Fast regulation of axonal growth cone motility by electrical activity
Journal of Neuroscience. 2007-07-18; 27(29): 7684-7695
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1. J Neurosci. 2007 Jul 18;27(29):7684-95.
Fast regulation of axonal growth cone motility by electrical activity.
Ibarretxe G(1), Perrais D, Jaskolski F, Vimeney A, Mulle C.
(1)Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5091,
Bordeaux Neuroscience Institute, Université Bordeaux 2, 33077 Bordeaux, France.
Axonal growth cones are responsible for the correct guidance of developing axons
and the establishment of functional neural networks. They are highly motile
because of fast and continuous rearrangements of their actin-rich cytoskeleton.
Here we have used live imaging of axonal growth cones of hippocampal neurons in
culture and quantified their motility with a temporal resolution of 2 s. Using
novel methods of analysis of growth cone dynamics, we show that transient
activation of kainate receptors by bath-applied kainate induced a fast and
reversible growth cone stalling. This effect depends on electrical activity and
can be mimicked by the transient discharge of action potentials elicited in the
neuron by intracellular current injections at the somatic level through a patch
pipette. Growth cone stalling induced by electrical stimulation is mediated by
calcium entry from the extracellular medium as well as by calcium release from
intracellular stores that define spatially restricted microdomains directly
affecting cytoskeletal dynamics. We propose that growth cone motility is
dynamically controlled by transient bursts of spontaneous electrical activity,
which constitutes a prominent feature of developing neural networks in vivo.
PMID: 17634363 [Indexed for MEDLINE]