Intracellular astrocyte calcium waves in situ increase the frequency of spontaneous AMPA receptor currents in CA1 pyramidal neurons.
AuthorsFiacco TA, McCarthy KD
JournalJ Neurosci
PubMed ID14736858
'Spontaneous neurotransmitter release and activation of group I metabotropic glutamate receptors (mGluRs) each play a role in the plasticity of neuronal synapses. Astrocytes may contribute to short- and long-term synaptic changes by signaling to neurons via these processes. Spontaneous whole-cell AMPA receptor (AMPAR) currents were recorded in CA1 pyramidal cells ... More
Formation and function of synapses with respect to Schwann cells at the end of motor nerve terminal branches on mature amphibian (Bufo marinus) muscle.
AuthorsMacleod GT, Dickens PA, Bennett MR
JournalJ Neurosci
PubMed ID11264312
'A study has been made of the formation and regression of synapses with respect to Schwann cells at the ends of motor nerve terminal branches in mature toad (Bufo marinus) muscle. Synapse formation and regression, as inferred from the appearance and loss of N-(3-triethylammoniumpropyl)-4-(4-(dibutylamino)styryl) pyridinium dibromide (FM1-43)-stained vesicle clusters, occurred ... More
Ca2+ fluorescence imaging with pico- and femtosecond two-photon excitation: signal and photodamage.
AuthorsKoester HJ, Baur D, Uhl R, Hell SW
JournalBiophys J
PubMed ID10512842
'The signal and limitations of calcium florescence imaging using nonresonant multiphoton absorption of near-infrared femto- and picosecond laser pulses were examined. The fluorescence changes of various Ca(2+)-indicators induced by transient increases of the intradendritic calcium concentration were evaluated by evoking physiological activity in neocortical neurons in rat brain slices. Photodamage ... More
Action potentials reliably invade axonal arbors of rat neocortical neurons.
AuthorsCox CL, Denk W, Tank DW, Svoboda K
JournalProc Natl Acad Sci U S A
PubMed ID10931955
'Neocortical pyramidal neurons have extensive axonal arborizations that make thousands of synapses. Action potentials can invade these arbors and cause calcium influx that is required for neurotransmitter release and excitation of postsynaptic targets. Thus, the regulation of action potential invasion in axonal branches might shape the spread of excitation in ... More
Buffer kinetics shape the spatiotemporal patterns of IP3-evoked Ca2+ signals.
AuthorsDargan SL, Parker I
JournalJ Physiol
PubMed ID14555715
'Ca2+ liberation through inositol 1,4,5-trisphosphate receptors (IP3Rs) plays a universal role in cell regulation, and specificity of cell signalling is achieved through the spatiotemporal patterning of Ca2+ signals. IP3Rs display Ca2+-induced Ca2+ release (CICR), but are grouped in clusters so that regenerative Ca2+ signals may remain localized to individual clusters, ... More
Axonal speeding: shaping synaptic potentials in small neurons by the axonal membrane compartment.
AuthorsMejia-Gervacio S, Collin T, Pouzat C, Tan YP, Llano I, Marty A
JournalNeuron
PubMed ID17359919
'The role of the axonal membrane compartment in synaptic integration is usually neglected. We show here that in interneurons of the cerebellar molecular layer, where dendrites are so short that the somatodendritic domain can be considered isopotential, the axonal membrane contributes a significant part of the cell input capacitance. We ... More
Light dependence of calcium and membrane potential measured in blowfly photoreceptors in vivo.
AuthorsOberwinkler J, Stavenga DG
JournalJ Gen Physiol
PubMed ID9689022
'Light adaptation in insect photoreceptors is caused by an increase in the cytosolic Ca2+ concentration. To better understand this process, we measured the cytosolic Ca2+ concentration in vivo as a function of adapting light intensity in the white-eyed blowfly mutant chalky. We developed a technique to measure the cytosolic Ca2+ ... 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
Dopaminergic regulation of dendritic calcium: fast multisite calcium imaging.
AuthorsZhou WL, Oikonomou KD, Short SM, Antic SD,
JournalMethods Mol Biol
PubMed ID23296782
'Optimal dopamine tone is required for the normal cortical function; however it is still unclear how cortical-dopamine-release affects information processing in individual cortical neurons. Thousands of glutamatergic inputs impinge onto elaborate dendritic trees of neocortical pyramidal neurons. In the process of ensuing synaptic integration (information processing), a variety of calcium ... 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
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
Ca2+ dynamics along identified synaptic terminals in Drosophila larvae.
AuthorsLnenicka GA, Grizzaffi J, Lee B, Rumpal N
JournalJ Neurosci
PubMed ID17122054
'Changes in intracellular Ca2+ concentration ([Ca2+]i) play an important role in the function and plasticity of synapses. We characterized the changes in [Ca2+]i produced by action potentials (APs) along two identified motor terminals found on separate muscle fibers in Drosophila larvae and examined factors that influence the amplitude and duration ... More
NMDA spikes in basal dendrites of cortical pyramidal neurons.
