The ultrastructure fluctuations and complex dynamics of the multi-layered membrane structure of myelin are fundamental for understanding and control its formation process and the processes associated with degeneration and repair in neurological diseases such as multiple sclerosis (MS). Myelin is considered a quasi-crystalline material due to limitations of the available standard techniques that do not allow to solve heterogeneity and fluctuations in matter at nanoscale and mesoscale . To overcome this limitation in this work we  used Scanning micro X-ray Diffraction (S{\mu}XRD) , which is a unique non-invasive probe of both k-space and real space allowing to visualize statistical fluctuations of myelin order with high spatial resolution in real space. We have used this method to examine the myelin sheath in the sciatic nerve of Xenopus laevis. We have found that the stable periodic arrangement of myelin is ensured by large and anti-correlated fluctuations at nanoscale, between hydrophobic and hydrophilic layers. The correlated disorder of spatial fluctuations in the functional state is lost with early stage degeneration. Our results open the way for a deeper understanding of different states such as degradation and death in biomaterials like neurons, cells and tissues, by associating these states with dynamical structural fluctuations at the nanoscale .
The ultrastructure fluctuations and complex dynamics of the multi-layered membrane structure of myelin are fundamental for understanding and control its formation process and its degeneration and repair in neurological diseases such as multiple sclerosis (MS). Myelin is considered a liquid-crystal but information are confined to its average structure due to limitations of the available standard techniques . To overcome this limitation in this work we have used Scanning micro X-ray Diffraction (S{\mu}XRD) which is a unique non-invasive probe of both k-space and real space allowing to visualize disorder in myelin with high spatial resolution in real space. We have used this method to examine the myelin sheath in the sciatic nerve of Xenopus laevis. Our results open could open new venues for understanding formation and degradation of myelin .
R
the processes associated with
its
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quasi-crystalline material
liquid-crystal but information are confined to its average structure
D
that do not allow to solve heterogeneity and fluctuations in matter at nanoscale and mesoscale
A
have
D
,
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statistical fluctuations of myelin order
disorder in myelin
D
We have found that the stable periodic arrangement of myelin is ensured by large and anti-correlated fluctuations at nanoscale, between hydrophobic and hydrophilic layers. The correlated disorder of spatial fluctuations in the functional state is lost with early stage degeneration.
R
the way for a deeper understanding of different states such as degradation and death in biomaterials like neurons, cells and tissues, by associating these states with dynamical structural fluctuations at the nanoscale
could open new venues for understanding formation and degradation of myelin