Dissemin is shutting down on January 1st, 2025

Published in

The Company of Biologists, Development, 13(142), p. 2385-2385, 2015

DOI: 10.1242/dev.127316

The Company of Biologists, Development, 20(132), p. 4545-4552, 2005

DOI: 10.1242/dev.02029

Links

Tools

Export citation

Search in Google Scholar

Adaptation is not required to explain the long-term response of axons tomolecular gradients

Journal article published in 2005 by J. Xu, W. J. Rosoff, J. S. Urbach, G. J. Goodhill ORCID
This paper was not found in any repository, but could be made available legally by the author.
This paper was not found in any repository, but could be made available legally by the author.

Full text: Unavailable

Green circle
Preprint: archiving allowed
Orange circle
Postprint: archiving restricted
Orange circle
Published version: archiving restricted
Data provided by SHERPA/RoMEO

Abstract

It has been suggested that growth cones navigating through the developing nervous system might display adaptation, so that their response to gradient signals is conserved over wide variations in ligand concentration. Recently however, a new chemotaxis assay that allows the effect of gradient parameters on axonal trajectories to be finely varied has revealed a decline in gradient sensitivity on either side of an optimal concentration. We show that this behavior can be quantitatively reproduced with a computational model of axonal chemotaxis that does not employ explicit adaptation. Two crucial components of this model required to reproduce the observed sensitivity are spatial and temporal averaging. These can be interpreted as corresponding, respectively, to the spatial spread of signaling effects downstream from receptor binding, and to the finite time over which these signaling effects decay. For spatial averaging, the model predicts that an effective range of roughly one-third of the extent of the growth cone is optimal for detecting small gradient signals. For temporal decay, a timescale of about 3 minutes is required for the model to reproduce the experimentally observed sensitivity.