Abstract
Laminin, a large extracellular matrix molecule, is associated with axonal outgrowth during development and regeneration of the nervous system in a variety of animals. In the leech central nervous system, laminin immunoreactivity appears after axon injury in advance of the regenerating axons. Although studies of vertebrate nervous system in culture have implicated glial and Schwann cells as possible sources, the cells that deposit laminin at sites crucial for regeneration in the living animal are not known. We have made a direct test to determine whether, in the central nervous system of the leech, cells other than ensheathing glial cells can produce laminin. Ensheathing glial cells of adult leeches were ablated selectively by intracellular injection of a protease. As a result, leech laminin accumulated within 10 days in regions of the central nervous system where it is not normally found, and undamaged, intact axons began to sprout extensively. In normal leeches laminin immunoreactivity is situated only in the base-ment membrane that surrounds the central nervous system, whereas after ablation of ensheathing glia it appeared in spaces through which neurons grew. Within days of ablation of the glial cell, small mobile phagocytes, or microglia, accumulated in the spaces formerly occupied by the glial cell. Microglia were concentrated at precisely the sites of new laminin appearance and axon sprouting. These results suggest that in the animal, as in culture, leech laminin promotes sprouting and that microglia may be responsible for its appearance.
| Original language | English |
|---|---|
| Pages (from-to) | 4966-4970 |
| Number of pages | 5 |
| Journal | Proceedings of the National Academy of Sciences of the United States of America |
| Volume | 90 |
| Issue number | 11 |
| State | Published - Jun 1 1993 |
| Externally published | Yes |
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Keywords
- Desheathment
- Leech
- Microglia
- Regeneration
- Serotonin
ASJC Scopus subject areas
- General
- Genetics
Cite this
Axonal sprouting and laminin appearance after destruction of glial sheaths. / Masuda-Nakagawa, Liria M.; Muller, Kenneth J; Nicholls, John G.
In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 90, No. 11, 01.06.1993, p. 4966-4970.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Axonal sprouting and laminin appearance after destruction of glial sheaths
AU - Masuda-Nakagawa, Liria M.
AU - Muller, Kenneth J
AU - Nicholls, John G.
PY - 1993/6/1
Y1 - 1993/6/1
N2 - Laminin, a large extracellular matrix molecule, is associated with axonal outgrowth during development and regeneration of the nervous system in a variety of animals. In the leech central nervous system, laminin immunoreactivity appears after axon injury in advance of the regenerating axons. Although studies of vertebrate nervous system in culture have implicated glial and Schwann cells as possible sources, the cells that deposit laminin at sites crucial for regeneration in the living animal are not known. We have made a direct test to determine whether, in the central nervous system of the leech, cells other than ensheathing glial cells can produce laminin. Ensheathing glial cells of adult leeches were ablated selectively by intracellular injection of a protease. As a result, leech laminin accumulated within 10 days in regions of the central nervous system where it is not normally found, and undamaged, intact axons began to sprout extensively. In normal leeches laminin immunoreactivity is situated only in the base-ment membrane that surrounds the central nervous system, whereas after ablation of ensheathing glia it appeared in spaces through which neurons grew. Within days of ablation of the glial cell, small mobile phagocytes, or microglia, accumulated in the spaces formerly occupied by the glial cell. Microglia were concentrated at precisely the sites of new laminin appearance and axon sprouting. These results suggest that in the animal, as in culture, leech laminin promotes sprouting and that microglia may be responsible for its appearance.
AB - Laminin, a large extracellular matrix molecule, is associated with axonal outgrowth during development and regeneration of the nervous system in a variety of animals. In the leech central nervous system, laminin immunoreactivity appears after axon injury in advance of the regenerating axons. Although studies of vertebrate nervous system in culture have implicated glial and Schwann cells as possible sources, the cells that deposit laminin at sites crucial for regeneration in the living animal are not known. We have made a direct test to determine whether, in the central nervous system of the leech, cells other than ensheathing glial cells can produce laminin. Ensheathing glial cells of adult leeches were ablated selectively by intracellular injection of a protease. As a result, leech laminin accumulated within 10 days in regions of the central nervous system where it is not normally found, and undamaged, intact axons began to sprout extensively. In normal leeches laminin immunoreactivity is situated only in the base-ment membrane that surrounds the central nervous system, whereas after ablation of ensheathing glia it appeared in spaces through which neurons grew. Within days of ablation of the glial cell, small mobile phagocytes, or microglia, accumulated in the spaces formerly occupied by the glial cell. Microglia were concentrated at precisely the sites of new laminin appearance and axon sprouting. These results suggest that in the animal, as in culture, leech laminin promotes sprouting and that microglia may be responsible for its appearance.
KW - Desheathment
KW - Leech
KW - Microglia
KW - Regeneration
KW - Serotonin
UR - http://www.scopus.com/inward/record.url?scp=0027198860&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0027198860&partnerID=8YFLogxK
M3 - Article
C2 - 8506343
AN - SCOPUS:0027198860
VL - 90
SP - 4966
EP - 4970
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
SN - 0027-8424
IS - 11
ER -