Biology:Anode break excitation

Anode break excitation (ABE) is an electrophysiological phenomenon whereby a neuron fires action potentials in response to termination of a hyperpolarizing current.

When a hyperpolarizing current is applied across a membrane, the electrical potential across the membrane falls (becomes negative of the resting potential); this fall is followed by a drop in the threshold required for action potential (since the threshold is directly linked to the potential across the membrane - they rise and fall together).

ABE arises after the hyperpolarizing current is terminated: the potential across the cell rises rapidly with the absence of hyperpolarizing stimulus, but the action potential threshold stays at its lowered value. As a result, the potential is suprathreshold: sufficient to cause an action potential within the cell.

Further reading

• "A quantitative description of membrane current and its application to conduction and excitation in nerve". The Journal of Physiology 117 (4): 500–44. August 1952. doi:10.1113/jphysiol.1952.sp004764. PMID 12991237. 

External links

• A description of anode break excitation.

See also

• Action potential
• Hodgkin–Huxley model
• Neural accommodation