Neurotransmitter release is modulated by multiple regulatory mechanisms that control several stages of synaptic vesicle (SV) exocytosis. At the final stage, SV fusion with the presynaptic membrane requires calcium influx through voltage-gated calcium channels, and regulatory mechanisms that alter the surface expression or conductance of calcium channels have large effects on neurotransmitter release. To determine how these mechanisms contribute to synapse-specific modulations of neurotransmitter release and synaptic strength, we require a means to monitor presynaptic calcium transients at individual synapses. Genetically encoded calcium indicators (GECIs), engineered proteins that change their fluorescence emission properties upon calcium binding, generally lack the sensitivity to measure such transients in response to isolated stimuli. Therefore, we modified the GECI, GCaMP3, by altering its sensitivity for calcium. Our results suggest the modified GCaMP-based presynaptically targeted GECIs are excellent tools to quantify presynaptic calcium transients at individual synapses in response to isolated action potentials.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:NSHD.ca#10222/50610 |
| Date | 27 September 2012 |
| Creators | Gilyan, Andrew |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
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