Shunting inhibition
Mechanism
Mechanism
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Shunting inhibition is theorized to be a type of [gain control](/wiki/Control_theory "Control theory") mechanism, regulating the responses of [neurons](/wiki/Neuron "Neuron"). Simple inhibition such as [hyperpolarization](/wiki/Hyperpolarization_%28biology%29 "Hyperpolarization (biology)") has a subtractive effect on the [depolarization](/wiki/Depolarization "Depolarization") caused by concurrent excitation, whereas shunting inhibition can in some cases account for a divisive effect.

Some evidence exists that shunting inhibition can have a divisive effect on neuronal responses, at least on [subthreshold postsynaptic potentials](/wiki/Subthreshold_conduction "Subthreshold conduction"). In a 2005 article, researchers Abbott and Chance state that "Although the importance of gain modulation and multiplicative interaction in general has been appreciated for many years, it has proven difficult to uncover a realistic biophysical mechanism by which it can occur. It is important to note that, despite comments in the literature to the contrary (see above), divisive inhibition of neuronal responses cannot arise from shunting inhibition. This has been shown theoretically as well as experimentally – inhibition has the same subtractive effect on firing rates whether it is of the shunting or hyperpolarizing variety." Thus, shunting inhibition does not provide a plausible mechanism for [neuronal gain modulation](/wiki/Neuromodulation "Neuromodulation").


How does shunting inhibition relate to other types of gain control mechanisms?