AuthorsSchiller J, Major G, Koester HJ, Schiller Y
JournalNature
PubMed ID10749211
'Basal dendrites are a major target for synaptic inputs innervating cortical pyramidal neurons. At present little is known about signal processing in these fine dendrites. Here we show that coactivation of clustered neighbouring basal inputs initiated local dendritic spikes, which resulted in a 5.9 +/- 1.5 mV (peak) and 64.4 ... More
Pollen tubes exhibit regular periodic membrane trafficking events in the absence of apical extension.
'The growing pollen tube provides an excellent single cell model system in which to study the mechanisms determining growth regulation, polarity and periodic behaviour. Previously, using FM4-64, we identified periodic movements within the apical vesicle accumulation that were related to the period of oscillatory growth. This suggested a more complex ... More
NMDA receptor-mediated subthreshold Ca(2+) signals in spines of hippocampal neurons.
AuthorsKovalchuk Y, Eilers J, Lisman J, Konnerth A
JournalJ Neurosci
PubMed ID10684880
'We have used rapid confocal microscopy to investigate the mechanism of Ca(2+) signals in individual dendritic spines of hippocampal CA1 pyramidal cells. The experiments focused on the signals that occur during single weak synaptic responses that were subthreshold for triggering postsynaptic action potentials. These Ca(2+) signals were not strongly affected ... More
Dendritic calcium transients in the leech giant glial cell in situ.
AuthorsLohr C, Deitmer JW
JournalGlia
PubMed ID10384876
'Glial cells have been shown to respond to neuronal activity with changes in the membrane potential and the intracellular Ca2+ concentration. In order to get closer to glial structures associated with neuronal synapses, we have now looked at Ca2+ signalling in the glial processes ("glial dendrites") in response to neurotransmitters ... More
A nucleoporin is required for induction of Ca2+ spiking in legume nodule development and essential for rhizobial and fungal symbiosis.
AuthorsKanamori N, Madsen LH, Radutoiu S, Frantescu M, Quistgaard EM, Miwa H, Downie JA, James EK, Felle HH, Haaning LL, Jensen TH, Sato S, Nakamura Y, Tabata S, Sandal N, Stougaard J
JournalProc Natl Acad Sci U S A
PubMed ID16407163
'Nuclear-cytoplasmic partitioning and traffic between cytoplasmic and nuclear compartments are fundamental processes in eukaryotic cells. Nuclear pore complexes mediate transport of proteins, RNAs and ribonucleoprotein particles in and out of the nucleus. Here we present positional cloning of a plant nucleoporin gene, Nup133, essential for a symbiotic signal transduction pathway ... More
Extrusion of Ca2+ from mouse motor terminal mitochondria via a Na+-Ca2+ exchanger increases post-tetanic evoked release.
AuthorsGarcía-Chacón LE, Nguyen KT, David G, Barrett EF
JournalJ Physiol
PubMed ID16613870
'Mitochondria sequester much of the Ca2+ that enters motor nerve terminals during repetitive stimulation at frequencies exceeding 10-20 Hz. We studied the post-stimulation extrusion of Ca2+ from mitochondria by measuring changes in matrix [Ca2+] with fluorescent indicators loaded into motor terminal mitochondria in the mouse levator auris longus muscle. Trains ... 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
Characterization of postsynaptic Ca2+ signals at the Drosophila larval NMJ.
AuthorsDesai SA, Lnenicka GA,
JournalJ Neurophysiol
PubMed ID21593388
'Postsynaptic intracellular Ca(2+) concentration ([Ca(2+)](i)) has been proposed to play an important role in both synaptic plasticity and synaptic homeostasis. In particular, postsynaptic Ca(2+) signals can alter synaptic efficacy by influencing transmitter release, receptor sensitivity, and protein synthesis. We examined the postsynaptic Ca(2+) transients at the Drosophila larval neuromuscular junction ... More
In vivo two-photon laser-scanning microscopy of Ca2+ dynamics in visual motion-sensitive neurons.
AuthorsKalb J, Nielsen T, Fricke M, Egelhaaf M, Kurtz R
JournalBiochem Biophys Res Commun
PubMed ID15020223
'We applied two-photon laser-scanning microscopy (TPLSM) to motion-sensitive visual interneurons of the fly to study Ca(2+) dynamics in vivo at a higher spatial and temporal resolution than possible with conventional fluorescence microscopy. Based on a custom-built two-photon microscope, we performed line scans to measure changes in presynaptic Ca(2+) concentrations elicited ... More
Fluorescence changes of genetic calcium indicators and OGB-1 correlated with neural activity and calcium in vivo and in vitro.
AuthorsHendel T, Mank M, Schnell B, Griesbeck O, Borst A, Reiff DF,
JournalJ Neurosci
PubMed ID18632944
'Recent advance in the design of genetically encoded calcium indicators (GECIs) has further increased their potential for direct measurements of activity in intact neural circuits. However, a quantitative analysis of their fluorescence changes (DeltaF) in vivo and the relationship to the underlying neural activity and changes in intracellular calcium concentration ... More
T-type Ca(2+) channels mediate neurotransmitter release in retinal bipolar cells.
