Outflow from cut ends of nerve fibres

Abstract

When the axoplasm of isolated nerve fibres of frog is fluid, the content emerges slowly from the cut ends of the fibres, forming a spherical droplet of axoplasm invested by a layer of myelin.

The volume of the discharged axoplasm is proportional to the square root of the time.

The terminal portion of the fibre narrows during the outflow. The reduction of diameter is most marked at the cross-section and fades gradually away with the increasing distance from the cut end.

When the outflowing drop reaches a definite magnitude, the flow is arrested and the volume of the drop becomes for a time stationary. The stationary period is ended when the myelin membrane coating the drop bursts. The outflow is resumed immediately afterwards.

The mechanism of the outflow from cut nerve fibres is discussed.