GCOE global education seminar"Composition of postsynaptic proteins during synaptic plasticity"

The postsynaptic density (PSD) contains proteins crucial for synaptic functions, but the molecular architecture retaining its structure and components remains elusive. In this talk, I will first focus on two separate polymeric complexes exist in postsynaptic structure, Homer-Shank and CaMKII-actin. Both are abundant constituents in the PSD and form two or three dimensional polymeric structures, which are important for maintaining postsynaptic and dendritic spine structure. However, they demonstrate very distinct patterns of dynamics during LTP. While CaMKII-actin are delivered to the synapse at very early time point after LTP induction, Homer-Shank did not increase up to 1 hour observation. When we expand our analyses, we observed a predominant increase of actin and actin-binding proteins in early phase of LTP while PSD scaffolding proteins are slow to increase in dendritic spine. There is a clear order of transport of different postsynaptic proteins after LTP induction. This may explain so-called “metaplasticity” phenomenon, where potentiated pathway is more susceptible to depotentiation protocol.