Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Making sense of astrocytic calcium signals — from acquisition to interpretation

Abstract

Astrocytes functionally interact with neurons and with other brain cells. Although not electrically excitable, astrocytes display a complex repertoire of intracellular Ca2+ signalling that evolves in space and time within single astrocytes and across astrocytic networks. Decoding the physiological meaning of these dynamic changes in astrocytic Ca2+ activity has remained a major challenge. This Review describes experimental preparations and methods for recording and studying Ca2+ activity in astrocytes, focusing on the analysis of Ca2+ signalling events in single astrocytes and in astrocytic networks. The limitations of existing experimental approaches and ongoing technical and conceptual challenges in the interpretation of astrocytic Ca2+ events and their spatio-temporal patterns are also discussed.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.

$32.00

All prices are NET prices.

Fig. 1: Visualization of astrocytic Ca2+ signals.
Fig. 2: Spatio-temporal analysis of astrocytic Ca2+ activity.
Fig. 3: Signal processing in astrocytes and neurons.
Fig. 4: Different levels of interaction between neurons and astrocytes.

References

  1. Bazargani, N. & Attwell, D. Astrocyte calcium signaling: the third wave. Nat. Neurosci. 19, 182–189 (2016).

    CAS  PubMed  Google Scholar 

  2. Verkhratsky, A. & Nedergaard, M. Physiology of astroglia. Physiol. Rev. 98, 239–389 (2018).

    CAS  PubMed  Google Scholar 

  3. Araque, A. et al. Gliotransmitters travel in time and space. Neuron 81, 728–739 (2014).

    CAS  PubMed  PubMed Central  Google Scholar 

  4. Ma, Z., Stork, T., Bergles, D. E. & Freeman, M. R. Neuromodulators signal through astrocytes to alter neural circuit activity and behaviour. Nature 539, 428–432 (2016).

    CAS  PubMed  PubMed Central  Google Scholar 

  5. Mu, Y. et al. Glia accumulate evidence that actions are futile and suppress unsuccessful behavior. Cell 178, 27–43 (2019). This and the study by Ma et al. (2016) elegantly show in Drosophila and zebrafish models that astrocytic Ca2+ transients follow similar rules and respond to the same set of neuromodulatory signals as those described in rodents to modify behaviour.

    CAS  PubMed  Google Scholar 

  6. Schummers, J., Yu, H. & Sur, M. Tuned responses of astrocytes and their influence on hemodynamic signals in the visual cortex. Science 320, 1638–1643 (2008).

    CAS  PubMed  Google Scholar 

  7. Navarrete, M. et al. Astrocyte calcium signal and gliotransmission in human brain tissue. Cereb. Cortex 23, 1240–1246 (2013).

    PubMed  Google Scholar 

  8. Cornell-Bell, A., Finkbeiner, S., Cooper, M. & Smith, S. Glutamate induces calcium waves in cultured astrocytes: long-range glial signaling. Science 247, 470–473 (1990). Pioneering observation of spontaneous astrocytic Ca2+ signals demonstrating that astrocytes react to the neurotransmitter glutamate.

    CAS  PubMed  Google Scholar 

  9. Shigetomi, E., Kracun, S., Sofroniew, M. V. & Khakh, B. S. A genetically targeted optical sensor to monitor calcium signals in astrocyte processes. Nat. Neurosci. 13, 759–766 (2010).

    CAS  PubMed  PubMed Central  Google Scholar 

  10. Lange, S. C., Bak, L. K., Waagepetersen, H. S., Schousboe, A. & Norenberg, M. D. Primary cultures of astrocytes: their value in understanding astrocytes in health and disease. Neurochem. Res. 37, 2569–2588 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  11. Carmignoto, G., Pasti, L. & Pozzan, T. On the role of voltage-dependent calcium channels in calcium signaling of astrocytes in situ. J. Neurosci. 18, 4637–4645 (1998).

    CAS  PubMed  PubMed Central  Google Scholar 

  12. Foo, L. C. et al. Development of a method for the purification and culture of rodent astrocytes. Neuron 71, 799–811 (2011).

    CAS  PubMed  PubMed Central  Google Scholar 

  13. Gavrilov, N. et al. Astrocytic coverage of dendritic spines, dendritic shafts, and axonal boutons in hippocampal neuropil. Front. Cell. Neurosci. https://doi.org/10.3389/fncel.2018.00248 (2018).

    Article  PubMed  PubMed Central  Google Scholar 

  14. Khakh, B. S. & Sofroniew, M. V. Diversity of astrocyte functions and phenotypes in neural circuits. Nat. Neurosci. 18, 942–952 (2015).

    CAS  PubMed  PubMed Central  Google Scholar 

  15. Mulligan, S. J. & MacVicar, B. A. Calcium transients in astrocyte endfeet cause cerebrovascular constrictions. Nature 431, 195–199 (2004).

    CAS  PubMed  Google Scholar 

  16. Medvedev, N. et al. Glia selectively approach synapses on thin dendritic spines. Philos. Trans. R. Soc. Lond. B Biol. Sci. 369, 20140047 (2014).

