According to Roian Egnor, her research into the neural basis of natural animal behaviors, a field called neuroethology, involves too many different scientific disciplines for one person to master in a lifetime. “So you have to find good collaborators,” she says. But in many institutions, getting people with different skill sets together is difficult. So when she learned about Janelia Farm’s focus on a highly collaborative approach to neuroscience, she thought, “Wow. This is exactly what we need.”
Science has long been a part of Egnor’s life. She spent her early childhood in Tunisia, where her father taught science at a middle school for the children of American families living abroad. “We would go camping in the Sahara, and I can remember crawling out of my tent in the early morning and seeing desert foxes,” she says. “I’ve always been interested in watching animals. If you stop and watch for a while, you realize there is a lot going on there.”
She received a degree in biology with a focus on integrative neuroscience at Bryn Mawr College, where a professor introduced her to the work of Masakazu “Mark” Konishi, a pioneering neuroethologist at the California Institute of Technology.
Two years after graduating from Bryn Mawr—a period that encompassed working in Parisian AIDS clinics, training dolphins to recognize specific frequencies of sound, and tracking monk seals in the remote northwestern Hawaiian Islands—Egnor joined Konishi’s lab, where she contributed to the ongoing study of barn owl hearing.
Few animals can track sounds better than barn owls. Through evolution they have become so adept at it that they can catch a mouse in complete darkness just by tracking the rustling of leaves the rodent makes as it scurries about. This acuity stems from the parabolic sound collectors built into the owls' heart-shaped faces and the “massively” developed auditory pathways that analyze those sounds in their brains. The pathway is ideal for study, says Egnor.
“We know that barn owls, like humans, use differences in the intensity and arrival time of sounds at the two ears to figure out where a sound is coming from,” she says. “In the owl, intensity and time are processed in two separate neural circuits, and converge in the midbrain to form a map of auditory space.”
“We knew from previous work,” says Egnor, “that these neurons need both time and intensity information to form their map.” She then interfered with their ability to analyze time differences by playing totally unrelated sounds through the two sides of custom-made headphones.
According to Egnor, that should have prevented the owls from being able to track noises, but it didn’t. The owls still oriented to sounds, but their reactions were slower and less accurate. Similar results from lesion experiments implicate forebrain circuitry in these sloppier orients. This distinction—between a precise, fast, but demanding midbrain circuit, and a sloppier, slower, but more forgiving, forebrain circuit—may be a general feature of neural circuit design, says Egnor.
From Caltech, Egnor moved to Mark Hauser’s lab at Harvard and began working with the complex social vocalizations of a small New World monkey called the cotton-top tamarin.
Egnor says her work with owls, dolphins, and monkeys has focused on single animals in controlled conditions—simple systems that remove much of the complexity of real world social interactions. Part of the reason, she says, is technological; the tools don’t exist to study animals in natural, uncontrolled situations.
“As a neurobiologist, we’re always studying the behaviors we can study,” she says. “But that’s not how behavior works. Behavior is complicated and messy and there are lots of animals involved and they are never doing just one thing at a time.” Egnor says the draw of Janelia is the freedom to take the leap and try to develop the tools to make those more complex studies possible.
Her experiments will attempt to record and characterize the vocalizations of 40 or more mice in the same enclosure going about their daily, uncontrolled lives. “Problem number one is just keeping track of all the mice,” she says. “Then, you have to keep track of what they’re paying attention to as they vocalize: Are they thinking about what they smell or are they thinking about what they see or are they thinking about both? They are right next to this female, but are they thinking about the female across the cage?”
RESEARCH ABSTRACT SUMMARY:
Roian Egnor uses multigenerational groups of socially housed mice to study the neural basis of complex vocal and social behavior.
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Photo: Paul Fetters