Electrical Activity of the Nervous System

The subject of this article was suggested by work done recently in Cambridge on what may be called the driving mechanism of the nervous system. But my associates and I have been led to it by way of the peripheral nerves, and this account must follow the same path, starting, as anatomists would say, at the outside and working inward and upward. Such a course has much to commend it. There are many nervous reactions which can be studied most readily in the peripheral nerve fiber, although present in other parts of the neuron. One of them is the reaction with which I am concerned today, the sudden outburst of activity which is associated with a change of electrical potential. In the nerve fiber this reaction is familiar as the nerve impulse, the brief flash of activity which spreads rapidly and is the basis of all nervous signaling. The messages