We have shown previously that synaptic AMPA receptor (AMPAR) accumulation can be bidirectionally adjusted within a few hours after changes in network activity (Wierenga et al., 2005; Ibata et al., 2008). We are now examining the biophysical and molecular mechanisms underlying bidirectional AMPAR accumulation characterized by synaptic scaling. Using a combination of FRAP, PAGFP photoactivation and modeling approaches, we are currently investigating the AMPAR turnover during synaptic scaling. Our data suggest that scaling up and down are not reciprocal processes, but instead are achieved by targeting distinct biophysical pathways of receptor turnover.
 
We are also probing the molecular mechanism of synaptic scaling by focusing on PSD-95, a postsynaptic protein that is important for regulating synaptic transmission and is suggested to contribute to some forms of synaptic plasticity. Our data suggest that PSD-95 plays distinct and developmentally regulated roles in synaptic scaling up and down.
Synaptic Scaling, AMPAR and Scaffolding Protein Dynamics
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Ibata, Sun & Turrigiano, 2008.
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