An antidromic impulse in an axon

Axon

An axon is a long, slender projection of a nerve cell, or neuron, that conducts electrical impulses away from the neuron's cell body or soma....

 refers to conduction opposite of the normal (orthodromic

Orthodromic

An orthodromic impulse runs along an axon in its normal direction, away from the soma.In the heart, orthodromic may also refer to an impulse going in the correct direction from the atria to the ventricles, in contrast to some impulses in re-entry....

) direction. That is, it refers to conduction along the axon away from the axon terminal

Axon terminal

Axon terminals are distal terminations of the branches of an axon. An axon nerve fiber is a long, slender projection of a nerve cell, or neuron, that conducts electrical impulses away from the neuron's cell body, or soma, in order to transmit those impulses to other neurons.Neurons are...

(s) and towards the soma

Soma (biology)

The soma , or perikaryon , or cyton, is the bulbous end of a neuron, containing the cell nucleus. The word "soma" comes from the Greek σῶμα, meaning "body"; the soma of a neuron is often called the "cell body"...

. For most neurons, their dendrites, soma

Soma (biology)

The soma , or perikaryon , or cyton, is the bulbous end of a neuron, containing the cell nucleus. The word "soma" comes from the Greek σῶμα, meaning "body"; the soma of a neuron is often called the "cell body"...

, or axons are depolarized

Depolarization

In biology, depolarization is a change in a cell's membrane potential, making it more positive, or less negative. In neurons and some other cells, a large enough depolarization may result in an action potential...

 forming an action potential

Action potential

In physiology, an action potential is a short-lasting event in which the electrical membrane potential of a cell rapidly rises and falls, following a consistent trajectory. Action potentials occur in several types of animal cells, called excitable cells, which include neurons, muscle cells, and...

that moves from the starting point of the depolarization (near the cell body) along the axons of the neuron. Antidromic activation is usually induced experimentally by direct electrical stimulation of a presumed target structure. Antidromic activation is usually used to confirm that a neuron being recorded from projects to the structure of interest.