Spatially organised mitochondrial calcium uptake through a novel pathway in chick neurones.
AuthorsCoatesworth W, Bolsover S
JournalCell Calcium
PubMed ID16338004
'A brief depolarisation of chick sensory neurones evokes a calcium increase in mitochondria that peaks 1-2s after the depolarisation event and then decays over tens of seconds. Peripheral mitochondria take up more calcium than do central ones, even when the cytosolic calcium increase is spatially homogeneous. The calcium influx into ... More
Modulation of [Ca2+]i signaling dynamics and metabolism by perinuclear mitochondria in mouse parotid acinar cells.
AuthorsBruce JI, Giovannucci DR, Blinder G, Shuttleworth TJ, Yule DI
JournalJ Biol Chem
PubMed ID14699167
'Parotid acinar cells exhibit rapid cytosolic calcium signals ([Ca2+]i) that initiate in the apical region but rapidly become global in nature. These characteristic [Ca2+]i signals are important for effective fluid secretion, which critically depends on a synchronized activation of spatially separated ion fluxes. Apically restricted [Ca2+]i signals were never observed ... More
Imaging mitochondrial calcium signalling with fluorescent probes and single or two photon confocal microscopy.
AuthorsDavidson SM, Duchen MR,
JournalMethods Mol Biol
PubMed ID22057570
The concentration of calcium ions in the mitochondria has a profound impact on mitochondrial function, modulating respiratory activity at physiological concentrations, while causing lethal damage during calcium overload. The ... More
Predicting and avoiding subcellular compartmentalization artifacts arising from acetoxymethyl ester calcium imaging probes. The case of fluo-3 AM and a general account of the phenomenon including a problem avoidance chart.
AuthorsThompson K, Dockery P, Horobin RW,
JournalBiotech Histochem
PubMed ID22984940
Stimulated by difficulties experienced when using fluo-3 AM, we developed a general mechanistic model to aid understanding and practical application of calcium probes applied as acetoxymethyl (AM) esters. Several practical issues previously overlooked or under-emphasized are considered by this model. First, some AM ester probes are ... More
Spatially discordant alternans in cardiomyocyte monolayers.
Authorsde Diego C, Pai RK, Dave AS, Lynch A, Thu M, Chen F, Xie LH, Weiss JN, Valderrábano M,
JournalAm J Physiol Heart Circ Physiol
PubMed ID18223190
Repolarization alternans is a harbinger of sudden cardiac death, particularly when it becomes spatially discordant. Alternans, a beat-to-beat alternation in the action potential duration (APD) and intracellular Ca (Cai), can arise from either tissue heterogeneities or dynamic factors. Distinguishing between these mechanisms in normal cardiac tissue is difficult because of ... More
Stimulation-induced mitochondrial [Ca2+] elevations in mouse motor terminals: comparison of wild-type with SOD1-G93A.
AuthorsVila L, Barrett EF, Barrett JN
JournalJ Physiol
PubMed ID12717010
Changes in mitochondrial matrix [Ca2+] evoked by trains of action potentials were studied in levator auris longus motor terminals using Ca2+-sensitive fluorescent indicator dyes (rhod-2, rhod-5F). During a 2500 impulse 50 Hz train, mitochondrial [Ca2+] in most wild-type terminals increased within 5-10 s to a plateau level that was sustained ... More
Presynaptic mitochondrial calcium sequestration influences transmission at mammalian central synapses.
AuthorsBillups B, Forsythe ID
JournalJ Neurosci
PubMed ID12122046
Beyond their role in generating ATP, mitochondria have a high capacity to sequester calcium. The interdependence of these functions and limited access to presynaptic compartments makes it difficult to assess the role of sequestration in synaptic transmission. We addressed this important question using the calyx of Held as a model ... More
Effects of electrical shocks on Cai2+ and Vm in myocyte cultures.
AuthorsFast VG, Cheek ER, Pollard AE, Ideker RE
JournalCirc Res
PubMed ID15155528
Changes in intracellular calcium concentration (DeltaCa(i)2+) induced by electrical shocks may play an important role in defibrillation, but high-resolution DeltaCa(i)2+ measurements in a multicellular cardiac tissue and their relationship to corresponding Vm changes (DeltaVm) are lacking. Here, we measured shock-induced DeltaCa(i)2+ and DeltaV(m) in geometrically defined myocyte cultures. Cell strands ... More