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
The sources and sequestration of Ca(2+) contributing to neuroeffector Ca(2+) transients in the mouse vas deferens.
AuthorsBrain KL, Cuprian AM, Williams DJ, Cunnane TC
JournalJ Physiol
PubMed ID14500773
'The detection of focal Ca(2+) transients (called neuroeffector Ca(2+) transients, or NCTs) in smooth muscle of the mouse isolated vas deferens has been used to detect the packeted release of ATP from nerve terminal varicosities acting at postjunctional P2X receptors. The present study investigates the sources and sequestration of Ca(2+) ... More
Control of IP(3)-mediated Ca2+ puffs in Xenopus laevis oocytes by the Ca2+-binding protein parvalbumin.
AuthorsJohn LM, Mosquera-Caro M, Camacho P, Lechleiter JD
JournalJ Physiol
PubMed ID11507154
'1. Elementary events of Ca2+ release (Ca2+ puffs) can be elicited from discrete clusters of inositol 1,4,5 trisphosphate receptors (IP(3)Rs) at low concentrations of IP(3). Ca(2+) puffs have rarely been observed unless elicited by either hormone treatment or introduction of IP(3) into the cell. However, cells appear to have sufficient ... More
Calcium in sympathetic varicosities of mouse vas deferens during facilitation, augmentation and autoinhibition.
AuthorsBrain KL, Bennett MR
JournalJ Physiol
PubMed ID9279805
'1. The sympathetic nerve terminals of the mouse vas deferens were loaded with the calcium indicator Oregon Green 488 BAPTA-1 by orthograde transport along the postganglionic nerves. Changes in the calcium concentration in the varicosity (delta [Ca2+]v) were determined following single impulses, and short (5-impulse) and long (200-impulse) trains at ... More
Coupling of calcium homeostasis to axonal sodium in axons of mouse optic nerve.
AuthorsVerbny Y, Zhang CL, Chiu SY
JournalJ Neurophysiol
PubMed ID12163532
'Axonal populations in neonatal and mature optic nerves were selectively stained with calcium dyes for analysis of calcium homeostasis and its possible coupling to axonal Na. Repetitive nerve stimulation causes a rise in axonal [Ca(2+)](i) the posttetanus recovery of which is impeded by increasing the number of action potentials in ... More
Tyrosine kinase inhibitors block sperm-induced egg activation in Xenopus laevis.
AuthorsGlahn D, Mark SD, Behr RK, Nuccitelli R
JournalDev Biol
PubMed ID9882505
'Fertilization of Xenopus laevis eggs triggers a wave of increased [Ca2+]i. The exact signal transduction pathway culminating in this Ca2+ wave remains unknown. To determine whether increases in tyrosine kinase activity are part of this pathway, we microinjected tyrosine kinase inhibitors into unfertilized eggs. Upon fertilization, signs of activation were ... More
Live imaging of neural structure and function by fibred fluorescence microscopy.
AuthorsVincent P, Maskos U, Charvet I, Bourgeais L, Stoppini L, Leresche N, Changeux JP, Lambert R, Meda P, Paupardin-Tritsch D
JournalEMBO Rep
PubMed ID17008931
'Only a few methods permit researchers to study selected regions of the central and peripheral nervous systems with a spatial and time resolution sufficient to image the function of neural structures. Usually, these methods cannot analyse deep-brain regions and a high-resolution method, which could repeatedly probe dynamic processes in any ... More
Requirement of TRPC channels in netrin-1-induced chemotropic turning of nerve growth cones.
AuthorsWang GX, Poo MM
JournalNature
PubMed ID15758951
'Ion channels formed by the TRP (transient receptor potential) superfamily of proteins act as sensors for temperature, osmolarity, mechanical stress and taste. The growth cones of developing axons are responsible for sensing extracellular guidance factors, many of which trigger Ca2+ influx at the growth cone; however, the identity of the ... More
alpha-Latrotoxin releases calcium in frog motor nerve terminals.
AuthorsTsang CW, Elrick DB, Charlton MP
JournalJ Neurosci
PubMed ID11102474
'alpha-Latrotoxin (alpha-LTX) is a neurotoxin that accelerates spontaneous exocytosis independently of extracellular Ca(2+). Although alpha-LTX increases spontaneous transmitter release at synapses, the mechanism is unknown. We tested the hypothesis that alpha-LTX causes transmitter release by mobilizing intracellular Ca(2+) in frog motor nerve terminals. Transmitter release was measured electrophysiologically and with ... More
Mechanisms of calcium elevation in the micromeres of sea urchin embryos.
