1
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Abstract
The Na+-Ca 2+ exchanger is a secondary active antiporter found in all excitable cells. This transporter couples transmembrane fluxes of Na+ to opposite fluxes of Ca2+. Under normal conditions, the energy stored in the electrochemical Na+ gradient is used to export Ca 2+ from the cytoplasm, thus contributing to cellular Ca2+ homeostasis, such as termination of Ca2+ transients during synaptic transmission in nerve terminals. The reversible and electrogenic properties of the Na+-Ca2+ exchanger suggest an interesting additional role of controlled Ca2+ entry, e.g., during action potential generation in axons. Moreover, under pathological conditions, such as anoxia/ischemia, the exchanger may function either to help extrude damaging Ca2+ loads entering via other pathways in neurons or mediate Ca2+ overload in axons. Cell geometry will influence the rate and extent of collapse of the Na+ gradient and membrane potential, the two main driving forces acting on the exchanger, which will in turn dictate to what extent and in which direction Ca2+ will be transported. The Na+-Ca2+ exchanger is subject to complex regulatory control by several ions and chemical messengers, and several recently identified isoforms are undoubtedly tailored for specific roles in different regions of the CNS. NEUROSCIENTIST 2:162-171, 1996
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Affiliation(s)
| | - Peter K. Stys
- Neurosciences Loeb Institute Ottawa Civic Hospital Ottawa,
Ontario
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2
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Limitations of PET and lesion studies in defining the role of the human cerebellum in motor learning. Behav Brain Sci 2011. [DOI: 10.1017/s0140525x00081899] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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3
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4
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5
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Eyeblink conditioning, motor control, and the analysis of limbic-cerebellar interactions. Behav Brain Sci 2011. [DOI: 10.1017/s0140525x00081929] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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6
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7
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Grasping cerebellar function depends on our understanding the principles of sensorimotor integration: The frame of reference hypothesis. Behav Brain Sci 2011. [DOI: 10.1017/s0140525x00081607] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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8
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Dysmetria of thought: Correlations and conundrums in the relationship between the cerebellum, learning, and cognitive processing. Behav Brain Sci 2011. [DOI: 10.1017/s0140525x00081851] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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9
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10
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11
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Q: Is the cerebellum an adaptive combiner of motor and mental/motor activities? A: Yes, maybe, certainly not, who can say? Behav Brain Sci 2011. [DOI: 10.1017/s0140525x00082017] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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12
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13
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What behavioral benefit does stiffness control have? An elaboration of Smith's proposal. Behav Brain Sci 2011. [DOI: 10.1017/s0140525x00081917] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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14
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15
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Abstract
Sodium-calcium counter-transport represents one of a number of processes for transporting calcium ions across cellular membranes. The physiological importance of the exchanger is outlined and its underlying mechanism discussed in terms of a comparison of the partial reactions of Na+-Ca2+ exchange in intact cells with those of plasma membrane vesicles.
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16
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Török TL. Electrogenic Na+/Ca2+-exchange of nerve and muscle cells. Prog Neurobiol 2007; 82:287-347. [PMID: 17673353 DOI: 10.1016/j.pneurobio.2007.06.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2006] [Revised: 04/12/2007] [Accepted: 06/12/2007] [Indexed: 12/19/2022]
Abstract
The plasma membrane Na(+)/Ca(2+)-exchanger is a bi-directional electrogenic (3Na(+):1Ca(2+)) and voltage-sensitive ion transport mechanism, which is mainly responsible for Ca(2+)-extrusion. The Na(+)-gradient, required for normal mode operation, is created by the Na(+)-pump, which is also electrogenic (3Na(+):2K(+)) and voltage-sensitive. The Na(+)/Ca(2+)-exchanger operational modes are very similar to those of the Na(+)-pump, except that the uncoupled flux (Na(+)-influx or -efflux?) is missing. The reversal potential of the exchanger is around -40 mV; therefore, during the upstroke of the AP it is probably transiently activated, leading to Ca(2+)-influx. The Na(+)/Ca(2+)-exchange is regulated by transported and non-transported external and internal cations, and shows ATP(i)-, pH- and temperature-dependence. The main problem in determining the role of Na(+)/Ca(2+)-exchange in excitation-secretion/contraction coupling is the lack of specific (mode-selective) blockers. During recent years, evidence has been accumulated for co-localisation of the Na(+)-pump, and the Na(+)/Ca(2+)-exchanger and their possible functional interaction in the "restricted" or "fuzzy space." In cardiac failure, the Na(+)-pump is down-regulated, while the exchanger is up-regulated. If the exchanger is working in normal mode (Ca(2+)-extrusion) during most of the cardiac cycle, upregulation of the exchanger may result in SR Ca(2+)-store depletion and further impairment in contractility. If so, a normal mode selective Na(+)/Ca(2+)-exchange inhibitor would be useful therapy for decompensation, and unlike CGs would not increase internal Na(+). In peripheral sympathetic nerves, pre-synaptic alpha(2)-receptors may regulate not only the VSCCs but possibly the reverse Na(+)/Ca(2+)-exchange as well.