    PubMed  PubMed Central  Google Scholar 

  17. Rungta, R. L. et al. Ca2+ transients in astrocyte fine processes occur via Ca2+ influx in the adult mouse hippocampus. Glia 64, 2093–2103 (2016).

    PubMed  Google Scholar 

  18. Nett, W. J., Oloff, S. H. & McCarthy, K. D. Hippocampal astrocytes in situ exhibit calcium oscillations that occur independent of neuronal activity. J. Neurophysiol. 87, 528–537 (2002).

    PubMed  Google Scholar 

  19. Di Castro, M. A. et al. Local Ca2+ detection and modulation of synaptic release by astrocytes. Nat. Neurosci. 14, 1276–1284 (2011).

    PubMed  Google Scholar 

  20. Porter, J. T. & McCarthy, K. D. Hippocampal astrocytes in situ respond to glutamate released from synaptic terminals. J. Neurosci. 16, 5073–5081 (1996). One of the first observations in hippocampal slices showing that synaptic activity leads to astrocytic Ca2+ signals.

    CAS  PubMed  PubMed Central  Google Scholar 

  21. Wu, Y.-W. et al. Spatiotemporal calcium dynamics in single astrocytes and its modulation by neuronal activity. Cell Calcium 55, 119–129 (2014). These authors analyse the spatio-temporal properties of Ca2+ events in hippocampal slices and demonstrate that neuronal stimulation modulates their properties (for example, spread) rather than triggers new events.

    CAS  PubMed  Google Scholar 

  22. Pasti, L., Volterra, A., Pozzan, T. & Carmignoto, G. Intracellular calcium oscillations in astrocytes: a highly plastic, bidirectional form of communication between neurons and astrocytes in situ. J. Neurosci. 17, 7817–7830 (1997).

    CAS  PubMed  PubMed Central  Google Scholar 

  23. Navarrete, M. & Araque, A. Endocannabinoids mediate neuron-astrocyte communication. Neuron 57, 883–893 (2008).

    CAS  PubMed  Google Scholar 

  24. Takano, T. et al. Rapid manifestation of reactive astrogliosis in acute hippocampal brain slices. Glia 62, 78–95 (2014).

    PubMed  Google Scholar 

  25. Hirase, H., Qian, L., Bartho, P. & Buzsaki, G. Calcium dynamics of cortical astrocytic networks in vivo. PLoS Biol. 2, E96 (2004). Pioneering work showing recordings of astrocytic Ca2+ activity in vivo. The authors demonstrate that increased neuronal discharges are associated with increased astrocytic Ca2+ activity in individual cells.

    PubMed  PubMed Central  Google Scholar 

  26. Wang, X. et al. Astrocytic Ca2+ signaling evoked by sensory stimulation in vivo. Nat. Neurosci. 9, 816–823 (2006).

    CAS  PubMed  Google Scholar 

  27. Thrane, A. S. et al. General anesthesia selectively disrupts astrocyte calcium signaling in the awake mouse cortex. Proc. Natl Acad. Sci. USA 109, 18974–18979 (2012). This study uses two-photon imaging in vivo to show that the use of anaesthetics blocks Ca2+ transients in astrocytes.

    CAS  PubMed  Google Scholar 

  28. Dombeck, D. A., Khabbaz, A. N., Collman, F., Adelman, T. L. & Tank, D. W. Imaging large-scale neural activity with cellular resolution in awake, mobile mice. Neuron 56, 43–57 (2007). This work demonstrates an association between mouse running and astrocytic Ca2+ signals.

    CAS  PubMed  PubMed Central  Google Scholar 

  29. Ding, F. et al. α1-Adrenergic receptors mediate coordinated Ca2+ signaling of cortical astrocytes in awake, behaving mice. Cell Calcium 54, 387–394 (2013).

    CAS  PubMed  Google Scholar 

  30. Sonoda, K., Matsui, T., Bito, H. & Ohki, K. Astrocytes in the mouse visual cortex reliably respond to visual stimulation. Biochem. Biophys. Res. Commun. 505, 1216–1222 (2018).

    CAS  PubMed  Google Scholar 

  31. Paukert, M. et al. Norepinephrine controls astroglial responsiveness to local circuit activity. Neuron 82, 1263–1270 (2014).

    CAS  PubMed  PubMed Central  Google Scholar 

  32. King, C. M. et al. Local resting Ca2+ controls the scale of astroglial Ca2+ signals. Cell Rep. 30, 3466–3477 (2020). This quantitative Ca2+ imaging study reveals that the local resting Ca2+ level dynamically controls the magnitude of astrocytic Ca2+ transients in both acute brain slices and awake mice.

    CAS  PubMed  PubMed Central  Google Scholar 

  33. Kislin, M. et al. Flat-floored air-lifted platform: a new method for combining behavior with microscopy or electrophysiology on awake freely moving rodents. J. Vis. Exp. https://doi.org/10.3791/51869 (2014).

    Article  PubMed  PubMed Central  Google Scholar 

  34. Royer, S. et al. Control of timing, rate and bursts of hippocampal place cells by dendritic and somatic inhibition. Nat. Neurosci. 15, 769–775 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  35. Thurley, K. & Ayaz, A. Virtual reality systems for rodents. Curr. Zool. 63, 109–119 (2016).

