MYONEURAL JUNCTION ABNORMALITY IN MUSCULAR DYSTROPHY

Control of the dystrophic process in muscles should follow discovery of the fundamental defects involved in the structure, chemistry, and function of the affected tissue. Complete understanding will be based upon correlations of biochemical and morphologic lesions with disordered physiology. Accumulated evidence indicates that there is both functional and structural abnormality at the myoneural junction and in its immediate environment, in addition to the basic disorder of the muscle fiber itself. It will be important to determine whether the abnormalities at the myoneural junction produce a loss of stabilizing influence over the entire muscle membrane, and whether the changes are primary in the dystrophic process involving the muscle, or secondary to the more internal lesions of the fiber, as in sarcoplasm and endoplasmic reticulum.

To evaluate localized functional abnormalities, Conrad and Glaser recently investigated the characteristics of miniature end-plate potentials spontaneously appearing at the myoneural junction in dystrophic muscle of