Speed of neuronal growth cones in chick dorsal root ganglion neurons

Range ≤18.5 µm/sec
Organism Chicken Gallus gallus
Reference Hochmuth RM, Shao J, Dai J, Sheetz MP (1996) Deformation and flow of membrane into tethers extracted from neuronal growth cones. Biophys J 70: 358 –369. doi:10.1016/S0006-3495(96)79577-2 p.363 right column bottom paragraphPubMed ID8770212
Method P.363 right column 2nd paragraph: "Extraction of tethers from neuronal growth cones: Neuronal growth cones from chick embryos were cultured and prepared for study as described by Dai and Sheetz (1995a). Latex beads (Duke Scientific, Palo Alto, CA) coated with rat IgG (Sigma, St. Louis, MO) were allowed to adhere to growth cones that, in turn, were adhering to a cover slip in a chamber mounted upon a microscope stage. The latex beads were held in a laser-tweezers trap, and the stage was moved with a piezoceramic driver (Wye Creek Instruments, Frederick, MD) at a constant velocity away from the bead being held in the laser trap, creating a tether."
Comments P.363 right column 2nd paragraph: "The movement of the bead in the trap is proportional to the force exerted on the bead by the tether. The force was calibrated with the method of Kuo and Sheetz (1993), and the nanometer displacements of the bead were tracked (Gelles et al., 1988). The results of the measurements of tether force versus velocity are shown in Fig. 5a. Here 57 data points are plotted for velocities as large as 18.5 µm/s. This plot includes 26 data points from the work of Dai and Sheetz (1995a) in which the maximum velocity was ~6µm/s. In that paper the slope, from a straight-line fit, of the force-versus-velocity data was 1.51 pN×s/µm, whereas here it is somewhat less and has a value of 0.861 pN×s/µm."
Entered by Uri M
ID 112557