2020
Volume 20, Number 1, pp. 16-21
Comparative electron microscopic study of the ultrastructure of the hippocampus in adolescent, adult and senescent rats
Nino Lomidze,1 Nino Gogokhia,1 Nino Pochkhidze,1,2 Mzia Zhvania,1,2 Nadezhda Japaridze2 and Tamar Lordkipanidze1,2
1 School of Natural Sciences and Medicine, Ilia State University. 3/5 K. Cholokashvili Avenue, 0162 Tbilisi, Georgia
2 Department of Brain Ultrastructure and Nanoarchitecture, Ivane Beritashvili Centre of Experimental Biomedicine. 14 Gotua Street, 0160 Tbilisi, Georgia
Aging, the time-related decline of physiological functions necessary for survival, affects all individuals of all species. The brain is especially vulnerable to aging. Many neurological and neurodegenerative disorders, including alterations in cognition, are associated with aging. Even normal aging, which is not accompanied by age-related pathological states, is often characterized by changes in cognition. One of the key directions in the neurobiology of aging is the evaluation of aging-related structural changes in brain regions associated with cognition, in order to identify what types of alterations are related to normal aging and what types reflect the onset of age-associated brain disease. Here we elucidate the ultrastructure of the hippocampus in adult male rats. The results revealed almost the same morphology in adolescent and adult rats. The only difference was in the organization of dendritic spines. In senescent animals moderate alterations in a few neurons and synapses were detected. The alterations include the concentration of lipofuscin in neurons, focal chromatolysis of cells, atypical structure of synapses, mild changes of organelles, appearance of small pathological inclusions and signs of compensatory processes. Most of these changes can be considered as age-related.
Keywords: aging, cognition, brain areas, fine morphology