AuthorsPan ZH, Hu HJ, Perring P, Andrade R
JournalNeuron
PubMed ID11604141
'Transmitter release in neurons is thought to be mediated exclusively by high-voltage-activated (HVA) Ca(2+) channels. However, we now report that, in retinal bipolar cells, low-voltage-activated (LVA) Ca(2+) channels also mediate neurotransmitter release. Bipolar cells are specialized neurons that release neurotransmitter in response to graded depolarizations. Here we show that these ... More
Zymogen granule exocytosis is characterized by long fusion pore openings and preservation of vesicle lipid identity.
AuthorsThorn P, Fogarty KE, Parker I
JournalProc Natl Acad Sci U S A
PubMed ID15090649
'The dynamics of the fusion pore that forms between a secretory vesicle and the plasma membrane are important in the regulation of both exocytosis and endocytosis. Here, we describe characteristics of fusion during zymogen granule exocytosis in exocrine pancreatic acinar cells. By using fluorescence recovery after photobleaching techniques, we show ... More
'Our understanding of the underlying mechanisms of Ca2+ signaling as well as our appreciation for its ubiquitous role in cellular processes has been rapidly advanced, in large part, due to the development of fluorescent Ca2+ indicators. In this chapter, we discuss some of the most common chemical Ca2+ indicators that ... More
Modulation by K+ channels of action potential-evoked intracellular Ca2+ concentration rises in rat cerebellar basket cell axons.
AuthorsTan YP, Llano I
JournalJ Physiol
PubMed ID10517801
'1. Action potential-evoked [Ca2+]i rises in basket cell axons of rat cerebellar slices were studied using two-photon laser scanning microscopy and whole-cell recording, to identify the K+ channels controlling the shape of the axonal action potential. 2. Whole-cell recordings of Purkinje cell IPSCs were used to screen K+ channel subtypes ... More
Extracellular Ca2+ depletion contributes to fast activity-dependent modulation of synaptic transmission in the brain.
AuthorsRusakov DA, Fine A
JournalNeuron
PubMed ID12546823
'Synaptic activation is associated with rapid changes in intracellular Ca(2+), while the extracellular Ca(2+) level is generally assumed to be constant. Here, using a novel optical method to measure changes in extracellular Ca(2+) at high spatial and temporal resolution, we find that brief trains of synaptic transmission in hippocampal area ... More
Presynaptic inhibition caused by retrograde signal from metabotropic glutamate to cannabinoid receptors.
AuthorsMaejima T, Hashimoto K, Yoshida T, Aiba A, Kano M
JournalNeuron
PubMed ID11516402
'We report a type of synaptic modulation that involves retrograde signaling from postsynaptic metabotropic glutamate receptors (mGluRs) to presynaptic cannabinoid receptors. Activation of mGluR subtype 1 (mGluR1) expressed in cerebellar Purkinje cells (PCs) reduced neurotransmitter release from excitatory climbing fibers. This required activation of G proteins but not Ca2+ elevation ... More
Imaging in vivo: watching the brain in action.
AuthorsKerr JN, Denk W,
JournalNat Rev Neurosci
PubMed ID18270513
'The appeal of in vivo cellular imaging to any neuroscientist is not hard to understand: it is almost impossible to isolate individual neurons while keeping them and their complex interactions with surrounding tissue intact. These interactions lead to the complex network dynamics that underlie neural computation which, in turn, forms ... More
Modulation of presynaptic Ca2+ entry by AMPA receptors at individual GABAergic synapses in the cerebellum.
AuthorsRusakov DA, Saitow F, Lehre KP, Konishi S
JournalJ Neurosci
PubMed ID15901774
'Cerebellar Purkinje cells (PCs) receive GABAergic input that undergoes powerful retrograde modulation by presynaptic cannabinoid and glutamate receptors. Here we examine a distinct modulatory mechanism at these synapses, which does not require postsynaptic depolarization and acts via presynaptic AMPA receptors. We find that this mechanism operates mainly in the somatic ... More
Local calcium release in dendritic spines required for long-term synaptic depression.
AuthorsMiyata M, Finch EA, Khiroug L, Hashimoto K, Hayasaka S, Oda SI, Inouye M, Takagishi Y, Augustine GJ, Kano M
JournalNeuron
PubMed ID11086997
'We have used rats and mice with mutations in myosin-Va to evaluate the range and function of IP3-mediated Ca2+ signaling in dendritic spines. In these mutants, the endoplasmic reticulum and its attendant IP3 receptors do not enter the postsynaptic spines of parallel fiber synapses on cerebellar Purkinje cells. Long-term synaptic ... More
Two-photon imaging in living brain slices.
AuthorsMainen ZF, Maletic-Savatic M, Shi SH, Hayashi Y, Malinow R, Svoboda K
JournalMethods
PubMed ID10356355
'Two-photon excitation laser scanning microscopy (TPLSM) has become the tool of choice for high-resolution fluorescence imaging in intact neural tissues. Compared with other optical techniques, TPLSM allows high-resolution imaging and efficient detection of fluorescence signal with minimal photobleaching and phototoxicity. The advantages of TPLSM are especially pronounced in highly scattering ... More
Target cell-dependent normalization of transmitter release at neocortical synapses.
