Vesicle-associated proteins and calcium in nerve terminals of chick ciliary ganglia during development of facilitation.
AuthorsLin YQ, Brain KL, Nichol KA, Morgan JJ, Bennett MR
JournalJ Physiol
PubMed ID9003550
'1. The developmental appearance of synaptic vesicle-associated proteins and nerve terminal calcium ([Ca2+]i) sequestering processes were determined for the chick ciliary ganglia in relation to the maturation of the different phase of increased efficacy of transmitter release following nerve impulses. The maturation phases studied were from stages 34-35, at the ... More
Ca2+ influx does more than provide releasable Ca2+ to maintain repetitive spiking in human umbilical vein endothelial cells.
AuthorsMorgan AJ, Jacob R
JournalBiochem J
PubMed ID8973560
'We investigated why oscillations of intracellular Ca2+ concentrations ([Ca2+]i) in endothelial cells challenged by sub-maximal histamine run down in Ca(2+)-free medium despite stores retaining most of their Ca2+. One explantation is that only a small subpopulation of the Ca2+ stores oscillate and are completely emptied of Ca2+. To investigate if ... More
Maturation promoting factor in ascidian oocytes is regulated by different intracellular signals at meiosis I and II.
AuthorsRusso GL, Kyozuka K, Antonazzo L, Tosti E, Dale B
JournalDevelopment
PubMed ID8681780
'Using the fluorescent dye Calcium Green-dextran, we measured intracellular Ca2+ in oocytes of the ascidian Ciona intestinalis at fertilization and during progression through meiosis. The relative fluorescence intensity increased shortly after insemination in a single transient, the activation peak, and this was followed by several smaller oscillations that lasted for ... More
Calcium permeability of the neuronal nuclear envelope: evaluation using confocal volumes and intracellular perfusion.
AuthorsO'Malley DM
JournalJ Neurosci
PubMed ID7931542
'In many calcium-imaging studies, the nuclear envelope appears to maintain a gradient of free calcium between the nucleus and cytosol. This issue was examined by loading amphibian sympathetic neurons with the calcium indicator fluo 3 via whole-cell patch clamping. Confocal optical sectioning allowed acquisition of independent calibration curves for the ... More
Calcium signalling during chemotaxis.
AuthorsFay FS, Gilbert SH, Brundage RA
JournalCiba Found Symp
PubMed ID7587614
'The role of Ca2+ in chemotaxis of eosinophils from the newt Taricha granulosa was investigated using fluorescent indicators and digital imaging microscopy. In response to serum chemoattractant, cytoplasmic Ca2+ concentration ([Ca2+]i) rises prior to polarization. In polarized locomoting cells [Ca2+]i gradients (tail-high-front-low) are always seen, and when cells turn [Ca2+]i ... More
Visualization of calcium transients controlling orientation of ciliary beat.
AuthorsTamm SL, Terasaki M
JournalJ Cell Biol
PubMed ID8195294
'To image changes in intraciliary Ca controlling ciliary motility, we microinjected Ca Green dextran, a visible wavelength fluorescent Ca indicator, into eggs or two cell stages of the ctenophore Mnemiopsis leidyi. The embryos developed normally into free-swimming, approximately 0.5 mm cydippid larvae with cells and ciliary comb plates (approximately 100 ... More
Elemental propagation of calcium signals in response-specific patterns determined by environmental stimulus strength.
AuthorsGoddard H, Manison NF, Tomos D, Brownlee C
JournalProc Natl Acad Sci U S A
PubMed ID10677557
'Plant cells can respond qualitatively and quantitatively to a wide range of environmental signals. Ca(2+) is used as an intracellular signal for volume regulation in response to external osmotic changes. We show here that the spatiotemporal patterns of hypo-osmotically induced Ca(2+) signals vary dramatically with stimulus strength in embryonic cells ... More
Calcium in the nerve terminals of chick ciliary ganglia during facilitation, augmentation and potentiation.
AuthorsBrain KL, Bennett MR
JournalJ Physiol
PubMed ID8788930
'1. The calyciform nerve terminals of chick ciliary ganglia were loaded with the calcium indicators calcium green 1 or fura-2. These were used to determine the change in calcium concentration in the terminal, [Ca2+]t, following short (10 impulses) and long (600 impulses) trains of high-frequency (30 Hz) stimulation. 2. Following ... More
Calcium permeation of the turtle hair cell mechanotransducer channel and its relation to the composition of endolymph.
AuthorsRicci AJ, Fettiplace R
JournalJ Physiol
PubMed ID9481679
'1. Recordings of mechanoelectrical transducer currents were combined with calcium imaging of hair bundles in turtle auditory hair cells located near the high-frequency end of the cochlea. The external face of the hair bundles was perfused with a range of Ca2+ concentrations to study the quantitative relationship between Ca2+ influx ... More
Signal transduction in Jurkat T lymphocytes. Evidence for early Ca2+ movements between the cytoplasm and the nucleoplasm in activated cells.
AuthorsGagné D, Ahnadi CE, Martel J, Payet MD, Dupuis G
JournalJ Leukoc Biol
PubMed ID9400830
'Spatial analyses of the distribution of Ca2+ in resting and activated T and B lymphocytes have shown that the bulk of increased [Ca2+]i appears to be associated with the nuclear region. These observations suggest that Ca2+ is released from the perinuclear space or that it diffuses to the nucleoplasm, or ... More
In vivo imaging of functional inhibitory networks on the mauthner cell of larval zebrafish.
AuthorsTakahashi M, Narushima M, Oda Y
JournalJ Neurosci
PubMed ID12019312
'Noninvasive in vivo calcium imaging was used to observe and characterize inhibitory circuitry in intact larval zebrafish. In the teleost hindbrain, the inhibitory network onto the major pair of reticulospinal neurons known as Mauthner cells (M-cells) has been described in detail. There are three sources of inhibition onto M-cells: recurrent ... More
Longitudinal spread of second messenger signals in isolated rod outer segments of lizards.
