In some clinical applications, it is desirable to arrest or block propagating action potentials and eliminate the possibility of neurotransmitter release from the axons. Action potentials are propagating signals that are transmitted by neurons and can be initiated by natural or artificial inputs to their neuronal membrane. When the initiating signal causes a change in the local transmembrane potential a self-propagating depolarization signal can be generated. This self-propagating action potential signal, which is an active process by entry of Sodium through ion channels in the membrane, travels along the length of the axon.
The conduction of this signal can be prevented by rendering a section of the axon unresponsive to this traveling wave of depolarization. Bio-toxins like Tetradotoxin and some local anesthetics like Lidocaine do this by binding to the Sodium channels. These chemical methods cannot be reversed quickly and can have wider responses on other organ systems. Manipulating the excitability of the membrane ion channels through applied electric fields or altering the temperature may enable one to rapidly induce and reverse block of action potential propagation.