    PubMed  PubMed Central  Google Scholar 

  36. Yang, G., Pan, F., Parkhurst, C. N., Grutzendler, J. & Gan, W.-B. Thinned-skull cranial window technique for long-term imaging of the cortex in live mice. Nat. Protoc. 5, 201–208 (2010).

    CAS  PubMed  PubMed Central  Google Scholar 

  37. Vasile, F., Dossi, E. & Rouach, N. Human astrocytes: structure and functions in the healthy brain. Brain Struct. Funct. 222, 2017–2029 (2017).

    CAS  PubMed  PubMed Central  Google Scholar 

  38. Oberheim, N. A. et al. Uniquely hominid features of adult human astrocytes. J. Neurosci. 29, 3276–3287 (2009).

    CAS  PubMed  PubMed Central  Google Scholar 

  39. Bedner, P., Jabs, R. & Steinhäuser, C. Properties of human astrocytes and NG2 glia. Glia 68, 756–767 (2020).

    PubMed  Google Scholar 

  40. Paşca, A. M. et al. Functional cortical neurons and astrocytes from human pluripotent stem cells in 3D culture. Nat. Methods 12, 671–678 (2015).

    PubMed  PubMed Central  Google Scholar 

  41. Hansen, M. G., Tornero, D., Canals, I., Ahlenius, H. & Kokaia, Z. in Neural Stem Cells: Methods and Protocols (ed. Daadi M. M.) 73–88 (Springer, 2019).

  42. Bindocci, E. et al. Three-dimensional Ca2+ imaging advances understanding of astrocyte biology. Science https://doi.org/10.1126/science.aai8185 (2017). These authors propose the use of 3D imaging to monitor Ca2+ activity.

    Article  PubMed  Google Scholar 

  43. Kuchibhotla, K. V., Lattarulo, C. R., Hyman, B. T. & Bacskai, B. J. Synchronous hyperactivity and intercellular calcium waves in astrocytes in Alzheimer mice. Science 323, 1211–1215 (2009).

    CAS  PubMed  PubMed Central  Google Scholar 

  44. Zheng, K. et al. Time-resolved imaging reveals heterogeneous landscapes of nanomolar Ca2+ in neurons and astroglia. Neuron 88, 277–288 (2015).

    CAS  PubMed  PubMed Central  Google Scholar 

  45. Agarwal, A. et al. Transient opening of the mitochondrial permeability transition pore induces microdomain calcium transients in astrocyte processes. Neuron 93, 587–605 e587 (2017). This study shows that mitochondria are involved in Ca2+ release and uptake at astrocyte microdomains and that cellular stress increases microdomain Ca2+ transients. The authors develop a smart-ROI-based and machine learning-based algorithm (CaSCaDe) for the analysis of Ca2+ signals in astrocytes.

    CAS  PubMed  PubMed Central  Google Scholar 

  46. Stobart, J. L. et al. Cortical circuit activity evokes rapid astrocyte calcium signals on a similar timescale to neurons. Neuron 98, 726–735 e724 (2018).

    CAS  PubMed  Google Scholar 

  47. Sabatini, B. L. & Regehr, W. G. Optical measurement of presynaptic calcium currents. Biophys. J. 74, 1549–1563 (1998).

    CAS  PubMed  PubMed Central  Google Scholar 

  48. Savtchenko, L. P. et al. Disentangling astroglial physiology with a realistic cell model in silico. Nat. Commun. 9, 3554 (2018).

    PubMed  PubMed Central  Google Scholar 

  49. Kuga, N., Sasaki, T., Takahara, Y., Matsuki, N. & Ikegaya, Y. Large-scale calcium waves traveling through astrocytic networks in vivo. J. Neurosci. 31, 2607–2614 (2011).

    CAS  PubMed  PubMed Central  Google Scholar 

  50. Shibasaki, K., Ikenaka, K., Tamalu, F., Tominaga, M. & Ishizaki, Y. A novel subtype of astrocytes expressing TRPV4 (transient receptor potential vanilloid 4) regulates neuronal excitability via release of gliotransmitters. J. Biol. Chem. 289, 14470–14480 (2014).

    CAS  PubMed  PubMed Central  Google Scholar 

  51. Dunn, K. M., Hill-Eubanks, D. C., Liedtke, W. B. & Nelson, M. T. TRPV4 channels stimulate Ca2+ release in astrocytic endfeet and amplify neurovascular coupling responses. Proc. Natl Acad. Sci. USA 110, 6157–6162 (2013).

    CAS  PubMed  Google Scholar 

  52. Jacobson, J. & Duchen, M. R. Mitochondrial oxidative stress and cell death in astrocytes — requirement for stored Ca2+ and sustained opening of the permeability transition pore. J. Cell Sci. 115, 1175–1188 (2002).

    CAS  PubMed  Google Scholar 

  53. Sacconi, L., Dombeck, D. A. & Webb, W. W. Overcoming photodamage in second-harmonic generation microscopy: real-time optical recording of neuronal action potentials. Proc. Natl Acad. Sci. USA 103, 3124–3129 (2006).

    CAS  PubMed  Google Scholar 

  54. Knight, M. M., Roberts, S. R., Lee, D. A. & Bader, D. L. Live cell imaging using confocal microscopy induces intracellular calcium transients and cell death. Am. J. Physiol. Cell Physiol. 284, C1083–C1089 (2003).

