Nonlinear [Ca2+] signaling in dendrites and spines caused by activity-dependent depression of Ca2+ extrusion

Scheuss, V., Yasuda, R., Sobczyk, A., Svoboda, K. (2006) Nonlinear [Ca2+] signaling in dendrites and spines caused by activity-dependent depression of Ca2+ extrusion. J Neurosci, 26 (31). pp. 8183-94. ISSN 1529-2401 (Electronic)

URL: http://www.jneurosci.org/cgi/content/full/26/31/81...
DOI: 10.1523/jneurosci.1962-06.2006

Abstract

Spine Ca2+ triggers the induction of synaptic plasticity and other adaptive neuronal responses. The amplitude and time course of Ca2+ signals specify the activation of the signaling pathways that trigger different forms of plasticity such as long-term potentiation and depression. The shapes of Ca2+ signals are determined by the dynamics of Ca2+ sources, Ca2+ buffers, and Ca2+ extrusion mechanisms. Here we show in rat CA1 pyramidal neurons that plasma membrane Ca2+ pumps (PMCAs) and Na+/Ca2+ exchangers are the major Ca2+ extrusion pathways in spines and small dendrites. Surprisingly, we found that Ca2+ extrusion via PMCA and Na+/Ca2+ exchangers slows in an activity-dependent manner, mediated by intracellular Na+ and Ca2+ accumulations. This activity-dependent depression of Ca2+ extrusion is, in part, attributable to Ca2+-dependent inactivation of PMCAs. Ca2+ extrusion recovers from depression with a time constant of 0.5 s. Depression of Ca2+ extrusion provides a positive feedback loop, converting small differences in stimuli into large differences in Ca2+ concentration. Depression of Ca2+ extrusion produces Ca2+ concentration dynamics that depend on the history of neuronal activity and therefore likely modulates the induction of synaptic plasticity.

Item Type: Paper
Uncontrolled Keywords: Animals Biological Transport Active physiology Calcium metabolism Calcium Signaling physiology Cells Cultured Computer Simulation Dendrites metabolism Hippocampus physiology Kinetics Models Neurological Nonlinear Dynamics Pyramidal Cells physiology Rats Rats Sprague-Dawley Sodium-Calcium Exchanger metabolism
Subjects: organs, tissues, organelles, cell types and functions > cell types and functions > cell types > dendritic cells
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > dendritic cells
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > dendritic cells

organs, tissues, organelles, cell types and functions > cell types and functions > cell types > neurons
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > neurons
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > neurons

organs, tissues, organelles, cell types and functions > sub-cellular tissues: types and functions > synapse
CSHL Authors:
Depositing User: CSHL Librarian
Date Deposited: 09 Dec 2011 15:14
Last Modified: 09 Dec 2011 15:14
URI: http://repository.cshl.edu/id/eprint/22893

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