Mice Like a Song to Set the Mood
Mickey Mouse has been crooning his heart out for decades, but scientists have now discovered that real mice are also capable of carrying a tune.
Scientists have known that male mice produce high-frequency sounds when they pick up the scent of a female. But their vocalizations -- at frequencies too high to be heard by human ears -- had never been thoroughly analyzed.
In a study published online this week in Public Library of Science Biology, researchers said the mouse chirps meet two key criteria for song: distinct syllables and recurring themes.
The pattern in mouse songs is like a “melodic hook in a catchy tune,” said lead author Timothy E. Holy, a neurobiologist at Washington University in St. Louis.
Individual males also seem to sing their own unique melodies, he said.
Holy didn’t set out to study singing mice. He had been trying to figure out how mice brains stored the complex smells of pheromones -- chemicals used to attract members of the opposite sex.
To sort out the reactions of male mice, he first had to understand the riotous noises they produced when they caught the scent of females.
Holy recorded the sounds and played them back at a pitch four octaves lower and at one-sixteenth the original speed. They sounded like bird songs.
That “was an ‘aha’ moment for me,” Holy said.
The males produced rapid “chirp-like” syllables, about 10 per second. Holy analyzed a set of 750 syllables produced by one mouse during a 210-second trial and found clusters of pitch changes that followed a distinct pattern.
Mice join a short list of singing creatures, including songbirds, humans, bats and cetaceans, such as dolphins and whales.
That, Holy said, could have important medical implications.
Since music is thought to be related to language, scientists have long studied singing animals to understand language-related brain disorders such as autism. Whereas songbirds, bats and cetaceans can be hard to study, Holy said, “you can’t ask for a better research subject than the mouse.”
