Calcium entry initiates processes that restore a barrier to dye entry in severed earthworm giant axons.
After severance, axons can restore structural barriers that are necessary for recovery of their electrical function. In earthworm myelinated axons, such a barrier to dye entry is mediated by many vesicles and myelin-derived membranous structures. From time-lapse confocal fluorescence and DIC images, we now report that Ca2+ entry and not axonal injury per se initiates the processes that form a dye barrier, as well as the subsequent structural changes in this barrier and associated membranous structures. The time required to restore a dye barrier after transection also depends only on the time of Ca2+ entry.
Blanchette
A R
AR
Department of Zoology, The University of Texas at Austin 78712-106, USA.
Ballinger
M L
ML
Fishman
H M
HM
Bittner
G D
GD
D000818:Animals; D001369:Axons / Q000378:metabolism* / Q000648:ultrastructure; D002118:Calcium / Q000378:metabolism* / Q000502:physiology*; D004396:Coloring Agents / Q000493:pharmacokinetics*; D003911:Dextrans; D005452:Fluoresceins; D007202:Indicators and Reagents; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D009835:Oligochaeta / Q000378:metabolism*
D004396:Coloring Agents; D003911:Dextrans; D005452:Fluoresceins; D007202:Indicators and Reagents; C052526:fluorescein-dextran; D002118:Calcium