Homogeneous longitudinal profiles and synchronous fluctuations of mitochondrial transmembrane potential

This study reports for the first time (a) the longitudinal profile of the transmembrane potential (m Delta psi) of single mitochondria using a Nernstian fluorescent probe and (b) the distribution of m Delta psi fluctuations of mitochondria undergoing permanent depolarization. Our findings show that (1) mitochondria in different energetic conditions coexist in the same cell, (2) m Delta psi is rather homogeneous along the entire length of single mitochondria, (3) m Delta psi is not influenced by the surrounding cytoplasmic environment and (4) m Delta psi fluctuations occur simultaneously in groups of mitochondria connected in a network. Taken together, these findings provide further evidence for a functional relationship between mitochondrial arrangement and energetic condition, (C) 2000 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.