Light-induced changes in extracellular calcium concentration in the compound eye of Calliphora, Locusta and Apis

Sandler, C.; Kirschfeld, K

doi:10.1007/bf00194106

Cited by 3 publications

(2 citation statements)

References 49 publications

(55 reference statements)

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“…Light stim ulation evoked small ( < 0.2 mM) changes in Ca0 (not shown). In five of the seven retinas tested, increases predom inated, in agreem ent with the report of Sandler & Kirschfeld (1992).…”

Section: (D) Calciumsupporting

confidence: 88%

The composition of the interstitial fluid in the retina of the honeybee drone: implications for the supply of substrates of energy metabolism from blood to neurons

Cardinaud

Coles

Perrottet³

et al. 1994

Proc. R. Soc. Lond. B

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Section: (D) Calciumsupporting

confidence: 88%

The composition of the interstitial fluid in the retina of the honeybee drone: implications for the supply of substrates of energy metabolism from blood to neurons

Cardinaud

Coles

Perrottet³

et al. 1994

Proc. R. Soc. Lond. B

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“…Both of these techniques are likely to strongly influence the extracellular ion concentrations and hence to affect Ca i . In an alternative approach, the light dependence of the Ca 2+ homeostasis in insect photoreceptors has been studied via measurements of the Ca 2+ concentration in the extracellular space (Sandler and Kirschfeld, 1988, 1991, 1992; Rom-Glas et al, 1992; Peretz et al, 1994 a ); however, the possibly strong influence of intracellular Ca 2+ buffering (Hardie, 1996 a ) and of Ca 2+ release from intracellular stores (Walz et al, 1995; Hardie, 1996 b ) on Ca i could not be studied in this way.…”

Section: Introductionmentioning

confidence: 99%

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

Oberwinkler

Stavenga

1998

The Journal of General Physiology

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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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Chapter 10 Modeling primary visual processes in insect photoreceptors

Stavenga

Oberwinkler

Postma

2000

Handbook of Biological Physics

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Light-induced changes in extracellular calcium concentration in the compound eye of Calliphora, Locusta and Apis

Cited by 3 publications

References 49 publications

The composition of the interstitial fluid in the retina of the honeybee drone: implications for the supply of substrates of energy metabolism from blood to neurons

The composition of the interstitial fluid in the retina of the honeybee drone: implications for the supply of substrates of energy metabolism from blood to neurons

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

Chapter 10 Modeling primary visual processes in insect photoreceptors

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