Do you play music or sports? When you first learned how to play, you probably started by copying someone who was more experienced (like a coach, or an instructor), and you probably had to practice quite a bit in order to become good. Have you ever wondered what was going on in your brain when you learned these skills? The answer might actually lie in the brain of a musical bird called the zebra finch.
Zebra finches take courtship very seriously because they are monogamous. Males perform a song and dance to woo females. It is apparent that their song is vital to their mating rituals. Each bird’s song is unique, but it shares similarities to the song of that bird’s father. That’s because zebra finches first learn to sing by copying their dads. They start by “babbling,” then imitate each note that their father sings until they develop their own stereotyped song.
In the last few decades, neuroscientists have started to study how the zebra finches learn their songs. As a result, they’ve discovered some stunning likenesses to our own brains. For example, we now know that the birds learn and produce songs with a series of brain regions which are much like the parts of our brain that plan out motor sequences (such as swinging a tennis racket or playing scales on a musical instrument).
There are quite a few parallels between zebra finch songs and these learned motor sequences. Almost every one of these sequences starts out as an awkward jumble of partial actions. A novice musician has to think about each note in a scale as they’re playing it, while a professional can play almost any scale off the top of their head. An amateur basketball player might not have a very polished jump shot, but with coaching, they can make their motion more fluid. Just like the finches’ songs, a human’s learned motor sequences are very individualized. For example, if you look at many baseball players throwing pitches in slow-motion, you’ll notice tons of small differences in their deliveries.
When neuroscientists study zebra finch songs, they hope to learn more about how we create, develop, and maintain these personalized behavioral sequences. Imagine being able to see everything happening inside Joshua Bell’s brain as he became a violin virtuoso, or looking inside Ken Griffey Jr.’s brain as he develops his swing.
Want to know more about the state of the art in zebra finch research? You’re in luck! Michael Long, a neuroscientist at NYU, is coming to speak at UCSD as part of the DART Neuroscience Seminar Series.
What type of stuff is he going to talk about? In one recent publication, he described a mechanism that the birds use to prevent changes to a song once it’s been learned. It’s kind of like the finch’s version of saving a document as “read only.” Dr. Long found this mechanism by studying a finch brain area called HVC (which is analogous to the human “premotor cortex,” an area we use for action planning). Previous work has shown that HVC neurons become more active when anesthetized birds hear their tutor’s song. The Long Lab has developed a sophisticated way to monitor HVC cells in awake birds. They noticed that, when the finches weren’t unconscious, HVC activity during songs actually changed over development: juvenile animals had lots of activity, while adult birds had very little.
Through a series of very technically challenging experiments, Dr. Long and his lab discovered why this change occurred. They showed that HVC was actually being inhibited when the finches heard part of a song from their tutor that they already knew well. Since the adult birds knew their songs already, their HVC neurons were practically silent. The researchers proposed that this inhibition of HVC was a mechanism for protecting the developing song from being changed.
This is a huge finding in the field. It confirms that the song-learning circuit is specifically “tuning out” parts of songs that it already knows, and (most importantly) proposes a mechanism for how the bird brain can do that. There’s a good chance that our brains use analogous mechanisms to learn motor skills from a tutor or coach; perhaps someday scientists can apply this knowledge to human motor actions.
If you’re interested in learning more about zebra finches, come to The Marilyn Farquhar Auditorium this Tuesday at 4 PM (in the Center for Neural Circuits and Behavior building). It’s going to be a great lecture.
Sam Asinof is a first-year grad student in the UCSD Neurosciences program. He’s currently rotating in Dr. Tina Gremel’s laboratory, where he studies how mice form habits. In his free time, he loves to both play music and watch sports.