Sensory gating

Sensory gating is a process by which the brain adjusts its response to stimuli. It is a largely automatic process.

When one stimulus is presented, there is a response. But when it is followed by a second stimulus soon after, the response to the second stimulus is blunted. This is an adaptive mechanism to prevent overstimulation. It helps to focus on a stimulus among a host of other distracing stimuli.

The mechanism of sensory gating involves feed-forward and feed-back inhibition of the stimulus perceived. It involves GABA-ergic and α7 nicotinergic receptor-mediated inhibiton of the pyramidal neurons in the cornu ammonis (CA3) region of the hippocampus.