Theoretical model of postsynaptic AMPA receptor trafficking during synaptic plasticity

Abstract

Excitatory synaptic strength is reported to be positively related to the number of AMPARs in
postsynaptic domain (PSD), which indeed actively transfer among postsynaptic density, extrasynaptic
membrane (ESM), and dendritic cytosol. In this paper a biophysical model is developed
to dissect the kinetics of AMPAR trafficking in equilibrium as well as during induction of synaptic
plasticity. The analytical solutions are derived for both timescales of AMPAR exocytosisendocytosis
and equilibrium distribution of AMPARs. Our model indicates differential roles of
transition rates playing in inducing synaptic potentiation or depression, which include rate of
AMAPR exocytosis, rate of AMPAR endocytosis, and AMPAR hopping rate between PSD and
ESM region. In summary, our work highlights the underlying mechanism for AMPAR trafficking
during dynamic equilibrium and synaptic plasticity, and provides mathematical insights that
could be learned from to treat neurological diseases related to malfunctions of AMPAR
movement.