Adenosine triphosphate and electrical activity in chicken vagus

¹ Department of Comparative Biochemistry and Physiology, University of Kansas, Lawrence, Kansas

Chicken vagus nerves in vitro were placed in an atmosphere of nitrogen; some nerves were first immersed in iodoacetate to inhibit glycolysis. The electrical activity was observed and the nerves then chemically analyzed. The action potential reveals two populations of fibers, presumably nonmyelinated C fibers and small myelinated B fibers. Resting nerves in oxygen have 30 µm ATP/ g protein. In anoxia, ATP concentration and the compound action potential decrease rapidly; this occurs more rapidly when glycolysis is also inhibited. Electrical stimulation during energy deprivation decreases the spike height, conduction rate, and ATP proportionally to the amount of stimulation. The calculated ATP cost of activity is 540 pmoles/impulse per gram wet weight.

Key Words: nerve metabolism and electrical properties • energy cost (ATP) per nerve impulse • action potential and conduction rate of nonmyelinated C fibers • anoxia and glycolysis • inhibition in nonmyelinated C fibers • high-energy • phosphates and energy flow in nonmyelinated C fibers

Submitted on August 9, 1963