Homogeneous longitudinal profiles and synchronous fluctuations of mitochondrial transmembrane potential

This study reports for the first time (a) the longitudinal profile of the t ransmembrane potential (m Delta psi) of single mitochondria using a Nernsti an fluorescent probe and (b) the distribution of m Delta psi fluctuations o f 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 m itochondria, (3) m Delta psi is not influenced by the surrounding cytoplasm ic environment and (4) m Delta psi fluctuations occur simultaneously in gro ups of mitochondria connected in a network. Taken together, these findings provide further evidence for a functional relationship between mitochondria l arrangement and energetic condition, (C) 2000 Federation of European Bioc hemical Societies. Published by Elsevier Science B.V. All rights reserved.