@article {5213,
	title = {The spread of Ras activity triggered by activation of a single dendritic spine.},
	journal = {Science},
	volume = {321},
	year = {2008},
	month = {2008 Jul 4},
	pages = {136-40},
	abstract = {<p>In neurons, individual dendritic spines isolate N-methyl-d-aspartate (NMDA) receptor-mediated calcium ion (Ca2+) accumulations from the dendrite and other spines. However, the extent to which spines compartmentalize signaling events downstream of Ca2+ influx is not known. We combined two-photon fluorescence lifetime imaging with two-photon glutamate uncaging to image the activity of the small guanosine triphosphatase Ras after NMDA receptor activation at individual spines. Induction of long-term potentiation (LTP) triggered robust Ca2+-dependent Ras activation in single spines that decayed in approximately 5 minutes. Ras activity spread over approximately 10 micrometers of dendrite and invaded neighboring spines by diffusion. The spread of Ras-dependent signaling was necessary for the local regulation of the threshold for LTP induction. Thus, Ca2+-dependent synaptic signals can spread to couple multiple synapses on short stretches of dendrite.</p>
},
	keywords = {Animals, Calcium, Cell Membrane, Dendritic Spines, Diffusion, Fluorescence Resonance Energy Transfer, Glutamic Acid, GTPase-Activating Proteins, Guanine Nucleotide Exchange Factors, Hippocampus, Long-Term Potentiation, N-Methyl-D-Aspartate, Pyramidal Cells, ras Proteins, Rats, Receptors, Recombinant Fusion Proteins, Signal Transduction, Synapses, Transfection},
	issn = {1095-9203},
	doi = {10.1126/science.1159675},
	author = {Harvey, Christopher D and Yasuda, Ryohei and Zhong, Haining and Svoboda, Karel}
}
