As I step outside to begin my day, the leaves and grass are lush and green, and summer flowers are still in full bloom. But today, something tells me fall is here. It might be slightly cooler air, or it might be a subtle scent of drying leaves. In almost every appreciable way, today is no different from yesterday, except for one thing: I can smell the season changing.
And when I do, I am instantly transported to a hiking trail from my youth; playing in the backyard with my mom; flying a kite with my dad; watching bugs in a grassy meadow under the crisp autumn sun with 8-year-old eyes. The images, sounds and emotions within these long-ago moments are intact and I am transported into them with surprising immediacy and clarity, my experience evoked by the ethereal, nearly imperceptible, smell of fall.
There are countless “life scents” that connect us with the past, and each one can bring to the front of our consciousness a rich collection of feelings and memories associated with past events. Because of these powerful connections, studying the neuroscience of olfaction offers a unique window into the ways the brain acquires and stores information, and how it assembles sensation, context and meaning into a rich “mental snapshot” that can be retrieved with an associated odor.
I have been interested in how the brain processes information and controls behavior for as long as I can remember. I grew up in the mountains of rural Colorado, in a house on the edge of a vast forest filled with wildlife. There were days I was late to school because a herd of elk numbering in the hundreds was migrating across the road.
I wondered, how do these animals know where they are going, or how to get there? As a child, I imagined that they must have signposts along the way that they were able to read, and I tried to think of what kind of language they might use. I had many such encounters; I saw foxes, raccoons, bears, pumas and bobcats from my kitchen window, and each sighting sparked curiosity about how these animals could thrive in the expansive wilderness; how they found their way and each other; how they could read the seasons; and how they managed all of this without a house and family to tell them what to do.
I knew what I wanted to do when I got to college, but I didn’t know what it was called. I enrolled at Drake University as a psychology major because I wanted to learn more about how the brain influenced behavior. Soon after, I realized that I really wanted to know the biology of the brain and nervous system. But although I thrived on learning more about the chemistry and cellular biology that made cells function, my biology classes didn’t give me a sense of how simple chemical processes could be added together in a way to bring about complex behavior or the works of Shakespeare. Maybe, I thought, I should ditch it all and become a philosophy major.
At this point, one of my professors invited me to work in his lab as a research assistant, studying how drug use in pregnant rats affected the behavior of her pups. The very first project I worked on involved sitting in a dark room with a stopwatch, timing these pups as they learned how to navigate a maze. For hours, as I sat in the dark diligently recording these data, I was captivated by the thought that I was a part of a scientific community contributing knowledge that might lead to a greater understanding of the brain, and maybe even therapies, treatments or cures for human children whose mothers were addicted to alcohol or other drugs. I was hooked.
I learned the name of my passion: neuroscience. I worked in the lab as an undergraduate for two more years, and I had the chance to present my work at several national and international meetings. Thanks to this experience, I knew I wanted to be a part of the community of neuroscientists who could help improve human understanding of how the brain works.
I went to graduate school at the University of Wisconsin-Madison and realized the benefits of a large institution with abundant resources. Where my lab at Drake was full of hand-built equipment and repurposed supplies, my lab at UW was state-of-the-art, filled with the latest technologies to study the brain. We routinely used cutting-edge techniques that I never dreamed of using. It was like being a kid in a candy store; if I could design an experiment that was scientifically sound, I had the resources available to carry it out. I knew from that moment that I wanted to spend my career at a research university.
After earning my Ph.D. and working as a postdoctoral student, I took a faculty position at the University of Virginia. There, I wrote grants and conducted research with my graduate students, occasionally teaching introductory classes with 350 undergraduate students. I bought lots of modern equipment for my lab, and my graduate students and I completed many fascinating experiments. I enjoyed teaching, but I focused on grants and papers, as these were more important to my supervisors. After six years, and in the process of renegotiating my position at UVA, I interviewed for two other faculty positions: one in Colorado at a research university, the other at the University of St. Thomas.
My first interview was at St. Thomas. Meeting with the faculty and students here reminded me of my roots as an undergraduate at a liberal arts institution. I was impressed by the faculty’s commitment to engaging undergraduates in research, and by the administration’s support of it. And I was delighted to see state-of-the- art equipment in the laboratories, as well as the commitment of the faculty to excellence in undergraduate teaching. Then I went to my interview in Colorado, and the opportunity to return to my home turf. After that meeting, I knew there was something special about UST. The students, faculty and environment reminded me of my passion for teaching and working with students, something I had done only occasionally at Virginia. It was a surprisingly easy choice to leave my job, forgo the opportunity to return to the Rockies and move back to the Midwest.
Since arriving at the University of St. Thomas in 2009, my research has involved trying to decipher how rats use sensory cues to learn about their environment. My students and I have been exploring how rats navigate a simple digging task: They will rapidly learn to dig in a cup of sand to get a Froot Loop. (Rats love Froot Loops!) If we give them two cups containing different odors, young rats will learn immediately which odor signals the Froot Loop cup; on average, they will make only one error when learning the task.
Adult rats are a little slower to learn, making an average of 3-4 errors before learning which odorized cup contains the Froot Loop. But adolescent rats surprised us; they make an average of 13-14 mistakes before they learn which cup has the Froot Loop. Moreover, adolescent rats are more distractible, and are harder to keep “on-task” during these experiments than young rats or adult rats.
Why the difference? When young animals can perform the task so well, why does everything go so wrong in the adolescent years? The answer may lie in the changes that occur during normal brain development, and in changes to how sensory information is processed and learned. My students and I currently are using state-of-the-art genetic, anatomical, physiological and behavioral methods to explore these changes.
And as we do, I live my childhood aspiration of discovering how animals learn about their environment, and I get to accomplish my goal of being an active contributor in the scientific community. But more importantly, I get to share my passion by teaching and working closely with the undergraduate students in my lab, and exploring with them the mysteries of the brain.
Associate professor Dr. Kurt Illig teaches undergraduate courses in biology and neuroscience and is the director of the Interdisciplinary Neuroscience Program.
From Exemplars, a publication of the Grants and Research Office.
