scholarly journals Bulk Loading of Calcium Indicator Dyes to Study Astrocyte Physiology: Key Limitations and Improvements Using Morphological Maps

2011 ◽  
Vol 31 (25) ◽  
pp. 9353-9358 ◽  
Author(s):  
A. M. B. Reeves ◽  
E. Shigetomi ◽  
B. S. Khakh
Keyword(s):  
Calcium Indicator ◽  
Bulk Loading ◽  
Indicator Dyes

Practical Methods for In Vivo Cortical Physiology with 2-Photon Microscopy and Bulk Loading of Fluorescent Calcium Indicator Dyes

2014 ◽  
pp. 117-141
Author(s):  
Stephen D. Van Hooser ◽  
Elizabeth N. Johnson ◽  
Ye Li ◽  
Mark Mazurek ◽  
Julie H. Culp ◽  
...  
Keyword(s):  
Calcium Indicator ◽  
Bulk Loading ◽  
Cortical Physiology ◽  
Indicator Dyes

Measurement and Interpretation of Cytoplasmic [Ca2+] Signals From Calcium-Indicator Dyes

Physiology ◽  
2000 ◽  
Vol 15 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Stephen M. Baylor ◽  
Stephen Hollingworth
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fibers ◽  
Skeletal Muscle Fibers ◽  
Calcium Indicator ◽  
Indicator Dyes

Ca2+-indicator dyes are widely used in biology yet difficult to characterize inside cells. Studies in skeletal muscle fibers provide important information about indicator behavior and about Ca2+ signaling within the cytoplasm.

scholarly journals Calcium waves along the cleavage furrows in cleavage-stage Xenopus embryos and its inhibition by heparin.

1996 ◽  
Vol 135 (1) ◽  
pp. 181-190 ◽  
Author(s):  
A Muto ◽  
S Kume ◽  
T Inoue ◽  
H Okano ◽  
K Mikoshiba
Keyword(s):  
Calcium Transients ◽  
Free Calcium ◽  
Calcium Waves ◽  
Cleavage Furrow ◽  
Cleavage Stage ◽  
Xenopus Embryos ◽  
Calcium Indicator ◽  
Spatio Temporal ◽  
Indicator Dyes ◽  
Insp3 Receptor

Calcium signaling is known to be associated with cytokinesis; however, the detailed spatio-temporal pattern of calcium dynamics has remained unclear. We have studied changes of intracellular free calcium in cleavage-stage Xenopus embryos using fluorescent calcium indicator dyes, mainly Calcium Green-1. Cleavage formation was followed by calcium transients that localized to cleavage furrows and propagated along the furrows as calcium waves. The calcium transients at the cleavage furrows were observed at each cleavage furrow at least until blastula stage. The velocity of the calcium waves at the first cleavage furrow was approximately 3 microns/s, which was much slower than that associated with fertilization/egg activation. These calcium waves traveled only along the cleavage furrows and not in the direction orthogonal to the furrows. These observations imply that there exists an intracellular calcium-releasing activity specifically associated with cleavage furrows. The calcium waves occurred in the absence of extracellular calcium and were inhibited in embryos injected with heparin an inositol 1,4,5-trisphosphate (InsP3) receptor antagonist. These results suggest that InsP3 receptor-mediated calcium mobilization plays an essential role in calcium wave formation at the cleavage furrows.

Measurement of [Ca] in single cells and pH in single organelles by fluorescence microscopy

1988 ◽  
Vol 46 ◽  
pp. 46-47
Author(s):  
F.R. Maxfield ◽  
M.L. Shelanski
Keyword(s):  
Single Cells ◽  
Living Cells ◽  
Free Calcium ◽  
Ion Concentrations ◽  
Calcium Indicator ◽  
Controlled Illumination ◽  
Computer Controlled ◽  
Temporal And Spatial ◽  
Intracellular Sorting ◽  
Indicator Dyes

Microscope spectrofluorometry and digital image processing provide the ability to study changes in ion concentrations in living cells with high temporal and spatial resolution. We have used fluorescein labeled macromolecules to measure the pH of specific endosomal compartments (1-3). The ratio of fluorescence intensities at 450 nm and 490 nm excitation provides a measure of the pH (4). The acidification of endosomes detected by this technique provide an explanation for endosome functions including intracellular sorting of ligands and receptors, release of iron from transferrin, and penetration of viruses and toxins into the cytosol (3).Using the tetracarboxylate calcium indicator dyes synthesized by R. Tsien and his colleagues (5), the same instruments can be used for measuring intracellular free calcium, [Ca2+]i, in single cells. We have used the system to measure [Ca2+]i changes associated with cell motility (6-9).Cells are examined using a Leitz Diavert microscope with a computer-controlled illumination and photometry system.

Effects of aluminum on the growth and distribution of calcium in roots of an aluminum-sensitive cultivar of barley (Hordeum vulgare)

1995 ◽  
Vol 73 (12) ◽  
pp. 1849-1858 ◽  
Author(s):  
B. E. Nichol ◽  
L. A. Oliveira
Keyword(s):  
Cell Division ◽  
Hordeum Vulgare ◽  
Root Growth ◽  
Cell Expansion ◽  
Cytosolic Calcium ◽  
Root Growth Inhibition ◽  
Hordeum Vulgare L ◽  
Calcium Indicator ◽  
Meristematic Region ◽  
Indicator Dyes

