The influence of the long-term emotional pain stress on the methylation of histone H3 in the cells of the hippocampus and amygdala of rats with different excitability of the nervous system

Abstract

We performed an immunohistochemical study of histone H3 methylation at lysine 4 (H3K4medi+ tri) in the neurons of the hippocampus (CA3 area) and basolateral amygdala in rats with different levels of nervous system excitability under normal conditions and at different time points (24 hours, 2 weeks, and 2 months) after long-term emotional pain stress (LEPS). We found higher immunoreactivity of cells in both brain structures under normal conditions in the control groups of low-excitability rats of the HT strain in comparison with high-excitability rats of the LT strain. We describe the structural and temporal patterns of the influence of long-term emotional pain stress on the level of histone H3 methylation (K4), which depend on the excitability of the nervous system of the examined strains.