ABSTRACT
The principles of microdifferential holography are developed primarily from nonmathematical argument, and the method's capabilities are compared with those of x-ray and optical diffraction. Microdifferential holography is very sensitive to small displacements of strongly scattering elements of a specimen whether or not they can be optically resolved. We present and interpret differential images of electrical activity of neurons and of contractile activity of isolated skeletal fibers. The latter confirm the suggestion of earlier work that the dynamic regions of contracting muscle are organized along myofibrillar segments rather than by sarcomeres.
ABSTRACT
Unbalanced holographic difference images of contracting skeletal muscle fibers reveal that activation affects the amplitude of the light scattered by individual myofibrils. The results suggest that the unit of activation is not the sarcomeric structural unit, but a monomyofibrillar segment containing 20 to 40 contiguous sarcomeres.