Determination of Features from Super-Resolution Data

Abstract

Stochastic narrow escape arises in the problem of determining physical features of a neuronal membrane from a large number of short receptor trajectories generated by the method of single particle tracking with photo-activated localization microscopy (sptPALM) applied to diffusing molecules (Manley et al. 2008) or AMPARs on hippocampal cultured neurons (Hoze et al. 2012). The features, such as potential wells and narrow passages, can be determined from long dwell times of the trajectories in certain parts of the neuronal membrane. However, the dwell time of a receptor diffusing in a microdomain on a neuronal membrane cannot be obtained directly from the short recorded fragments of trajectories, because they are much shorter than the dwell times in potential wells and than NETs from other traps. Moreover, longer trajectories obtained by other techniques (such as quantum dot) provide only partial sampling of space-time, which cannot be used to compute transition probabilities between different regions.