Decoding the mechanisms of amyloid-β in synaptic toxicity

Area of Science:

• Neuroscience
• Pathophysiology
• Alzheimer's Disease Research

Background:

• Amyloid-beta (Aβ) aggregation is a key feature in Alzheimer's disease (AD) pathophysiology.
• Aβ aggregates disrupt synaptic function, calcium balance, and mitochondrial health, causing excitotoxicity and impairing synaptic plasticity.
• Early synaptic and neuronal circuit alterations precede irreversible damage and cognitive decline in AD.

Purpose of the Study:

• To review the diverse effects of Aβ across its aggregation states (monomeric, oligomeric, protofibrillar, fibrillar) on synaptic and neuronal circuits.
• To comprehensively map Aβ-induced mechanisms disrupting neuronal electrical function using electrophysiological evidence.
• To focus on preclinical stages of cognitive decline in Alzheimer's disease.

Main Methods:

• Review of electrophysiological evidence from neuronal cultures.
• Analysis of data from animal models of Alzheimer's disease.
• Examination of studies involving human patients with cognitive decline.

Main Results:

• Aβ aggregation, in various forms, significantly impacts neuronal electrical function and synaptic integrity.
• Electrophysiological data reveal specific mechanisms by which Aβ disrupts neuronal activity.
• Synaptic alterations occur early, before significant cognitive impairment, highlighting preclinical AD pathology.

Conclusions:

• Aβ-induced synaptic toxicity is a critical factor in early AD pathogenesis.
• Aβ synaptic toxicity can potentially serve as a biomarker for brain deterioration in AD.
• This synaptic toxicity may also function as a readout for evaluating the efficacy of current AD therapies.