Spine Ca2+ signaling in spike-timing-dependent plasticity

Nevian, Thomas; Sakmann, Bert (2006). Spine Ca2+ signaling in spike-timing-dependent plasticity. Journal of neuroscience, 26(43), pp. 11001-13. Washington, D.C.: Society for Neuroscience 10.1523/JNEUROSCI.1749-06.2006

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Calcium is a second messenger, which can trigger the modification of synaptic efficacy. We investigated the question of whether a differential rise in postsynaptic Ca2+ ([Ca2+]i) alone is sufficient to account for the induction of long-term potentiation (LTP) and long-term depression (LTD) of EPSPs in the basal dendrites of layer 2/3 pyramidal neurons of the somatosensory cortex. Volume-averaged [Ca2+]i transients were measured in spines of the basal dendritic arbor for spike-timing-dependent plasticity induction protocols. The rise in [Ca2+]i was uncorrelated to the direction of the change in synaptic efficacy, because several pairing protocols evoked similar spine [Ca2+]i transients but resulted in either LTP or LTD. The sequence dependence of near-coincident presynaptic and postsynaptic activity on the direction of changes in synaptic strength suggested that LTP and LTD were induced by two processes, which were controlled separately by postsynaptic [Ca2+]i levels. Activation of voltage-dependent Ca2+ channels before metabotropic glutamate receptors (mGluRs) resulted in the phospholipase C-dependent (PLC-dependent) synthesis of endocannabinoids, which acted as a retrograde messenger to induce LTD. LTP required a large [Ca2+]i transient evoked by NMDA receptor activation. Blocking mGluRs abolished the induction of LTD and uncovered the Ca2+-dependent induction of LTP. We conclude that the volume-averaged peak elevation of [Ca2+]i in spines of layer 2/3 pyramids determines the magnitude of long-term changes in synaptic efficacy. The direction of the change is controlled, however, via a mGluR-coupled signaling cascade. mGluRs act in conjunction with PLC as sequence-sensitive coincidence detectors when postsynaptic precede presynaptic action potentials to induce LTD. Thus presumably two different Ca2+ sensors in spines control the induction of spike-timing-dependent synaptic plasticity.

Item Type:

Journal Article (Original Article)

Division/Institute:

04 Faculty of Medicine > Pre-clinic Human Medicine > Institute of Physiology

UniBE Contributor:

Nevian, Thomas

ISSN:

0270-6474

ISBN:

17065442

Publisher:

Society for Neuroscience

Language:

English

Submitter:

Factscience Import

Date Deposited:

04 Oct 2013 14:45

Last Modified:

17 Mar 2015 21:43

Publisher DOI:

10.1523/JNEUROSCI.1749-06.2006

PubMed ID:

17065442

Web of Science ID:

000241553900009

URI:

https://boris.unibe.ch/id/eprint/18524 (FactScience: 705)

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