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Affiliation(s)
- Tamás L Török
- Department of Pharmacodynamics, Semmelweis University, P.O. Box 370, VIII. Nagyvárad-tér 4, H-1445 Budapest, Hungary.
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17
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Abstract
Owing to the central role of Ca
2+
in signal transduction processes, it is important to measure membrane fluxes of Ca
2+
in cells which are as undisturbed as possible, particularly when studying the control of these fluxes. To this end, techniques have been developed to measure Ca
2+
fluxes in intact, turgid plant cells. The measurements are principally of influx across the plasma membrane where Ca
2+
transport is likely to occur through cation-selective channels. The most direct method measures tracer fluxes of Ca
2+
, but special procedures are required to distinguish between influx and extracellular binding of Ca
2+
. Unfortunately, such techniques are currently only applicable to giant cells where surgical separation of the intracellular contents from the cell wall is possible. The influx of Ca
2+
into normal, resting cells of the green alga
Chara corallina
is usually about 0.3 nmol m
-2
s
-1
(at an external Ca
2+
concentration of 0.5 mol m
-3
). This flux is up to 5 times higher in actively growing cells, 20 times higher in cells depolarized by 20 mol m
-3
K
+
and 1000 times higher during an action potential. Reducing cell turgor by a wide range of solutes increases Ca
2+
influx, especially near plasmolysis. Ca
2+
influx is sensitive to alterations in both external and cytosolic pH, but is inhibited by complete darkness and by low concentrations of La
3+
. Various organic Ca
2+
channel antagonists had mixed effects on Ca
2+
influx into
Chara
. The work described in this paper should enable further study of the control of Ca
2+
fluxes into intact, turgid plant cells, and their role in signal transduction and the control of cellular activities.
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18
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We know a lot about the cerebellum, but do we know what motor learning is? Behav Brain Sci 1996. [DOI: 10.1017/s0140525x00081875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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19
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Sensorimotor learning in structures “upstream” from the cerebellum. Behav Brain Sci 1996. [DOI: 10.1017/s0140525x00081905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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20
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Cerebellar arm ataxia: Theories still have a lot to explain. Behav Brain Sci 1996. [DOI: 10.1017/s0140525x00081723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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21
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22
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Resilient cerebellar theory complies with stiff opposition. Behav Brain Sci 1996. [DOI: 10.1017/s0140525x00082005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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23
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The cerebellum and cerebral cortex: Contrasting and converging contributions to spatial navigation and memory. Behav Brain Sci 1996. [DOI: 10.1017/s0140525x00081826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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24
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Cerebellum does more than recalibration of movements after perturbations. Behav Brain Sci 1996. [DOI: 10.1017/s0140525x00081632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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25
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A cerebellar long-term depression update. Behav Brain Sci 1996. [DOI: 10.1017/s0140525x00081942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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26
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What has to be learned in motor learning? Behav Brain Sci 1996. [DOI: 10.1017/s0140525x0008153x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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27
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Further evidence for the involvement of nitric oxide in trans-ACPD-induced suppression of AMPA responses in cultured chick Purkinje neurons. Behav Brain Sci 1996. [DOI: 10.1017/s0140525x00081802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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28
