Controlling the urge for a Ca super(2+) surge: all-or-none Ca super(2+) release in neurons

• Published in: BioEssays Vol. 21; no. 9; pp. 743 - 750
• Main Authors: Usachev, Y M, Thayer, SA
• Format: Journal Article
• Language: English
• Published: 01-09-1999
• ISSN: 0265-9247

Changes in the intracellular calcium concentration ([Ca super(2+)] sub(i)) convey signals that are essential to the life and death of neurons. Ca super(2+)-induced Ca super(2+)-release (CICR), a process in which a modest elevation in [Ca super(2+)] sub(i) is amplified by a secondary release of Ca super(2+) from stores within the cell, plays a prominent role in shaping neuronal [Ca super(2+)] sub(i) signals. When CICR becomes regenerative, an explosive increase in [Ca super(2+)] sub(i) generates a Ca super(2+) 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 Ca super(2+) signal. This gatekeeper function seems to control some forms of Ca super(2+)-triggered plasticity in neurons.