Psycho-emotional status but not cognition is changed under the combined effect of ionizing radiations at doses related to deep space missions

Abstract

Human spaceflight launch is the big challenge that the humanity work on. The astronauts’ task performance vulnerability to ionizing radiations is one of the major factors limiting deep space missions. In this work, we study the effect of ionizing radiations (γ-quanta and 12C6+ in combination) on cognitive abilities and psycho-emotional status of Wistar rats. Irradiation led to the hyperlocomotion, increase of anxiety-like behavior, suppression of depressive-like behavior and enhancement of spatial learning. These data are consistent with the neurochemical/molecular analysis: enhanced monoaminergic innervation within the hypothalamus (HYP), inhibition of serotonin turnover in the prefrontal cortex and neurokenin 1 receptor overexpression in the amygdala (AMY). In addition, we observe decreased expression of certain biomolecules in the AMY (5-HT2c and 5-HT3) and in the HYP (5-HT2a, 5-HT4 and VMAT2) that can be explained as neuroadaptive changes. Thus, the ionizing radiation exposure significantly modulates the psycho-emotional status. With that, for the first time we received data that radiation effects in the doses and composition of interplanetary space (in terrestrial modeling) could be relatively safe for cognitive functions.