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29
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More models of the cerebellum. Behav Brain Sci 1996. [DOI: 10.1017/s0140525x0008198x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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30
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Cerebellar rhythms: Exploring another metaphor. Behav Brain Sci 1996. [DOI: 10.1017/s0140525x0008184x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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31
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The notions of joint stiffness and synaptic plasticity in motor memory. Behav Brain Sci 1996. [DOI: 10.1017/s0140525x00081784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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32
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How and what does the cerebellum learn? Behav Brain Sci 1996. [DOI: 10.1017/s0140525x00081644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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33
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Plasticity of cerebro-cerebellar interactions in patients with cerebellar dysfunction. Behav Brain Sci 1996. [DOI: 10.1017/s0140525x00081930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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34
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How to link the specificity of cerebellar anatomy to motor learning? Behav Brain Sci 1996. [DOI: 10.1017/s0140525x00081863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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35
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Long-term changes of synaptic transmission: A topic of long-term interest. Behav Brain Sci 1996. [DOI: 10.1017/s0140525x00081565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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36
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Nitric oxide is involved in cerebellar long-term depression. Behav Brain Sci 1996. [DOI: 10.1017/s0140525x00081814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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37
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No more news from the cerebellum. Behav Brain Sci 1996. [DOI: 10.1017/s0140525x00081978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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38
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A bridge between cerebellar long-term depression and discrete motor learning: Studies on gene knockout mice. Behav Brain Sci 1996. [DOI: 10.1017/s0140525x00081966] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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39
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Cellular mechanisms of long-term depression: From consensus to open questions. Behav Brain Sci 1996. [DOI: 10.1017/s0140525x00081954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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40
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How can the cerebellum match “error signal” and “error correction”? Behav Brain Sci 1996. [DOI: 10.1017/s0140525x00081590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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41
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Abstract
Highly branched dendritic shapes are distinguishing characteristics of neurons and certain other cell types, but the physical mechanisms responsible for their formation are not well understood. Here, we model the growth of cells under the control of diffusible growth-regulating factors (morphogens such as calcium ion) whose local internal concentration results from influx and active extrusion across the cell membrane. Nonlinearities in voltage-dependent ionic permeabilities enhance unstable growth, so that branching dendritic outgrowths results from self-sustaining internal morphogen gradients. Simulations display complex patterns of branching growth, influenced by membrane conductance, galvanotropism and chemotropism. This self-organizing pattern formation is in agreement with the development of real neurons under corresponding conditions.
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Affiliation(s)
- H G Hentschel
- Department of Physics, Emory University, Atlanta, Georgia 30322, USA
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42
