Axonal transport is typically divided into two components, which can be distinguished by their mean velocity. The fast component includes steady trafficking of different organelles and vesicles actively transported by motor proteins. The slow component comprises nonmembranous materials that undergo infrequent bidirectional motion. The underlying mechanism of slow axonal transport has been under debate during the past three decades. We propose a simple displacement mechanism that may be central for the distribution of molecules not carried by vesicles. It relies on the cytoplasmic drag induced by organelle movement and readily accounts for key experimental observations pertaining to slow-component transport. The induced cytoplasmic drag is predicted to depend mainly on the distribution of microtubules in the axon and the organelle transport rate.
Bibliographical noteFunding Information:
H.D. acknowledges support from the Israel Science Foundation (grant no. 8/10). U.N. acknowledges support from a European Union Marie Curie Institutional Research grant (MMDTIAN) and an Israel Science Foundation grant (1156/12).
ASJC Scopus subject areas