Turbidity, birefringence, and fluorescence changes in skeletal muscle coincident with the action potential.

Electrical stimulation of frog striated muscle was found to prduce trasient changes in turbidity. birefringence, and fluorescence (of fibers stained with pyronine B). The initial phase of these optical changes Was coinicident with the action potential. These findings suggest that there is a macromolecular conformational change in muscle membrane during excitation.