The Effect of Metabolic and Ion Transport Inhibitors on the Impulse Activity and Oxygen Uptake of an Isolated Crustacean Neurone

The effect of 19 metabolic and ion transport inhibitors acting at various enzymatic levels within several metabolic pathways was investigated upon a single neurone preparation of the crayfish stretch receptor organ. Both the nerve cell function as judged by its impulse activity and its metabolism expressed by oxygen uptake were studied. Each inhibitor was tried at various concentrations and pH values. The effect of the respiratory inhibitors, especially rotenone and antimycin A, suggests a coupling of respiration and impulse activity in the crustacean nerve cell. The marked effect of the glycolytic inhibitors and of Na‐malonate strongly suggests a link between glycolysis and Krebs' cycle from one side and maintenance of impulse activity from the other. This view is also supported by the effect of glucose restoring activity after the block caused by several inhibitors. Ouabain and digoxin inhibit both impulse activity and oxygen uptake. In general respiration seems to be less sensitive to inhibitors than the impulse activity, indicating the presence of a safety factor for respiratory processes.