It may not be the most beautiful, or the most complex, or the most well known, but the simple song of the zebra finch is helping Professor John Kirn learn more about how new information is acquired and old information preserved during adult neurogenesis.
Kirn, chair and professor of biology, recently received a three-year $225,000 grant from the Whitehall Foundation to look at the activity patterns of vocal control neurons formed in adult zebra finches. “We’re trying to get a better idea of what these new cells might be contributing,” Kirn said. “One thought is that new neurons are being added if they contribute to what a bird is trying to produce vocally. The question is, why? What can a new neuron do better than an older one?”
The zebra finch, like other birds, experiences neurogenesis throughout its life. But while some songbirds learn many songs over the course of a lifetime, the zebra finch learns just one simple song as a juvenile, and it sings only that song for its entire life. “While the rate of neuron addition is highest when the bird is actively engaged in song learning as a juvenile, new neurons are still added when song learning is complete—and yet that one song remains consistent over the bird’s lifetime,” Kirn said. “In fact, even when we interrupt the song structure, the same song gradually comes back as new cells are added.”
While the evidence is only correlational at this point, Kirn’s most recent findings support the idea that neurogenesis may play a role in knowledge retention, as well as in new learning. “People tend to think of neurogenesis as a key to learning new things,” he said. “But it may be that new neurons not only contribute to learning, but also help to preserve memories.”
As he begins his next phase of study, Kirn is the first to admit that his avian research only indirectly relates to humans. Still, he doesn’t rule out the possibility of it someday helping to open the door to a better understanding of our own cognitive function. “Adult neurogenesis was first proven in birds, and I believe those studies helped launch the entire field of stem cell research,” Kirn said. “If we find new neurons do, in fact, help preserve information, researchers might be able to use that information to determine whether memory loss due to brain damage or neurodegenerative diseases such as Alzheimer’s and Parkinson’s can be counteracted in the future.”
The Whitehall Foundation is a not-for-profit corporation focused exclusively on assisting basic research in vertebrate (excluding clinical) and invertebrate neurobiology in the United States, particularly neural mechanisms involved in sensory, motor and other complex functions of the whole organism as these relate to behavior.