The dynamics of free calcium in dendritic spines in response to repetitive synaptic input
- Creators
- Gamble, Edward
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Koch, Christof
Abstract
Increased levels of intracellular calcium at either pre- or postsynaptic sites are thought to precede changes in synaptic strength. Thus, to induce long-term potentiation in the hippocampus, periods of intense synaptic stimulation would have to transiently raise the levels of cytosolic calcium at postsynaptic sites--dendritic spines in the majority of cases. Since direct experimental verification of this hypothesis is not possible at present, calcium levels have been studied by numerically solving the appropriate electro-diffusion equations for two different postsynaptic structures. Under the assumption that voltage-dependent calcium channels are present on dendritic spines, free intracellular calcium in spines can reach micromolar levels after as few as seven spikes in 20 milliseconds. Moreover, a short, but high-frequency, burst of presynaptic activity is more effective in raising levels of calcium and especially of the calcium-calmodulin complex than sustained low-frequency activity. This behavior is different from that seen at the soma of a typical vertebrate neuron.
Additional Information
9 December 1986 ; accepted 7 April 1987. This research has profited from many discussions with H. Robinson of the Physiological Laboratory in Cambridge, England. E.G. was supported by a Fairchild Fellowship and C.K. by a grant from the Office of Naval Research, Engineering Psychology Division awarded to T. Poggio and in part by the National Science Foundation under grant PHY82-17853, supplemented by funds from the National Aeronautics and Space Administration. We thank H. Lester for critically reading the manuscript and both the Artificial Intelligence Laboratory at the Massachusetts Institute of Technology and the Institute of Theoretical Physics at the University of California at Santa Barbara for the kind use of their facilities.Additional details
- Eprint ID
- 40379
- DOI
- 10.1126/science.3495885
- Resolver ID
- CaltechAUTHORS:20130816-103143758
- Fairchild Fellowship
- U.S. Office of Naval Research . Engineering Psychology Division
- PHY82-17853
- NSF
- NASA
- Created
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2010-03-11Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field
- Caltech groups
- Koch Laboratory (KLAB)