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Hentschel HG, Fine A. Instabilities in Cellular Dendritic Morphogenesis. PHYSICAL REVIEW LETTERS 1994; 73:3592-3595. [PMID: 10057422 DOI: 10.1103/physrevlett.73.3592] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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43
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Powis DA, Clark CL, O'Brien KJ. Lanthanum can be transported by the sodium-calcium exchange pathway and directly triggers catecholamine release from bovine chromaffin cells. Cell Calcium 1994; 16:377-90. [PMID: 7859252 DOI: 10.1016/0143-4160(94)90031-0] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A comparison of the effectiveness of the trivalent cation, lanthanum (La3+) relative to Ca2+ in causing catecholamine release from bovine chromaffin cells has been made, together with a determination of the pathway by which La3+ enters these cells. In chromaffin cells maintained in tissue culture and permeabilised with digitonin, both La3+ and Ca2+ caused 3H release from cells preloaded with [3H]-noradrenaline; La3+ and Ca2+ caused similar maximal release but the EC50 for La3+ was an order of magnitude less than that for Ca2+. At maximal release caused by either La3+ or Ca2+ (approximately 14% of cell 3H content in 15 min), the other cation caused a small, but significant, further release. At submaximal effective concentrations the effects of the two cations were exactly additive. Using 3H release as an indicator of cytosolic La3+, its route of entry into intact chromaffin cells was investigated. With La(3+)-containing medium there was no release evoked by nicotine or by K(+)-depolarisation indicating that La3+ does not enter either via the nicotinic receptor linked ion channel or via voltage-sensitive (Ca2+) channels. However, in sodium-loaded chromaffin cells (ouabain incubation in Ca(2+)-free medium for 15 min) exposure to bathing media containing either Ca2+ or La3+ caused 3H release. La3+ (0.1 mM) caused a release similar in magnitude to that caused by Ca2+ (about 1 mM). La3+ at low concentrations had an additive (0.1 mM La3+) or synergistic (0.25-0.45 mM La3+) action with Ca2+ (< 3.6 mM) on 3H release. At higher concentrations (> 0.9 mM) the effects of La3+ predominated and prevented the expected effects of Ca2+. In other experiments, La3+ (1 mM) blocked export of 45Ca2+ via both Nao-dependent and independent pathways, i.e. sodium-calcium exchange and the calcium pump. The results indicate that La3+ can enter bovine chromaffin cells via the Nai/Cao exchange pathway independently of, or together with, Ca2+ but, that concentrations above 0.9 mM block the influx or efflux of Ca2+. However, Ca2+, even at 3.6 mM, did not block the influx of La3+. The results further indicate that, within chromaffin cells, La3+ is at least as effective as Ca2+ in triggering catecholamine release and maintaining prolonged release. La3+ also appears to act cooperatively with Ca2+ at the release pathway.
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Affiliation(s)
- D A Powis
- Neuroscience Group, Faculty of Medicine, University of Newcastle, New South Wales, Australia
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44
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Linden DJ, Smeyne M, Connor JA. Induction of cerebellar long-term depression in culture requires postsynaptic action of sodium ions. Neuron 1993; 11:1093-100. [PMID: 7506045 DOI: 10.1016/0896-6273(93)90222-d] [Citation(s) in RCA: 105] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Cerebellar long-term depression (LTD) is a persistent attenuation of the parallel fiber-Purkinje neuron (PF-PN) synapse induced by conjunctive stimulation of PF and climbing fiber (CF) inputs. A similar phenomenon is seen in the voltage-clamped PN in tissue culture when iontophoretic quisqualate application and PN depolarization are substituted for PF and CF stimulation, respectively. In this model, LTD induction requires activation of both AMPA and metabotropic receptors, together with PN depolarization. We have sought to determine the role of the AMPA receptor in LTD induction. The AMPA receptor does not appear to exert its effect by directly gating Ca2+ influx. Replacement of external Na+ during quisqualate/depolarization conjunction with permeant ions caused a blockade of LTD induction, suggesting that Na+ influx through the AMPA-associated channel is necessary for this process. Similarly, pairing quisqualate pulses with depolarizing steps near ENa also failed to induce LTD. The present results indicate that postsynaptic Na+ influx is necessary for LTD induction. While a portion of the relevant Na+ influx is provided by voltage-gated channels, the AMPA-associated ion channel is most important in this regard.