AuthorsYazaki I, Abe M, Santella L, Koyama Y
JournalBiol Cell
PubMed ID15050370
'The micromeres, the first cells to be specified in sea urchin embryos, are generated by unequal cleavage at the fourth cell division. The micromeres differentiate autonomously to form spicules and dispatch signals to induce endomesoderm in the neighbouring macromeres cells in the embryo. Using a calcium indicator Fura-2/AM and a ... More
Selective labeling of retinal ganglion cells with calcium indicators by retrograde loading in vitro.
Here we present a retrograde loading technique that makes it possible for the first time to rapidly load a calcium indicator in the majority of retinal ganglion cells (RGCs) in salamander retina, and then to observe physiological activity of these dye-loaded cells. Dextran-conjugated calcium indicator, dissolved in water, was applied ... More
Electrical activity modulates growth cone guidance by diffusible factors.
AuthorsMing G, Henley J, Tessier-Lavigne M, Song H, Poo M
JournalNeuron
PubMed ID11239434
Brief periods of electrical stimulation of cultured Xenopus spinal neurons resulted in a marked alteration in the turning responses of the growth cone induced by gradients of attractive or repulsive guidance cues. Netrin-1-induced attraction was enhanced, and the repulsion induced by myelin-associated glycoprotein (MAG) or myelin membrane fragments was converted ... More
NAADP mobilizes Ca(2+) from reserve granules, lysosome-related organelles, in sea urchin eggs.
AuthorsChurchill GC, Okada Y, Thomas JM, Genazzani AA, Patel S, Galione A
JournalCell
PubMed ID12464181
Nicotinic acid adenine dinucleotide phosphate (NAADP) mobilizes Ca(2+) in many cells and species. Unlike other Ca(2+)-mobilizing messengers, NAADP mobilizes Ca(2+) from an unknown store that is not the endoplasmic reticulum, the store traditionally associated with messenger-mediated Ca(2+) signaling. Here, we demonstrate the presence of a Ca(2+) store in sea urchin ... More
Effective sensory modality activating an escape triggering neuron switches during early development in zebrafish.
AuthorsKohashi T, Nakata N, Oda Y,
JournalJ Neurosci
PubMed ID22539843
Developing nervous systems grow to integrate sensory signals from different modalities and to respond through various behaviors. Here, we examined the development of escape behavior in zebrafish [45-170 h postfertilization (hpf)] to study how developing sensory inputs are integrated into sensorimotor circuits. Mature fish exhibit fast escape upon both auditory/vestibular ... More
Multianalyte single-cell analysis with multiple cell lines using a fiber-optic array.
AuthorsWhitaker RD, Walt DR,
JournalAnal Chem
PubMed ID17973503
A single-cell drug screening method is described that produces rich single-cell data and discriminates between single-cell responses from clonal populations stimulated with different agonists. Ligand-induced receptor activation is commonly detected by observing intracellular Ca2+ oscillations using high-throughput screening (HTS) methods. In most cases, HTS results in an average signal from ... More
Biolistic delivery of Ca2+ dyes into plant and algal cells.
In eukaryotes, changes in cytosolic Ca2+ concentrations ([Ca2+]cyt) are associated with a number of environmental and developmental stimuli. However, measuring [Ca2+]cyt changes in single plant or algal cells is often problematic. Although a wide range of Ca2+-sensitive fluorescent dyes is available, they are often difficult to introduce into plant cells. ... More
Organelle selection determines agonist-specific Ca2+ signals in pancreatic acinar and beta cells.
AuthorsYamasaki M, Masgrau R, Morgan AJ, Churchill GC, Patel S, Ashcroft SJ, Galione A
JournalJ Biol Chem
PubMed ID14660554
How different extracellular stimuli can evoke different spatiotemporal Ca2+ signals is uncertain. We have elucidated a novel paradigm whereby different agonists use different Ca2+-storing organelles ("organelle selection") to evoke unique responses. Some agonists select the endoplasmic reticulum (ER), and others select lysosome-related (acidic) organelles, evoking spatial Ca2+ responses that mirror ... More
In vivo simultaneous tracing and Ca(2+) imaging of local neuronal circuits.
AuthorsNagayama S, Zeng S, Xiong W, Fletcher ML, Masurkar AV, Davis DJ, Pieribone VA, Chen WR
JournalNeuron
PubMed ID17359915
A central question about the brain is how information is processed by large populations of neurons embedded in intricate local networks. Answering this question requires not only monitoring functional dynamics of many neurons simultaneously, but also interpreting such activity patterns in the context of neuronal circuitry. Here, we introduce a ... More
Fast calcium signals in Drosophila motor neuron terminals.
