A new study suggests myelin sheaths undergo structural transitions when triggered by changes in local environmental conditions, such as salt concentration and temperature. These transitions, according to the study, render the body vulnerable to autoimmune attacks that can lead to multiple sclerosis. Because researchers believe these structural modifications result in myelin membrane vulnerability to the immune system attacks, it can help explain the causes of MS and perhaps pave the way for a treatment or a cure.

Tel Aviv University researchers said they found that under certain environmental conditions, such as elevated salinity and temperature, myelin sheaths protecting neurons undergo structural transitions consistent with pathological myelin structures in MS. Physiological conditions are regulated in the body itself, but temperature and salinity are subject to localized external changes. The results presented in the study suggest that even minor changes in these conditions may trigger MS.

The researchers used X-ray scattering and cryogenic transmission electron microscopy to track and measure the myelin sheaths in healthy and diseased animal models. They found that healthy lamellar membranes spontaneously changed into different structures of nanoscale tubes called inverted hexagonal shapes.

The findings highlight that local environmental conditions are critical for myelin function. The authors said these conditions should be considered as alternative possibilities for early diagnosis and as a means of avoiding the onset of demyelination. 

Results of mouse model studies sometimes do not translate to humans and may be years away from being a marketable treatment. However, because they now have a new biophysical understanding to investigate the degradation of myelin sheaths, they are following up on other candidates that can induce such structural transition. There are several molecular candidates, including specific proteins and other alterations in the myelin's fatty acids that may unravel further insights to fight MS.

The findings were published in the Proceedings of the National Academy of Sciences of the USA.