AuthorsKoester HJ, Johnston D
JournalScience
PubMed ID15774725
'The efficacy and short-term modification of neocortical synaptic connections vary with the type of target neuron. We investigated presynaptic Ca2+ and release probability at single synaptic contacts between pairs of neurons in layer 2/3 of the rat neocortex. The amplitude of Ca2+ signals in boutons of pyramids contacting bitufted or ... More
Ratiometric sensing using dual-frequency lifetime discrimination.
AuthorsKostov Y, Harms P, Rao G
JournalAnal Biochem
PubMed ID11567535
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
Electrophysiology in the age of light.
AuthorsScanziani M, Häusser M,
JournalNature
PubMed ID19829373
Electrophysiology, the 'gold standard' for investigating neuronal signalling, is being challenged by a new generation of optical probes. Together with new forms of microscopy, these probes allow us to measure and control neuronal signals with spatial resolution and genetic specificity that already greatly surpass those of electrophysiology. We predict that ... More
Activity-dependent accumulation of Ca2+ in axon and dendrites of the leech Leydig neuron.
AuthorsLohr C, Beck A, Deitmer JW
JournalNeuroreport
PubMed ID11726767
We have investigated Ca2+ changes evoked by single action potentials (APs) in axon and dendrites of leech Leydig neurons. Dendritic Ca2+ transients induced by an AP were twice as large as in the axon, and Ca2+ recovery was significantly faster in the dendrites as compared to the axon. The AP-induced ... More
Optical recording of light-evoked calcium signals in the functionally intact retina.
AuthorsDenk W, Detwiler PB
JournalProc Natl Acad Sci U S A
PubMed ID10359834
Using two-photon excitation of fluorescent indicator dyes, we measured calcium concentration transients in retinal ganglion and amacrine cells without destroying the light sensitivity of the retina by maximally activating or bleaching the photoreceptors. This allowed an immediate assessment of the cellular morphology and study of the calcium signals evoked by ... More
Emergence of input specificity of ltp during development of retinotectal connections in vivo.
AuthorsTao HW, Zhang LI, Engert F, Poo M
JournalNeuron
PubMed ID11545716
Input specificity of activity-induced synaptic modification was examined in the developing Xenopus retinotectal connections. Early in development, long-term potentiation (LTP) induced by theta burst stimulation (TBS) at one retinal input spreads to other unstimulated converging inputs on the same tectal neuron. As the animal develops, LTP induced by the same ... More
Microdomains for neuron-glia interaction: parallel fiber signaling to Bergmann glial cells.
AuthorsGrosche J, Matyash V, Möller T, Verkhratsky A, Reichenbach A, Kettenmann H
JournalNat Neurosci
PubMed ID10195197
Astrocytes are considered a reticulate network of cells, through which calcium signals can spread easily. In Bergmann glia, astrocytic cells of the cerebellum, we identified subcellular compartments termed 'glial microdomains'. These elements have a complex surface consisting of thin membrane sheets, contain few mitochondria and wrap around synapses. To test ... More
Directionally selective calcium signals in dendrites of starburst amacrine cells.
AuthorsEuler T, Detwiler PB, Denk W
JournalNature
PubMed ID12192402
The detection of image motion is fundamental to vision. In many species, unique classes of retinal ganglion cells selectively respond to visual stimuli that move in specific directions. It is not known which retinal cell first performs the neural computations that give rise to directional selectivity in the ganglion cell. ... More
The life cycle of Ca(2+) ions in dendritic spines.
AuthorsSabatini BL, Oertner TG, Svoboda K
JournalNeuron
PubMed ID11832230
Spine Ca(2+) is critical for the induction of synaptic plasticity, but the factors that control Ca(2+) handling in dendritic spines under physiological conditions are largely unknown. We studied [Ca(2+)] signaling in dendritic spines of CA1 pyramidal neurons and find that spines are specialized structures with low endogenous Ca(2+) buffer capacity ... More
Construction of a two-photon microscope for video-rate Ca(2+) imaging.
AuthorsNguyen QT, Callamaras N, Hsieh C, Parker I
JournalCell Calcium
PubMed ID11728133
We describe the construction of a video-rate two-photon laser scanning microscope, compare its performance to a similar confocal microscope, and illustrate its use for imaging local Ca(2+) transients from cortical neurons in brain slices. Key features include the use of a Ti-sapphire femtosecond laser allowing continuous tuning over a wide ... More
High-speed, low-photodamage nonlinear imaging using passive pulse splitters.
AuthorsJi N, Magee JC, Betzig E,
JournalNat Methods
PubMed ID18204458
Pulsed lasers are key elements in nonlinear bioimaging techniques such as two-photon fluorescence excitation (TPE) microscopy. Typically, however, only a percent or less of the laser power available can be delivered to the sample before photoinduced damage becomes excessive. Here we describe a passive pulse splitter that converts each laser ... More
Compartmentalized dendritic plasticity and input feature storage in neurons.
AuthorsLosonczy A, Makara JK, Magee JC,
JournalNature
PubMed ID18368112
Although information storage in the central nervous system is thought to be primarily mediated by various forms of synaptic plasticity, other mechanisms, such as modifications in membrane excitability, are available. Local dendritic spikes are nonlinear voltage events that are initiated within dendritic branches by spatially clustered and temporally synchronous synaptic ... More
A simple method for quantitative calcium imaging in unperturbed developing neurons.
