Rapid Assessment of Internodal Myelin Integrity in CNS Tissue

This research explores using x-ray diffraction (XRD) to quickly check the structural health of myelin, the protective coating around nerve fibers, in preserved tissue samples. XRD measures the repeating patterns in myelin. The study found that XRD can differentiate between healthy and damaged myelin, motor and sensory tracts in the spinal cord, and young versus old primate brain tissue. It also distinguishes between spinal cord and nerve roots. The researchers suggest XRD could be a valuable tool for rapidly quantifying myelin in studies of diseases and injuries affecting the central nervous system (CNS), helping to speed up the development of new treatments.

• 1
  Fixation introduces variation in myelin periodicity and amount. The range in myelin periodicity (155–190 Å) and the broadened x-ray reflections show fixation-dependent effects.
• 2
  XRD can distinguish motor from sensory tracts in well-fixed spinal cords because motor tracts have stronger x-ray patterns. The relative amount of myelin in the sensory tracts was about one-half as much as in the motor tracts
• 3
  XRD can differentiate between CNS and PNS myelins. The peaks were centered at different channel positions compared to those from the CNS, indicating a different period.