    CAS  PubMed  Google Scholar 

  55. Freitas, H. R. et al. Glutathione-induced calcium shifts in chick retinal glial cells. PLoS ONE 11, e0153677 (2016).

    PubMed  PubMed Central  Google Scholar 

  56. Martinovich, G. G., Golubeva, E. N., Martinovich, I. V. & Cherenkevich, S. N. Redox regulation of calcium signaling in cancer cells by ascorbic acid involving the mitochondrial electron transport chain. J. Biophys. 2012, 921653 (2012).

    PubMed  PubMed Central  Google Scholar 

  57. Neher, E. & Augustine, G. J. Calcium gradients and buffers in bovine chromaffin cells. J. Physiol. 450, 273–301 (1992).

    CAS  PubMed  PubMed Central  Google Scholar 

  58. McMahon, S. M. & Jackson, M. B. An inconvenient truth: calcium sensors are calcium buffers. Trends Neurosci. 41, 880–884 (2018).

    CAS  PubMed  PubMed Central  Google Scholar 

  59. Jafri, M. S. & Keizer, J. On the roles of Ca2+ diffusion, Ca2+ buffers, and the endoplasmic reticulum in IP3-induced Ca2+ waves. Biophys. J. 69, 2139–2153 (1995).

    CAS  PubMed  PubMed Central  Google Scholar 

  60. Matthews, E. A. & Dietrich, D. Buffer mobility and the regulation of neuronal calcium domains. Front. Cell. Neurosci. https://doi.org/10.3389/fncel.2015.00048 (2015).

    Article  PubMed  PubMed Central  Google Scholar 

  61. Wang, Z., Tymianski, M., Jones, O. T. & Nedergaard, M. Impact of cytoplasmic calcium buffering on the spatial and temporal characteristics of intercellular calcium signals in astrocytes. J. Neurosci. 17, 7359–7371 (1997).

    CAS  PubMed  PubMed Central  Google Scholar 

  62. Yu, X., Nagai, J. & Khakh, B. S. Improved tools to study astrocytes. Nat. Rev. Neurosci. 21, 121–138 (2020).

    CAS  PubMed  Google Scholar 

  63. Wang, Y. et al. Accurate quantification of astrocyte and neurotransmitter fluorescence dynamics for single-cell and population-level physiology. Nat. Neurosci. 22, 1936–1944 (2019). These authors further improve the method of detection of spatio-temporal Ca2+ events in astrocytes and suggest a measure of event propagation path, direction and speed.

    CAS  PubMed  PubMed Central  Google Scholar 

  64. Jung, P., Cornell-Bell, A., Madden, K. S. & Moss, F. Noise-induced spiral waves in astrocyte syncytia show evidence of self-organized criticality. J. Neurophysiol. 79, 1098–1101 (1998). These authors suggest a new method for quantitatively measuring the spatio-temporal extent of Ca2+ waves in cultured astrocytes. They report a power-law distribution of wave sizes, which is characteristic of self-organized critical phenomena.

    CAS  PubMed  Google Scholar 

  65. Nakayama, R., Sasaki, T., Tanaka, K. F. & Ikegaya, Y. Subcellular calcium dynamics during juvenile development in mouse hippocampal astrocytes. Eur. J. Neurosci. 43, 923–932 (2016). These authors examine developmental changes in the spatio-temporal patterns of Ca2+ activity in single hippocampal astrocytes.

    PubMed  Google Scholar 

  66. Asada, A. et al. Subtle modulation of ongoing calcium dynamics in astrocytic microdomains by sensory inputs. Physiol. Rep. https://doi.org/10.14814/phy2.12454 (2015).

    Article  PubMed  PubMed Central  Google Scholar 

  67. Wu, Y.-W. et al. Morphological profile determines the frequency of spontaneous calcium events in astrocytic processes. Glia 67, 246–262 (2019).

    PubMed  Google Scholar 

  68. Stobart, J. L. et al. Long-term in vivo calcium imaging of astrocytes reveals distinct cellular compartment responses to sensory stimulation. Cereb. Cortex 28, 184–198 (2018).

    PubMed  Google Scholar 

  69. Kittler, J. & Illingworth, J. Minimum error thresholding. Pattern Recognit. 19, 41–47 (1986).

    Google Scholar 

  70. Stevens, B. et al. The classical complement cascade mediates CNS synapse elimination. Cell 131, 1164–1178 (2007).

    CAS  PubMed  Google Scholar 

  71. Torborg, C. L. & Feller, M. B. Unbiased analysis of bulk axonal segregation patterns. J. Neurosci. Methods 135, 17–26 (2004).

    CAS  PubMed  Google Scholar 

  72. Clements, J. D. & Bekkers, J. M. Detection of spontaneous synaptic events with an optimally scaled template. Biophys. J. 73, 220–229 (1997).

    CAS  PubMed  PubMed Central  Google Scholar 

  73. Pernía-Andrade, A. J. et al. A deconvolution-based method with high sensitivity and temporal resolution for detection of spontaneous synaptic currents in vitro and in vivo. Biophys. J. 103, 1429–1439 (2012).