AuthorsMacleod GT, Hegström-Wojtowicz M, Charlton MP, Atwood HL
JournalJ Neurophysiol
PubMed ID12424301
Drosophila is a powerful model for neuroscientists, but physiological techniques have not kept pace with advances in molecular genetics. We introduce a reliable assay for intracellular calcium dynamics in Drosophila larval motor neuron terminals, and a new physiological solution that improves the longevity of the larval preparation. By loading calcium ... More
Acetylcholine and calcium signalling regulates muscle fibre formation in the zebrafish embryo.
AuthorsBrennan C, Mangoli M, Dyer CE, Ashworth R
JournalJ Cell Sci
PubMed ID16249237
Nerve activity is known to be an important regulator of muscle phenotype in the adult, but its contribution to muscle development during embryogenesis remains unresolved. We used the zebrafish embryo and in vivo imaging approaches to address the role of activity-generated signals, acetylcholine and intracellular calcium, in vertebrate slow muscle ... More
Gbetagamma acts at the C terminus of SNAP-25 to mediate presynaptic inhibition.
Presynaptic inhibition mediated by G protein-coupled receptors may involve a direct interaction between G proteins and the vesicle fusion machinery. The molecular target of this pathway is unknown. We demonstrate that Gbetagamma-mediated presynaptic inhibition in lamprey central synapses occurs downstream from voltage-gated Ca(2+) channels. Using presynaptic microinjections of botulinum toxins ... More
Transmitter-evoked local calcium release stabilizes developing dendrites.
AuthorsLohmann C, Myhr KL, Wong RO
JournalNature
PubMed ID12110889
In the central nervous system, dendritic arborizations of neurons undergo dynamic structural remodelling during development. Processes are elaborated, maintained or eliminated to attain the adult pattern of synaptic connections. Although neuronal activity influences this remodelling, it is not known how activity exerts its effects. Here we show that neurotransmission-evoked calcium ... More
Approaches to measuring calcium in zebrafish: focus on neuronal development.
AuthorsAshworth R
JournalCell Calcium
PubMed ID15003849
Calcium ions are known to act as important cellular signals during nervous system development. In vitro studies have provided significant information on the role of calcium signals during neuronal development; however, the function of this messenger in nervous system maturation in vivo remains to be established. The zebrafish has emerged ... More
Ballistic labeling and dynamic imaging of astrocytes in organotypic hippocampal slice cultures.
AuthorsBenediktsson AM, Schachtele SJ, Green SH, Dailey ME
JournalJ Neurosci Methods
PubMed ID15585287
Protoplasmic astrocytes in mammalian CNS tissues in vivo have a highly complex 3D morphology, but in dissociated cell cultures they often assume a flattened, fibroblast-like morphology bearing only a few, simple processes. By fluorescent labeling and confocal reconstruction we show that many astrocytes in organotypic hippocampal slice cultures exhibit a ... More
Ca2+ signalling and membrane current activated by cADPr in starfish oocytes.
AuthorsMoccia F, Nusco GA, Lim D, Ercolano E, Gragnaniello G, Brown ER, Santella L
JournalPflugers Arch
PubMed ID12756567
Cyclic ADP-ribose (cADPr) is a second messenger that regulates intracellular free [Ca2+] ([Ca2+](i)) in a variety of cell types, including immature oocytes from the starfish Astropecten auranciacus. In this study, we employed confocal laser scanning microscopy and voltage clamp techniques to investigate the source of the cADPr-elicited Ca2+ wave originating ... More
Simultaneous measurements of cytosolic and mitochondrial Ca2+ transients in HT29 cells.
AuthorsRicken S, Leipziger J, Greger R, Nitschke R
JournalJ Biol Chem
PubMed ID9857027
Loading of HT29 cells with the Ca2+ dye fura-2/AM resulted in an nonhomogeneous intracellular distribution of the dye. Cellular compartments with high fura-2 concentrations were identified by correlation with mitochondrial markers, cellular autofluorescence induced by UV, and dynamic measurement of autofluorescence after inhibition of oxidative phosphorylation. Stimulation with carbachol (10(-4) ... More
Calcium influx factor is synthesized by yeast and mammalian cells depleted of organellar calcium stores.
AuthorsCsutora P, Su Z, Kim HY, Bugrim A, Cunningham KW, Nuccitelli R, Keizer JE, Hanley MR, Blalock JE, Marchase RB
JournalProc Natl Acad Sci U S A
PubMed ID9874782
Depletion of endoplasmic reticulum Ca2+ stores leads to the entry of extracellular Ca2+ into the cytoplasm, a process termed capacitative or store-operated Ca2+ entry. Partially purified extracts were prepared from the human Jurkat T lymphocyte cell line and yeast in which Ca2+ stores were depleted by chemical and genetic means, ... More
Ryanodine receptor type I and nicotinic acid adenine dinucleotide phosphate receptors mediate Ca2+ release from insulin-containing vesicles in living pancreatic beta-cells (MIN6).
