The study of axonal transport using microinjected fluorescent beads

Chang Wang, Purdue University

Abstract

Dynein and kinesin have been implicated as the "motors" for fast axonal transport, with kinesin moving organelles anterogradely and dynein retrogradely. Although it has been shown that both kinesin and dynein can move beads on microtubules in vitro, and they are both found to be on the surface of organelles in vivo, there is no direct evidence for the involvement of either kinesin or dynein in the movement of any particles, living or artificial, in living cells in the directions suggested. In these experiments, carboxylated fluorescent beads were injected into living Mauthner axons of the lamprey spinal cord and these beads were transported in both anterograde and retrograde directions at velocity similar to fast axonal transport. Transport was dependent on microtubules and ATP hydrolysis. After UV irradiation of axons that were injected with vanadate, similar to conditions that produce V1 photolysis of dynein in vitro, retrograde transport was abolished but anterograde movement proceeded unimpeded. This result suggests that dynein or a dynein-like molecule is responsible for retrograde transport in vivo.

Degree

Ph.D.

Advisors

Robinson, Purdue University.

Subject Area

Neurology

COinS