    PubMed  PubMed Central  Google Scholar 

  74. Friedrich, J., Zhou, P. & Paninski, L. Fast online deconvolution of calcium imaging data. PLoS Comput. Biol. 13, e1005423 (2017).

    PubMed  PubMed Central  Google Scholar 

  75. Szymanska, A. F. et al. Accurate detection of low signal-to-noise ratio neuronal calcium transient waves using a matched filter. J. Neurosci. Methods 259, 1–12 (2016).

    CAS  PubMed  Google Scholar 

  76. Mukamel, E. A., Nimmerjahn, A. & Schnitzer, M. J. Automated analysis of cellular signals from large-scale calcium imaging data. Neuron 63, 747–760 (2009).

    CAS  PubMed  PubMed Central  Google Scholar 

  77. Srinivasan, R. et al. Ca2+ signaling in astrocytes from IP3R2–/– mice in brain slices and during startle responses in vivo. Nat. Neurosci. 18, 708–717 (2015).

    CAS  PubMed  PubMed Central  Google Scholar 

  78. Semyanov, A. Spatiotemporal pattern of calcium activity in astrocytic network. Cell Calcium 78, 15–25 (2019).

    CAS  PubMed  Google Scholar 

  79. Wang, T.-f., Zhou, C., Tang, A.-h., Wang, S.-q. & Chai, Z. Cellular mechanism for spontaneous calcium oscillations in astrocytes. Acta Pharmacol. Sin. 27, 861–868 (2006).

    CAS  PubMed  Google Scholar 

  80. Sun, M. Y. et al. Astrocyte calcium microdomains are inhibited by bafilomycin A1 and cannot be replicated by low-level Schaffer collateral stimulation in situ. Cell Calcium 55, 1–16 (2014).

    PubMed  Google Scholar 

  81. Bojarskaite, L. et al. Astrocytic Ca2+ signaling is reduced during sleep and is involved in the regulation of slow wave sleep. Nat. Commun. 11, 3240 (2020).

    PubMed  PubMed Central  Google Scholar 

  82. Denizot, A., Arizono, M., Nägerl, U. V., Soula, H. & Berry, H. Simulation of calcium signaling in fine astrocytic processes: Effect of spatial properties on spontaneous activity. PLoS Comput. Biol. 15, e1006795 (2019).

    CAS  PubMed  PubMed Central  Google Scholar 

  83. Parri, H. R., Gould, T. M. & Crunelli, V. Spontaneous astrocytic Ca2+ oscillations in situ drive NMDAR-mediated neuronal excitation. Nat. Neurosci. 4, 803–812 (2001).

    CAS  PubMed  Google Scholar 

  84. Khakh, B. S. & McCarthy, K. D. Astrocyte calcium signaling: from observations to functions and the challenges therein. Cold Spring Harb. Perspect. Biol. 7, a020404 (2015).

    PubMed  PubMed Central  Google Scholar 

  85. Foskett, J. K., White, C., Cheung, K.-H. & Mak, D.-O. D. Inositol trisphosphate receptor Ca2+ release channels. Physiol. Rev. 87, 593–658 (2007).

    CAS  PubMed  PubMed Central  Google Scholar 

  86. Sherwood, M. W. et al. Astrocytic IP3Rs: contribution to Ca2+ signalling and hippocampal LTP. Glia 65, 502–513 (2017).

    PubMed  Google Scholar 

  87. Wang, W. et al. Superoxide flashes in single mitochondria. Cell 134, 279–290 (2008).

    CAS  PubMed  PubMed Central  Google Scholar 

  88. Bánsághi, S. et al. Isoform- and species-specific control of inositol 1,4,5-trisphosphate (IP3) receptors by reactive oxygen species. J. Biol. Chem. 289, 8170–8181 (2014).

    PubMed  PubMed Central  Google Scholar 

  89. Faust, T. E. et al. Astrocyte redox dysregulation causes prefrontal hypoactivity: sulforaphane treats non-ictal pathophysiology in ALDH7A1-mediated epilepsy. bioRxiv https://doi.org/10.1101/796474 (2019).

    Article  Google Scholar 

  90. Boddum, K. et al. Astrocytic GABA transporter activity modulates excitatory neurotransmission. Nat. Commun. 7, 13572 (2016).

    CAS  PubMed  PubMed Central  Google Scholar 

  91. Rose, C. R., Ziemens, D. & Verkhratsky, A. On the special role of NCX in astrocytes: translating Na+ transients into intracellular Ca2+ signals. Cell Calcium 86, 102154 (2020).

    CAS  PubMed  Google Scholar 

  92. Brazhe, A. R., Verisokin, A. Y., Verveyko, D. V. & Postnov, D. E. Sodium–calcium exchanger can account for regenerative Ca2+ entry in thin astrocyte processes. Front. Cell. Neurosci. https://doi.org/10.3389/fncel.2018.00250 (2018).

    Article  PubMed  PubMed Central  Google Scholar 

  93. Durkee, C. A. et al. Gi/o protein-coupled receptors inhibit neurons but activate astrocytes and stimulate gliotransmission. Glia 67, 1076–1093 (2019).

