MORPHOFUNCTIONAL ACTIVITY OF NEURONS OF SUPRAOPTIC NUCLEI OF RAT HYPOTHALAMUS UNDER STRESS

Abstract

The article discusses the study results of the morphofunctional state of supraoptical nuclei neurons of the rat hypothalamus under conditions of different duration of light regime. Under standard light conditions in rats, the diurnal rhythm of the morphofunctional activity of supraoptical neurons with a maximum of activity in the daytime is recorded (up to 2 p.m.). In animals exposed to prolonged light effect, more pronounced changes in the morphofunctional state of the neurons of the supraoptical nuclei of the hypothalamus are observed at 2 a.m., as compared to 2 p.m. Thus, the area of the nucleus of the neuron is 94.08±9.55 μm2 and is significantly larger than that in intact animals. The nuclear-cytoplasmic ratio of the neuron of the supraoptical nuclei of the hypothalamus at 2 a.m. is lower than that in intact animals due to a decrease in the specific volume of the nucleus. Compared with the daytime period (2 p.m.), up to 2 a.m., a decrease in the body area of the neurons of the supraoptical nuclei of the hypothalamus is revealed, which is due to a possible decrease in the area of the nucleus and nucleoli of the cells. This cause an increase in the night-time observation of the nuclearcytoplasmic ratio in the studied neurons, which amounts to 2.51±0.023 units. Constant light mode does not cause an inversion of the rhythm of the morphofunctional activity of the studied neurons; maximum values, as in intact animals, occur in the daytime observation period.