Summary
In the first six days after division myelinated axons in the proximal stump of rat sciatic nerves produce collateral and terminal sprouts. These are present as circumscribed “groups” which are positively distinguishable from clusters of non-myelinated axons. Two types of “groups” are identifiable, and their distribution in some of the nerve segments is analysed. Their evolution was followed in sequential nerve segments, the initial ‘tight’ structure becoming looser between 7 and 10 days, and myelinated axons appeared in them during this time. At this stage a complete basal lamina was present surrounding the entire “group”. Some of the cells in the “groups” did not have the characteristics of Schwann cells. Between 7 and 10 days after division alveolate vesicles and densely staining material in the cisternae of the rough surfaced endoplasmic reticulum were prominent in Schwann cells in the distal part of the proximal stump. It is thought that both types of “group” are developed from single myelinated axons and the name “regenerating unit” is proposed for both types. Their relationship to “clusters”, seen in the distal stump of regenerating peripheral nerves, and “onion bulbs”, present in some peripheral neuropathies, is discussed.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
Author information
Authors and Affiliations
Additional information
Medical Research Council Scholar.
McLoughlin Fellow.
The authors have great pleasure in acknowledging the expert technical assistance of Mrs. Frances Burton. G. W. would also like to thank the British Medical Research Council, the Wellcome Trust and LEPRA (British leprosy relief association) for financial assistance without which this work could not have been completed.
Rights and permissions
About this article
Cite this article
Morris, J.H., Hudson, A.R. & Weddell, G. A study of degeneration and regeneration in the divided rat sciatic nerve based on electron microscopy. Z. Zellforsch. 124, 103–130 (1972). https://doi.org/10.1007/BF00981944
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00981944