Influence of nerve fiber K+ depolarization and altered membrane protein conformation on the state of myelin

Using Raman spectrometry and fluorescence microscopy, we studied the rearrangement of carotenoid molecules and membrane-bound Ca _mb ²⁺ in myelinated nerve fibers after K⁺ depolarization, K⁺-channel blocking, and altering the membrane protein conformation. We observed a decrease in Ca _mb ²⁺ and an increase of microviscosity in myelin after depolarization. Changes in Ca _mb ²⁺ and microviscosity were registered after blocking the K⁺ channels and modifying proteins with PCMB. Our results suggest an interconnection between the condition of nerve fiber membrane proteins, Ca _mb ²⁺ distribution, and myelin microviscosity.