title: A new chemotaxis assay shows the extreme sensitivity of axons to molecular gradients.
abstract: Axonal chemotaxis is believed to be important in wiring up the developing and regenerating nervous system, but little is known about how axons actually respond to molecular gradients. We report a new quantitative assay that allows the long-term response of axons to gradients of known and controllable shape to be examined in a three-dimensional gel. Using this assay, we show that axons may be nature's most-sensitive gradient detectors, but this sensitivity exists only within a narrow range of ligand concentrations. This assay should also be applicable to other biological processes that are controlled by molecular gradients, such as cell migration and morphogenesis.
authors.affiliation: Department of Neuroscience, Georgetown University Medical Center, Washington, DC 20007, USA.
authors.forename: William J
authors.initials: WJ
authors.lastname: Rosoff
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Urbach
authors.forename: Mark A
authors.initials: MA
authors.lastname: Esrick
authors.forename: Ryan G
authors.initials: RG
authors.lastname: McAllister
authors.forename: Linda J
authors.initials: LJ
authors.lastname: Richards
authors.forename: Geoffrey J
authors.initials: GJ
authors.lastname: Goodhill
mesh_terms: D000818:Animals; D001370:Axonal Transport / Q000502:physiology; D001369:Axons / Q000502:physiology*; D002633:Chemotaxis / Q000502:physiology*; D005727:Ganglia, Spinal / Q000166:cytology / Q000502:physiology; D020439:Growth Cones / Q000502:physiology; D051381:Rats