The role of the cytoskeleton in volume regulation and beading transitions in PC12 neurites

Abstract

We present investigations on volume regulation and beading shape transitions in PC12 neurites conducted using a flow chamber technique By disrupting the cell cytoskeleton with specific drugs we investigate the role of its individual components in the volume regulation response We find that microtubule disruption increases both swelling rate and maximum volume attained but does not affect the ability of the neurite to recover its initial volume In addition investigation of axonal beading also known as pearling instability provides additional clues on the mechanical state of the neurite We conclude that volume recovery is driven by passive diffusion of osmolites and propose that the initial swelling phase is mechanically slowed down by microtubules Our experiments provide a framework to investigate the role of cytoskeletal mechanics in volume homeostasis