Ca2+-H+ antiport activity in synaptic vesicles isolated from sheep brain cortex

Gonçalves, Paula P.; Meireles, Sandra M; Gravato, Carlos; Vale, M.G.P.

doi:10.1016/s0304-3940(98)00256-0

Cited by 30 publications

(34 citation statements)

References 23 publications

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“…However, both values contrast sharply with the optimal Ca 2ϩ concentration (500 M) for inducing H ϩ release from SVs isolated from sheep brain (Gonçalves et al, 1998). If Ca 2ϩ at a concentration comparable with extracellular levels (ϳ2 mM) is trapped inside newly endocytosed SVs, then the Ca 2ϩ gradient across the SV membrane in vivo (10…”

Section: Sv Ca 2؉ Transporters: Physiological Implicationsmentioning

confidence: 98%

“…Israel et al, 1980;50 M, Michaelson et al, 1980;52 M, Rephaeli and Parsons, 1982). Ca 2ϩ -H ϩ antiport activity in isolated SVs was optimally activated by 500 M Ca 2ϩ (Gonçalves et al, 1998). To obtain an estimate of [Ca 2ϩ ] i during trains of highfrequency activity in the MN, such as those expected during locomotion, we used the ratiometric indicator fura (Fig.…”

Section: [Ca 2؉ ] I Kinetics During Short Highfrequency Stimulation Tmentioning

confidence: 99%

“…Apart from their principal role in sequestering and releasing transmitter substances, data from in vitro studies indicate that SVs may also participate in Ca 2ϩ sequestration (Israel et al, 1980;Michaelson et al, 1980;Rephaeli and Parsons, 1982;Gonçalves et al, 1998). In addition, voltage-gated Ca 2ϩ channels (VGCCs), which respond to depolarization by admitting Ca 2ϩ close to sites of exocytosis in the synaptic active zone (Catterall, 2000), may be regulated through interactions with SVs.…”

Section: Introductionmentioning

confidence: 99%

“…Ion channels in the SV membranes may allow Ca 2ϩ entry (for review, see Rahamimoff et al, 1990;Woodbury, 1995). A Ca 2ϩ -H ϩ exchange has been demonstrated in SV membranes in which elevated Ca 2ϩ (ϳ500 M) induced H ϩ release from SVs isolated from sheep brain cortex (Gonçalves et al, 1998). In addition, a high-affinity ATPdependent Ca 2ϩ pump takes up Ca 2ϩ in isolated SVs (Torpedo electric organ synapses, Israel et al, 1980;Michaelson et al, 1980;Rephaeli and Parsons, 1982 …”

Section: Introductionmentioning

confidence: 99%

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Synaptic Vesicles: Test for a Role in Presynaptic Calcium Regulation

Macleod¹,

Marin²,

Charlton³

et al. 2004

J. Neurosci.

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Section: Sv Ca 2؉ Transporters: Physiological Implicationsmentioning

confidence: 98%

Section: [Ca 2؉ ] I Kinetics During Short Highfrequency Stimulation Tmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Synaptic Vesicles: Test for a Role in Presynaptic Calcium Regulation

Macleod¹,

Marin²,

Charlton³

et al. 2004

J. Neurosci.

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show abstract

“…From a variety of cell types, Ca 2+ -ATPases, Ca 2+ /H + and Ca 2+ /Na + antiporters (e.g. Gonçalves et al, 1998) and Ca 2+ /phosphate co-transporters (Ambudkar et al, 1984) have been described. Depending on the transporter's structure, ions may pass the membrane either with or without their hydration sphere (Gouaux and MicKinnon, 2005), although (partial) dehydration increases the selectivity greatly (see also Gussone et al, 2003).…”

Section: Ca 2+ Transport In Foraminiferamentioning

confidence: 99%

Biomineralization in perforate foraminifera

Nooijer

Spero

Erez

et al. 2014

Earth-Science Reviews

201

190

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a b s t r a c t a r t i c l e i n f oIn this paper, we review the current understanding of biomineralization in perforate foraminifera. Ideas on the mechanisms responsible for the flux of Ca 2+ and inorganic carbon from seawater into the test were originally based on light and electron microscopic observations of calcifying foraminifera. From the 1980s onward, tracer experiments, fluorescent microscopy and high-resolution test geochemical analysis have added to existing calcification models. Despite recent insights, no general consensus on the physiological basis of foraminiferal biomineralization exists. Current models include seawater vacuolization, transmembrane ion transport, involvement of organic matrices and/or pH regulation, although the magnitude of these controls remain to be quantified. Disagreement between currently available models may be caused by the use of different foraminiferal species as subject for biomineralization experiments and/or lack of a more systematic approach to study (dis)similarities between taxa. In order to understand foraminiferal controls on element incorporation and isotope fractionation, and thereby improve the value of foraminifera as paleoceanographic proxies, it is necessary to identify key processes in foraminiferal biomineralization and formulate hypotheses regarding the involved physiological pathways to provide directions for future research.

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Quantal acetylcholine release: Vesicle fusion or intramembrane particles?

Dunant¹

2000

Microsc. Res. Tech.

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Images of vesicle openings in the presynaptic membrane have regularly been shown to increase in number after stimulation of cholinergic nerves. However, with a very few exceptions, the occurrence of vesicle openings is delayed in time with respect to the precise moment of transmitter release. In contrast, a transient change in the size and distribution of intramembrane particles (IMPs) has constantly been found as a characteristic change affecting the presynaptic membrane in a strict time coincidence with the release of acetylcholine quanta. This is illustrated here in a rapid‐freezing experiment performed on small specimens of the Torpedo electric organ during transmission of a single nerve impulse. A marked change affected IMPs in the presynaptic membrane for 3–4 ms, i.e., a population of IMPs larger than 10 nm momentarily occurred in coincidence with the passage of the impulse. The nicotinic receptors, abundantly visible in the postsynaptic membranes, also underwent very fleeting structural changes during synaptic transmission. In conclusion, for rapidly operating neurotransmitters like acetylcholine, a characteristic IMP change was regularly found to coincide in the presynaptic membrane with the production of neurotransmitter quanta, whereas images of vesicles fusion were either delayed or even dissociated from the release process. This is discussed in connection to the different modes of release recently described for other secreting systems. Microsc. Res. Tech. 49:38–46, 2000. © 2000 Wiley‐Liss, Inc.

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Ca2+-H+ antiport activity in synaptic vesicles isolated from sheep brain cortex

Cited by 30 publications

References 23 publications

Synaptic Vesicles: Test for a Role in Presynaptic Calcium Regulation

Synaptic Vesicles: Test for a Role in Presynaptic Calcium Regulation

Biomineralization in perforate foraminifera

Quantal acetylcholine release: Vesicle fusion or intramembrane particles?

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