AuthorsMitchell KJ, Lai FA, Rutter GA
JournalJ Biol Chem
PubMed ID12538591
We have demonstrated recently (Mitchell, K. J., Pinton, P., Varadi, A., Tacchetti, C., Ainscow, E. K., Pozzan, T., Rizzuto, R., and Rutter, G. A. (2001) J. Cell Biol. 155, 41-51) that ryanodine receptors (RyR) are present on insulin-containing secretory vesicles. Here we show that pancreatic islets and derived beta-cell lines ... More
Nicotinic acetylcholine receptors in mouse and rat optic nerves.
AuthorsZhang CL, Verbny Y, Malek SA, Stys PK, Chiu SY
JournalJ Neurophysiol
PubMed ID14762152
Receptor-mediated calcium signaling in axons of mouse and rat optic nerves was examined by selectively staining the axonal population with a calcium indicator. Nicotine (1-50 microM) induced an axonal calcium elevation that was eliminated when calcium was removed from the bath, suggesting that nicotine induces calcium influx into axons. The ... More
Na+-dependent sources of intra-axonal Ca2+ release in rat optic nerve during in vitro chemical ischemia.
AuthorsNikolaeva MA, Mukherjee B, Stys PK
JournalJ Neurosci
PubMed ID16251444
The contribution of intracellular stores to axonal Ca2+ overload during chemical ischemia in vitro was examined by confocal microscopy. Ca2+ accumulation was measured by fluo-4 dextran (low-affinity dye, KD approximately 4 microM) or by Oregon Green 488 BAPTA-1 dextran (highaffinity dye, KD approximately 450 nM). Axonal Na+ was measured using ... More
Dissection of nodulation signaling using pea mutants defective for calcium spiking induced by nod factors and chitin oligomers.
AuthorsWalker SA, Viprey V, Downie JA
JournalProc Natl Acad Sci U S A
PubMed ID11078515
Changes in intracellular calcium in pea root hairs responding to Rhizobium leguminosarum bv. viciae nodulation (Nod) factors were analyzed by using a microinjected calcium-sensitive fluorescent dye (dextran-linked Oregon Green). Within 1-2 min after Nod-factor addition, there was usually an increase in fluorescence, followed about 10 min later by spikes in ... More
Intermittent ATP release from nerve terminals elicits focal smooth muscle Ca2+ transients in mouse vas deferens.
AuthorsBrain KL, Jackson VM, Trout SJ, Cunnane TC
JournalJ Physiol
PubMed ID12068045
A confocal Ca2+ imaging technique has been used to detect ATP release from individual sympathetic varicosities on the same nerve terminal branch. Varicose nerve terminals and smooth muscle cells in mouse vas deferens were loaded with the Ca2+ indicator Oregon Green 488 BAPTA-1. Field (nerve) stimulation evoked discrete, focal increases ... More
NMDA receptor-mediated control of presynaptic calcium and neurotransmitter release.
AuthorsCochilla AJ, Alford S
JournalJ Neurosci
PubMed ID9870950
Before action potential-evoked Ca2+ transients, basal presynaptic Ca2+ concentration may profoundly affect the amplitude of subsequent neurotransmitter release. Reticulospinal axons of the lamprey spinal cord receive glutamatergic synaptic input. We have investigated the effect of this input on presynaptic Ca2+ concentrations and evoked release of neurotransmitter. Paired recordings were made ... More
Role of phospholipase C-zeta domains in Ca2+-dependent phosphatidylinositol 4,5-bisphosphate hydrolysis and cytoplasmic Ca2+ oscillations.
AuthorsNomikos M, Blayney LM, Larman MG, Campbell K, Rossbach A, Saunders CM, Swann K, Lai FA
JournalJ Biol Chem
PubMed ID16000311
The sperm-specific phospholipase C-zeta (PLCzeta) elicits fertilization-like Ca2+ oscillations and activation of embryo development when microinjected into mammalian eggs (Saunders, C. M., Larman, M. G., Parrington, J., Cox, L. J., Royse, J., Blayney, L. M., Swann, K., and Lai, F. A. (2002) Development (Camb.) 129, 3533-3544; Cox, L. J., Larman, ... More
Egg activation in physiologically polyspermic newt eggs: involvement of IP₃ receptor, PLCγ, and microtubules in calcium wave induction.
Authors
JournalInt J Dev Biol
PubMed ID25354451
TMBIM6 (transmembrane BAX inhibitor motif containing 6) enhances autophagy through regulation of lysosomal calcium.
Authors
JournalAutophagy
PubMed ID32167007
Neto-α Controls Synapse Organization and Homeostasis at the Drosophila Neuromuscular Junction.