Blockage of voltage-gated calcium signaling impairs migration of glial cells in vivo.
Migration of glial cells is an essential step in the development of the antennal lobe, the primary olfactory center of insects, to establish well-defined borders between olfactory glomeruli required for odor discrimination. In the present study, we used two-photon microscopy to visualize calcium signaling in developing antennal lobe glial cells of the sphinx moth Manduca sexta. We found a correlation between the upregulation of functional voltage-gated calcium channels and the onset of glial cell migration. In addition, glial cells migrating into the center of the antennal lobe express larger voltage-gated calcium transients than glial cells that remain at the periphery. Migration behavior and calcium signaling of glial cells in vivo were manipulated either by deafferentation, by injection of the calcium channel blockers diltiazem, verapamil, and flunarizine, or by injection of the calcium chelators BAPTA-AM and Fluo-4-AM. In deafferented antennal lobes, glial cells failed to express functional voltage-gated calcium channels and did not migrate. Calcium channel blockage or reducing glial calcium signals by calcium chelators prevented glial cell migration and resulted in antennal lobes lacking glial borders around glomeruli, indicating that voltage-gated calcium signaling is required for the migration of antennal lobe glial cells and the development of mature olfactory glomeruli.
Lohr
Christian
C
Abteilung für Allgemeine Zoologie, Universität Kaiserslautern, 67653 Kaiserslautern, Germany. clohr@rhrk.uni-kl.de
Heil
Jan E
JE
Deitmer
Joachim W
JW
D000818:Animals; D001921:Brain / Q000166:cytology / Q000254:growth & development; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000187:drug effects / Q000502:physiology*; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology*; D002465:Cell Movement / Q000502:physiology*; D002614:Chelating Agents / Q000494:pharmacology; D003714:Denervation; D018402:Manduca; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009434:Neural Pathways / Q000166:cytology / Q000254:growth & development; D009457:Neuroglia / Q000166:cytology / Q000502:physiology*; D019581:Neuropil / Q000166:cytology / Q000502:physiology; D009833:Olfactory Pathways / Q000166:cytology / Q000254:growth & development*; D013569:Synapses / Q000648:ultrastructure; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D002614:Chelating Agents