Internal seminar - Jonas Ranft

Abstract: 

Synaptic strength is the key determinant for network function and is thought to underlie learning and memory. A rough proxy for synapse strength is the size of the postsynaptic domain (PSD), which is largely constituted of scaffold proteins that provide binding sites for neurotransmitter receptors. Yet how exactly PSD size is regulated or maintained remains unclear, not least because PSDs of both excitatory and inhibitory synapses are highly dynamic structures with a constant exchange between intra- and extrasynaptic pools. Inspired by synaptic domains but on a more theoretical note, I will first discuss models of non-equilibrium domain formation in the presence of particle turnover. I will then present more recent work where by combining advanced imaging techniques and biophysical modeling of PSD formation and maintenance, we quantitatively characterized receptor and scaffold protein kinetics at inhibitory synapses, highlighting in particular the importance of receptor-scaffold interactions for stable synaptic receptor copy numbers. More generally, I aim to show how hypothesis-driven modeling can drive new prediction-driven experiments, which in turn allow us to refine our theoretical understanding of underlying processes.