The neurobiology of dementia: Spatial and temporal dynamics of Alzheimer's disease major biomarkers

Abstract

Dementia, with most prevailing cause Alzheimer's disease (AD), is a condition characterized by memory loss and decline of other cognitive functions, of particular severity to affect one's routine. AD illustrates as an array of symptoms permeating thinking, planning and implementation. It has been commonly described as senility, due to the prevalence of the condition among the elderly, and attributed to the general diminution of body functions. In the past decades, researchers highlighted a single molecular mechanism in the development of AD and confirmed the role of amyloid β-protein (Aβ) in neurodegeneration. However, dementia, as well as AD, is still considered to be prompted by multiple factors and botched processes, including Aβ precursor severing, Aβ deposition and clearance, τ metabolism, protein trafficking, lipid recycling, neuroinflammation and redox signaling. Surprisingly, these processes are affected by aging; metabolism and stress leave their hallmarks in the adult brain during the asymptomatic period, and momentum is imposed by the genetic background. The impairment of cholinergic signaling has been also implicated in AD manifestation. However, recently serotonin (5-HT) signaling, and especially 5-HT6 receptor functionality, has been emerging as a possible culprit for cognitive decline. These findings accentuate the contribution of mood and emotions to memory consolidation and retrieval and they further emphasize on a multimodal approach in preventing and treating dementia, beyond the classical therapeutic schemes. © 2018 P.Ziti and Co. All rights reserved.