Related Experiment Videos
Conduction in segmentally demyelinated mammalian central axons
Summary
Central nervous system axons demyelinated by multiple sclerosis (MS) can still conduct electrical signals. This restoration of conduction in demyelinated axons likely contributes to symptom remission in MS.
Area of Science:
- Neuroscience
- Cellular Biology
- Pathology
Background:
- Central demyelinating diseases, like multiple sclerosis (MS), cause symptoms due to axonal conduction deficits.
- Mechanisms of symptom remission in MS are not fully understood, particularly regarding axonal function restoration without remyelination.
Purpose of the Study:
- To investigate whether demyelinated central axons can conduct impulses without remyelination.
- To determine if conduction in demyelinated central axons contributes to disease remission.
Main Methods:
- Intra-axonal recordings were performed on central axons with demyelinating lesions.
- Axons were iontophoretically labeled for subsequent identification.
- Ultrastructural examination of labeled preparations was conducted.
Main Results:
- Some segmentally demyelinated central axons demonstrated the capacity to conduct impulses.
- Conduction occurred over continuous demyelinated segments exceeding several internodes (2500 microns).
- Demyelinated axons exhibited reduced conduction velocity and significantly prolonged refractory periods of transmission (RPT), up to 2-5 times normal.
Conclusions:
- Segmentally demyelinated central axons possess the ability to conduct electrical signals.
- Restoration of conduction in these demyelinated axons is a probable factor in the remissions observed in diseases like MS.