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Updated: Jan 25, 2026

A High-content Assay for Monitoring AMPA Receptor Trafficking
Published on: January 28, 2019
Acute inactivation of PSD-95 destabilizes AMPA receptors at hippocampal synapses
Guillermo A Yudowski1, Olav Olsen, Hillel Adesnik
1Department of Anatomy & Neurobiology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico. Guillermo.yudowski@upr.edu
Abstract:
Postsynatptic density protein (PSD-95) is a 95 kDa scaffolding protein that assembles signaling complexes at synapses. Over-expression of PSD-95 in primary hippocampal neurons selectively increases synaptic localization of AMPA receptors; however, mice lacking PSD-95 display grossly normal glutamatergic transmission in hippocampus. To further study the scaffolding role of PSD-95 at excitatory synapses, we generated a recombinant PSD-95-4c containing a tetracysteine motif, which specifically binds a fluorescein derivative and allows for acute and permanent inactivation of PSD-95. Interestingly, acute inactivation of PSD-95 in rat hippocampal cultures rapidly reduced surface AMPA receptor immunostaining, but did not affected NMDA or transferrin receptor localization. Acute photoinactivation of PSD-95 in dissociated neurons causes ∼80% decrease in GluR2 surface staining observed by live-cell microscopy within 15 minutes of PSD-95-4c ablation. These results confirm that PSD-95 stabilizes AMPA receptors at postsynaptic sites and provides insight into the dynamic interplay between PSD-95 and AMPA receptors in live neurons.
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