AuthorsGray-Keller M, Denk W, Shraiman B, Detwiler PB
JournalJ Physiol
PubMed ID10457083
'1. In vertebrate rods activation of the phototransduction cascade by light triggers changes in the concentrations of at least two diffusible intracellular second messengers (cGMP and Ca2+) whose actions depend on how far they spread from their site of production or entry. To address questions about their spatial spread, cell-attached ... More
Evidence that fertilization activates starfish eggs by sequential activation of a Src-like kinase and phospholipase cgamma.
AuthorsGiusti AF, Xu W, Hinkle B, Terasaki M, Jaffe LA
JournalJ Biol Chem
PubMed ID10747984
'Recent evidence has indicated a requirement for a Src family kinase in initiating Ca(2+) release at fertilization in starfish eggs (Giusti, A. F., Carroll, D. J., Abassi, Y. A., Terasaki, M., Foltz, K. R., and Jaffe, L. A. (1999) J. Biol. Chem. 274, 29318-29322). We now show that injection of ... More
Local calcium transients regulate the spontaneous motility of dendritic filopodia.
AuthorsLohmann C, Finski A, Bonhoeffer T
JournalNat Neurosci
PubMed ID15711541
'During development, dendrites, and in particular dendritic filopodia, undergo extensive structural remodeling, presumably to help establish synaptic contacts. Here, we investigated the role of calcium signaling in dendritic plasticity by simultaneously recording calcium dynamics and filopodial growth in rat hippocampal slice cultures. Local calcium transients occurred in dendritic filopodia and ... More
Optical recordings of the effects of cholinergic ligands on neurons in the ganglion cell layer of mammalian retina.
AuthorsBaldridge WH
JournalJ Neurosci
PubMed ID8756436
'Cholinergic regulation of the activity of rabbit retinal ganglion cells and displaced amacrine cells was investigated using optical recording of changes in intracellular free calcium ([Ca2+]i). Labeling of neurons in the mature retina was achieved by injecting calcium green-1 dextran (CaGD) into the isolated retina. Nicotine increased ganglion cell [Ca2+]i, ... More
A localized elevation of cytosolic free calcium is associated with cytokinesis in the zebrafish embryo.
AuthorsChang DC, Meng C
JournalJ Cell Biol
PubMed ID8522610
'Cytokinesis, a key step in cell division, is known to be precisely regulated both in its timing and location. At present, the regulatory mechanism of cytokinesis is not well understood, although it has been suggested that calcium signaling may play an important role in this process. To test this notion, ... More
Real-time imaging of neurons retrogradely and anterogradely labelled with calcium-sensitive dyes.
AuthorsO'Donovan MJ, Ho S, Sholomenko G, Yee W
JournalJ Neurosci Methods
PubMed ID8474261
'Membrane-impermeant calcium indicator dyes were used to retrogradely label dorsal root ganglia, spinal motoneurons and interneurons in the spinal cord of the chick embryo. The dyes were also used to label anterogradely primary afferent axons in the spinal cord and synaptic endings in the ciliary ganglion. Labelled neurons were imaged ... More
Combined retrograde labeling and calcium imaging in spinal cord and brainstem neurons of the lamprey.
AuthorsMcClellan AD, McPherson D, O'Donovan MJ
JournalBrain Res
PubMed ID7531597
'Neurons in the brainstem and spinal cord of the lamprey were retrogradely labeled with Calcium Green-dextran, an indicator dye that increases its fluorescence when intracellular calcium levels increase. Optical signals could be recorded from these labeled neurons during spinal cord stimulation, nerve stimulation, or spontaneous activity, up to 4 days ... More
Presynaptic inhibition of primary olfactory afferents mediated by different mechanisms in lobster and turtle.
AuthorsWachowiak M, Cohen LB
JournalJ Neurosci
PubMed ID10516300
'Presynaptic regulation of transmission at the first olfactory synapse was investigated by selectively imaging axon terminals of receptor neurons in the lobster olfactory lobe and turtle olfactory bulb. In both species, action potential propagation into axon terminals after olfactory nerve stimulation was measured using voltage-sensitive dyes. In addition, in the ... More
Inositol trisphosphate and cyclic ADP-ribose-mediated release of Ca2+ from single isolated pancreatic zymogen granules.
'In pancreatic acinar cells low (physiological) agonist concentrations evoke cytosolic Ca2+ spikes specifically in the apical secretory pole that contains a high density of secretory (zymogen) granules (ZGs). Inositol 1,4,5-trisphosphate (IP3) is believed to release Ca2+ from the endoplasmic reticulum, but we have now tested whether the Ca(2+)-releasing messengers IP3 ... More
The nucleus of HeLa cell contains tubular structures for Ca2+ signalling.
AuthorsLui PP, Kong SK, Kwok TT, Lee CY
JournalBiochem Biophys Res Commun
PubMed ID9636660
'It has long been assumed that Ca2+ are translocated from the cytosol to the cell nucleus by a long distance to activate transcription machinery buried deep in the nucleoplasm. However, this model has been recently challenged. When HeLa cells were loaded with fluo-3, highly fluorescent spots of approximately 2 microns ... More
Regulation of cell movement is mediated by stretch-activated calcium channels.
AuthorsLee J, Ishihara A, Oxford G, Johnson B, Jacobson K
JournalNature
PubMed ID10432119
'Intracellular calcium regulates many of the molecular processes that are essential for cell movement. It is required for the production of actomyosin-based contractile forces, the regulation of the structure and dynamics of the actin cytoskeletons, and the formation and disassembly of cell-substratum adhesions. Calcium also serves as a second messenger ... More
Fluorescent calcium indicators: subcellular behavior and use in confocal imaging.
AuthorsO'Malley DM, Burbach BJ, Adams PR
JournalMethods Mol Biol
PubMed ID10231797
Calcium and endoplasmic reticulum dynamics during oocyte maturation and fertilization in the marine worm Cerebratulus lacteus.
