Whether it’s a distant bird call, a whispered conversation or a suspicious sound in the house, we all behave in the same way when straining to hear something: stand stock still and be as quiet as possible. Unbeknownst to us, an equivalent correction is constantly taking place within the brain, keeping us responsive to sound throughout our many noisy activities. This is achieved by neurons [nerve cells], shown in green (in a section of mouse brain) which project from the motor cortex, an area responsible for controlling movement, to the auditory cortex, which processes signals from our ears. When mice are grooming, running or feeding, these neurons send signals to inhibit other cells in the auditory cortex, dampening their response to sound. By reducing sensitivity to the sounds of our own body, this mechanism is thought to maintain our ability to detect other, more important noises in the environment.
Written by Emmanuelle Briolat
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