Aluminum-induced inhibition of root growth in the Al-sensitive cultivar Kearney of barley (Hordeum vulgare L.) is the result of disruption of both cell division in the meristematic region and cell expansion in the zone of elongation of the roots. In seedlings directly germinated in 50 μM Al, inhibition of root growth is detected 48 h after initiation of germination and it results primarily from the disruption of cell elongation. In seedlings germinated for 2 days under Al-free conditions, inhibition of root growth is apparent 8 h after transfer to 50 μM Al. In this instance, root growth inhibition is mainly the result of disruption of cell division in the meristematic region of the root. The calcium indicator dyes chlorotetracycline and Fluo-3 are used to study the distribution of intracellular calcium and its relationship to aluminum phototoxicity. Aluminum increases both chlorotetracycline and Fluo-3 fluorescence intensities. Fluorescence of the cytosolic calcium indicator dye Fluo-3 increases primarily in the zone of elongation of the roots of seedlings directly germinated in 50 μM aluminum. The increase in Fluo-3 fluorescence occurs concomitantly with major changes in both the length and width of the cells in the zone of elongation. The evidence suggests that changes in calcium homeostasis occurring in cells of the zone of elongation may be a major factor in the disruption of cell expansion and consequently root growth in seedlings directly germinated in 50 μM aluminum. Key words: aluminum, calcium, barley, chlorotetracycline, Fluo-3.

IMAGING CALCIUM WAVES IN EGGS AND EMBRYOS

1993 ◽  
Vol 184 (1) ◽  
pp. 213-219 ◽  
Author(s):  
I Gillot ◽  
M Whitaker
Keyword(s):  
Latent Period ◽  
Calcium Concentration ◽  
Calcium Influx ◽  
Embryonic Cell ◽  
Calcium Wave ◽  
Free Calcium ◽  
Calcium Indicator ◽  
Free Calcium Concentration ◽  
Indicator Dyes ◽  
Indicator Dye

Sea urchin eggs and those of most other deuterostomes are activated at fertilization by an increase in cytoplasmic free calcium concentration ([Ca2+]i) that triggers the onset of the embryonic cell division cycles. We can image the calcium wave using fluorescent calcium indicator dyes and confocal microscopy. There are two components to the [Ca2+]i increase at fertilization. The first is due to a rapid calcium influx caused by a calcium action potential; this leads to a small increase in [Ca2+]i just beneath the plasma membrane with spherical symmetry. After a latent period of some 15 s, there is a second large and rapid increase in [Ca2+]i localized to the region of sperm-egg contact: during the latent period [Ca2+]i does not change but within 1 s of the end of the latent period [Ca2+]i reaches 2 micromolar. The calcium wave then spreads across the egg with a velocity of 5 micrometre s-1. Behind the advancing wavefront, the calcium concentration is uniformly high, even within the egg nucleus, though there are no indications that intranuclear calcium concentration differs from [Ca2+]i. [Ca2+]i falls uniformly towards resting levels over the next 500 s. In cases where there is an apparent inhomogeneity in [Ca2+]i in either the cortex or the nucleus, we find that the calcium indicator dye is inhomogeneously distributed. This appears to be due to uptake of the indicator dye (Fluo-3), probably into mitochondria. The artefact can be avoided by using a dextran-conjugated dye.

scholarly journals Caffeine Interaction with Fluorescent Calcium Indicator Dyes

1999 ◽  
Vol 77 (1) ◽  
pp. 577-586 ◽  
Author(s):  
M. Muschol ◽  
B.R. Dasgupta ◽  
B.M. Salzberg
Keyword(s):  
Calcium Indicator ◽  
Indicator Dyes

scholarly journals Light Dependence of Calcium and Membrane Potential Measured in Blowfly Photoreceptors In Vivo

1998 ◽  
Vol 112 (2) ◽  
pp. 113-124 ◽  
Author(s):  
Johannes Oberwinkler ◽  
Doekele G. Stavenga
Keyword(s):  
Membrane Potential ◽  
Light Intensity ◽  
Light Adaptation ◽  
Photoreceptor Cell ◽  
Dynamic Range ◽  
Bright Light ◽  
Molecular Probes ◽  
Calcium Indicator ◽  
Indicator Dyes

Light adaptation in insect photoreceptors is caused by an increase in the cytosolic Ca2+ concentration. To better understand this process, we measured the cytosolic Ca2+ concentration in vivo as a function of adapting light intensity in the white-eyed blowfly mutant chalky. We developed a technique to measure the cytosolic Ca2+ concentration under conditions as natural as possible. The calcium indicator dyes Oregon Green 1, 2, or 5N (Molecular Probes, Inc., Eugene, OR) were iontophoretically injected via an intracellular electrode into a photoreceptor cell in the intact eye; the same electrode was also used to measure the membrane potential. The blue-induced green fluorescence of these dyes could be monitored by making use of the optics of the facet lens and the rhabdomere waveguide. The use of the different Ca2+-sensitive dyes that possess different affinities for Ca2+ allowed the quantitative determination of the cytosolic Ca2+ concentration in the steady state. Determining the cytosolic Ca2+ concentration as a function of the adapting light intensity shows that the Ca2+ concentration is regulated in a graded fashion over the whole dynamic range where a photoreceptor cell can respond to light. When a photoreceptor is adapted to bright light, the cytosolic Ca2+ concentration reaches stable values higher than 10 μM. The data are consistent with the hypothesis that the logarithm of the increase in cytosolic Ca2+ concentration is linear with the logarithm of the light intensity. From the estimated values of the cytosolic Ca2+ concentration, we conclude that the Ca2+-buffering capacity is limited. The percentage of the Ca2+ influx that is buffered gradually decreases with increasing Ca2+ concentrations; at cytosolic Ca2+ concentration levels above 10 μM, buffering becomes minimal.

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