AuthorsStricker SA, Silva R, Smythe T
JournalDev Biol
PubMed ID9808782
'To monitor calcium and endoplasmic reticulum (ER) dynamics during oocyte maturation and fertilization, oocytes of the marine worm Cerebratulus lacteus were injected with the calcium-sensitive indicator calcium green dextran and/or the ER-specific probe "DiI." Based on time-lapse confocal imaging of such specimens, prophase-arrested immature oocytes failed to develop normally after ... More
A cell cycle-associated change in Ca2+ releasing activity leads to the generation of Ca2+ transients in mouse embryos during the first mitotic division.
AuthorsKono T, Jones KT, Bos-Mikich A, Whittingham DG, Carroll J
JournalJ Cell Biol
PubMed ID8603922
'We have used Ca2+-sensitive fluorescent dyes to monitor intracellular Ca2+ during mitosis in one-cell mouse embryos. We find that fertilized embryos generate Ca2+ transients at nuclear envelope breakdown (NEBD) and during mitosis. In addition, fertilized embryos arrested in metaphase using colcemid continue to generate Ca2+ transients. In contrast, parthenogenetic embryos ... More
Cytoplasmic Ca2+ oscillation coordinates the formation of actin filaments in the sea urchin eggs activated with phorbol ester.
AuthorsArai A, Kyozuka K, Nakazawa T
JournalCell Motil Cytoskeleton
PubMed ID9915582
'Changes in the intracellular Ca2+ concentration ([Ca2+]i) and the formation of actin filaments were investigated in unfertilized eggs of the sea urchin Hemicentrotus pulcherrimus after activation with a phorbol ester, 12-O-tetradecanoyl phorbol13-acetate (TPA). Intracellular Ca2+ oscillation was observed using a fluorescent Ca2+ indicator dye, calcium green dextran. From about 20 ... More
The passage of Ca2+ and fluorescent markers between the sperm and egg after fusion in the mouse.
AuthorsJones KT, Soeller C, Cannell MB
JournalDevelopment
PubMed ID9806912
'Mouse sperm-egg fusion was examined using two-photon and confocal microscopy. A delay of several minutes occurred between the first observable event of fusion (which was the diffusion of Ca2+-sensitive dyes from egg into sperm) and any change in egg cytoplasmic Ca2+. When indo-1 dextran was used to obtain ratiometric two-photon ... More
Distribution of Ca2+ extrusion sites on the mouse pancreatic acinar cell surface.
AuthorsBelan P, Gerasimenko O, Petersen OH, Tepikin AV
JournalCell Calcium
PubMed ID9232347
'The localizations of Ca2+ extrusion sites in mouse pancreatic acinar cells during elevation of the intracellular free calcium concentration ([Ca2+]i) have been studied. During an agonist stimulated calcium elevation as well as when intracellular calcium is released from a ''caged compound'', Ca2+ is primarily extruded from the apical secretory pole ... More
Two-photon imaging of brain pericytes in vivo using dextran-conjugated dyes.
AuthorsHirase H, Creso J, Singleton M, Barthó P, Buzsáki G
JournalGlia
PubMed ID14999817
'Pericytes in the central nervous system (CNS) are hypothesized to be involved in important circulatory functions, including local blood flow regulation, angiogenesis, immune reaction, and regulation of blood-brain barrier. Despite these putative functions, functional correlates of pericytes in vivo are scarce. We have labeled CNS pericytes using the dextran-conjugated fluorescent ... More
Practical aspects of measuring [Ca2+] with fluorescent indicators.
AuthorsKao JP
JournalMethods Cell Biol
PubMed ID8201975
Study of calcium signaling in cell cleavage using confocal microscopy.
AuthorsMeng CL, Chang DC
JournalBiol Bull
PubMed ID7811793
Cyclic AMP-induced repair of zebrafish spinal circuits.
AuthorsBhatt DH, Otto SJ, Depoister B, Fetcho JR
JournalScience
PubMed ID15247482
Neurons in the human central nervous system (CNS) are unable to regenerate, as a result of both an inhibitory environment and their inherent inability to regrow. In contrast, the CNS environment in fish is permissive for growth, yet some neurons still cannot regenerate. Fish thus offer an opportunity to study ... More
Store-operated calcium entry inactivates at the germinal vesicle breakdown stage of Xenopus meiosis.
AuthorsMachaca K, Haun S
JournalJ Biol Chem
PubMed ID10991950
Store-operated calcium entry (SOCE) is the predominant Ca(2+) influx pathway in non-excitable cells and is activated in response to depletion of intracellular Ca(2+) stores. We have studied SOCE regulation during Xenopus oocyte meiosis. SOCE can be measured readily in stage VI Xenopus oocytes arrested at the G(2)-M transition of the ... More
Elementary calcium-release units induced by inositol trisphosphate.
AuthorsHorne JH, Meyer T
JournalScience
PubMed ID9180077
The extent to which inositol 1,4,5-trisphosphate (InsP3)-induced calcium signals are localized is a critical parameter for understanding the mechanism of effector activation. The spatial characteristics of InsP3-mediated calcium signals were determined by targeting a dextran-based calcium indicator to intracellular membranes through the in situ addition of a geranylgeranyl lipid group. ... More
In vivo nuclear Ca2+-ATPase phosphorylation triggers intermediate size molecular transport to the nucleus.
AuthorsGensburger C, Freyermuth S, Klein C, Malviya AN
JournalBiochem Biophys Res Commun
PubMed ID12684066
Outer nuclear membrane is endowed with a SERCA type Ca(2+)-ATPase which pumps calcium into the nuclear envelope lumen and creates calcium stores. Variation in this calcium pool, among other things, regulates nuclear transport. The transport of Nuclear Localization Signal (NLS)-containing molecules into the nucleus is well established. Intermediate size molecules ... More
Monitoring presynaptic calcium dynamics in projection fibers by in vivo loading of a novel calcium indicator.
