As scientists from the Watson School of Biological Sciences discovered, calcium ion-dependent synaptic signals in neurons can spread to couple multiple synapses on short stretches of dendrites. Individual dendritic spines segregate calcium ion accumulations from the dendrite and other spines. The accumulations were mediated by the N-methyl-D-aspartate (NMDA) receptor.

The aim of the study was to analyse further, to which degree the dendritic spines split the signalling events occurring downstream of calcium ion influx. The scientists displayed the activity of the small guanosine triphosphatase Ras after NMDA receptor activation of individual spines, using a combination of two-photon fluorescence lifetime imaging and two-photon glutamate uncaging.

By induction of a long-term potentiation (LTP), calcium ion-dependent Ras activation was triggered in individual spines. The activation lasted for ~5 minutes. The Ras activity was able to spread over ~10 µm of dendrite and was carried on to adjacent spines by means of diffusion. The spread of Ras-dependent signalling was crucial for the local regulation of the threshold for long-term potentiation induction.

Related antibodies on antibodies-online.com:

NMDA receptors

Ras

Glutamate

Dendritic cells

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