Abstract
We have developed a vibrating calcium-specific electrode to measure minute extracellular calcium gradients and thus infer the patterns of calcium currents that cross the surface of various cells and tissues. Low-resistance calcium electrodes (routinely approximately 500 M omega) are vibrated by means of orthogonally stacked piezoelectrical pushers, driven by a damped square wave at an optimal frequency of 0.5 Hz. Phase- sensitive detection of the electrode signal is performed with either analogue or digital electronics. The resulting data are superimposed on a video image of the preparation that is being measured. Depending on the background calcium concentration, this new device can readily and reliably measure steady extracellular differences of calcium concentration which are as small as 0.01% with spatial and temporal resolutions of a few microns and a few seconds, respectively. The digital version can attain a noise level of less than 1 microV. In exploratory studies, we have used this device to map and measure the patterns of calcium currents that cross the surface of growing fucoid eggs and tobacco pollen, moving amebae and Dictyostelium slugs, recently fertilized ascidian eggs, as well as nurse cells of Sarcophaga follicles. This approach should be easily extendable to other specific ion currents.
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- Azarnia R., Chambers E. L. The role of divalent cations in activation of the sea urchin egg. I. Effect of fertilization on divalent cation content. J Exp Zool. 1976 Oct;198(1):65–77. doi: 10.1002/jez.1401980109. [DOI] [PubMed] [Google Scholar]
- Bruce D. L., Marshall J. M., Jr Some ionic and bioelectric properties of the ameba Chaos chaos. J Gen Physiol. 1965 Sep;49(1):151–178. doi: 10.1085/jgp.49.1.151. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bumann J., Malchow D., Wurster B. Oscillations of Ca++ concentration during the cell differentiation of Dictyostelium discoideum: their relation to oscillations in cyclic AMP and other components. Differentiation. 1986;31(2):85–91. doi: 10.1111/j.1432-0436.1986.tb00387.x. [DOI] [PubMed] [Google Scholar]
- Cooper B. A. Quantitative studies of pinocytosis induced in Amoeba proteus by simple cations. C R Trav Lab Carlsberg. 1968;36(21):385–403. [PubMed] [Google Scholar]
- Harold F. M. Transcellular ion currents in tip-growing organisms: where are they taking us? Prog Clin Biol Res. 1986;210:359–366. [PubMed] [Google Scholar]
- Jaffe L. A., Weisenseel M. H., Jaffe L. F. Calcium accumulations within the growing tips of pollen tubes. J Cell Biol. 1975 Nov;67(2PT1):488–492. doi: 10.1083/jcb.67.2.488. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jaffe L. F., Nuccitelli R. An ultrasensitive vibrating probe for measuring steady extracellular currents. J Cell Biol. 1974 Nov;63(2 Pt 1):614–628. doi: 10.1083/jcb.63.2.614. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jaffe L. F. Sources of calcium in egg activation: a review and hypothesis. Dev Biol. 1983 Oct;99(2):265–276. doi: 10.1016/0012-1606(83)90276-2. [DOI] [PubMed] [Google Scholar]
- Kropf D. L., Caldwell J. H., Gow N. A., Harold F. M. Transcellular ion currents in the water mold Achlya. Amino acid proton symport as a mechanism of current entry. J Cell Biol. 1984 Aug;99(2):486–496. doi: 10.1083/jcb.99.2.486. [DOI] [PMC free article] [PubMed] [Google Scholar]
- MacWilliams H. K., Bonner J. T. The prestalk-prespore pattern in cellular slime molds. Differentiation. 1979;14(1-2):1–22. doi: 10.1111/j.1432-0436.1979.tb01006.x. [DOI] [PubMed] [Google Scholar]
- Maeda Y., Maeda M. The calcium content of the cellular slime mold, Dictyostelium discoideum, during development and differentiation. Exp Cell Res. 1973 Nov;82(1):125–130. doi: 10.1016/0014-4827(73)90253-x. [DOI] [PubMed] [Google Scholar]
- Njus D., Kelley P. M., Harnadek G. J. Bioenergetics of secretory vesicles. Biochim Biophys Acta. 1986;853(3-4):237–265. doi: 10.1016/0304-4173(87)90003-6. [DOI] [PubMed] [Google Scholar]
- Overall R., Jaffe L. F. Patterns of ionic current through Drosophila follicles and eggs. Dev Biol. 1985 Mar;108(1):102–119. doi: 10.1016/0012-1606(85)90013-2. [DOI] [PubMed] [Google Scholar]
- Robinson K. R., Jaffe L. F. Polarizing fucoid eggs drive a calcium current through themselves. Science. 1975 Jan 10;187(4171):70–72. doi: 10.1126/science.1167318. [DOI] [PubMed] [Google Scholar]
- Sardet C., Speksnijder J., Inoue S., Jaffe L. Fertilization and ooplasmic movements in the ascidian egg. Development. 1989 Feb;105(2):237–249. doi: 10.1242/dev.105.2.237. [DOI] [PubMed] [Google Scholar]
- Speksnijder J. E., Corson D. W., Sardet C., Jaffe L. F. Free calcium pulses following fertilization in the ascidian egg. Dev Biol. 1989 Sep;135(1):182–190. doi: 10.1016/0012-1606(89)90168-1. [DOI] [PubMed] [Google Scholar]
- Taylor D. L., Blinks J. R., Reynolds G. Contractile basis of ameboid movement. VII. Aequorin luminescence during ameboid movement, endocytosis, and capping. J Cell Biol. 1980 Aug;86(2):599–607. doi: 10.1083/jcb.86.2.599. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Troxell C. L., Scheffey C., Pickett-Heaps J. D. Ionic currents during wall morphogenesis in Micrasterias and Closterium. Prog Clin Biol Res. 1986;210:105–112. [PubMed] [Google Scholar]
- Weisenseel M. H., Nuccitelli R., Jaffe L. F. Large electrical currents traverse growing pollen tubes. J Cell Biol. 1975 Sep;66(3):556–567. doi: 10.1083/jcb.66.3.556. [DOI] [PMC free article] [PubMed] [Google Scholar]