Mechanisms of Neurocognitive Adaptation during Aging Process

Human aging is associated with an increased risk of various geriatric syndromes, cognitive impairment being among the most frequent. The most prominent form of the cognitive impairment—dementia—has become one of the major course of dependency in older and oldest old patients. Nevertheless, it has been shown that despite the fact that various parts of the brain change structurally over time due to natural aging or diseases, it does not necessarily manifest into clinical symptoms for some older people. Therefore, there is a dissociation of the severity of morphological and functional brain changes. The review presents current data on adaptive mechanisms that ensure the preservation of neurocognitive activity during aging process. In addition to the concept of brain and cognitive reserves, it discusses different mechanisms of neurocognitive maintenance and compensation both in the norm and in the development of Alzheimer’s disease. The possibility of their clinical and instrumental assessment and practical significance are discussed.