MS Nerve Damage May Not Be Permanent After All

Myelin Swellings: Not the Point of No Return

A groundbreaking international study has overturned decades of assumption about multiple sclerosis by revealing that early myelin damage can reverse itself. Researchers from Amsterdam UMC, VU LaserLab, the Netherlands Institute for Neuroscience, and the University of Edinburgh have discovered that myelin swellings, previously considered permanent precursors to MS lesions, are in fact dynamic structures capable of shrinking and even recovering completely.

Advanced Imaging Reveals Hidden Dynamics

Using third-harmonic generation microscopy and two-photon microscopy, the team was able to observe myelin changes in three dimensions over time across zebrafish, mouse, and human brain tissue. Traditional chemical preservation methods had previously obscured the dynamic nature of these structures, leading scientists to wrongly assume the damage was irreversible.

The Rest-to-Repair Connection

Perhaps the most striking finding is the relationship between nerve activity and myelin damage. Increased neuronal activity was shown to exacerbate swelling and decrease the survival of oligodendrocytes, the cells responsible for producing myelin. Conversely, reducing nerve activity mitigated damage across both animal models and human tissue samples, a finding that prompted accompanying commentary in Science titled Rest to Repair.

Cross-Species Confirmation

In human postmortem MS tissue, the team confirmed that myelin swellings were prevalent around active and chronic active lesions. High-resolution imaging of acute postmortem tissue revealed that swellings could change dynamically and show signs of resolution even in human brain samples, suggesting the nervous system has a powerful and previously unrecognised ability to withstand early myelin damage.

Future Therapeutic Possibilities

The research teams plan to investigate why nerve fibre activity influences swelling dynamics and what role other brain cells play in the process. Addressing this early damage before myelin is permanently lost could offer new treatment possibilities for MS and help keep myelin healthy for longer. The study was funded by the MS Society and Wellcome Trust.