Studying Songbird Neurology to Unlock Language Acquisition

UT Southwestern ❘ Discovery@UTSW 2026 ❘ P10–11 Songbirds

By mapping connections in the brain of the zebra finch, UTSW neuroscientists are finding parallels in how humans develop vocal learning.

When he was just 6 months old, Todd Roberts moved with his family from Houston to Brazil to support his scientist father’s research on malaria and other mosquito-borne diseases. There, he simultaneously learned Brazilian Portuguese and English, becoming the most fluent bilingual speaker in his household. But soon after moving back to the U.S. at age 7, he stopped speaking Portuguese and lost the ability to understand the language.

Spotlight on a Songbird

As an undergraduate neuroscience major at the University of Maryland, he became fascinated by how vocal learning is gained and lost. He has pursued that mystery ever since, using as his model the zebra finch – a common pet in the U.S. that’s one of an estimated 4,000 extant songbird species.

Today, Todd Roberts, Ph.D., is Professor of Neuroscience and an Investigator in the Peter O’Donnell Jr. Brain Institute at UT Southwestern. His latest study, published in eLife, reports the first “wiring diagram” of interconnected circuits in a critical region of the songbird brain, providing important insights into how vocal learning occurs in songbirds that could help researchers develop better models of human speech.

“Learned vocalizations are controlled by a complex of interconnected sensory and motor circuits in the brain, but the details of how these different sensory and motor pathways ‘talk’ to each other has been difficult to ascertain using standard approaches,” says Dr. Roberts, who co-led the study with Massimo Trusel, Ph.D., Instructor of Neuroscience. “This research breaks new ground by providing the first cell-type specific functional mapping of connectivity within core sensory and motor pathways critical for vocal learning.”

Like other songbirds, zebra finches learn their vocalizations through imitation, a type of learning that shares many behavioral and genetic features with how humans learn to talk. Unlike other common lab models, such as mice, rats, and flies, these birds can shed light on the process behind how language acquisition takes place, as well as conditions in which it sometimes goes awry, such as with autism spectrum disorder.

For decades, researchers have known that an area of the avian brain called the HVC is critical for birdsong. Earlier anatomical studies have shown that the HVC acts like a hub, receiving information from four upstream brain regions and sending outputs to three downstream brain regions. But how these input and output circuits are wired to transfer information through this hub has been unclear.

Finding Hidden Connections

To illuminate this process, the UTSW researchers used a technique called optogenetic circuit mapping, in which they inserted a gene into targeted neurons, allowing their activity to be controlled by light. By stimulating individual groups of neurons delivering inputs to the HVC and then measuring the electrical activity of outputting neurons, they could see which neurons communicated with one another.

Their findings revealed an unexpectedly high degree of specificity in how input circuits wire with output circuits to transfer information through this hub. The researchers also found that two of these input pathways directly communicate with each other, revealing a previously unknown connection within this well-studied circuit.

“Complex vocal learning is not ubiquitous among animals; it seems to be extraordinarily special, shared by songbirds, humans, and just a few other species,” Dr. Roberts says. “By studying this special form of learning in birds, we are unlocking new knowledge of what makes us human.”

“This represents the most extensive simultaneous circuit interrogation ever conducted in any vertebrate, not only in birds, and granted us a comprehensive understanding of how sensory, thalamic, and premotor circuits integrate to orchestrate skilled motor behavior,” Dr. Trusel adds.

Driven by Curiosity

William T. Dauer, M.D., Director of the O’Donnell Brain Institute and Professor of Neurology and Neuroscience, says Dr. Roberts’ research is “the kind of discovery the O’Donnell Brain Institute exists to foster – cross-disciplinary, mechanistically deep, and driven by curiosity about how the brain works.”

“Dr. Roberts has an extraordinary ability to ask elegant, fundamental questions about how the brain learns and acts,” Dr. Dauer says. “His mapping of the songbird’s HVC reflects a combination of conceptual clarity, technical mastery, and creativity that defines his work.”

The strong emphasis at UT Southwestern and O’Donnell Brain Institute on interdisciplinary collaboration, linking behavior, systems neuroscience, and molecular tools, has given life to his research that wouldn’t have been possible elsewhere, Dr. Roberts says.

“The combination of our intellectually vibrant environment, world-class neuroscience expertise, open communication across labs, and access to advanced imaging and computational resources has been invaluable,” he says. “Just as importantly, the supportive culture and generosity of colleagues here have provided both the technical guidance and creative energy that continually push my work forward.”