AuthorsAlbantakis L, Lohmann C,
JournalJ Neurosci Methods
PubMed ID19682493
Calcium imaging has been widely used to address questions of neuronal function and development. To gain deeper insights into the actions of calcium as a second messenger, but also to measure synaptic function, it is necessary to quantify the level of calcium at rest and during calcium transients. While quantification ... More
Regional differences in hippocampal calcium handling provide a cellular mechanism for limiting plasticity.
AuthorsSimons SB, Escobedo Y, Yasuda R, Dudek SM,
JournalProc Natl Acad Sci U S A
PubMed ID19666491
Although much is known about the mechanisms underlying synaptic plasticity, the cellular mechanisms that negatively regulate plasticity in some brain regions are considerably less studied. One region where neurons do not reliably express long-term potentiation (LTP) is the CA2 subfield of the hippocampus. Given the connection between synaptic plasticity and ... More
Three-dimensional random access multiphoton microscopy for functional imaging of neuronal activity.
The dynamic ability of neuronal dendrites to shape and integrate synaptic responses is the hallmark of information processing in the brain. Effectively studying this phenomenon requires concurrent measurements at multiple sites on live neurons. Substantial progress has been made by optical imaging systems that combine confocal and multiphoton microscopy with ... More
Light evokes Ca2+ spikes in the axon terminal of a retinal bipolar cell.
AuthorsProtti DA, Flores-Herr N, von Gersdorff H
JournalNeuron
PubMed ID10707985
Bipolar cells in the vertebrate retina have been characterized as nonspiking interneurons. Using patch-clamp recordings from goldfish retinal slices, we find, however, that the morphologically well-defined Mb1 bipolar cell is capable of generating spikes. Surprisingly, in dark-adapted retina, spikes were reliably evoked by light flashes and had a long (1-2 ... More
Dye loading with patch pipettes.
AuthorsEilers J, Konnerth A,
JournalCSH Protoc
PubMed ID20147143
This protocol describes the loading of individual cells with fluorescent probes via patch pipettes. The patch-clamp methodology has been successfully used for single-cell dye labeling in cultured neurons, brain slices, and in vivo preparations. A broad range of dyes can be used with this loading technique. Markers for morphological reconstruction ... More
Ca(2+) binding protein frequenin mediates GDNF-induced potentiation of Ca(2+) channels and transmitter release.
AuthorsWang CY, Yang F, He X, Chow A, Du J, Russell JT, Lu B
JournalNeuron
PubMed ID11604142
Molecular mechanisms underlying long-term neurotrophic regulation of synaptic transmission and plasticity are unknown. We report here that long-term treatment of neuromuscular synapses with glial cell line-derived neurotrophic factor (GDNF) potentiates spontaneous and evoked transmitter release, in ways very similar to presynaptic expression of the Ca(2+) binding protein frequenin. GDNF enhances ... More
Intraglomerular inhibition: signaling mechanisms of an olfactory microcircuit.
AuthorsMurphy GJ, Darcy DP, Isaacson JS
JournalNat Neurosci
PubMed ID15696160
Microcircuits composed of principal neuron and interneuron dendrites have an important role in shaping the representation of sensory information in the olfactory bulb. Here we establish the physiological features governing synaptic signaling in dendrodendritic microcircuits of olfactory bulb glomeruli. We show that dendritic gamma-aminobutyric acid (GABA) release from periglomerular neurons ... More
Local excitatory circuits in the intermediate gray layer of the superior colliculus.
AuthorsPettit DL, Helms MC, Lee P, Augustine GJ, Hall WC
JournalJ Neurophysiol
PubMed ID10085368
We have used photostimulation and whole cell patch-clamp recording techniques to examine local synaptic interactions in slices from the superior colliculus of the tree shrew. Uncaging glutamate 10-75 microm from the somata of neurons in the intermediate gray layer elicited a long-lasting inward current, due to direct activation of glutamate ... More
Importance of AMPA receptors for hippocampal synaptic plasticity but not for spatial learning.
AuthorsZamanillo D, Sprengel R, Hvalby O, Jensen V, Burnashev N, Rozov A, Kaiser KM, Köster HJ, Borchardt T, Worley P, Lübke J, Frotscher M, Kelly PH, Sommer B, Andersen P, Seeburg PH, Sakmann B
JournalScience
PubMed ID10364547
Gene-targeted mice lacking the L-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) receptor subunit GluR-A exhibited normal development, life expectancy, and fine structure of neuronal dendrites and synapses. In hippocampal CA1 pyramidal neurons, GluR-A-/- mice showed a reduction in functional AMPA receptors, with the remaining receptors preferentially targeted to synapses. Thus, the CA1 soma-patch currents were ... More
Single synaptic events evoke NMDA receptor-mediated release of calcium from internal stores in hippocampal dendritic spines.
AuthorsEmptage N, Bliss TV, Fine A
JournalNeuron
PubMed ID10027294
We have used confocal microscopy to monitor synaptically evoked Ca2+ transients in the dendritic spines of hippocampal pyramidal cells. Individual spines respond to single afferent stimuli (<0.1 Hz) with Ca2+ transients or failures, reflecting the probability of transmitter release at the activated synapse. Both AMPA and NMDA glutamate receptor antagonists ... More
Spread of dendritic excitation in layer 2/3 pyramidal neurons in rat barrel cortex in vivo.
