Volume electron microscopy reveals oligodendrocyte axon selection patterns and spatial assembly of myelin and nodes.

Authors

Martina Monaco, Vanessa Chiappini, Maria Fernanda Veloz Castillo, Kalpana Kare, Marinella Clerico, Luca Bartesaghi, Corrado Calì

Published in

iScience. Volume 29. Issue 11. Pages 117773. Nov 20, 2026. Epub Oct 07, 2026.

Abstract

Oligodendrocytes myelinate multiple axons, requiring single cells to coordinate target selection, sheath growth, and node formation across complex cortical geometry. We combined serial block-face electron microscopy, complete segmentation, and three-dimensional reconstruction to analyze early-myelinating oligodendrocytes in the somatosensory cortex of a postnatal day 14 rat at single-cell and nanoscale resolution. Individual oligodendrocytes initiated myelination across all contacted axons, while early ensheathment decreased with increasing process distance from the soma. Each oligodendrocyte also contacted axons within a restricted caliber range, independently of wrapping progression. At prospective nodes of Ranvier, transient cytoplasmic projections extended into axonal domains from adjacent oligodendrocytes and converged near presumptive paranodes. These observations support a structural model in which oligodendrocyte geometry, cell-specific axon selection, and intercellular interactions jointly organize early cortical myelination and nodal assembly, providing testable hypotheses for developmental myelination and repair after demyelination.

PMID:
42894637
Bibliographic data and abstract were imported from PubMed on 19 Oct 2026.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.