Helium effect on isolated nerve activity.

Various gases were administered to isolated frog sciatic nerves in which action potential amplitudes were recorded in sheathed and desheathed preparations. In the sheathed preparation, nitrogen and argon showed significant anesthetic effects while in the desheathed preparation, helium also depressed the action potential amplitude. In the desheathed frog sciatic nerve, helium demonstrates an anesthetic effect similar to 10(-6) M lidocaine suggesting that at long exposure periods helium may demonstrate anesthetic properties.