AuthorsKreitzer AC, Gee KR, Archer EA, Regehr WG
JournalNeuron
PubMed ID10939328
Fluorometric calcium measurements have revealed presynaptic residual calcium (Ca(res)) to be an important regulator of synaptic strength. However, in the mammalian brain, it has not been possible to monitor Ca(res) in fibers that project from one brain region to another. Here, we label neuronal projections by injecting dextran-conjugated calcium indicators ... More
Calcium spiking in plant root hairs responding to Rhizobium nodulation signals.
AuthorsEhrhardt DW, Wais R, Long SR
JournalCell
PubMed ID8646776
SUMMARY: Rhizobium lipochitooligosaccharide signal molecules stimulate multiple responses in legume host plants, including changes in host gene expression, cell growth, and mitoses leading to root nodule development. The basis for signal transduction in the plant is not known. We examined cytoplasmic free calcium in host root hairs using calcium-sensitive reporter ... More
Photoactivation of caged compounds in single living cells: an application to the study of cell locomotion.
AuthorsIshihara A, Gee K, Schwartz S, Jacobson K, Lee J
JournalBiotechniques
PubMed ID9266081
Caged compounds are molecules whose biological function is masked until UV light induces a photo-chemical reaction that converts the molecules into a biologically active state. These probes provide very powerful tools in cell biology research, since the activation can be precisely controlled temporally and spatially by limiting their exposure to ... More
A new technique for assessing the microscopic distribution of cellular calcium exit sites.
AuthorsBelan PV, Gerasimenko OV, Berry D, Saftenku E, Petersen OH, Tepikin AV
JournalPflugers Arch
PubMed ID9019724
This paper contains a description of a new method designed to monitor the distribution of Ca2+ efflux from cells or small cellular aggregates. The idea behind this method is to use a fluorescent Ca2+ indicator bound to dextrans of high molecular weight to slow down Ca2+ diffusion. Due to the ... More
Ca2+ oscillations in plant cells: initiation by rapid elevation in cytosolic free Ca2+ levels.
AuthorsCalder GM, Franklin-Tong VE, Shaw PJ, Drøbak BK
JournalBiochem Biophys Res Commun
PubMed ID9175777
Temporal increases in intracellular [Ca2+] are now recognized to be key triggers for a wide range of important physiological events in eukaryotic cells. In mammalian cells, signal-induced Ca2+-elevations have been found to be of a pulsatile nature and Ca2+ spikes display a high degree of spatiotemporal complexity. In plant cells ... More
An ensemble and single-molecule fluorescence spectroscopy investigation of Calcium Green 1, a calcium-ion sensor.
AuthorsLu Y, Paige MF,
JournalJ Fluoresc
PubMed ID17638063
The calcium-ion indicator dye, Calcium Green 1 (CG-1), has been characterized using a combination of ensemble and single-molecule optical spectroscopy measurements. In terms of ensemble measurements, CG-1 demonstrated a strong increase in fluorescence emission as a function of increasing [Ca(2+)]. This was accompanied by a change in the relative proportions ... More
Wide-field and two-photon imaging of brain activity with voltage- and calcium-sensitive dyes.
AuthorsHomma R, Baker BJ, Jin L, Garaschuk O, Konnerth A, Cohen LB, Bleau CX, Canepari M, Djurisic M, Zecevic D,
JournalMethods Mol Biol
PubMed ID18839087
This chapter presents three examples of imaging brain activity with voltage- or calcium-sensitive dyes. Because experimental measurements are limited by low sensitivity, the chapter then discusses the methodological aspects that are critical for optimal signal-to-noise ratio. Two of the examples use wide-field (1-photon) imaging and the third uses two-photon scanning ... More
An anaphase calcium signal controls chromosome disjunction in early sea urchin embryos.
AuthorsGroigno L, Whitaker M
JournalCell
PubMed ID9458044
A transient increase in intracellular calcium concentration [Ca2+]i occurs throughout the cell as sea urchin embryos enter anaphase of the first cell cycle. The transient just precedes chromatid disjunction and spindle elongation. Microinjection of calcium chelators or heparin, an InsP3 receptor antagonist, blocks chromosome separation. Photorelease of calcium or InsP3 ... More
The nucleus is insulated from large cytosolic calcium ion changes.
Authorsal-Mohanna FA, Caddy KW, Bolsover SR
JournalNature
PubMed ID7993399
Extracellular events regulate functions in the cell nucleus by means of calcium ions acting through effector enzymes. Recently, the traditional view of the nuclear pore as freely permeable to small ions has been questioned as a result of reports that nuclear calcium can be regulated independently of cytosolic calcium. We ... More
Synchronization of calcium waves by mitochondrial substrates in Xenopus laevis oocytes.
AuthorsJouaville LS, Ichas F, Holmuhamedov EL, Camacho P, Lechleiter JD
JournalNature
PubMed ID7566122
In Xenopus oocytes, as well as other cells, inositol-1,4,5-trisphosphate (Ins(1,4,5)P3)-induced Ca2+ release is an excitable process that generates propagating Ca2+ waves that annihilate upon collision. The fundamental property responsible for excitability appears to be the Ca2+ dependency of the Ins(1,4,5)P3 receptor. Here we report that Ins(1,4,5)P3-induced Ca2+ wave activity is ... More
Patterns of elevated free calcium and calmodulin activation in living cells.
AuthorsHahn K, DeBiasio R, Taylor DL
JournalNature
PubMed ID1436037
The temporal and spatial dynamics of intracellular signals and protein effectors are being defined as a result of imaging using fluorescent reagents within living cells. We have described a new class of fluorescent analogues termed optical biosensors, which sense chemical or molecular events through their effects on protein transducers. One ... More
Localization of Ca2+ extrusion sites in pancreatic acinar cells.