    PubMed  PubMed Central  Google Scholar 

  94. Turovsky, E. et al. Mechanisms of CO2/H+ sensitivity of astrocytes. J. Neurosci. 36, 10750–10758 (2016).

    CAS  PubMed  PubMed Central  Google Scholar 

  95. Angelova, P. R. et al. Functional oxygen sensitivity of astrocytes. J. Neurosci. 35, 10460–10473 (2015).

    CAS  PubMed  PubMed Central  Google Scholar 

  96. Tran, C. H. T., Peringod, G. & Gordon, G. R. Astrocytes integrate behavioral state and vascular signals during functional hyperemia. Neuron 100, 1133–1148 (2018).

    CAS  PubMed  Google Scholar 

  97. Marina, N. et al. Astrocytes monitor cerebral perfusion and control systemic circulation to maintain brain blood flow. Nat. Commun. 11, 131 (2020).

    CAS  PubMed  PubMed Central  Google Scholar 

  98. Ma, Z. & Freeman, M. R. TrpML-mediated astrocyte microdomain Ca2+ transients regulate astrocyte-tracheal interactions in CNS. bioRxiv https://doi.org/10.1101/865659 (2019).

    Article  Google Scholar 

  99. Petravicz, J., Fiacco, T. A. & McCarthy, K. D. Loss of IP3 receptor-dependent Ca2+ increases in hippocampal astrocytes does not affect baseline CA1 pyramidal neuron synaptic activity. J. Neurosci. 28, 4967–4973 (2008). This study shows that IP3R2 is the main IP3R subtype in astrocytes, and that IP3R2-null mutant mice lack neurotransmitter-evoked and neuromodulator-evoked Ca2+ signals.

    CAS  PubMed  PubMed Central  Google Scholar 

  100. Bonder, D. E. & McCarthy, K. D. Astrocytic Gq-GPCR-linked IP3R-dependent Ca2+ signaling does not mediate neurovascular coupling in mouse visual cortex in vivo. J. Neurosci. 34, 13139–13150 (2014).

    CAS  PubMed  PubMed Central  Google Scholar 

  101. Patrushev, I., Gavrilov, N., Turlapov, V. & Semyanov, A. Subcellular location of astrocytic calcium stores favors extrasynaptic neuron–astrocyte communication. Cell Calcium 54, 343–349 (2013).

    CAS  PubMed  Google Scholar 

  102. Grosche, J. et al. Microdomains for neuron–glia interaction: parallel fiber signaling to Bergmann glial cells. Nat. Neurosci. 2, 139–143 (1999). This study uses serial electron microscopy and Ca2+ imaging to identify subcellular compartments called ‘microdomains’ in Bergmann glial cells (astrocyte-like cells in the cerebellum). These glial microdomains autonomously interact with synapses through Ca2+ signalling.

    CAS  PubMed  Google Scholar 

  103. Arizono, M. et al. Structural basis of astrocytic Ca2+ signals at tripartite synapses. Nat. Commun. 11, 1906 (2020).

    CAS  PubMed  PubMed Central  Google Scholar 

  104. Plata, A. et al. Astrocytic atrophy following status epilepticus parallels reduced Ca2+ activity and impaired synaptic plasticity in the rat hippocampus. Front. Mol. Neurosci. https://doi.org/10.3389/fnmol.2018.00215 (2018).

    Article  PubMed  PubMed Central  Google Scholar 

  105. Molotkov, D., Zobova, S., Arcas, J. M. & Khiroug, L. Calcium-induced outgrowth of astrocytic peripheral processes requires actin binding by profilin-1. Cell Calcium 53, 338–348 (2013).

    CAS  PubMed  Google Scholar 

  106. Tanaka, M. et al. Astrocytic Ca2+ signals are required for the functional integrity of tripartite synapses. Molecular Brain 6, 6 (2013).

    CAS  PubMed  PubMed Central  Google Scholar 

  107. Clopath, C., Büsing, L., Vasilaki, E. & Gerstner, W. Connectivity reflects coding: a model of voltage-based STDP with homeostasis. Nat. Neurosci. 13, 344 (2010).

    CAS  PubMed  Google Scholar 

  108. Hasselmo, M. E. & Stern, C. E. Theta rhythm and the encoding and retrieval of space and time. NeuroImage 85, 656–666 (2014).

    PubMed  Google Scholar 

  109. Eichenbaum, H., Dudchenko, P., Wood, E., Shapiro, M. & Tanila, H. The hippocampus, memory, and place cells: is it spatial memory or a memory space? Neuron 23, 209–226 (1999).

    CAS  PubMed  Google Scholar 

  110. Otsu, Y. et al. Calcium dynamics in astrocyte processes during neurovascular coupling. Nat. Neurosci. 18, 210–218 (2015).

    CAS  PubMed  Google Scholar 

  111. Lind, B. L. et al. Fast Ca2+ responses in astrocyte end-feet and neurovascular coupling in mice. Glia 66, 348–358 (2018).

    PubMed  Google Scholar 

  112. Jain, A., Bansal, R., Kumar, A. & Singh, K. D. A comparative study of visual and auditory reaction times on the basis of gender and physical activity levels of medical first year students. Int. J. Appl. Basic Med. Res. 5, 124–127 (2015).

