Synaptic Plasticity, Dementia and Alzheimer Disease

Area of Science:

• Neuroscience
• Neuroplasticity
• Neurodegenerative Diseases

Background:

• Neuroplasticity modulates responses to neuronal injury and activity, involving structural and functional changes in neurons.
• Neurodegenerative diseases, like Alzheimer's disease (AD), present significant challenges, with research shifting towards mechanistic understanding.
• Neuropathological hallmarks of AD include amyloid-beta (Aβ) plaques and tau tangles, with early synaptic dysfunction linked to soluble Aβ oligomers.

Purpose of the Study:

• To provide a critical overview of synaptic dysfunction in neurodegenerative diseases, focusing on Alzheimer's disease.
• To explore both amyloid- and non-amyloid-driven mechanisms underlying synaptic dysfunction in AD.
• To review emerging therapeutic strategies for cognitive and memory deficits in AD.

Main Methods:

• Review of current knowledge on synaptic plasticity and its modulation.
• Analysis of neuropathological findings in Alzheimer's disease, particularly the role of amyloid-beta.
• Examination of molecular mechanisms affecting synaptic structure and function, including dendritic spines.

Main Results:

• Soluble Aβ oligomers can impair synaptic structure and plasticity at low concentrations, preceding widespread neurodegeneration.
• Loss of dendritic spine density is associated with cognitive impairment in AD, though mechanisms are under investigation.
• Both amyloid-dependent and independent pathways contribute to synaptic dysfunction in neurodegenerative conditions.

Conclusions:

• Synaptic dysfunction is a critical early event in Alzheimer's disease pathogenesis.
• Targeting synaptic mechanisms offers potential therapeutic avenues for AD.
• Further elucidation of molecular pathways is needed to develop effective treatments for cognitive decline.