Morphological characteristics of secretory neurons of the nuclei of the hypothalamus under the influence of dark deprivation in female rats

In an experiment on 4-month-old mongrel female rats, the effect of 30-day dark deprivation (light-dark mode 24/0 h, artificial illumination 300 Lux) on the suprachiasmatic and arcuate nuclei of the hypothalamus was studied. The study showed that with constant artificial lighting for 30 days, the morphometric parameters of the SCN of hypothalamus decrease: the area and volume of the SCN pericaryon by 8.6 % (p 0.001) and 4.6 % (p 0.001); the area and volume of the nucleus by 7.6 % (p 0.05) and 11.6 %. A decrease in the size of the AN was revealed: the area and volume of the pericaryon by 41.3 % (p 0.001) and 56.8 % (p 0.001); the area and volume of the core increased by 42.7 % (p 0.001) and 54.4 % (p 0.001). The morphometric characteristics of SCN and AN were almost completely restored to the values of the control group within 14 days after the cancellation of dark deprivation, which reflects the processes of reversible damage to neurons due to the implementation of compensatory adaptive mechanisms.