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Updated: May 17, 2026
04:41
Preparation of Oligomeric β-amyloid1-42 and Induction of Synaptic Plasticity Impairment on Hippocampal Slices
Published on: July 14, 2010
Effects of different amyloid β-protein analogues on synaptic function
Cristian Ripoli1, Roberto Piacentini, Elisa Riccardi
1Institute of Human Physiology, Università Cattolica, Rome, Italy.
Neurobiology of Aging
|October 11, 2012
Summary
Oxidation of methionine 35 in amyloid-beta 42 (Aβ42) is critical for its toxic effects on synapses in Alzheimer's disease. This oxidation prevents Aβ42 from impairing synaptic function and structure.
Area of Science:
- Neuroscience
- Molecular Biology
- Biochemistry
Background:
- Perisynaptic amyloid-beta protein (Aβ) aggregates are implicated in Alzheimer's disease (AD) cognitive decline.
- Oxidation of methionine at position 35 (Met35) in Aβ is a hallmark of AD brains.
Purpose of the Study:
- To investigate the role of Met35 oxidation in Aβ42-induced synaptotoxicity.
- To determine if oxidized Aβ42 (Met35 sulfoxide) retains its ability to impair synaptic function.
Main Methods:
- Electrophysiological recordings in hippocampal slices and autaptic neurons.
- Assessment of synaptic transmission, including long-term potentiation and basal synaptic transmission.
- Evaluation of Aβ42 effects on dendritic spine density and key pre- and postsynaptic protein expression.
Main Results:
- Wild-type Aβ42 significantly inhibited long-term potentiation and basal synaptic transmission, reducing excitatory postsynaptic current amplitude, vesicle release probability, and miniature excitatory postsynaptic current frequency.
- Aβ42 with oxidized Met35 (Met35 sulfoxide) did not cause these impairments.
- Extended Aβ exposure affected presynaptic and postsynaptic function, dendritic spine density, and protein expression, with oxidized Aβ42 showing reduced impact.
Conclusions:
- Oxidation of Met35 is crucial for the molecular, structural, and functional synaptotoxicity of Aβ42.
- Targeting Met35 oxidation could be a therapeutic strategy for Alzheimer's disease.
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