Underlying brain circuitry prevents you from biting your tongue while chewing food.

Eating appears to be a basic biological job, much like breathing and sleeping. Yet a complex interplay must take place between the tongue and jaw to keep the tongue positioned properly between the teeth and keep it out of the way when chomping down on food. Without this co-ordination, the tongue would be bitten while chewing.

Lead author Edward Stanek IV, a graduate student at Duke University School of Medicine, and colleagues conducted a study involving the use of a sophisticated tracing technique in lab rats that mapped the brain circuitry that keeps the tongue out of the way while eating. The study could shed light on many human behaviors, including vocalizations and grinding of the teeth.

“Chewing is an activity that you can consciously control, but if you stop paying attention these interconnected neurons in the brain actually do it all for you. We were interested in understanding how this all works, and the first step was figuring out where these neurons reside,” said Stanek in a statement.

Previous studies were unable to provide a clear picture of the chewing control center. Scientists were aware that special neurons govern the movement of jaw and tongue muscles while eating, but the precise nature of such connections has never been defined.

The researchers are looking into using their technique to go even further back into the brain of the mouse, and eventually map the circuitry right up to the cortex.

The findings of the study are published in eLife.