AM-loading of fluorescent Ca2+ indicators into intact single fibers of frog muscle.
AuthorsZhao M, Hollingworth S, Baylor SM
JournalBiophys J
PubMed ID9168048
'The AM loading of a number of different fluorescent Ca2+ indicators was compared in intact single fibers of frog muscle. Among the 13 indicators studied, loading rates (the average increase in the fiber concentration of indicator per first 60 min of loading) varied approximately 100-fold, from approximately 3 microM/h to ... More
Intracellular Ca2+ dynamics during spontaneous and evoked activity of leech heart interneurons: low-threshold Ca currents and graded synaptic transmission.
AuthorsIvanov AI, Calabrese RL
JournalJ Neurosci
PubMed ID10864951
'In oscillatory neuronal networks that pace rhythmic behavior, Ca(2+) entry through voltage-gated Ca channels often supports bursting activity and mediates graded transmitter release. We monitored simultaneously membrane potential and/or ionic currents and changes of Ca fluorescence (using the fluorescence indicator Ca Orange) in spontaneously active and experimentally manipulated oscillator heart ... More
The role of Ca(2+) in stimulated bioluminescence of the dinoflagellate Lingulodinium polyedrum.
Authorsvon Dassow P, Latz MI
JournalJ Exp Biol
PubMed ID12200401
'Many marine dinoflagellates emit bright discrete flashes of light nearly instantaneously in response to either laminar or turbulent flows as well as to direct mechanical stimulation. The flash involves a unique pH-dependent luciferase and a proton-mediated action potential across the vacuole membrane. The mechanotransduction process initiating this action potential is ... More
Ryanodine receptor mutations associated with stress-induced ventricular tachycardia mediate increased calcium release in stimulated cardiomyocytes.
AuthorsGeorge CH, Higgs GV, Lai FA
JournalCirc Res
PubMed ID12919952
'Ca2+ release from the sarcoplasmic reticulum mediated by the cardiac ryanodine receptor (RyR2) is a fundamental event in cardiac muscle contraction. RyR2 mutations suggested to cause defective Ca2+ channel function have recently been identified in catecholaminergic polymorphic ventricular tachycardia (CPVT) and arrhythmogenic right ventricular dysplasia (ARVD) affected individuals. We report ... More
Cell-permeant Ca2+ chelators reduce early excitotoxic and ischemic neuronal injury in vitro and in vivo.
AuthorsTymianski M, Wallace MC, Spigelman I, Uno M, Carlen PL, Tator CH, Charlton MP
JournalNeuron
PubMed ID8102532
'We report the characterization of the first successful treatment of neuronal ischemic injury in vivo by cell-permeant Ca2+ chelators. The chelators attenuated glutamate-induced intracellular Ca2+ increases and neurotoxicity in neuronal explant cultures. When infused intravenously in rats, permeant fluorescent BAPTA analogs accumulated in neurons in several brain regions. BAPTA-AM, infused ... More
Biological effects of menadione photochemistry: effects of menadione on biological systems may not involve classical oxidant production.
'Because cell-mediated reduction of menadione leads to the generation of reactive oxygen species (ROS), this quinone is widely used to investigate the effects of ROS on cellular functions. We report that A549 human lung epithelial cells exposed to menadione demonstrate a dose-dependent increase in both intracellular calcium ([Ca(2+)](i)) and ROS ... More
Excitation spectra and brightness optimization of two-photon excited probes.
'Two-photon probe excitation data are commonly presented as absorption cross section or molecular brightness (the detected fluorescence rate per molecule). We report two-photon molecular brightness spectra for a diverse set of organic and genetically encoded probes with an automated spectroscopic system based on fluorescence correlation spectroscopy. The two-photon action cross ... More
Dendro-dendritic interactions between motion-sensitive large-field neurons in the fly.
AuthorsHaag J, Borst A
JournalJ Neurosci
PubMed ID11943823
'For visual course control, flies rely on a set of motion-sensitive neurons called lobula plate tangential cells (LPTCs). Among these cells, the so-called CH (centrifugal horizontal) cells shape by their inhibitory action the receptive field properties of other LPTCs called FD (figure detection) cells specialized for figure-ground discrimination based on ... More
Intracellular ionized calcium.
