antidromic

Antidromic refers to the propagation of an action potential in a direction opposite to the normal physiological flow of information along a neuron. In many neurons, signals typically travel from the soma toward the axon terminals (orthodromic conduction). Antidromic conduction occurs when an impulse travels toward the soma or dendritic region, effectively traveling backward along the axon.

In experimental and clinical neurophysiology, antidromic activation is produced by stimulating the distal part of an axon or nerve and recording the resulting spike as it propagates toward the neuron's cell body. This property is used to study conduction properties, axonal integrity, and neural connections. A key concept associated with antidromic conduction is the collision phenomenon: an orthodromic impulse traveling toward the axon terminal can collide with an antidromic impulse traveling toward the soma on the same axon, annihilating one another and confirming that the impulses share the same axon.

Antidromic stimulation has applications in nerve conduction studies and neurophysiological mapping, where it helps assess conduction velocity and the integrity of motor or sensory pathways. It is often discussed as a tool in research to elucidate synaptic organization and axonal properties, rather than as a typical mode of physiological signaling in everyday nervous system function.

See also orthodromic conduction, backpropagation, and nerve conduction studies. While antidromic phenomena are important in experimental approaches, normal neural communication typically relies on orthodromic conduction from the cell body toward synaptic targets.