abstract: Recent developments of super-resolution microscopy techniques allows to image and track different types of individual molecules in living cells with resolutions of tens of nanometers. The theoretical analysis of such trajectories, for characterizing the type of motion and its characteristics, has however not been much developed, a large part of the conducted analyzes remaining static or based on mean squared displacement.
Our group previously developed a methodology to analyze trajectories based on the Smoluchowski limit of the Langevin Equation, characterizing local estimators for untangling deterministic forces acting on the molecules from thermal fluctuations. These estimators however rely on large number of redundant trajectories that cannot be attained when only few molecules of a type are used locally by the cell or the molecules exhibit very heterogeneous motion or the geometry of the domain imposes strong constraints on their motion.
I will present recent advances of the group where we characterized. 1. a flow motion for the luminal Endoplasmic Reticulum (ER) protein calreticulin made possible by previously reconstructing the ER network from the trajectories and 2. transient arrests of the voltage dependent calcium channels CaV2.1 at active zones of hippocampal synapses and the quantification of confinement times.