CHANGES IN THE CEREBRAL CORTEX NEURON ULTRASTRUCTURE IN RATS WITH PARTIAL CEREBRAL ISCHEMIA

The ultrastructural characteristics of neuronal organelles are significant indicators of brain damage under ischemic exposure, which necessitates the study of changes in the ultrastructure of brain neurons. The aim of the study was to examine the disorders of brain neurons under its partial ischemia at the ultrastructural level using an experimental model. Materials and Methods. The experimental group included 12 male rats weighing 260±20 g, the control group consisted of 6 falsely operated male rats of the same weight. Partial cerebral ischemia (PCI) was modeled by right common carotid artery ligation. The material was taken 1 hour after the operation. Results. The study showed that the size and shape of the mitochondria of neurons of the parietal cortex and the hippocampus in PCI rats did not differ from those of the control group (p>0.05), except for a smaller number of cristae per unit area in the mitochondria of parietal cortex neurons (by 18 %, p<0.05). The size and shape of the Golgi complex and lysosomes did not differ in the groups either. However, there was an increase in the number of free ribosomes in the cytoplasm of neurons in the parietal cortex and hippocampus of PCI rats, by 58 % and 54 %, respectively (p<0.05). The ratio of fixed and free ribosomes in control rats decreased from 3.4 to 0.8 in the parietal cortex (p<0.05) and from 2.33 to 0.7 in the hippocampus (p<0.05). Conclusions. In general, the neuron ultrastructure in PCI rats was similar to that in the control group, which might be due to blood flow compensation in the circle of Willis. An increase in the number of free ribosomes is a sign of deranged protein biosynthesis in neurons. A decrease in the number of mitochondrial cristae in neurons in the parietal cortex indicates energy deficiency.