How a mouse’s brain controls time

Life has a difficult rhythm. Sometimes it moves faster or slower than we would like. Nevertheless, we adapt. We resume the rhythm of conversations. We follow the rhythm of the crowds walking on the city sidewalks.

“There are many cases where we have to perform the same action but at different rates, so the question is how the brain does it,” says Arkarup Banerjee, assistant professor at Cold Spring Harbor Laboratory.

Banerjee and colleagues have discovered a new clue suggesting that the brain adapts our processing of time to our needs. And that’s partly thanks to a noisy creature from Costa Rica called the Alston singing mouse.

This special breed is known for its vocalizations audible to humans, which last for several seconds. One mouse will sing a longing cry and another will respond with its own melody. Notably, the song varies in length and speed. Banerjee and her team sought to determine how the neural circuits in the mice’s brains govern the tempo of their song.

Their research is published in Natural neuroscience.

The researchers pretended to engage in duets with the mice while analyzing a region of their brains called the orofacial motor cortex (MOC). They recorded the activity of the neurons for several weeks. They then looked for differences between songs with distinct durations and tempos.

They discovered that OMC neurons engage in a process called temporal scaling. “Instead of encoding absolute time like a clock, neurons track something like relative time,” says Banerjee. “They actually slow down or speed up the interval. So it’s not like one or two seconds, but 10%, 20%.”

The discovery offers new insights into how the brain generates vocal communication. But Banerjee suspects its implications go beyond language or music. This could help explain how time is calculated in other parts of the brain, allowing us to adjust various behaviors accordingly. And it could tell us more about how our beautifully complex brain works.

“It’s this three-pound lump of flesh that lets you do everything from reading a book to sending people to the moon,” Banerjee says. “It gives us flexibility. We can change on the fly. We adapt. We learn. If everything was a response to a stimulus, with no opportunity to learn, with nothing changing, with no long-term goals, we wouldn’t We wouldn’t need a brain. We think the cortex exists to add flexibility to behavior.

In other words, it helps make us who we are. Banerjee’s discovery could bring science closer to understanding how our brains allow us to interact with the world. The possible implications for technology, education and therapy are as limitless as our imaginations.