| Autor: |
Hardingham, Neil R., Bannister, Neil J., Read, Jenny C. A., Fox, Kevin D., Hardingham, Giles E., Jack, J. Julian B. |
| Předmět: |
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| Zdroj: |
Journal of Neuroscience; 6/7/2006, Vol. 26 Issue 23, p6337-6345, 9p, 6 Graphs |
| Abstrakt: |
Bursts of synaptic transmission are known to induce transient depletion of Ca2+ within the synaptic cleft. Although Ca2+ depletion has been shown to lower presynaptic release probability, effects on the postsynaptic cell have not been reported. In this study, we show that physiologically relevant reductions in extracellular Ca2+ lead to a decrease in synaptic strength between synaptically coupled layer 2/3 cortical pyramidal neurons. Using quantal analysis and mEPSP analysis, we demonstrate that a lowered extracellular Ca2+size in addition to its known effect on release probability. An elevated Mg2+ level can prevent this reduction in postsynaptic efficacy at subphysiological Ca2+ levels. We show that the calcium-dependent effect on postsynaptic quantal size is mediated by group 1 metabotropic glutamate receptors, acting via CaMKII (Ca2+/calmodulin-dependent protein kinase II) and PKC. Therefore, physiologically relevant changes in extracellular Ca2+ can regulate information transfer at cortical synapses via both presynaptic and postsynaptic mechanisms. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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