Abstract
Cooling can induce Ca(2+) signaling via activation of temperature-sensitive ion channels such as TRPM8, TRPA1 and ryanodine receptor channels. Here we have studied the mechanism of cooling-evoked Ca(2+) signaling in mouse olfactory ensheathing cells (OECs), a specialized type of glial cells in the olfactory nerve layer of the olfactory bulb. Reducing the temperature from above 30°C to 28°C and below triggered Ca(2+) transients that persisted in the absence of external Ca(2+), but were suppressed after Ca(2+) store depletion by cyclopiazonic acid. Cooling-evoked Ca(2+) transients were present in mice deficient of TRPM8 and TRPA1, and were not inhibited by ryanodine receptor antagonists. Inhibition of InsP(3) receptors with 2-APB and caffeine entirely blocked cooling-evoked Ca(2+) transients. Moderate Ca(2+) increases, as evoked by flash photolysis of NP-EGTA (caged Ca(2+)) and cyclopiazonic acid, triggered InsP(3) receptor-mediated Ca(2+) release at 22°C, but not at 31°C. The results suggest that InsP(3) receptors mediate Ca(2+)-induced Ca(2+) release in OECs, and that this Ca(2+) release is temperature-sensitive and can be suppressed at temperatures above 28°C.
Copyright © 2012 Elsevier Ltd. All rights reserved.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Boron Compounds / pharmacology
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Caffeine / pharmacology
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Calcium / metabolism*
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Calcium Channel Blockers / pharmacology
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Calcium Signaling / drug effects
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Cells, Cultured
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Female
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Indoles / pharmacology
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Inositol 1,4,5-Trisphosphate Receptors / antagonists & inhibitors
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Inositol 1,4,5-Trisphosphate Receptors / metabolism*
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Male
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Mice
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Mice, Inbred C57BL
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Mice, Knockout
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Neuroglia / cytology
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Neuroglia / metabolism*
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Olfactory Bulb / cytology
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Ryanodine Receptor Calcium Release Channel / chemistry
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Ryanodine Receptor Calcium Release Channel / metabolism
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TRPA1 Cation Channel
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TRPM Cation Channels / deficiency
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TRPM Cation Channels / genetics
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TRPM Cation Channels / metabolism
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Temperature*
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Transient Receptor Potential Channels / deficiency
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Transient Receptor Potential Channels / genetics
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Transient Receptor Potential Channels / metabolism
Substances
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Boron Compounds
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Calcium Channel Blockers
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Indoles
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Inositol 1,4,5-Trisphosphate Receptors
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Ryanodine Receptor Calcium Release Channel
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TRPA1 Cation Channel
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TRPM Cation Channels
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TRPM8 protein, mouse
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Transient Receptor Potential Channels
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Trpa1 protein, mouse
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Caffeine
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2-aminoethoxydiphenyl borate
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Calcium
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cyclopiazonic acid