Relationship between resting cytosolic Ca2+ and responses induced byN-methyl-d-aspartate in hippocampal neurons

Nakajima, Kazuki; Harada, Kunihiko; Ebina, Yoshio; Yoshimura, Takumi; Ito, Hiroki; Ban, Takashi; Shingai, Ryuzo

doi:10.1016/0006-8993(93)91255-q

Cited by 13 publications

(9 citation statements)

References 10 publications

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“…This is in perfect agreement with previous studies on noncardiac myocytes (20,23). Cellular resting [Ca 2þ ] may also vary (20-200 nM) depending on the state and type of the cell (33). In cardiac myocytes, it is usually assumed to be in the range of %100 nM.…”

Section: Stimulation Frequency-dependent Changes In [Ca 2d ] Nuc Verssupporting

confidence: 90%

In Situ Calibration of Nucleoplasmic versus Cytoplasmic Ca2+ Concentration in Adult Cardiomyocytes

Ljubojevic

Walther

Asgarzoei

et al. 2011

Biophysical Journal

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Quantification of subcellularly resolved Ca²⁺ signals in cardiomyocytes is essential for understanding Ca²⁺ fluxes in excitation-contraction and excitation-transcription coupling. The properties of fluorescent indicators in intracellular compartments may differ, thus affecting the translation of Ca²⁺-dependent fluorescence changes into [Ca²⁺] changes. Therefore, we determined the in situ characteristics of a frequently used Ca²⁺ indicator, Fluo-4, and a ratiometric Ca²⁺ indicator, Asante Calcium Red, and evaluated their use for reporting and quantifying cytoplasmic and nucleoplasmic Ca²⁺ signals in isolated cardiomyocytes. Ca²⁺ calibration curves revealed significant differences in the apparent Ca²⁺ dissociation constants of Fluo-4 and Asante Calcium Red between cytoplasm and nucleoplasm. These parameters were used for transformation of fluorescence into nucleoplasmic and cytoplasmic [Ca²⁺]. Resting and diastolic [Ca²⁺] were always higher in the nucleoplasm. Systolic [Ca²⁺] was usually higher in the cytoplasm, but some cells (15%) exhibited higher systolic [Ca²⁺] in the nucleoplasm. Ca²⁺ store depletion or blockade of Ca²⁺ leak pathways eliminated the resting [Ca²⁺] gradient between nucleoplasm and cytoplasm, whereas inhibition of inositol 1,4,5-trisphosphate receptors by 2-APB reversed it. The results suggest the presence of significant nucleoplasmic-to-cytoplasmic [Ca²⁺] gradients in resting myocytes and during the cardiac cycle. Nucleoplasmic [Ca²⁺] in cardiomyocytes may be regulated via two mechanisms: diffusion from the cytoplasm and active Ca²⁺ release via inositol 1,4,5-trisphosphate receptors from perinuclear Ca²⁺ stores.

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Section: Stimulation Frequency-dependent Changes In [Ca 2d ] Nuc Verssupporting

confidence: 90%

In Situ Calibration of Nucleoplasmic versus Cytoplasmic Ca2+ Concentration in Adult Cardiomyocytes

Ljubojevic

Walther

Asgarzoei

et al. 2011

Biophysical Journal

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“…Measurements of [Ca 2ϩ ] regulation in hippocampal pyramidal cells reported in this paper are mostly similar to values previously reported with ratiometric indicators. The range of [Ca 2ϩ ] 0 was 32-59 nM, at the low end of the range reported in cultured neurons (Nakajima et al, 1993), and distributed over a narrower range, perhaps reflecting our method's accuracy. Single action potential [Ca 2ϩ ] transients were, on average, around 250 nM, somewhat higher than previous pyramidal cell estimates (Helmchen et al, 1996).…”

Section: Measurements Of Intracellular Ca 2؉ Levels and Regulationmentioning

confidence: 74%

“…Furthermore, it is not clear where experimental measurements fall within the range of the indicator: the fluorescence at rest, f 0 , can differ from f min in an uncontrolled way. The reason for this is that cellular resting [Ca 2ϩ ] levels appear to vary widely (20 -200 nM) (Nakajima et al, 1993) and depend on the state and type of the cell and the quality of the recording (Kennedy and Thomas, 1996;O'Malley et al, 1999). Such resting levels are far from negligible for highaffinity calcium indicators (K D Ϸ 200 nM), typically making f 0 much larger than f min .…”

