説明
<jats:p>Using the mitochondrial membrane potential (ΔΨ<jats:sub>m</jats:sub>)-sensitive fluorescent dyes 5,5′,6,6′-tetrachloro-1,1′,3,3′-tetraethylbenzimidazolocarbocyanine iodide (JC-1) and tetramethylrhodamine methyl ester (TMRM), we have observed spontaneous changes in the ΔΨ<jats:sub>m</jats:sub>of cultured forebrain neurons. These fluctuations in ΔΨ<jats:sub>m</jats:sub>appear to represent partial, transient depolarizations of individual mitochondria. The frequency of these ΔΨ<jats:sub>m</jats:sub>fluctuations can be significantly lowered by exposure to a photo-induced oxidant burden, an ATP synthase inhibitor, or a glutamate-induced sodium load, without changing overall JC-1 fluorescence intensity. These spontaneous fluctuations in JC-1 signal were not inhibited by altering plasma membrane activity with tetrodotoxin or MK-801 or by blocking the mitochondrial permeability transition pore (PTP) with cyclosporin A. Neurons loaded with TMRM showed similar, low-amplitude, spontaneous fluctuations in ΔΨ<jats:sub>m</jats:sub>. We hypothesize that these ΔΨ<jats:sub>m</jats:sub>fluctuations are dependent on the proper functioning of the mitochondria and reflect mitochondria alternating between the active and inactive states of oxidative phosphorylation.</jats:p>
収録刊行物
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- The Journal of Neuroscience
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The Journal of Neuroscience 21 (14), 5054-5065, 2001-07-15
Society for Neuroscience