AuthorsSvoboda K, Helmchen F, Denk W, Tank DW
JournalNat Neurosci
PubMed ID10195182
In layer 2/3 pyramidal neurons of barrel cortex in vivo, calcium ion concentration ([Ca2+]) transients in apical dendrites evoked by sodium action potentials are limited to regions close to the soma. To study the mechanisms underlying this restricted pattern of calcium influx, we combined two-photon imaging of dendritic [Ca2+] dynamics ... More
Calcium stores in hippocampal synaptic boutons mediate short-term plasticity, store-operated Ca2+ entry, and spontaneous transmitter release.
AuthorsEmptage NJ, Reid CA, Fine A
JournalNeuron
PubMed ID11182091
Evoked transmitter release depends upon calcium influx into synaptic boutons, but mechanisms regulating bouton calcium levels and spontaneous transmitter release are obscure. To understand these processes better, we monitored calcium transients in axons and presynaptic terminals of pyramidal neurons in hippocampal slice cultures. Action potentials reliably evoke calcium transients in ... 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
Hypocretin and nicotine excite the same thalamocortical synapses in prefrontal cortex: correlation with improved attention in rat.
AuthorsLambe EK, Olausson P, Horst NK, Taylor JR, Aghajanian GK
JournalJ Neurosci
PubMed ID15917462
Thalamic projections to prefrontal cortex are important for executive aspects of attention. Using two-photon imaging in prefrontal brain slices, we show that nicotine and the wakefulness neuropeptide hypocretin (orexin) excite the same identified synapses of the thalamocortical arousal pathway within the prefrontal cortex. Although it is known that attention can ... More
Ca2+ requirements for cerebellar long-term synaptic depression: role for a postsynaptic leaky integrator.
AuthorsTanaka K, Khiroug L, Santamaria F, Doi T, Ogasawara H, Ellis-Davies GC, Kawato M, Augustine GJ
JournalNeuron
PubMed ID17553426
Photolysis of a caged Ca(2+) compound was used to characterize the dependence of cerebellar long-term synaptic depression (LTD) on postsynaptic Ca(2+) concentration ([Ca(2+)](i)). Elevating [Ca(2+)](i) was sufficient to induce LTD without requiring any of the other signals produced by synaptic activity. A sigmoidal relationship between [Ca(2+)](i) and LTD indicated a ... More
Quantification of spread of cerebellar long-term depression with chemical two-photon uncaging of glutamate.
AuthorsWang SS, Khiroug L, Augustine GJ
JournalProc Natl Acad Sci U S A
PubMed ID10890882
Localized, chemical two-photon photolysis of caged glutamate was used to map the changes in alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-type glutamate receptors caused by long-term synaptic depression (LTD) in cerebellar Purkinje cells. LTD produced by pairing parallel fiber activity with depolarization was accompanied by a decline in the response of Purkinje cells to uncaged ... More
Selective stimulation of astrocyte calcium in situ does not affect neuronal excitatory synaptic activity.
Astrocytes are considered the third component of the synapse, responding to neurotransmitter release from synaptic terminals and releasing gliotransmitters--including glutamate--in a Ca(2+)-dependent manner to affect neuronal synaptic activity. Many studies reporting astrocyte-driven neuronal activity have evoked astrocyte Ca(2+) increases by application of endogenous ligands that directly activate neuronal receptors, making ... More
Synaptic calcium transients in single spines indicate that NMDA receptors are not saturated.
AuthorsMainen ZF, Malinow R, Svoboda K
JournalNature
PubMed ID10335844
At excitatory synapses in the central nervous system, the number of glutamate molecules released from a vesicle is much larger than the number of postsynaptic receptors. But does release of a single vesicle normally saturate these receptors? Answering this question is critical to understanding how the amplitude and variability of ... More
Postsynaptic excitability is necessary for strengthening of cortical sensory responses during experience-dependent development.
AuthorsKomai S, Licznerski P, Cetin A, Waters J, Denk W, Brecht M, Osten P
JournalNat Neurosci
PubMed ID16921372
Sensory experience is necessary for normal cortical development. This has been shown by sensory deprivation and pharmacological perturbation of the cortex. Because these manipulations affect the cortical network as a whole, the role of postsynaptic cellular properties during experience-dependent development is unclear. Here we addressed the developmental role of somatodendritic ... More
Protein kinase A regulates calcium permeability of NMDA receptors.
AuthorsSkeberdis VA, Chevaleyre V, Lau CG, Goldberg JH, Pettit DL, Suadicani SO, Lin Y, Bennett MV, Yuste R, Castillo PE, Zukin RS
JournalNat Neurosci
PubMed ID16531999
Calcium (Ca2+) influx through NMDA receptors (NMDARs) is essential for synaptogenesis, experience-dependent synaptic remodeling and plasticity. The NMDAR-mediated rise in postsynaptic Ca2+ activates a network of kinases and phosphatases that promote persistent changes in synaptic strength, such as long-term potentiation (LTP). Here we show that the Ca2+ permeability of neuronal ... More
Cooperative Ca2+ removal from presynaptic terminals of the spiny lobster neuromuscular junction.
