The effect of chronic low-dose gamma-irradiation on the behavior of mice and their offspring

In the last decade, there has been scientific interest in the potential non-cancer effects of low (<0.1 Gy) and moderate (0.1-0.5 Gy) doses of ionizing radiation. In particular, special attention has been paid to the cognitive and neurodegenerative effects of low-dose radiation therapy for tumors and low doses of gamma- and X-ray radiation after medical procedures. The aim of the work was to study the effect of chronic low-dose -irradiation on the behavior of mice and their offspring in the acute period after the exposure. Male SHK mice (F0, 4 weeks) were totally irradiated with the use of 60Co unit (dose rate 3.9 cGy/day, IBC RAS, Pushchino) until a total dose of 0.1 Gy was accumulated. In 2 weeks after irradiation, the males were crossed with non-irradiated females to obtain F1 offspring. The general activity and anxiety level, spatial learning, long-term and short-term hippocampus-dependent memory were assessed in irradiated males 1 day after exposure, and in offspring – upon reaching the age of 4 weeks. The obtained results revealed the absence of anxiety in both F0 and F1 groups of mice, while animals subjected to long-term gamma-irradiation at a dose of 0.1 Gy were characterized by higher locomotor activity and a reliable increase in the total time spent in the central zone of the open field test. In addition, the irradiated males demonstrated the fastest dynamics of skill acquisition in the Barnes maze with preservation of the memory trace, indicating the absence of disturbances in spatial learning and long-term hippocampus-dependent memory. At the same time, irradiated animals showed a disturbance of episodic memory in the novel object recognition test. Unchanged behavioral pattern and cognitive abilities compared to control animals were observed in the F1 group of mice, indicating the absence of genetic instability in the offspring of irradiated males for the studied behavioral parameters.