AuthorsJune CH, Rabinovitch PS
JournalMethods Cell Biol
PubMed ID7861962
Confocal Ca2+ imaging of organelles, cells, tissues, and organs.
AuthorsWilliams DA, Bowser DN, Petrou S
JournalMethods Enzymol
PubMed ID10506988
The use of confocal microscopy in the investigation of cell structure and function in the heart, vascular endothelium and smooth muscle cells.
AuthorsBkaily G, Pothier P, D'Orléans-Juste P, Simaan M, Jacques D, Jaalouk D, Belzile F, Hassan G, Boutin C, Haddad G, Neugebauer W
JournalMol Cell Biochem
PubMed ID9278244
In recent years, fluorescence microscopy imaging has become an important tool for studying cell structure and function. This non invasive technique permits characterization, localisation and qualitative quantification of free ions, messengers, pH, voltage and a pleiad of other molecules constituting living cells. In this paper, we present results using various ... More
Hydrogen sulfide induces calcium waves in astrocytes.
AuthorsNagai Y, Tsugane M, Oka J, Kimura H
JournalFASEB J
PubMed ID14734631
Hydrogen sulfide (H2S) modifies hippocampal long-term potentiation (LTP) and functions as a neuromodulator. Here, we show that H2S increases intracellular Ca2+ and induces Ca2+ waves in primary cultures of astrocytes as well as hippocampal slices. H2S increases the influx of Ca2+ and to a lesser extent causes the release from ... More
Monitoring cytosolic calcium in the dinoflagellate Crypthecodinium cohnii with calcium orange-AM.
AuthorsLam CM, Yeung PK, Wong JT
JournalPlant Cell Physiol
PubMed ID15829511
Calcium plays several important roles in the signal transduction pathways of dinoflagellates. We describe here the development of calcium orange-AM as an intracellular calcium reporter for the heterotrophic dinoflagellate Crypthecodinium cohnii. We demonstrated with confocal microscopy that by restricting the incubation period to 30-45 min, no compartmentalization of the dye ... More
Differential regulation of a hyperthermophilic alpha-amylase with a novel (Ca,Zn) two-metal center by zinc.
AuthorsLinden A, Mayans O, Meyer-Klaucke W, Antranikian G, Wilmanns M
JournalJ Biol Chem
PubMed ID12482867
The crystal structure of the alpha-amylase from the hyperthermophilic archaeon Pyrococcus woesei was solved in the presence of three inhibitors: acarbose, Tris, and zinc. In the absence of exogenous metals, this alpha-amylase bound 1 and 4 molar eq of zinc and calcium, respectively. The structure reveals a novel, activating, two-metal ... More
Adenosine induces inositol 1,4,5-trisphosphate receptor-mediated mobilization of intracellular calcium stores in basal forebrain cholinergic neurons.
AuthorsBasheer R, Arrigoni E, Thatte HS, Greene RW, Ambudkar IS, McCarley RW
JournalJ Neurosci
PubMed ID12196591
In the cholinergic basal forebrain, we found previously that the extracellular adenosine concentration increase that accompanies sleep deprivation, acting via the A1 receptor, led to activation of the transcription factor nuclear factor-kappaB and to the upregulation of A1 adenosine receptor mRNA. We thus began to examine intracellular signaling mechanisms. We ... More
Cytosolic calcium transients: spatial localization and role in Drosophila photoreceptor cell function.
Drosophila phototransduction is a phosphoinositide-mediated and Ca(2+)-regulated signaling cascade ideal for the dissection of feedback regulatory mechanisms. To study the roles of intracellular Ca2+ ([Ca2+]i) in this process, we developed novel techniques for the measurement of [Ca2+]i in intact photoreceptors. We genetically engineered flies that express a UV-specific rhodopsin in ... More
Simultaneous optical recording of evoked and spontaneous transients of membrane potential and intracellular calcium concentration with high spatio-temporal resolution.
AuthorsSinha SR, Patel SS, Saggau P
JournalJ Neurosci Methods
PubMed ID8544487
We have developed a system for simultaneous optical recording of transients of membrane potential and intracellular calcium concentration from mammalian brain slice preparations with high spatio-temporal resolution. Simultaneous recording was achieved by using two dedicated photodetectors together with two fluorescent indicators. Specifically, the calcium-sensitive dye Calcium Orange and the voltage-sensitive ... More
A comparison of fluorescent Ca2+ indicator properties and their use in measuring elementary and global Ca2+ signals.