We have investigated the localization of Ca2+ extrusion sites in mouse pancreatic acinar cells. Employing a new technique, in which high resolution localization of cellular Ca2+ exit is achieved by confocal microscopy and a Ca2+-sensitive fluorescent probe coupled to heavy dextran to slow down diffusion of extracellular Ca2+, it is ... More
Diffusion across the nuclear envelope inhibited by depletion of the nuclear Ca2+ store.
AuthorsStehno-Bittel L, Perez-Terzic C, Clapham DE
JournalScience
PubMed ID8525380
Intact, isolated nuclei and a nuclear membrane (ghost) preparation were used to study regulation of the movement of small molecules across the Xenopus laevis oocyte nuclear membrane. In contrast to models of the nuclear pore complex, which assume passive bidirectional diffusion of molecules less than 70 kilodaltons, diffusion of intermediate-sized ... More
Retrograde inhibition of presynaptic calcium influx by endogenous cannabinoids at excitatory synapses onto Purkinje cells.
AuthorsKreitzer AC, Regehr WG
JournalNeuron
PubMed ID11301030
Brief depolarization of cerebellar Purkinje cells was found to inhibit parallel fiber and climbing fiber EPSCs for tens of seconds. This depolarization-induced suppression of excitation (DSE) is accompanied by altered paired-pulse plasticity, suggesting a presynaptic locus. Fluorometric imaging revealed that postsynaptic depolarization also reduces presynaptic calcium influx. The inhibition of ... 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
Simultaneous detection of catecholamine exocytosis and Ca2+ release from single bovine chromaffin cells using a dual microsensor.
AuthorsXin Q, Wightman RM
JournalAnal Chem
PubMed ID9599575
A dual microsensor with a 5 microns radius was fabricated to detect simultaneously Ca2+ and catecholamines following their secretion from individual biological cells. Detection of Ca2+ was based on changes in fluorescence as a result of its binding with a surface-attached dye, and catecholamines were detected by amperometry. The fluorescent ... 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
Effect on sperm-induced activation current and increase of cytosolic Ca2+ by agents that modify the mobilization of [Ca2+]i. I. Heparin and pentosan polysulfate.
AuthorsMohri T, Ivonnet PI, Chambers EL
JournalDev Biol
PubMed ID7589794
The mechanism of the elevation of intracellular free Ca2+ ([Ca2+]i) induced by a single sperm in eggs of the sea urchin Lytechinus variegatus was investigated. Simultaneous measurements of [Ca2+]i, and of the activation current, were carried out on eggs microinjected with Ca Green-1 or Ca Green dextran, and voltage clamped ... More
ATP-dependent accumulation and inositol trisphosphate- or cyclic ADP-ribose-mediated release of Ca2+ from the nuclear envelope.
Uptake and release of Ca2+ from isolated liver nuclei were studied with fluorescent probes. We show with the help of digital imaging and confocal microscopy that the Ca(2+)-sensitive fluorescent probe Fura 2 is concentrated in or around the nuclear envelope and that the distribution of Fura 2 fluorescence is similar ... More
Localized calcium signals along the cleavage furrow of the Xenopus egg are not involved in cytokinesis.
AuthorsNoguchi T, Mabuchi I
JournalMol Biol Cell
PubMed ID11950937
It has been proposed that a localized calcium (Ca) signal at the growing end of the cleavage furrow triggers cleavage furrow formation in large eggs. We have examined the possible role of a Ca signal in cleavage furrow formation in the Xenopus laevis egg during the first cleavage. We were ... More
Gibberellic acid and abscisic acid coordinately regulate cytoplasmic calcium and secretory activity in barley aleurone protoplasts.
AuthorsGilroy S, Jones RL
JournalProc Natl Acad Sci U S A
PubMed ID1533046
The effects of gibberellic acid (GA3) and abscisic acid (ABA) on the temporal and spatial dynamics of cytosolic calcium concentration ([Ca2+]i) in aleurone protoplasts of barley (Hordeum vulgare L. cv. Himalaya) were measured by using fluorescence ratio analysis and confocal microscopy. After 4-6 h of treatment, GA3 induced a sustained ... 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
Source of nuclear calcium signals.
AuthorsAllbritton NL, Oancea E, Kuhn MA, Meyer T
JournalProc Natl Acad Sci U S A
PubMed ID7809059
Transient increases of Ca2+ concentration in the nucleus regulate gene expression and other nuclear processes. We investigated whether nuclear Ca2+ signals could be regulated independently of the cytoplasm or were controlled by cytoplasmic Ca2+ signals. A fluorescent Ca2+ indicator that is targeted to the nucleus was synthesized by coupling a ... More
Classes and mechanisms of calcium waves.
AuthorsJaffe LF
JournalCell Calcium
PubMed ID8131190
The best known calcium waves move at about 5-30 microns/s (at 20 degrees C) and will be called fast waves to distinguish them from slow (contractile) ones which move at 0.1-1 microns/s as well as electrically propagated, ultrafast ones. Fast waves move deep within cells and seem to underlie most ... More
Requirement of a Src family kinase for initiating calcium release at fertilization in starfish eggs.
AuthorsGiusti AF, Carroll DJ, Abassi YA, Terasaki M, Foltz KR, Jaffe LA
JournalJ Biol Chem
PubMed ID10506191
Signal transduction leading to calcium release in echinoderm eggs at fertilization requires phospholipase Cgamma-mediated production of inositol trisphosphate (IP(3)), indicating that a tyrosine kinase is a likely upstream regulator. Because previous work has shown a fertilization-dependent association between the Src homology 2 (SH2) domains of phospholipase Cgamma and a Src ... More
Changes in either cytosolic or nucleoplasmic inositol 1,4,5-trisphosphate levels can control nuclear Ca2+ concentration.