AuthorsOhnuma K, Kazawa T, Ogawa S, Suzuki N, Miwa A, Kijima H
JournalBiophys J
PubMed ID10096881
Stimulation-induced changes in presynaptic free calcium concentration ([Ca2+]i) were examined by fluorescent imaging at the spiny lobster excitor motor nerve terminals. The Ca2+ removal process in the terminal was analyzed based on a single compartment model, under the assumption that the Ca2+ removal rate from the terminal cytoplasm is proportional ... More
A high-resolution, confocal laser-scanning microscope and flash photolysis system for physiological studies.
AuthorsParker I, Callamaras N, Wier WG
JournalCell Calcium
PubMed ID9223680
We describe the construction of a high-resolution confocal laser-scanning microscope, and illustrate its use for studying elementary Ca2+ signalling events in cells. An avalanche photodiode module and simple optical path provide a high efficiency system for detection of fluorescence signals, allowing use of a small confocal aperture giving near diffraction-limited ... More
State-dependent dendritic computation in hippocampal CA1 pyramidal neurons.
AuthorsGasparini S, Magee JC
JournalJ Neurosci
PubMed ID16481442
Depending on the behavioral state, hippocampal CA1 pyramidal neurons receive very distinct patterns of synaptic input and likewise produce very different output patterns. We have used simultaneous dendritic and somatic recordings and multisite glutamate uncaging to investigate the relationship between synaptic input pattern, the form of dendritic integration, and action ... More
Inhibition of inositol 1,4,5-trisphosphate-induced Ca2+ release by cAMP-dependent protein kinase in a living cell.
AuthorsTertyshnikova S, Fein A
JournalProc Natl Acad Sci U S A
PubMed ID9465064
Interaction of intracellular free calcium ([Ca2+]i) and cAMP signaling mechanisms was examined in intact single megakaryocytes by using a combination of single-cell fluorescence microscopy to measure [Ca2+]i and flash photolysis of caged Ca2+, inositol 1,4, 5-trisphosphate (IP3), or cAMP to elevate rapidly the concentration of these compounds inside the cell. ... More
Photolytic manipulation of [Ca2+]i reveals slow kinetics of potassium channels underlying the afterhyperpolarization in hippocampal pyramidal neurons.
AuthorsSah P, Clements JD
JournalJ Neurosci
PubMed ID10233997
The identity of the potassium channel underlying the slow, apamin-insensitive component of the afterhyperpolarization current (sIAHP) remains unknown. We studied sIAHP in CA1 pyramidal neurons using simultaneous whole-cell recording, calcium fluorescence imaging, and flash photolysis of caged compounds. Intracellular calcium concentration ([Ca2+]i) peaked earlier and decayed more rapidly than sIAHP. ... More
Release of calcium from stores alters the morphology of dendritic spines in cultured hippocampal neurons.
AuthorsKorkotian E, Segal M
JournalProc Natl Acad Sci U S A
PubMed ID10518577
The ability to monitor ongoing changes in the shape of dendritic spines has important implications for the understanding of the functional correlates of the great variety of shapes and sizes of dendritic spines in central neurons. We have monitored and three-dimensionally reconstructed dendritic spines in cultured hippocampal neurons over several ... More
Young thrombocytes initiate the formation of arterial thrombi in zebrafish.
AuthorsThattaliyath B, Cykowski M, Jagadeeswaran P
JournalBlood
PubMed ID15769888
The zebrafish system is an excellent vertebrate genetic model to study hemostasis and thrombosis because saturation mutagenesis screens can identify novel genes that play a role in this vital physiologic pathway. To study hemostatic mutations, it is important to understand the physiology of zebrafish hemostasis and thrombosis. Previously, we identified ... 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
Application of multiline two-photon microscopy to functional in vivo imaging.
AuthorsKurtz R, Fricke M, Kalb J, Tinnefeld P, Sauer M
JournalJ Neurosci Methods
PubMed ID16442636
High spatial resolution and low risks of photodamage make two-photon laser-scanning microscopy (TPLSM) the method of choice for biological imaging. However, the study of functional dynamics such as neuronal calcium regulation often also requires a high temporal resolution. Hitherto, acquisition speed is usually increased by line scanning, which restricts spatial ... More
Calcium transients in subcompartments of the leech Retzius neuron as induced by single action potentials.
AuthorsBeck A, Lohr C, Deitmer JW
JournalJ Neurobiol
PubMed ID11391646
Regional Ca(2+) influx into neurons plays an essential role for fast signal processing, yet it is little understood. We have investigated intracellular Ca(2+) transients induced by a single action potential (AP) in Retzius neurons in situ of isolated ganglia of the leech Hirudo medicinalis using confocal laser scanning microscopy in ... More
Functional triads consisting of ryanodine receptors, Ca(2+) channels, and Ca(2+)-activated K(+) channels in bullfrog sympathetic neurons. Plastic modulation of action potential.
