Modulation of NF Kinetics and Axonal Morphology Near the Excavation of the Mouse Optic Nerve
Neurofilaments (NFs) are the most abundant cytoskeletal structures in the axon and also cargo of axonal transport. Neurofilaments are synthesized in the neuronal cell body and transported bidirectionally along microtubule tracks in the axon with a net anterograde movement toward the nerve terminal. Based on this dual role of neurofilaments as space filling structures and cargo of axonal transport we hypothesize that neurofilament transport velocity regulates axon caliber. In this study, we combine results from a previous study of neurofilament kinetics in optic nerve with published morphometric features of the mouse optic nerve near the excavation to show that the sharp increase in the caliber of optic nerve is consistent with a slowing of neurofilament velocity.
YL acknowledges financial support from the Chinese Natural Science foundation for Young Scientist No. 31601145 and support from Fundamental Research Funds for Central Universities, China (Y. Li). P. Jung is supported by the US National Science Foundation by grant IOS-1656765. We are grateful for extensive discussion with Anthony Brown from the Department of Neuroscience of Ohio State University, Columbus, Ohio.
- 2.A. Brown, Slow axonal transport. Encycl. Neurosci. 9, 1–9 (2009)Google Scholar
- 5.R.A. Nixon, P.A. Paskevich, R.K. Sihag, C.Y. Thayer, Phosphorylation on carboxyl terminus domains of neurofilament proteins in retinal ganglion cell neurons in vivo: influences on regional neurofilament accumulation, interneurofilament spacing, and axon caliber. J. Cell Biol. 126, 1031–1046 (1994)CrossRefGoogle Scholar
- 11.J.Q. Trojanowski, V.M.Y. Lee, Aggregation of neurofilament and alpha-synuclein proteins in Lewy bodies: implications for the pathogenesis of Parkinson disease and Lewy body dementia. Arch. Neurol. 55, 151–152 (1998)Google Scholar
- 18.C.L. Walker, A. Uchida, Y. Li, N. Trivedi, J.D. Fenn, P.C. Monsma, R.C. Lariviére, J.-P. Julien, P. Jung, A. Brown, Local acceleration of neurofilament transport at nodes of Ranvier [submitted]Google Scholar
- 22.T. Nguyen, P. Jung, Neurofilament proximity to microtubules determines their motility [in preparation]Google Scholar
- 23.P. Hertz, Über den gegenseitigen durchschnittlichen Abstand von Punkten, die mit bekannter mittlerer Dichte im Raume angeordnet sind. Math. Ann. 67, 387–398 (1909)Google Scholar