Wehnekamp, F. et al. Elife 8, e46059 (2019)

A new study reports the development of a 3D orbital single particle tracking (SPT) microscope allowing the high-resolution spatiotemporal tracking of individual mitochondria in sensory neurons of zebrafish larvae. Analysis of the 3D trajectory of the moving mitochondria identified 5 five motional states (a fast and a slow directional motion state in both the anterograde and retrograde directions, and a stationary state) and showed that changes in directionality were more likely to occur after longer pauses. Future possible applications of this approach include the use of 3D SPT to link single organelle dynamics to physiological and pathological neuronal changes in vivo.