[Frontiers in Bioscience 7, d1255-1279, May 1, 2002]
MODULATING CA2+ CLEARANCE FROM NEURONS
Stanley A. Thayer, Yuriy M. Usachev and William J. Pottorf, II
Department of Pharmacology, University of Minnesota, 6-120 Jackson Hall, 321 Church Street, SE, Minneapolis, MN 55455-0217
TABLE OF CONTENTS
Neurons are exquisitely sensitive to the duration, amplitude and localization of transient increases in intracellular Ca2+ concentration ([Ca2+]i). Modulation of Ca2+ uptake into the mitochondrion and endoplasmic reticulum, and efflux via the plasma membrane Ca2+ pump and Na+/Ca2+ exchange profoundly affect the shape of [Ca2+]i signals. Ca2+ clearance mechanisms are modulated by other signaling pathways, are sensitive to metabolic state and have a memory of the recent history of cell activation. We present here examples of pharmacologic and endogenous regulation of Ca2+ sequestration and efflux in neurons. Ca2+ clearance mechanisms differentially shape [Ca2+]i signals based on their affinity, capacity and location; their modulation alters specific neuronal functions. The increasingly apparent diversity of the molecular entities that make up the [Ca2+]i regulatory system reveals new sites or modulation. Specialized Ca2+ clearance mechanisms participate in unique cellular functions and thus, are important targets for pharmacological and physiological regulation of the neuron.