Axonal Ensheathment in the Nervous System of Lamprey: Implications for the Evolution of Myelinating Glia.

ABSTRACT: In the nervous system, myelination of axons enables rapid impulse conduction and is a specialized function of glial cells. Myelinating glia are the last cell type to emerge in the evolution of vertebrate nervous systems, presumably in ancient jawed vertebrates (gnathostomata) because jawless vertebrates (agnathans) lack myelin. We have hypothesized that, in these unmyelinated species, evolutionary progenitors of myelinating cells must have existed that should still be present in contemporary agnathan species. Here, we used advanced electron microscopic techniques to reveal axon-glia interactions in the sea lamprey Petromyzon marinus By quantitative assessment of the spinal cord and the peripheral lateral line nerve, we observed a marked maturation-dependent growth of axonal calibers

SUBMITTER: Weil MT 

PROVIDER: S-EPMC6705951 | biostudies-literature | 2018 Jul

REPOSITORIES: biostudies-literature