AuthorsThomas D, Tovey SC, Collins TJ, Bootman MD, Berridge MJ, Lipp P
JournalCell Calcium
PubMed ID11032777
Quantifying the magnitude of Ca2+ signals from changes in the emission of fluorescent indicators relies on assumptions about the indicator behaviour in situ. Factors such as osmolarity, pH, ionic strength and protein environment can affect indicator properties making it advantageous to calibrate indicators within the required cellular or subcellular environment. ... More
Regulation of Na+,K+-ATPase by persistent sodium accumulation in adult rat thalamic neurones.
AuthorsSenatorov VV, Stys PK, Hu B
JournalJ Physiol
PubMed ID10835038
The present study investigated the regulatory mechanism of the Na+, K+-ATPase and the level of internal Na+ and Ca2+ in response to persistent Na+ influx in acutely dissociated rat thalamic neurones. Whole-cell patch-clamp recordings and Na+ imaging revealed a stable [Na+]i and low background pump activity. Exposure to veratridine (50 ... 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
Hippocampal CA1 region neurodegeneration produced by ethanol withdrawal requires activation of intrinsic polysynaptic hippocampal pathways and function of N-methyl-D-aspartate receptors.
AuthorsPrendergast MA, Harris BR, Mullholland PJ, Blanchard JA, Gibson DA, Holley RC, Littleton JM
JournalNeuroscience
PubMed ID15026127
Long-term intake of ethanol produces adaptive alterations in multiple transmitter systems in the hippocampal formation that likely contribute to ethanol withdrawal-induced seizure and excitotoxicity. The present studies were designed to examine the role of N-methyl-d-aspartate receptor activation and cytosolic Ca(2+) accumulation in the neurotoxic effects of ethanol withdrawal. Further, these ... More
Activation kinetics of skinned cardiac muscle by laser photolysis of nitrophenyl-EGTA.
AuthorsMartin H, Bell MG, Ellis-Davies GC, Barsotti RJ
JournalBiophys J
PubMed ID14747333
The kinetics of Ca(2+)-induced contractions of chemically skinned guinea pig trabeculae was studied using laser photolysis of NP-EGTA. The amount of free Ca(2+) released was altered by varying the output from a frequency-doubled ruby laser focused on the trabeculae, while maintaining constant total [NP-EGTA] and [Ca(2+)]. The time courses of ... More
Modulation of spike-mediated synaptic transmission by presynaptic background Ca2+ in leech heart interneurons.
AuthorsIvanov AI, Calabrese RL
JournalJ Neurosci
PubMed ID12598609
At the core of the rhythmically active leech heartbeat central pattern generator are pairs of mutually inhibitory interneurons. Synaptic transmission between these interneurons consists of spike-mediated and graded components, both of which wax and wane on a cycle-by-cycle basis. Low-threshold Ca2+ currents gate the graded component. Ca imaging experiments indicate ... More
Adrenomedullin stimulates nitric oxide production from primary rat hypothalamic neurons: roles of calcium and phosphatases.
AuthorsXu Y, Krukoff TL
JournalMol Pharmacol
PubMed ID17446268
Adrenomedullin (ADM) in the brain plays important roles in the maintenance of homeostasis. Although in vivo evidence has suggested that nitric oxide (NO) mediates ADM's effects in the brain, mechanisms for ADM stimulation of NO production in neurons have not been identified. In the present study, primary hypothalamic neurons were ... More
Small molecules facilitate single factor-mediated sweat gland cell reprogramming.
Authors
JournalMil Med Res
PubMed ID35351192
Intracellular calcium ion concentration measurement using a phase-modulation fluorescence lifetime method with compensation for phase shift due to the presence of proteins.
Authors
JournalAnal Sci
PubMed ID23400285
CRYβA3/A1-Crystallin Knockout Develops Nuclear Cataract and Causes Impaired Lysosomal Cargo Clearance and Calpain Activation.
Authors
JournalPLoS One
PubMed ID26863613
Reactivation of Lysosomal Ca2+ Efflux Rescues Abnormal Lysosomal Storage in FIG4-Deficient Cells.