Section: Theory: Relationship Between Fluorescence and [Ca 2؉ ]mentioning

confidence: 99%

Estimating Intracellular Calcium Concentrations and Buffering without Wavelength Ratioing

Maravall

Mainen

Sabatini

et al. 2000

Biophysical Journal

374

446

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We describe a method for determining intracellular free calcium concentration ([Ca(2+)]) from single-wavelength fluorescence signals. In contrast to previous single-wavelength calibration methods, the proposed method does not require independent estimates of resting [Ca(2+)] but relies on the measurement of fluorescence close to indicator saturation during an experiment. Consequently, it is well suited to [Ca(2+)] indicators for which saturation can be achieved under physiological conditions. In addition, the method requires that the indicators have large dynamic ranges. Popular indicators such as Calcium Green-1 or Fluo-3 fulfill these conditions. As a test of the method, we measured [Ca(2+)] in CA1 pyramidal neurons in rat hippocampal slices using Oregon Green BAPTA-1 and 2-photon laser scanning microscopy (BAPTA: 1,2-bis(2-aminophenoxy)ethane-N,N,N', N'-tetraacetic acid). Resting [Ca(2+)] was 32-59 nM in the proximal apical dendrite. Monitoring action potential-evoked [Ca(2+)] transients as a function of indicator loading yielded estimates of endogenous buffering capacity (44-80) and peak [Ca(2+)] changes at zero added buffer (178-312 nM). In young animals (postnatal days 14-17) our results were comparable to previous estimates obtained by ratiometric methods (, Biophys. J. 70:1069-1081), and no significant differences were seen in older animals (P24-28). We expect our method to be widely applicable to measurements of [Ca(2+)] and [Ca(2+)]-dependent processes in small neuronal compartments, particularly in the many situations that do not permit wavelength ratio imaging.

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“…Changes in basal Ca2+ levels can also influence responses to agonists. For example, in acinar cells the pattern of agonist-induced Ca2+ oscillations is dependent on basal Ca2+ levels (Toescu et al, 1993), while hippocampal neurones with higher resting levels of [Ca2+] show increased responses to NMDA and K+ depolarization (Nakajima et al, 1993). An altered Ca2+ signalling may therefore be an important modulatory mechanism in Li+-sensitive cells.…”

Section: Discussionmentioning

confidence: 99%

Lithium‐induced decrease in spontaneous Ca²⁺ oscillations in single GH₃ rat pituitary cells

Varney

Galione

Watson

1994

British J Pharmacology

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Relationship between resting cytosolic Ca2+ and responses induced byN-methyl-d-aspartate in hippocampal neurons

Cited by 13 publications

References 10 publications

In Situ Calibration of Nucleoplasmic versus Cytoplasmic Ca2+ Concentration in Adult Cardiomyocytes

In Situ Calibration of Nucleoplasmic versus Cytoplasmic Ca2+ Concentration in Adult Cardiomyocytes

Estimating Intracellular Calcium Concentrations and Buffering without Wavelength Ratioing

Lithium‐induced decrease in spontaneous Ca²⁺ oscillations in single GH₃ rat pituitary cells

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Relationship between resting cytosolic Ca2+ and responses induced byN-methyl-d-aspartate in hippocampal neurons

Cited by 13 publications

References 10 publications

In Situ Calibration of Nucleoplasmic versus Cytoplasmic Ca2+ Concentration in Adult Cardiomyocytes

In Situ Calibration of Nucleoplasmic versus Cytoplasmic Ca2+ Concentration in Adult Cardiomyocytes

Estimating Intracellular Calcium Concentrations and Buffering without Wavelength Ratioing

Lithium‐induced decrease in spontaneous Ca2+ oscillations in single GH3 rat pituitary cells

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Lithium‐induced decrease in spontaneous Ca²⁺ oscillations in single GH₃ rat pituitary cells