AuthorsHennager DJ, Welsh MJ, DeLisle S
JournalJ Biol Chem
PubMed ID7890598
The free nucleoplasmic Ca2+ concentration ([Ca2+]n) may regulate many nuclear events, such as gene transcription. Since the nucleus may possess the enzymes necessary to generate the second messenger inositol 1,4,5-trisphosphate (Ins(1,4,5)P3), and because the nuclear envelope may enclose an Ins(1,4,5)P3-releasable Ca2+ store, we tested the hypothesis that nuclear and/or cytosolic ... More
Calcium release at fertilization in starfish eggs is mediated by phospholipase Cgamma.
AuthorsCarroll DJ, Ramarao CS, Mehlmann LM, Roche S, Terasaki M, Jaffe LA
JournalJ Cell Biol
PubMed ID9298985
Although inositol trisphosphate (IP3) functions in releasing Ca2+ in eggs at fertilization, it is not known how fertilization activates the phospholipase C that produces IP3. To distinguish between a role for PLCgamma, which is activated when its two src homology-2 (SH2) domains bind to an activated tyrosine kinase, and PLCbeta, ... More
Adenophostin A and inositol 1,4,5-trisphosphate differentially activate Cl- currents in Xenopus oocytes because of disparate Ca2+ release kinetics.
AuthorsMachaca K, Hartzell HC
JournalJ Biol Chem
PubMed ID9988722
Depletion of endoplasmic reticulum Ca2+ stores induces Ca2+ entry from the extracellular space by a process termed "store-operated Ca2+ entry" (SOCE). It has been suggested that the novel fungal metabolite adenophostin-A may be able to stimulate Ca2+ entry without stimulating Ca2+ release from stores. To test this idea further, we ... More
Imaging calcium dynamics in the nervous system by means of ballistic delivery of indicators.
AuthorsKettunen P, Demas J, Lohmann C, Kasthuri N, Gong Y, Wong RO, Gan WB
JournalJ Neurosci Methods
PubMed ID12234633
The use of fluorescence-based calcium indicators has, over the years, unraveled important calcium-dependent mechanisms underlying neuronal function and development. However, difficulties associated with the loading of calcium indicators have limited their widespread use, particularly for the study of neuronal processing in the adult nervous system. Here, we show that in ... 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
Calcium waves along the cleavage furrows in cleavage-stage Xenopus embryos and its inhibition by heparin.
AuthorsMuto A, Kume S, Inoue T, Okano H, Mikoshiba K
JournalJ Cell Biol
PubMed ID8858172
Calcium signaling is known to be associated with cytokinesis; however, the detailed spatio-temporal pattern of calcium dynamics has remained unclear. We have studied changes of intracellular free calcium in cleavage-stage Xenopus embryos using fluorescent calcium indicator dyes, mainly Calcium Green-1. Cleavage formation was followed by calcium transients that localized to ... More
Two dye two wavelength excitation calcium imaging: results from bovine adrenal chromaffin cells.
AuthorsOheim M, Naraghi M, Müller TH, Neher E
JournalCell Calcium
PubMed ID9793690
We tested a mixture of Calcium-Green-1 (CG-1) and Brilliantsulfaflavine (BS) for dual excitation ratiometric measurements of the intracellular free calcium concentration ([Ca2+]i) in bovine adrenal chromaffin cells. Dyes were coloaded (without being molecularly linked to each other) in the whole-cell configuration of the patch clamp technique. We compared the loading ... More
Injection of sperm extract mimics spatiotemporal dynamics of Ca2+ responses and progression of meiosis at fertilization of ascidian oocytes.
AuthorsKyozuka K, Deguchi R, Mohri T, Miyazaki S
JournalDevelopment
PubMed ID9735370
Sperm extract (SE) of the ascidian, Ciona savignyi, injected into oocytes induced repetitive intracellular Ca2+ increases with kinetics consistent with those at fertilization and caused reinitiation and progression of meiosis as in fertilized oocytes with the formation of polar bodies. The Ca2+ response comprised two sets of Ca2+ oscillations separated ... More
Calcium-regulated exocytosis is required for cell membrane resealing.
AuthorsBi GQ, Alderton JM, Steinhardt RA
JournalJ Cell Biol
PubMed ID8557742
Using confocal microscopy, we visualized exocytosis during membrane resealing in sea urchin eggs and embryos. Upon wounding by a laser beam, both eggs and embryos showed a rapid burst of localized Ca(2+)-regulated exocytosis. The rate of exocytosis was correlated quantitatively with successfully resealing. In embryos, whose activated surfaces must first ... More
Local perinuclear calcium signals associated with mitosis-entry in early sea urchin embryos.
AuthorsWilding M, Wright EM, Patel R, Ellis-Davies G, Whitaker M
JournalJ Cell Biol
PubMed ID8858173
Using calcium-sensitive dyes together with their dextran conjugates and confocal microscopy, we have looked for evidence of localized calcium signaling in the region of the nucleus before entry into mitosis, using the sea urchin egg first mitotic cell cycle as a model. Global calcium transients that appear to originate from ... More
Validity of the rapid buffering approximation near a point source of calcium ions.
AuthorsSmith GD, Wagner J, Keizer J
JournalBiophys J
PubMed ID8744292
In the presence of rapid buffers the full reaction-diffusion equations describing Ca2+ transport can be reduced using the rapid buffering approximation to a single transport equation for [Ca2+]. Here we simulate the full and reduced equations, exploring the conditions necessary for the validity of the rapid buffering approximation for an ... More
Electroporation-induced formation of individual calcium entry sites in the cell body and processes of adherent cells.
AuthorsTeruel MN, Meyer T
JournalBiophys J
PubMed ID9336174
Electroporation is a widely used method for introducing macromolecules into cells. We developed an electroporation device that requires only 1 microl of sample to load adherent cells in a 10-mm2 surface area while retaining greater than 90% cell survivability. To better understand this device, field-induced permeabilization of adherent rat basophilic ... More
Characterization of a dextran-based bifunctional calcium indicator immobilized in cells by the enzymatic addition of isoprenoid lipids.
