Unraveling the molecular links: Alzheimer's disease-induced mechanisms of memory impairment: A narrative review

Alzheimer's disease (AD) is a complex neurodegenerative disorder characterized by progressive memory impairment and cognitive decline, significantly impacting the quality of life for millions worldwide. Understanding the intricate molecular pathways linking AD pathology to memory dysfunction is crucial for developing effective therapies. This narrative review aims to elucidate the key molecular mechanisms underlying memory impairment in AD. We conducted a comprehensive literature search across major scientific databases (e.g., PubMed, Scopus, Web of Science) focusing on peer-reviewed studies (original research, reviews) exploring the molecular links between AD pathology and memory deficits. The review identifies and details several interconnected molecular pathways driving memory impairment in AD: (1) Synaptic dysfunction and neuronal loss triggered by amyloid-β (Aβ) peptide accumulation and aggregation; (2) Intracellular transport disruption and neurodegeneration caused by tau protein hyperphosphorylation and aggregation; (3) Exacerbation of cognitive deficits by neuroinflammation, mediated through activated microglia and pro-inflammatory cytokines (e.g., IL-1β, TNF-α, IL-6); (4) Impairment of synaptic plasticity and cognitive function due to dysregulation of neurotrophic factors, particularly brain-derived neurotrophic factor; (5) Contributory roles of oxidative stress, mitochondrial dysfunction, disrupted neurotransmission (e.g., acetylcholine, GABA), and apoptotic pathways. This review comprehensively unravels the critical molecular links between AD pathology and memory impairment, emphasizing the interplay of Aβ, tau, neuroinflammation, neurotrophic factor dysregulation, and other mechanisms. Targeting these interconnected pathways represents a promising strategic approach for developing therapies to mitigate cognitive decline and improve outcomes in AD patients.