抄録
Mitochondria exhibit dynamic movement and morphological changes. We have labeled mitochondria in cultured hippocampal neurons by expressing mitochondria-targeted fluorescent protein and investigated the intracellular signaling that regulates mitochondrial movement and morphology by real-time imaging. Glutamate-induced NMDA dependent Ca2+ elevation and calcineurin activation resulted in slow onset of cessation of movement and mitochondrial contraction, which is accompanied by cytochrome c release and neuronal death. High-K+ stimulation induced VDCC-dependent Ca2+ influx and CaMKI activation. Then, CaMKI phosphorylated dynamin-related protein 1 (Drp1) and induced Drp1 translocation to mitochondria, led to immediate freezing of movement and mitochondrial division, which protected neuron from excitatory toxicity. These results suggest mitochondrial dynamics and morphology are regulated by channel specific intracellular signaling and these changes control neuronal survival and death. [Jpn J Physiol 55 Suppl:S78 (2005)]
