, impaired motor functions, behavioral changes that could affect human performance and health. The remote risks for CNS are considered to be the following possible neuropsychiatric disorders: accelerated brain aging, Alzheimer’s disease and other types of dementia. The new radiocerebral dosedependent effect, when applied cognitive auditory evoked potentials P300 technique with a possible threshold dose of 0.05 Gy, manifesting in a form of disruption of information processing in the Wernicke’s area is under discussion. In order to identify neurophysiological biological markers of ionizing radiation further international researches with adequate dosimetry support are necessary.
Key words: neurocognitive deficit, central nervous system, ionizing radiation, accelerated aging, cognitive evoked potentials, Mars.

Problems of radiation medicine and radiobiology. 2017;22:38-68.