AuthorsHorne JH, Meyer T
JournalCell Calcium
PubMed ID10191955
Cellular processes can be controlled by cell-wide increases in the cytosolic Ca2+ concentration or, alternatively, by localized Ca2+ signals in micro- and nano-domains. The experimental characterization of such localized Ca2+ signals would be facilitated using an immobilized Ca2+ indicator, which could prevent the accelerated spatial spreading of Ca2+ ions that ... More
Polar localization of a dihydropyridine receptor on living Fucus zygotes.
AuthorsShaw SL, Quatrano RS
JournalJ Cell Sci
PubMed ID8838657
We have used a fluorescently-labeled dihydropyridine (FL-DHP) to vitally stain living Fucus zygotes during the establishment of cell polarity. Localization of FL-DHP is primarily at the plasma membrane and FL-DHP binding is competitively blocked by an unlabeled dihydropyridine. Distribution of FL-DHP is initially symmetrical before fixation of the polar axis, ... More
Effects of temperature on calcium-sensitive fluorescent probes.
The effect of temperature on the binding equilibria of calcium-sensing dyes has been extensively studied, but there are also important temperature-related changes in the photophysics of the dyes that have been largely ignored. We conducted a systematic study of thermal effects on five calcium-sensing dyes under calcium-saturated and calcium-free conditions. ... More
Proteases stimulate fertilization-like responses in starfish eggs.
AuthorsCarroll DJ, Jaffe LA
JournalDev Biol
PubMed ID7649394
Application of proteases to eggs of the starfish, Asterina miniata, caused several responses like those seen at fertilization. Cortical granule exocytosis and fertilization envelope elevation occurred within about 1 min after exposure to trypsin, chymotrypsin, or pronase; protease inhibitors prevented these responses. Kallikrein caused cortical granule exocytosis and fertilization envelope ... More
InsP3 signaling induces pulse-modulated Ca2+ signals in the nucleus of airway epithelial ciliated cells.
AuthorsQuesada I, Verdugo P
JournalBiophys J
PubMed ID15792976
The phenomenology of nuclear Ca(2+) dynamics has experienced important progress revealing the broad range of cellular processes that it regulates. Although several agonists can mobilize Ca(2+) from storage in the nuclear envelope (NE) to the intranuclear compartment (INC), the mechanisms of Ca(2+) signaling in the nucleus still remain uncertain. Here ... More
IP3-mediated cytosolic and nuclear calcium elevation in NRK-52E cells using 'caged' GPIP2.
AuthorsDavis MA, Chang SH, Trump BF
JournalCell Calcium
PubMed ID8521459
Alterations in calcium homeostasis play a pivotal role in the cellular response to injury. Increases in the concentration of cytosolic free calcium ([Ca2+]i) result in a variety of calcium mediated toxic responses such as cytoskeletal alterations, mitochondrial damage, and over-expression of gene products. Inositol trisphosphate is a second messenger that ... More
Visualization of active neural circuitry in the spinal cord of intact zebrafish.
AuthorsFetcho JR, O'Malley DM
JournalJ Neurophysiol
PubMed ID7714582
1. One of the major obstacles in studying vertebrate neural networks is the difficulty in simultaneously monitoring activity in a population of neurons. To take advantage of the transparency of larval zebrafish, we used confocal microscopy to look into the spinal cord of immobilized fish to monitor neural responses during ... More
ATP-independent luminal oscillations and release of Ca2+ and H+ from mast cell secretory granules: implications for signal transduction.
AuthorsQuesada I, Chin WC, Verdugo P
JournalBiophys J
PubMed ID12885643
InsP(3) is an important link in the intracellular information network. Previous observations show that activation of InsP(3)-receptor channels on the granular membrane can turn secretory granules into Ca(2+) oscillators that deliver periodic trains of Ca(2+) release to the cytosol (T. Nguyen, W. C. Chin, and P. Verdugo, 1998, Nature, 395:908-912; ... More
Presynaptic calcium measurements at physiological temperatures using a new class of dextran-conjugated indicators.
AuthorsBeierlein M, Gee KR, Martin VV, Regehr WG
JournalJ Neurophysiol
PubMed ID15212445
Presynaptic calcium (Ca(pre)) has been studied extensively because of its role in triggering and modulating neurotransmitter release. Although calcium regulation and calcium-driven processes can be strongly temperature dependent, technical difficulties have limited most studies of Ca(pre) to temperatures well below the physiological range. Here we assessed the use of membrane-permeant ... More
An image-based model of calcium waves in differentiated neuroblastoma cells.
Calcium waves produced by bradykinin-induced inositol-1,4, 5-trisphosphate (InsP(3))-mediated release from endoplasmic reticulum (ER) have been imaged in N1E-115 neuroblastoma cells. A model of this process was built using the "virtual cell," a general computational system for integrating experimental image, biochemical, and electrophysiological data. The model geometry was based on a ... More
Identification of PLCgamma-dependent and -independent events during fertilization of sea urchin eggs.
AuthorsCarroll DJ, Albay DT, Terasaki M, Jaffe LA, Foltz KR
JournalDev Biol
PubMed ID9986735
At fertilization, sea urchin eggs undergo a series of activation events, including a Ca2+ action potential, Ca2+ release from the endoplasmic reticulum, an increase in intracellular pH, sperm pronuclear formation, MAP kinase dephosphorylation, and DNA synthesis. To examine which of these events might be initiated by activation of phospholipase Cgamma ... More
Large plasma membrane disruptions are rapidly resealed by Ca2+-dependent vesicle-vesicle fusion events.
AuthorsTerasaki M, Miyake K, McNeil PL
JournalJ Cell Biol
PubMed ID9314529
A microneedle puncture of the fibroblast or sea urchin egg surface rapidly evokes a localized exocytotic reaction that may be required for the rapid resealing that follows this breach in plasma membrane integrity (Steinhardt, R.A,. G. Bi, and J.M. Alderton. 1994. Science (Wash. DC). 263:390-393). How this exocytotic reaction facilitates ... More
The intracellular calcium increase at fertilization in Urechis caupo oocytes: activation without waves.
