The life cycle of Ca(2+) ions in dendritic spines.
Spine Ca(2+) is critical for the induction of synaptic plasticity, but the factors that control Ca(2+) handling in dendritic spines under physiological conditions are largely unknown. We studied [Ca(2+)] signaling in dendritic spines of CA1 pyramidal neurons and find that spines are specialized structures with low endogenous Ca(2+) buffer capacity that allows large and extremely rapid [Ca(2+)] changes. Under physiological conditions, Ca(2+) diffusion across the spine neck is negligible, and the spine head functions as a separate compartment on long time scales, allowing localized Ca(2+) buildup during trains of synaptic stimuli. Furthermore, the kinetics of Ca(2+) sources governs the time course of [Ca(2+)] signals and may explain the selective activation of long-term synaptic potentiation (LTP) and long-term depression (LTD) by NMDA-R-mediated synaptic Ca(2+).
Sabatini
Bernardo L
BL
Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA.
Oertner
Thomas G
TG
Svoboda
Karel
K
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D001640:Bicuculline / Q000494:pharmacology; D002021:Buffers; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D003712:Dendrites / Q000378:metabolism*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005456:Fluorescent Dyes / Q000378:metabolism; D018756:GABA Antagonists / Q000494:pharmacology; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism*; D066298:In Vitro Techniques; D008433:Mathematics; D018613:Microscopy, Confocal; D008959:Models, Neurological; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism
D002021:Buffers; D018691:Excitatory Amino Acid Antagonists; D005456:Fluorescent Dyes; D018756:GABA Antagonists; D011810:Quinoxalines; D016194:Receptors, N-Methyl-D-Aspartate; C062865:2,3-dioxo-6-nitro-7-sulfamoylbenzo(f)quinoxaline; D002118:Calcium; D001640:Bicuculline