    PubMed  PubMed Central  Google Scholar 

  113. Amano, K. et al. Estimation of the timing of human visual perception from magnetoencephalography. J. Neurosci. 26, 3981–3991 (2006).

    CAS  PubMed  PubMed Central  Google Scholar 

  114. Matsuhashi, M. & Hallett, M. The timing of the conscious intention to move. Eur. J. Neurosci. 28, 2344–2351 (2008).

    PubMed  PubMed Central  Google Scholar 

  115. Nedergaard, M. Direct signaling from astrocytes to neurons in cultures of mammalian brain cells. Science 263, 1768–1771 (1994).

    CAS  PubMed  Google Scholar 

  116. Lazrak, A. & Peracchia, C. Gap junction gating sensitivity to physiological internal calcium regardless of pH in Novikoff hepatoma cells. Biophys. J. 65, 2002–2012 (1993).

    CAS  PubMed  PubMed Central  Google Scholar 

  117. Toyofuku, T. et al. Intercellular calcium signaling via gap junction in connexin-43-transfected cells. J. Biol. Chem. 273, 1519–1528 (1998).

    CAS  PubMed  Google Scholar 

  118. Fujii, Y., Maekawa, S. & Morita, M. Astrocyte calcium waves propagate proximally by gap junction and distally by extracellular diffusion of ATP released from volume-regulated anion channels. Sci. Rep. 7, 13115 (2017).

    PubMed  PubMed Central  Google Scholar 

  119. Slezak, M. et al. Distinct mechanisms for visual and motor-related astrocyte responses in mouse visual cortex. Curr. Biol. 29, 3120–3127 (2019).

    CAS  PubMed  PubMed Central  Google Scholar 

  120. Monai, H. et al. Calcium imaging reveals glial involvement in transcranial direct current stimulation-induced plasticity in mouse brain. Nat. Commun. 7, 11100 (2016).

    CAS  PubMed  PubMed Central  Google Scholar 

  121. Takata, N. et al. Astrocyte calcium signaling transforms cholinergic modulation to cortical plasticity in vivo. J. Neurosci. 31, 18155–18165 (2011).

    CAS  PubMed  PubMed Central  Google Scholar 

  122. Hirase, H., Iwai, Y., Takata, N., Shinohara, Y. & Mishima, T. Volume transmission signalling via astrocytes. Philos. Trans. R. Soc. Lond. B Biol. Sci. 369, 20130604 (2014).

    PubMed  PubMed Central  Google Scholar 

  123. Fuxe, K., Agnati, L. F., Marcoli, M. & Borroto-Escuela, D. O. Volume transmission in central dopamine and noradrenaline neurons and its astroglial targets. Neurochem. Res. 40, 2600–2614 (2015).

    CAS  PubMed  Google Scholar 

  124. Oe, Y. et al. Distinct temporal integration of noradrenaline signaling by astrocytic second messengers during vigilance. Nat. Commun. 11, 471 (2020).

    CAS  PubMed  PubMed Central  Google Scholar 

  125. Jennings, A. et al. Dopamine elevates and lowers astroglial Ca2+ through distinct pathways depending on local synaptic circuitry. Glia 65, 447–459 (2017).

    PubMed  Google Scholar 

  126. Corkrum, M. et al. Dopamine-evoked synaptic regulation in the nucleus accumbens requires astrocyte activity. Neuron 105, 1036–1047 (2020).

    CAS  PubMed  Google Scholar 

  127. Papouin, T., Dunphy, J. M., Tolman, M., Dineley, K. T. & Haydon, P. G. Septal cholinergic neuromodulation tunes the astrocyte-dependent gating of hippocampal NMDA receptors to wakefulness. Neuron 94, 840–854 (2017).

    CAS  PubMed  PubMed Central  Google Scholar 

  128. Garaschuk, O., Milos, R.-I. & Konnerth, A. Targeted bulk-loading of fluorescent indicators for two-photon brain imaging in vivo. Nat. Protoc. 1, 380–386 (2006).

    CAS  PubMed  Google Scholar 

  129. Nimmerjahn, A., K. F., Kerr, J. N. & Helmchen, F. Sulforhodamine 101 as a specific marker of astroglia in the neocortex in vivo. Nat. Methods 1, 31–37 (2004).

    PubMed  Google Scholar 

  130. Hill, R. A. & Grutzendler, J. In vivo imaging of oligodendrocytes with sulforhodamine 101. Nat. Methods 11, 1081–1082 (2014).

    CAS  PubMed  PubMed Central  Google Scholar 

  131. Kang, J. et al. Sulforhodamine 101 induces long-term potentiation of intrinsic excitability and synaptic efficacy in hippocampal CA1 pyramidal neurons. Neuroscience 169, 1601–1609 (2010).

    CAS  PubMed  PubMed Central  Google Scholar 

  132. Fink, S. et al. in Neuronal Network Analysis: Concepts and Experimental Approaches (eds Fellin, T. & Halassa M.) 21–43 (Humana, 2012).

  133. Henneberger, C., Papouin, T., Oliet, S. H. & Rusakov, D. A. Long-term potentiation depends on release of D-serine from astrocytes. Nature 463, 232–236 (2010).