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Affiliation(s)
- D J Linden
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
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45
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Gaididei YB. Ion-conformational interaction and charge transport through channels of biological membranes. J Biol Phys 1993. [DOI: 10.1007/bf00700128] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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46
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Quamme GA, Dirks JH. The Physiology of Renal Magnesium Handling. Compr Physiol 1992. [DOI: 10.1002/cphy.cp080240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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47
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Gallo V, Giovannini C, Levi G. Depression by Sodium Ions of Calcium Uptake Mediated by Non-N-Methyl-d-Aspartate Receptors in Cultured Cerebellar Neurons and Correlation with Evoked d-[3H]Aspartate Release. J Neurochem 1992; 58:406-15. [PMID: 1345937 DOI: 10.1111/j.1471-4159.1992.tb09737.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In a previous study we noted that the release of D-[3H]aspartate evoked by non-N-methyl-D-aspartate (non-NMDA) receptor agonists in cultured rat cerebellar granule cells was enhanced in the absence of extracellular Na+. To explain this apparent paradox, we tried in the present investigation to correlate the effect of Na+ removal on the kainate (KA)- and quisqualate (QA)-induced D-[3H]aspartate release with that on KA- and QA-induced 45Ca2+ accumulation. The releasing activity of KA, which was only partially Ca2+ dependent in the presence of Na+, became totally Ca2+ dependent in its absence. Moreover, the releasing activity of QA, which was Ca2+ independent in the presence of Na+, became 50% Ca2+ dependent in the absence of the monovalent cation. The releasing action of both agonists was in all cases antagonized by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), and that induced by KA was also sensitive to kynurenic acid. When glutamate was tested as an agonist in the presence of Na+, it was found that its D-[3H]aspartate releasing action was Ca2+ independent and was largely due to heteroexchange. The evoked release was Ca2+ independent, scarcely sensitive to CNQX, and insensitive to NMDA antagonists. In Na(+)-free medium, the glutamate-evoked D-[3H]aspartate release was lower (due to the abolishment of heteroexchange), but was totally Ca2+ dependent and antagonized by CNQX and kynurenate. KA (30 microM-1 mM) stimulated the accumulation of 45Ca2+ in a dose-dependent and CNQX-sensitive way, the effect being progressively higher as the Na+ concentration in the medium was decreased. Li+ affected KA-induced 45Ca2+ accumulation in a way similar to Na+, although 45Ca2+ uptake was somewhat lower in Li(+)-containing medium. The voltage-activated calcium channel antagonists La3+ and (-)-202-791 caused only a limited inhibition of the KA-induced 45Ca2+ influx both in the presence and in the absence of Na+. Under all the conditions tested [presence and absence of Na+ and of (-)-202-791], the kainate-induced 45Ca2+ uptake was scarcely sensitive to the NMDA antagonist 2-amino-5-phosphonovalerate. QA and alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid also stimulated 45Ca2+ influx in a CNQX-sensitive way, the effect being enhanced in Na(+)-free media. These agonists were, however, less effective than KA.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- V Gallo
- Section of Neurobiology, Istituto Superiore di Sanità, Rome, Italy
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48
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Török TL. Norepinephrine and catecholamine release from peripheral sympathetic nerves and chromaffin cells maintained in primary tissue culture. The role of sodium-calcium exchange. Ann N Y Acad Sci 1991; 639:631-41. [PMID: 1785891 DOI: 10.1111/j.1749-6632.1991.tb17360.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- T L Török
- Department of Pharmacodynamics, Semmelweis University of Medicine, Budapest, Hungary
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49
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Affiliation(s)
- L Beaugé
- Instituto M. y M. Ferreyra, Córdoba, Argentina
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50
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Piggott MA, Candy JM, Perry RH. [3H]nitrendipine binding in temporal cortex in Alzheimer's and Huntington's diseases. Brain Res 1991; 565:42-7. [PMID: 1663418 DOI: 10.1016/0006-8993(91)91734-i] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Specific [3H]nitrendipine binding which was shown to be calcium- and calmodulin-dependent was found to be significantly reduced in the temporal cortex in Alzheimer's disease compared to age-matched controls. Scatchard analysis revealed that this reduction was due to a loss in the number of cortical [3H]nitrendipine binding sites rather than a change in the affinity of the binding site in the Alzheimer patients. The reduction in cortical [3H]nitrendipine-specific binding was most marked in those Alzheimer's disease cases where the duration of the dementing illness was longer than two years. In contrast, no reduction in cortical [3H]nitrendipine binding was found in Huntington's disease. There was no significant correlation found between age (38-89 years) and [3H]nitrendipine binding in control cases, or between mean overall plaque counts and [3H]nitrendipine binding in the Alzheimer's disease cases. There was a significant correlation found between age (46-88 years) and [3H]nitrendipine binding in the Alzheimer's disease cases where the duration of the dementing illness was greater than two years.
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Affiliation(s)
- M A Piggott
- MRC Neurochemical Pathology Unit, Newcastle General Hospital, Newcastle upon Tyne U.K
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