Report

The Spread of Ras Activity Triggered by Activation of a Single Dendritic Spine

See allHide authors and affiliations

Science  04 Jul 2008:
Vol. 321, Issue 5885, pp. 136-140
DOI: 10.1126/science.1159675

You are currently viewing the abstract.

View Full Text

Log in to view the full text

Log in through your institution

Log in through your institution

Abstract

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 ∼5 minutes. Ras activity spread over ∼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.

    View Full Text