Effects of inhomogeneous myofibril morphology on optical diffraction in single muscle fibers

Laser diffraction is commonly used in physiological research that explores single muscle fibers. Although variations in sarcomere morphological properties have often been observed, their effects on laser diffraction have not been studied in detail. In this study, we applied three-dimensional coupled wave theory to a physical sarcomere model to investigate the effects of inhomogeneous morphological profiles in muscle fibers. The simulation results were compared with several those of published experimental studies. Our results indicate that by incorporating various myofibril inhomogeneities such as skew and domain effect in the theoretical model, a variety of observations in single fiber diffraction under different experimental conditions can be reproduced in the simulation.