    CAS  PubMed  PubMed Central  Google Scholar 

  134. Henneberger, C. & Rusakov, D. A. Monitoring local synaptic activity with astrocytic patch pipettes. Nat. Protoc. 7, 2171–2179 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  135. Gee, J. M. et al. Imaging activity in neurons and glia with a Polr2a-based and Cre-dependent GCaMP5G-IRES-tdTomato reporter mouse. Neuron 83, 1058–1072 (2014).

    CAS  PubMed  PubMed Central  Google Scholar 

  136. Nakai, J., Ohkura, M. & Imoto, K. A high signal-to-noise Ca2+ probe composed of a single green fluorescent protein. Nat. Biotechnol. 19, 137–141 (2001).

    CAS  PubMed  Google Scholar 

  137. Akerboom, J. et al. Optimization of a GCaMP calcium indicator for neural activity imaging. J. Neurosci. 32, 13819–13840 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  138. Okubo, Y. et al. Inositol 1,4,5-trisphosphate receptor type 2-independent Ca2+ release from the endoplasmic reticulum in astrocytes. Glia 67, 113–124 (2019).

    PubMed  Google Scholar 

  139. Suzuki, J. et al. Imaging intraorganellar Ca2+ at subcellular resolution using CEPIA. Nat. Commun. 5, 4153 (2014).

    CAS  PubMed  PubMed Central  Google Scholar 

  140. Ortinski, P. I. et al. Selective induction of astrocytic gliosis generates deficits in neuronal inhibition. Nat. Neurosci. 13, 584–591 (2010).

    CAS  PubMed  PubMed Central  Google Scholar 

  141. Atkin, S. D. et al. Transgenic mice expressing a chameleon fluorescent Ca2+ indicator in astrocytes and Schwann cells allow study of glial cell Ca2+ signals in situ and in vivo. J. Neurosci. Methods 181, 212–226 (2009).

    CAS  PubMed  PubMed Central  Google Scholar 

  142. Kanemaru, K. et al. In vivo visualization of subtle, transient, and local activity of astrocytes using an ultrasensitive Ca2+ indicator. Cell Rep. 8, 311–318 (2014).

    CAS  PubMed  Google Scholar 

  143. Hires, S. A., Tian, L. & Looger, L. L. Reporting neural activity with genetically encoded calcium indicators. Brain Cell Biol. 36, 69 (2008).

    CAS  PubMed  PubMed Central  Google Scholar 

  144. Agronskaia, A. V., Tertoolen, L. & Gerritsen, H. C. Fast fluorescence lifetime imaging of calcium in living cells. J. Biomed. Opt. 9, 1230–1237 (2004).

    CAS  PubMed  Google Scholar 

  145. Yellen, G. & Mongeon, R. Quantitative two-photon imaging of fluorescent biosensors. Curr. Opin. Chem. Biol. 27, 24–30 (2015).

    CAS  PubMed  PubMed Central  Google Scholar 

Download references

Acknowledgements

The research work of A.S.’s laboratory is supported by Russian Science Foundation grant 20-14-00241. The research work of A.A.’s laboratory is supported by the Chica and Heinz Schaller Research Foundation, the Brain & Behaviour Research Foundation via a National Alliance for Research on Schizophrenia & Depression (NARSAD) Young Investigator Award and grants from the Deutsche Forschungsgemeinschaft (DFG): SFB1134-B01, SFB1158-A09 and FOR2289-P8. C.H.’s laboratory is supported by DFG grants SFB1089 B03, SPP1757 HE6949/1, FOR2795 and HE6949/3.

Author information

Authors and Affiliations

Authors

Contributions

The authors contributed equally to all aspects of the article.

Corresponding authors

Correspondence to Alexey Semyanov, Christian Henneberger or Amit Agarwal.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information

Nature Reviews Neuroscience thanks the anonymous reviewers for their contribution to the peer review of this work.

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Related links

MATLAB: https://www.mathworks.com/products/matlab.html

Glossary

Deconvolution-based techniques

Deconvolution (reversing the inherent image distortion specific to a given microscope or other imaging instrument) is usually done by image-processing software as part of image generation.

Schaffer collaterals

Axon collaterals derived from CA3 pyramidal cells that project to hippocampal area CA1. Schaffer collaterals influence learning and memory via activity-dependent plasticity and are integral to hippocampal medial limbic and trisynaptic circuits.

InsP3 sponge

A recombinant peptide including modified ligand-binding domains from mouse inositol 1,4,5-trisphosphate (IP3) receptor type 1 (IP3R1), designed to sequester intracellular InsP3 owing to its ~1,000-fold higher affinity for InsP3 than for native IP3Rs.

APP/PS1 mice

A double-transgenic mouse model of Alzheimer disease that expresses both chimeric (mouse–human) amyloid precursor protein (APP) and mutant human presenilin 1 (PS1) specifically in CNS neurons.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Semyanov, A., Henneberger, C. & Agarwal, A. Making sense of astrocytic calcium signals — from acquisition to interpretation. Nat Rev Neurosci 21, 551–564 (2020). https://doi.org/10.1038/s41583-020-0361-8

Download citation

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41583-020-0361-8

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing