Measuring Mitochondrial Shape with ImageJ

Mitochondria are shaped by opposing fission (division) and fusion events. Mounting evidence indicates that mitochondrial shape influences numerous aspects of mitochondrial function, including ATP production, Ca2+ buffering, and quality control. Despite the recognized importance of mitochondrial dynamics, the literature is rife with subjective, categorical estimates of mitochondrial morphology, preventing reliable comparison of results between groups. This chapter describes stringent, but easily implemented methods for quantification of mitochondrial shape changes using the open-source software package ImageJ. While we provide examples for analysis of epifluorescence images of cultured primary neurons, these methods are easily generalized to other cell types and imaging techniques.