Genome destabilization under stress in cells of the prefrontal cortex, hippocampus and bone marrow of rats with contrast excitability of the nervous system

Abstract

We studied changes in the stability of the genome in cells of two brain regions (prefrontal cortex and hippocampus), as well as in the bone marrow of rats with a hereditary high and low thresholds of excitability of the nervous system (strains HT and LT, respectively) after prolonged exposure with emotional-pain stressor. To study the reactivity of the brain cells genome, phosphorylated histone -H2AX (-H2AX phospho Ser139) was used. The level of mitotic disturbances in bone marrow cells was also assessed. Between the animals of the control groups, there were no interstrain differences in the studied parameters. Stress exposure increases the immunoreactivity to -H2AX phospho Ser139 of the prefrontal cortex cells and the level of chromosomal aberrations in bone marrow cells in animals of both strains. In cells of the dentate gyrus of the hippocampus, a specific increase in immunoreactivity to -H2AX phospho Ser139 was revealed in rats of the low-excitable HT strain. The relationship between the reaction of cells of this zone of hippocampus to the stressor exposure with the hereditary level of excitability of the nervous system of animals is discussed.

Genome response of hippocampal cells to stress in male rats with different excitability of the nervous system

“…It was shown earlier that 2 hrs after PEPS, the cells of PFC of both HT and LT rats increase their reactivity to H2AX phosphoSer139, which is a marker of doublestrand breaks. At the same time, a dentate gyrus's cells show a similar increase only in HT rats (Pavlova et al, 2020). It is possible that the varied genome response to the same stressor is based on specific functional interactions of different brain areas.…”

“…The latter may be involved in the initiation and maintenance of pathological states. Moreover, this may or may not be related to inherited features of the animal's nervous system (Pavlova et al, 2020;Sivachenko et al, 2021).…”