Mitochondrial Ca2+ signalling in hippocampal neurons.

Autor: Young, Kenneth W., Bampton, Edward T.W., Pinòn, Lucia, Bano, Daniele, Nicotera, Pierluigi
Předmět:
Zdroj: Cell Calcium; Mar2008, Vol. 43 Issue 3, p296-306, 11p
Abstrakt: Abstract: High-resolution fluorescent imaging of mitochondrial-targeted probes was used to examine the ability of mitochondria to decode complex spatial and temporal Ca2+ signals evoked in synaptically active networks of hippocampal neurons. Green-to-red photoconversion of the mitochondrial-targeted probe, mito-Kaede, demonstrated that mitochondria were present as discrete organelles 2–6μm in length. Real-time imaging of mitochondrial-targeted ratiometric pericam (2 mtRP) visualised rapid, repetitive, transient mitochondrial Ca2+ fluxes in response to periods of synaptic activation. Mitochondrial Ca2+ fluxes within cellular compartments were dependent on the extent of synaptic recruitment, but independent of cross-talk with the endoplasmic reticulum or the presence of an interconnected mitochondrial network. Mitochondria in dendritic regions demonstrated a greater sensitivity to synaptic activation compared with somatic mitochondria. Temporal decoding of synaptic signals was rate-limited by the activity of the mitochondrial Na+/Ca2+ exchanger. Spatial regulation of mitochondrial Ca2+ uptake was determined by the magnitude of the cytosolic Ca2+ rise in each cellular compartment. [Copyright &y& Elsevier]
Databáze: Supplemental Index