This change triggers depolarization in the section of the axon next to it, and so on, until the rise and fall in charge has passed along the entire length of the axon.Īfter each section has fired, it enters a brief state of hyperpolarization, where its threshold is lowered, meaning it is less likely to be triggered again immediately. When the cell body of a nerve receives enough signals to trigger it to fire, a portion of the axon nearest the cell body depolarizes - the membrane potential quickly rises and then falls (in about 1,000th of a second). Neurons at rest are more negatively charged than the fluid that surrounds them this is referred to as the membrane potential. Once this threshold is exceeded, the neuron is triggered to send an impulse along its axon - this is called an action potential.Īn action potential is created by the movement of electrically charged atoms (ions) across the axon’s membrane. If a neuron receives a large number of inputs from other neurons, these signals add up until they exceed a particular threshold. Share on Pinterest Neurons carry messages via action potentials.
