Lactic dehydrogenase activities in single motoneurons in relation to amyotrophic lateral sclerosis

Histograms of LDH activity in anterior horn cells (AHCs) of rabbit, cat, monkey and man cannot be as clearly divided into 2 groups as can muscle fibers. However, on the basis of the difference in LDH activities between oculomotoneurons and AHCs, and between immature and mature feline AHCs, motoneurons can be divided functionally into 2 groups. From LDH activities of single motoneurons and muscle fibers and those of the remaining AHCs in amyotrophic lateral sclerosis (ALS) determined in this study, it may be assumed that the motoneurons in the high LDH activity group--a high activity being an immature quality--may be resistant to ALS.