FEATURES OF THE CASPASE-3 EXPRESSION IN THE HIPPOCAMPUS AT THE MODELLING OF THE EXPERIMENTAL ACUTE EPILEPTIC FIT

Abstract

Epilepsy is one of the most common neurological pathologies, but the biological substrate of the disease is still poorly understood. A few studies have shown that in experimental animals after an epileptic fit there is an increase in the level of some caspases, but the available data are not enough to fully understand the nature of the caspase cascade in epilepsy, and especially its terminal phase. Of particular interest is the analysis of morphological changes in the structures of the hippocampus on the background of an acute epileptic fit in the correlation between neuronal loss and the terminal phase of apoptosis or the quantitative assessment of caspase-3 activity. The aim of the study was the immunohistochemical evaluation of caspase-3 expression in the hippocampus in an experimental model of epilepsy in laboratory mice. The animals were divided into two groups, the animals of the first group (n=28) were intraperitoneally injected with pentilenetetrazole once at a dose of 45 μg/kg to simulate an acute epileptic fit, which was assessed by the modified Racine scale, the second group of animals was the control (n=20). Animals were taken out of the experiment after 3 hours and consecutively on days 1, 3, and 5 from the start of the drug administration for a dynamic study of changes in the hippocampus. Animals were withdrawn from the experiment by introducing high doses of anaesthetic. Animal brain fragments were examined by Nissl staining and caspase-3 expression was quantified by immunohistochemistry in the subregions CA1, CA3 and the dentate gyrus of the hippocampus. 24 hours after the modelling of an acute epileptic fit, the preparations showed signs of hippocampal sclerosis (gliosis, loss of neurons) and an increase in the number of neurons expressing caspase-3 by 2.68 times compared to the number of neurons in the preparations of animals in the control group. As a result of the experiment, it was revealed that the loss of neurons in the hippocampus of the CA3 subregion is associated with an increase in the expression of caspase-3 24 hours after the simulation of an acute generalized seizure using an injection of pentilenetetrazole.