AuthorsAkita T, Kuba K
JournalJ Gen Physiol
PubMed ID11055998
Fluorescent ryanodine revealed the distribution of ryanodine receptors in the submembrane cytoplasm (less than a few micrometers) of cultured bullfrog sympathetic ganglion cells. Rises in cytosolic Ca(2+) ([Ca(2+)](i)) elicited by single or repetitive action potentials (APs) propagated at a high speed (150 microm/s) in constant amplitude and rate of rise ... More
A continuum of InsP3-mediated elementary Ca2+ signalling events in Xenopus oocytes.
AuthorsSun XP, Callamaras N, Marchant JS, Parker I
JournalJ Physiol
PubMed ID9547382
1. The elementary release events underlying inositol 1,4, 5-trisphosphate (InsP3)-mediated calcium signalling were investigated in Xenopus oocytes by means of high-resolution confocal linescan imaging together with flash photolysis of caged InsP3. 2. Weak photolysis flashes evoked localized, transient calcium signals that arose at specific sites following random latencies of up ... More
Activation and co-ordination of InsP3-mediated elementary Ca2+ events during global Ca2+ signals in Xenopus oocytes.
AuthorsCallamaras N, Marchant JS, Sun XP, Parker I
JournalJ Physiol
PubMed ID9547383
1. The activation of elementary calcium release events ('puffs') and their co-ordination to generate calcium waves was studied in Xenopus oocytes by confocal linescan imaging together with photorelease of inositol 1,4,5-trisphosphate (InsP3) from a caged precursor. 2. Weak photolysis flashes evoked no responses or isolated calcium puffs, whereas flashes of ... More
Action potential-evoked Ca2+ signals and calcium channels in axons of developing rat cerebellar interneurones.
AuthorsForti L, Pouzat C, Llano I
JournalJ Physiol
PubMed ID10944168
Axonal [Ca2+] transients evoked by action potential (AP) propagation were studied by monitoring the fluorescence of the high-affinity calcium-sensitive dye Oregon Green 488 BAPTA-1, introduced through whole-cell recording pipettes in the molecular layer of interneurones from cerebellar slices of young rats. The spatiotemporal profile of Ca2+-dependent fluorescence changes was analysed ... More
Calcium dynamics, buffering, and buffer saturation in the boutons of dentate granule-cell axons in the hilus.
AuthorsJackson MB, Redman SJ
JournalJ Neurosci
PubMed ID12629165
The axons of dentate gyrus granule cells form synapses in the hilus. Ca(2+) signaling was investigated in the boutons of these axons using confocal fluorescence imaging. Boutons were loaded with various concentrations of the Ca(2+) indicator Oregon Green BAPTA-1 by patch-clamping the cell bodies and allowing the dye to diffuse ... More
Depolarization-induced pH microdomains and their relationship to calcium transients in isolated snail neurones.
AuthorsSchwiening CJ, Willoughby D
JournalJ Physiol
PubMed ID11790806
Neuronal electrical activity causes only modest changes in global intracellular pH (pH(i)). We have measured regional pH(i) differences in isolated patch-clamped neurones during depolarization, using confocal imaging of 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS) fluorescence. The pH(i) shifts in the soma were as expected; however, substantially larger shifts occurred in other regions. These ... More
Calcium influx into dendrites of the leech Retzius neuron evoked by 5-hydroxytryptamine.
AuthorsBeck A, Lohr C, Berthold H, Deitmer JW
JournalCell Calcium
PubMed ID12027387
5-Hydroxytryptamine (5-HT) is a ubiquitous neurotransmitter and neuromodulator that affects neural circuits and behaviours in vertebrates and invertebrates. In the present study, we have investigated 5-HT-induced Ca(2+) transients in subcellular compartments of Retzius neurons in the leech central nervous system using confocal laser scanning microscopy, and studied the effect of ... More
Widespread and Highly Correlated Somato-dendritic Activity in Cortical Layer 5 Neurons.
Authors
JournalNeuron
PubMed ID31178115
The number and organization of Ca2+ channels in the active zone shapes neurotransmitter release from Schaffer collateral synapses.
Authors
JournalJ Neurosci
PubMed ID23238730
Time-Resolved Imaging Reveals Heterogeneous Landscapes of Nanomolar Ca(2+) in Neurons and Astroglia.
Authors
JournalNeuron
PubMed ID26494277
Task-specific roles of local interneurons for inter- and intraglomerular signaling in the insect antennal lobe.
Authors
JournalElife
PubMed ID34554087
TRPC3 and NALCN channels drive pacemaking in substantia nigra dopaminergic neurons.
Authors
JournalElife
PubMed ID34409942
Release probability increases towards distal dendrites boosting high-frequency signal transfer in the rodent hippocampus.
Authors
JournalElife
PubMed ID33438578
LTP Induction Boosts Glutamate Spillover by Driving Withdrawal of Perisynaptic Astroglia.
Authors
JournalNeuron
PubMed ID32976770
Ca2+ entry through NaV channels generates submillisecond axonal Ca2+ signaling.
Authors
JournalElife
PubMed ID32553116
NOTCH1 is a mechanosensor in adult arteries.
Authors
JournalNat Commun
PubMed ID29158473
Monitoring intracellular nanomolar calcium using fluorescence lifetime imaging.