What is the source of the electrical impulse in a neuron?
The source of the impulse in a neuron is a rapid change in the polarity of the cell membrane in a restricted area. The direction of the electrical gradient is rapidly reversed and then returns to normal. The change in charge stimulates the process to happen in adjacent parts of the cell and the change in polarity travels down the neuron. The change in polarity does not go backward – the area immediately ‘behind’ the action potential is still returning to the resting state and is not stimulated to form another action potential. View the animation below, then complete the quiz to test your knowledge of the concept.
