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Spatially localized Ca(2+) domains are thought to play a key role in action potential (AP)-evoked neurotransmitter release at fast synapses. We used a stage-scan confocal spot-detection method and the low-affinity Ca(2+) indicator Oregon Green 488 BAPTA-5N to study the spatiotemporal profile of presynaptic AP-induced Ca(2+) domains. Families of scanned AP-induced fluorescence transients were detected from spot locations separated by 200-300 nm, within the vicinity of Ca(2+) entry sites. Typically, the largest transient in a particular scan peaked within approximately 1 msec and decayed with rapid (tau(1) of 1.7 msec) and slow components (tau(2) of 16 msec, tau(3) of 78 msec). As the spot was incrementally displaced, transients progressively exhibited a slowing in their time-to-peak and a loss of the fast decay component. Three-dimensional graphs of fluorescence versus time and spot displacement revealed the presence of AP-induced fluorescence domains that dissipated within approximately 7 msec. The size of fluorescence domains were estimated from the full-width at half-maximum of gaussian fits to isochronal DeltaF/F plots and ranged from 0.6 to 3.0 micrometer, with a mean +/- SD of 1.6 +/- 0.6 micrometer. Model simulations of a localized Ca(2+) entry site predicted the major features of the fluorescence transients and suggested that, within approximately 1 msec of the initiation of the Ca(2+) current, both the fluorescence domain and the underlying Ca(2+) domain do not extend significantly beyond the site of entry. Consistent with this prediction, the intracellular addition of EGTA (up to 2 mM) accelerated the decay of the measured transients but did not affect the domain size.
Adler,
Alien intracellular calcium chelators attenuate neurotransmitter release at the squid giant synapse.
1991, Pubmed
Adler,
Alien intracellular calcium chelators attenuate neurotransmitter release at the squid giant synapse.
1991,
Pubmed
Allbritton,
Range of messenger action of calcium ion and inositol 1,4,5-trisphosphate.
1992,
Pubmed
,
Xenbase
Atluri,
Determinants of the time course of facilitation at the granule cell to Purkinje cell synapse.
1996,
Pubmed
Augustine,
Calcium action in synaptic transmitter release.
1987,
Pubmed
Barrett,
The kinetics of transmitter release at the frog neuromuscular junction.
1972,
Pubmed
Bertram,
Modeling study of the effects of overlapping Ca2+ microdomains on neurotransmitter release.
1999,
Pubmed
Borst,
Calcium influx and transmitter release in a fast CNS synapse.
1996,
Pubmed
Buchanan,
Studies of nerve-muscle interactions in Xenopus cell culture: fine structure of early functional contacts.
1989,
Pubmed
,
Xenbase
Chad,
Calcium domains associated with individual channels can account for anomalous voltage relations of CA-dependent responses.
1984,
Pubmed
Church,
Single L-type calcium channel conductance with physiological levels of calcium in chick ciliary ganglion neurons.
1996,
Pubmed
Cohen,
Distribution of synaptic specializations along isolated motor units formed in Xenopus nerve-muscle cultures.
1987,
Pubmed
,
Xenbase
Cooper,
Synaptic structural complexity as a factor enhancing probability of calcium-mediated transmitter release.
1996,
Pubmed
Dai,
Presynaptic differentiation induced in cultured neurons by local application of basic fibroblast growth factor.
1995,
Pubmed
,
Xenbase
David,
Stimulation-induced changes in [Ca2+] in lizard motor nerve terminals.
1997,
Pubmed
DiGregorio,
Localized detection of action potential-induced presynaptic calcium transients at a Xenopus neuromuscular junction.
1997,
Pubmed
,
Xenbase
Escobar,
Localization of the site of Ca2+ release at the level of a single sarcomere in skeletal muscle fibres.
1994,
Pubmed
Escobar,
Kinetic properties of DM-nitrophen and calcium indicators: rapid transient response to flash photolysis.
1997,
Pubmed
Feller,
Presynaptic calcium dynamics at the frog retinotectal synapse.
1996,
Pubmed
Fogelson,
Presynaptic calcium diffusion from various arrays of single channels. Implications for transmitter release and synaptic facilitation.
1985,
Pubmed
Gabso,
Low mobility of the Ca2+ buffers in axons of cultured Aplysia neurons.
1997,
Pubmed
Hall,
Endogenous buffers limit the spread of free calcium in hair cells.
