Carbohydrate requirement of immature nerve fibers during repetitive stimulation

¹ Department of Physiology, Dartmouth Medical School, Hanover, New Hampshire

The compound action potential recorded from chick sciatic nerves was measured at 25 C during 10/sec stimulation after suspension in Ringer's solution containing 3, 10, and 20 mm glucose. Nerves sustained 90–100 min of 10/sec responses after 3 mm glucose, 200–285 min after 10 mm glucose, and 420–510 min after 20 mm glucose. Control responses from paired resting nerves diminished less than 5%. When the nerves no longer conducted impulses (blockade), a 2-hr suspension in 5 mm glucose restored the spike to 90%. Glucose utilization and oxygen consumption by the resting nerves are temperature dependent, but conduction survival is not. Oxygen uptake and glucose disappearance from the nerves were not accelerated by stimulation. Nerves in substrate-free Ringer's which block after 2 hr contain less than 5 µ glucose/ 100 mg nerve, but their oxygen consumption is unchanged. After blockade the nerves studied at 25 C contained 10–25 µ glucose, while at 35 C less than 5 µ was recovered.