NMDA receptor subunit-dependent [Ca2+] signaling in individual hippocampal dendritic spines

Sobczyk, A., Scheuss, V., Svoboda, K. (June 2005) NMDA receptor subunit-dependent [Ca2+] signaling in individual hippocampal dendritic spines. J Neurosci, 25 (26). pp. 6037-46. ISSN 1529-2401 (Electronic)

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URL: https://www.ncbi.nlm.nih.gov/pubmed/15987933
DOI: 10.1523/jneurosci.1221-05.2005

Abstract

Ca2+ influx through synaptic NMDA receptors (NMDA-Rs) triggers a variety of adaptive cellular processes. To probe NMDA-R-mediated [Ca2+] signaling, we used two-photon glutamate uncaging to stimulate NMDA-Rs on individual dendritic spines of CA1 pyramidal neurons in rat brain slices. We measured NMDA-R currents at the soma and NMDA-R-mediated [Ca2+] transients in stimulated spines (Delta[Ca2+]). Uncaging-evoked NMDA-R current amplitudes were independent of the size of the stimulated spine, implying that smaller spines contain higher densities of functional NMDA-Rs. The ratio of Delta[Ca2+] over NMDA-R current was highly variable (factor of 10) across spines, especially for small spines. These differences were not explained by heterogeneity in spine sizes or diffusional coupling between spines and their parent dendrites. In addition, we find that small spines have NMDA-R currents that are sensitive to NMDA-R NR2B subunit-specific antagonists. With block of NR2B-containing receptors, the range of Delta[Ca2+]/NMDA-R current ratios and their average value were much reduced. Our data suggest that individual spines can regulate the subunit composition of their NMDA-Rs and the effective fractional Ca2+ current through these receptors.

Item Type: Paper
Uncontrolled Keywords: Animals Calcium Signaling drug effects physiology Dendrites drug effects physiology Evoked Potentials Excitatory Amino Acid Antagonists pharmacology Hippocampus physiology Quinoxalines pharmacology Receptors N-Methyl-D-Aspartate physiology Synapses drug effects physiology
Subjects: organs, tissues, organelles, cell types and functions > cell types and functions > cell types > dendritic cells > dendritic spines
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > dendritic cells > dendritic spines
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > dendritic cells > dendritic spines

Investigative techniques and equipment > electrophysiology
CSHL Authors:
Communities: CSHL labs > Svoboda lab
Depositing User: CSHL Librarian
Date: 29 June 2005
Date Deposited: 06 Jan 2012 14:24
Last Modified: 06 Nov 2017 21:17
Related URLs:
URI: http://repository.cshl.edu/id/eprint/22710

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