ULTRASTRUCTURAL STUDY OF REMYELINATION IN AN EXPERIMENTAL LESION IN ADULT CAT SPINAL CORD

The Journal of Biophysical and Biochemical Cytology, 1961 · DOI: · Published: January 1, 1961

Simple Explanation

This study examines how myelin, the protective sheath around nerve fibers, reforms in the spinal cord of adult cats after it has been damaged. Researchers created lesions in the spinal cords of cats and then observed the process of remyelination using electron microscopy. After the damage, glial cells, which support nerve cells, extend processes to embrace the axons (nerve fibers). New myelin sheaths start appearing around 19 days after the injury, and by 64 days, most axons are thinly myelinated. The process of myelin reformation appears similar to how myelin is initially formed during development. This involves glial cell processes wrapping around the axon in a spiral, a mechanism also seen in peripheral nerves and the optic nerve.

Study Duration

19 to 460 days

Participants

Eleven cats

Evidence Level

Not specified

Key Findings

1
Remyelination occurs in adult mammalian central nervous tissue following demyelination induced by cerebrospinal fluid exchange.
2
Reactive macroglia, a cell type different from normal oligodendrocytes or fibrous astrocytes, are responsible for forming the new myelin sheaths.
3
The mechanism of remyelination involves spiral wrapping of glial cell processes around axons, similar to the process of initial myelin formation during development.

Research Summary

The study investigates the ultrastructural events of remyelination in adult cat spinal cord after experimentally induced lesions. Lesions were created via cerebrospinal fluid exchange, and tissue samples were examined at various time points post-injury. The research demonstrates that remyelination occurs in the adult mammalian central nervous system and is facilitated by reactive macroglia, which are distinct from typical oligodendrocytes and astrocytes. The myelin sheath is reformed through a process resembling initial myelinogenesis, involving spiral wrapping of glial cell processes around axons. This mechanism is similar to that observed in peripheral nerves and the optic nerve.

Practical Implications

Understanding Remyelination

The study provides insights into the cellular mechanisms underlying remyelination in the central nervous system.

Cellular Players

Identifies reactive macroglia as key cells involved in myelin repair, distinct from typical glial cells.

Therapeutic Targets

Suggests potential therapeutic strategies for promoting myelin repair in demyelinating diseases by targeting reactive macroglia and enhancing spiral wrapping.

Study Limitations

1
The origin of the myelin-forming cells and from which glial cells they are derived cannot be adequately studied by the sampling techniques employed in this ultrastructural study.
2
The study is limited to an experimental lesion model in cats, and the findings may not be directly applicable to all demyelinating conditions in other species, including humans.
3
The study relies on ultrastructural observations at specific time points, providing a snapshot of the remyelination process but lacking continuous real-time monitoring of cellular events.

Your Feedback

Was this summary helpful?

Back to Neurology