 Whether it is turned on or off is dependent on the nature of the input signal (either excitatory or inhibitory) from the presynaptic neuron.Gating can occur by shunting inhibition in which inhibitory interneurons change the membrane conductance of an excitatory target axon, thereby diffusing its excitatory signal.A gating signal from the gatekeeper triggers these inhibitory interneurons in order to prevent one set of neurons from firing even when stimulated by another set.