Features of the White Rats’ Neocortex, Archicortex and Amygdala Changes After Acute Ischemia

Abstract

The aim of the study is to evaluate neurons and synapses of the sensorimotor cortex, hippocampus and amygdala of the brain of white rats in the normal state and after 20-minute occlusion of the common carotid arteries. Material and methods. Light microscopy, immunohistochemistry (synaptophysin or P38) and morphometry were used to study the total numerical density of neurons and the area of sections of synaptic terminals of the brain in normal (n=5) and 1, 3, 7, 14, 30 days (n=25) after acute ischemia. Results. Within 30 days of the postischemic period, of the sensorimotor cortex in the layer III irreversible destruction have been 21.5% and in layer V of 19.0% of neurons in field CA 1 of the hippocampus - 33.0%, CA 3 - 17,4%, СА 4 - 5.3% of neurons in the amygdala - the 15.1% average and 6.2% of the large neurons. The decrease in the relative area of P38-positive material of mainly axospines and axodendritic synapses changed the ratio of functioning synapses on the bodies and dendrites of neurons in favor of axosomatic, which are mainly inhibitory. Conclusion. All of this could be the basis of recovery and of dysfunction of interneuronal relationships, predisposing to the development of postischemic encephalopathy.