Axon-glia communication evokes calcium signaling in olfactory ensheathing cells of the developing olfactory bulb.
Olfactory ensheathing cells (OECs) accompany receptor axons in the olfactory nerve and promote axonal growth into the central nervous system. The mechanisms underlying the communication between axons and OECs, however, have not been studied in detail yet. We investigated the effect of activity-dependent neuronal transmitter release on Ca(2+) signaling of OECs in acute mouse olfactory bulb slices using confocal Ca(2+) imaging. TTX-sensitive axonal activity upon electrical nerve stimulation triggers a rise in cytosolic Ca(2+) in OECs, which can be mimicked by application of DHPG, an agonist of metabotropic glutamate receptors (mGluRs). Both stimulation- and DHPG-induced Ca(2+) transients in OECs were abolished by depletion of intracellular Ca(2+) stores with cyclopiazonic acid (CPA). The mGluR(1)-specific antagonist CPCCOEt completely inhibited DHPG-evoked Ca(2+) transients, but reduced stimulation-induced Ca(2+) transients only partly, suggesting the involvement of another neurotransmitter. Application of ATP evoked CPA-sensitive Ca(2+) transients in OECs, which were inhibited by the P2Y(1)-specific antagonist MRS2179. Co-application of CPCCOEt and MRS2179 almost completely blocked the stimulation-induced Ca(2+) transients, indicating that they were mediated by mGluR(1) and P2Y(1) receptors. Our results show that OECs are able to respond to olfactory nerve activity with an increase in cytosolic Ca(2+) due to glutamate and ATP release.
Rieger
Anne
A
Abteilung für Allgemeine Zoologie, Technische Universität Kaiserslautern, Postfach 3049, 67653 Kaiserslautern, Germany. anne.rieger@biologie.uni-kl.de
Deitmer
Joachim W
JW
Lohr
Christian
C
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D001369:Axons / Q000187:drug effects / Q000502:physiology*; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology*; D002450:Cell Communication / Q000187:drug effects / Q000502:physiology*; D004558:Electric Stimulation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D007150:Immunohistochemistry; D007211:Indoles / Q000494:pharmacology; D008156:Luciferases / Q000378:metabolism; D008297:Male; D008734:Methoxyhydroxyphenylglycol / Q000031:analogs & derivatives / Q000494:pharmacology; D051379:Mice; D009457:Neuroglia / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D009830:Olfactory Bulb / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D058910:Purinergic P2 Receptor Agonists; D018094:Receptors, Metabotropic Glutamate / Q000819:agonists / Q000378:metabolism; D018048:Receptors, Purinergic P2 / Q000378:metabolism; D058472:Receptors, Purinergic P2Y1; D013779:Tetrodotoxin / Q000494:pharmacology
D004791:Enzyme Inhibitors; D007211:Indoles; C546383:P2ry1 protein, mouse; D058910:Purinergic P2 Receptor Agonists; D018094:Receptors, Metabotropic Glutamate; D018048:Receptors, Purinergic P2; D058472:Receptors, Purinergic P2Y1; C104077:metabotropic glutamate receptor type 1; D013779:Tetrodotoxin; D008734:Methoxyhydroxyphenylglycol; D000255:Adenosine Triphosphate; D008156:Luciferases; C010117:3,4-dihydroxyphenylglycol; C000543:cyclopiazonic acid