Controlling the urge for a Ca(2+) surge: all-or-none Ca(2+) release in neurons.
Changes in the intracellular calcium concentration ([Ca2+]i) convey signals that are essential to the life and death of neurons. Ca(2+)-induced Ca(2+)-release (CICR), a process in which a modest elevation in [Ca2+]i is amplified by a secondary release of Ca2+ from stores within the cell, plays a prominent role in shaping neuronal [Ca2+]i signals. When CICR becomes regenerative, an explosive increase in [Ca2+]i generates a Ca2+ wave that spreads throughout the cell. A discrete threshold controls activation of this all-or-none behavior and cellular context adjusts the threshold. Thus, the store acts as a switch that determines whether a given pattern of electrical activity will produce a local or global Ca2+ signal. This gatekeeper function seems to control some forms of Ca(2+)-triggered plasticity in neurons.
Usachev
Y M
YM
Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA.
Thayer
S A
SA
D000818:Animals; D002118:Calcium / Q000502:physiology*; D006801:Humans; D017136:Ion Transport; D009473:Neuronal Plasticity; D009474:Neurons / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*
D002118:Calcium