Morphological criteria of hypothalamus aging

Scientific research is devoted to the study of the morphological and functional organization of hypothalamus magno- and parvocellular nuclei in postnatal ontogenesis. Material for the study was the hypothalamus of 20 male rats Wistar line 3 and 24 months old. The following methods were used: histological (material was fixed in formol-alcohol solution, paraffin blocks were produced, sections were stained according to Nissl), electron-microscopic and immunohistochemical (detection of apoptotic cells by TUNEL-method (Apop Tag Plus Peroxidase In Situ Apoptosis Detection Kit), made by ?Milliporen?, USA). The main morphological criteria of magno- and parvocellular nuclei aging were found, namely the decrease of neurons and capillaries numerical density on the background of glial cells and glial index numerical density decrease; increase of TBA-active production on the background of catalase and ceruloplasmin activity decrease that leads to an increase in the number of vacuolated neurons. Violation of neuron-glial-capillary ratio and activation of lipid peroxidation processes leads to an increase in the apoptotic neurons number and apoptotic index in the hypothalamus, namely in the 24-month-old animals compared to 3-month-old the number of apoptotic neurons increases in insupraoptic nucleus to 0.66 ± 0.21 (p = 0.019) in paraventricular nucleus to 0.50 ± 0.22 (p = 0.045), in the arcuate nucleus to 1.17 ± 0.16 (p = 0.006), in ventromedial nuclei? to 1.33±0.21 (р=0.014). Apoptotic index in hypothalamus magnocellular nucleus (supraoptic and paraventicular) ranges between 0-1%, while in parvocellular nuclei (arcuate and ventromedial) it increases to 1-2%. Thus, the aging process is more distinct in parvocellular nuclei of the hypothalamus.