Cited by 416Advanced Fluorescence Microscopy TechniquesIon Channels and ReceptorsNeuroscience and Neuropharmacology Research

Estimating Intracellular Calcium Concentrations and Buffering without Wavelength Ratioing

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Maravall, M., Mainen, Z.F., Sabatini, B.L., Svoboda, K.·2000·Biophysical Journal

Abstract

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 neur…

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Crossref · 10.1016/s0006-3495(00)76809-3

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  • The resting level of intracellular Ca2+ is 20-50 nM.

    “relative to the resting level of intracellular Ca2+ (20–50 nM) (109–111)”

    From Synaptic memory and CaMKII (2023) · cites this paper as [110]

  • The unusually high Hill coefficient of ∼6 for CaMKII and the high requirement for Ca2+ compared to resting Ca2+ ensures maintenance of synapse specificity and the Hebbian nature of LTP.

    “The unusually high Hill coefficient of ∼6 for CaMKII (108) and the high requirement for Ca2+ (half maximal of ∼1.6 µM at saturating CaM) compared to the resting level of Ca2+ (20–50 nM) (109, 110) ensures maintenance of the synapse specificity and Hebbian nature of LTP (19).”

    From Synaptic memory and CaMKII (2023) · cites this paper as [110]

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Authors
Maravall, M., Mainen, Z. F., Sabatini, B. L., & Svoboda, K.
Affiliations
Cold Spring Harbor Laboratory (US)
Corresponding author
Svoboda, K.
Venue
Biophysical Journal
Publisher
Elsevier BV
Published
2000-05
Volume
78
Issue
5
Pages
2655-2667
ISSN
0006-3495 (ISSN-L)
OpenAlex
W1981195606
Cited by
416
References
46
Citations by year
2026: 8 · 2025: 11 · 2024: 18 · 2023: 13 · 2022: 11 · 2021: 10 · 2020: 13 · 2019: 19 · 2018: 25 · 2017: 18 · 2016: 17 · 2015: 23 · 2014: 22 · 2013: 21 · 2012: 31
FWCI
5.44
Type
journal article
Language
en
Open access
Locations
  • Biophysical Journal (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
  • Cold Spring Harbor Laboratory Institutional Repository (Cold Spring Harbor Laboratory) (acceptedVersion)
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Biophysics › Advanced Fluorescence Microscopy Techniques
  • Life Sciences › Neuroscience › Sensory Systems › Ion Channels and Receptors
  • Life Sciences › Neuroscience › Cellular and Molecular Neuroscience › Neuroscience and Neuropharmacology Research
Keywords
intracellular calcium concentration, CA1 pyramidal neurons, hippocampal slices, dendritic calcium
MeSH terms
Action Potentials, Animals, Biophysics, Buffers, Calcium, Intracellular Fluid, Models, Biological, Pyramidal Cells, Calcium Signaling, Rats, Biophysical Phenomena, In Vitro Techniques

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