1997,
Pubmed
Helmchen,
Calcium dynamics associated with a single action potential in a CNS presynaptic terminal.
1997,
Pubmed
Heuser,
Structural changes after transmitter release at the frog neuromuscular junction.
1981,
Pubmed
Hiraoka,
Determination of three-dimensional imaging properties of a light microscope system. Partial confocal behavior in epifluorescence microscopy.
1990,
Pubmed
Issa,
The entry and clearance of Ca2+ at individual presynaptic active zones of hair cells from the bullfrog's sacculus.
1996,
Pubmed
Llinás,
Relationship between presynaptic calcium current and postsynaptic potential in squid giant synapse.
1981,
Pubmed
Markram,
Competitive calcium binding: implications for dendritic calcium signaling.
1998,
Pubmed
Monck,
Pulsed laser imaging of rapid Ca2+ gradients in excitable cells.
1994,
Pubmed
Naraghi,
Linearized buffered Ca2+ diffusion in microdomains and its implications for calculation of [Ca2+] at the mouth of a calcium channel.
1997,
Pubmed
Naraghi,
T-jump study of calcium binding kinetics of calcium chelators.
1997,
Pubmed
Neher,
Vesicle pools and Ca2+ microdomains: new tools for understanding their roles in neurotransmitter release.
1998,
Pubmed
Obaid,
Micromolar 4-aminopyridine enhances invasion of a vertebrate neurosecretory terminal arborization: optical recording of action potential propagation using an ultrafast photodiode-MOSFET camera and a photodiode array.
1996,
Pubmed
,
Xenbase
Ohana,
Transmitter release modulation in nerve terminals of rat neocortical pyramidal cells by intracellular calcium buffers.
1998,
Pubmed
Pape,
Calcium release and its voltage dependence in frog cut muscle fibers equilibrated with 20 mM EGTA.
1995,
Pubmed
Parnas,
Effect of Ca2+ diffusion on the time course of neurotransmitter release.
1989,
Pubmed
Pumplin,
Are the presynaptic membrane particles the calcium channels?
1981,
Pubmed
Regehr,
Calcium transients in cerebellar granule cell presynaptic terminals.
1995,
Pubmed
Roberts,
Colocalization of ion channels involved in frequency selectivity and synaptic transmission at presynaptic active zones of hair cells.
1990,
Pubmed
Roberts,
Localization of calcium signals by a mobile calcium buffer in frog saccular hair cells.
1994,
Pubmed
Sabatini,
Timing of neurotransmission at fast synapses in the mammalian brain.
1996,
Pubmed
Sigworth,
The variance of sodium current fluctuations at the node of Ranvier.
1980,
Pubmed
Simon,
Compartmentalization of the submembrane calcium activity during calcium influx and its significance in transmitter release.
1985,
Pubmed
Sinha,
Presynaptic calcium dynamics and transmitter release evoked by single action potentials at mammalian central synapses.
1997,
Pubmed
Smith,
A stopped-flow investigation of calcium ion binding by ethylene glycol bis(beta-aminoethyl ether)-N,N'-tetraacetic acid.
1984,
Pubmed
Stockbridge,
Localized Ca2+ and calcium-activated potassium conductances in terminals of a barnacle photoreceptor.
,
Pubmed
Sugimori,
High-resolution measurement of the time course of calcium-concentration microdomains at squid presynaptic terminals.
1994,
Pubmed
Tucker,
Confocal imaging of calcium microdomains and calcium extrusion in turtle hair cells.
1995,
Pubmed
Umemiya,
Single-channel properties of four calcium channel types in rat motoneurons.
1995,
Pubmed
Weldon,
Development of synaptic ultrastructure at neuromuscular contacts in an amphibian cell culture system.
1979,
Pubmed
,
Xenbase
Xu,
Kinetic studies of Ca2+ binding and Ca2+ clearance in the cytosol of adrenal chromaffin cells.
1997,
Pubmed
Yamada,
Time course of transmitter release calculated from simulations of a calcium diffusion model.
1992,
Pubmed
Yazejian,
Direct measurements of presynaptic calcium and calcium-activated potassium currents regulating neurotransmitter release at cultured Xenopus nerve-muscle synapses.
1997,
Pubmed
,
Xenbase
Zucker,
Presynaptic calcium diffusion and the time courses of transmitter release and synaptic facilitation at the squid giant synapse.
1983,
Pubmed