AuthorsStephano JL, Gould MC
JournalDev Biol
PubMed ID9356171
The intracellular Ca2+ (Cai) increase at fertilization of the marine worm Urechis caupo (Echiura) was studied with conventional and confocal epifluorescence microscopy in oocytes microinjected with calcium green dextran or dually labeled with the calcium-insensitive dye tetramethylrhodamine dextran. Calcium green fluorescence was also measured with a photomultiplier system while the ... More
Calcium imaging of motoneuron activity in the en-bloc spinal cord preparation of the neonatal rat.
AuthorsLev-Tov A, O'Donovan MJ
JournalJ Neurophysiol
PubMed ID7500153
1. This paper describes the use of calcium imaging to monitor patterns of activity in neonatal rat motoneurons retrogradely labeled with the calcium-sensitive dye, calcium green-dextran. 2. Pressure ejection of calcium green-dextran into ventral roots and into the surgically peeled ventrolateral funiculi (VLF) at the lumbar cord labeled spinal motoneurons ... More
Calcium imaging of rhythmic network activity in the developing spinal cord of the chick embryo.
AuthorsO'Donovan M, Ho S, Yee W
JournalJ Neurosci
PubMed ID7965041
Video-rate imaging of spinal neurons loaded with calcium-sensitive dyes was used to investigate the calcium dynamics and cellular organization of spontaneously active rhythm-generating networks in the spinal cord of E9-E12 chick embryos. Spinal neurons were loaded with bath-applied fura-2am. Motoneurons were also loaded by retrograde labeling with dextran-conjugated, calcium-sensitive dyes. ... More
Caffeine-induced calcium release in sea urchin eggs and the effect of continuous versus pulsed application on the mitotic apparatus.
AuthorsHarris PJ
JournalDev Biol
PubMed ID8313989
Unfertilized and fertilized eggs of the sea urchins Strongylocentrotus purpuratus and Lytechinus pictus, injected with the fluorescent probe calcium green dextran (Molecular Probes, Inc.) and monitored with single cell fluorimetry, rarely responded to 10 mM caffeine, but with 20 mM caffeine they produced a transient rise in intracellular calcium. Unfertilized ... More
Time-lapse confocal imaging of calcium dynamics in starfish embryos.
AuthorsStricker SA
JournalDev Biol
PubMed ID7649379
During fertilization and cleavage, embryos undergo transient rises in their intracellular free calcium levels that are postulated to provide essential signals enabling normal development to proceed. In order to analyze the spatiotemporal patterns and possible biological significance of these calcium transients, time-lapse confocal microscopy was used to monitor starfish embryos ... More
Mitochondrial participation in the intracellular Ca2+ network.
AuthorsBabcock DF, Herrington J, Goodwin PC, Park YB, Hille B
JournalJ Cell Biol
PubMed ID9049249
Calcium can activate mitochondrial metabolism, and the possibility that mitochondrial Ca2+ uptake and extrusion modulate free cytosolic [Ca2+] (Cac) now has renewed interest. We use whole-cell and perforated patch clamp methods together with rapid local perfusion to introduce probes and inhibitors to rat chromaffin cells, to evoke Ca2+ entry, and ... More
The cytoplasmic C-terminal fragment of polycystin-1 regulates a Ca2+-permeable cation channel.
The cytoplasmic C-terminal portion of the polycystin-1 polypeptide (PKD1(1-226)) regulates several important cell signaling pathways, and its deletion suffices to cause autosomal dominant polycystic kidney disease. However, a functional link between PKD1 and the ion transport processes required to drive renal cyst enlargement has remained elusive. We report here that ... More
Sperm-egg fusion is the prelude to the initial Ca2+ increase at fertilization in the mouse.
AuthorsLawrence Y, Whitaker M, Swann K
JournalDevelopment
PubMed ID9006083
Fusion of sperm and egg plasma membranes is an early and essential event at fertilization but it is not known if it plays a part in the signal transduction mechanism that leads to the oscillations in the cytoplasmic free Ca2+ concentration ([Ca2+]i) that accompany mammalian egg activation. We have used ... More
Root hair growth in Arabidopsis thaliana is directed by calcium and an endogenous polarity.
AuthorsBibikova TN, Zhigilei A, Gilroy S
JournalPlanta
PubMed ID9421933
Tip growth of plant cells has been suggested to be regulated by a tip-focused gradient in cytosolic calcium concentration ([Ca2+]c). However, whether this gradient orients apical growth or follows the driving force for this process remains unknown. Using localized photoactivation of the caged calcium ionophore Br-A23187 we have been able ... More
Spatiotemporal dynamics of intracellular [Ca2+]i oscillations during the growth and meiotic maturation of mouse oocytes.
AuthorsCarroll J, Swann K, Whittingham D, Whitaker M
JournalDevelopment
PubMed ID7821218
Calcium oscillations occur during meiotic maturation of mouse oocytes. They also trigger activation at fertilization. We have monitored [Ca2+]i in oocytes at different stages of growth and maturation to examine how the calcium release mechanisms alter during oogenesis. Spontaneous calcium oscillations occur every 2-3 minutes in the majority of fully ... More
Vital staining from dye-coated microprobes identifies new olfactory interneurons for optical and electrical recording.
AuthorsGelperin A, Flores J
JournalJ Neurosci Methods
PubMed ID9128173
A versatile technique for dye application in living tissue is described, which results in labeling of viable cells from which electrophysiological or optical recordings can be obtained. The dye-coated surface of a glass microelectrode tip is used to apply anatomical tracers or calcium sensitive probes with spatial precision. A total ... More
In vivo Live Imaging of Calcium Waves and Other Cellular Processes during Fertilization in Caenorhabditis elegans.
Authors
JournalBio Protoc
PubMed ID34541214
Direct activation of the Mauthner cell by electric field pulses drives ultrarapid escape responses.