UMMS Affiliation

Department of Cell Biology

Publication Date


Document Type



Amyloid beta-Peptides; Animals; Calcium; Cell Membrane; Cells, Cultured; Cyclin-Dependent Kinase 5; Down-Regulation; Frontal Lobe; Glutamic Acid; Humans; Intracellular Signaling Peptides and Proteins; inhibitors; Membrane Proteins; N-Methylaspartate; Nerve Tissue Proteins; Neurons; Peptide Fragments; Proteasome Endopeptidase Complex; Rats; Rats, Wistar; Receptors, AMPA; Receptors, N-Methyl-D-Aspartate; Solubility; Synapses


Cell Biology


Amyloid-beta (Abeta) has been implicated in memory loss and disruption of synaptic plasticity observed in early-stage Alzheimer's disease. Recently, it has been shown that soluble Abeta oligomers target synapses in cultured rat hippocampal neurons, suggesting a direct role of Abeta in the regulation of synaptic structure and function. Postsynaptic density-95 (PSD-95) is a postsynaptic scaffolding protein that plays a critical role in synaptic plasticity and the stabilization of AMPA (AMPARs) and NMDA (NMDARs) receptors at synapses. Here, we show that exposure of cultured cortical neurons to soluble oligomers of Abeta(1-40) reduces PSD-95 protein levels in a dose- and time-dependent manner and that the Abeta1(1-40)-dependent decrease in PSD-95 requires NMDAR activity. We also show that the decrease in PSD-95 requires cyclin-dependent kinase 5 activity and involves the proteasome pathway. Immunostaining analysis of cortical cultured neurons revealed that Abeta treatment induces concomitant decreases in PSD-95 at synapses and in the surface expression of the AMPAR glutamate receptor subunit 2. Together, these data suggest a novel pathway by which Abeta triggers synaptic dysfunction, namely, by altering the molecular composition of glutamatergic synapses.

DOI of Published Version



J Neurosci. 2005 Nov 30;25(48):11061-70. Link to article on publisher's site

Journal/Book/Conference Title

The Journal of neuroscience : the official journal of the Society for Neuroscience

Related Resources

Link to Article in PubMed

PubMed ID


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Cell Biology Commons