February 24, 2025

Growing up in a large family taught Deborah Cory-Slechta, Ph.D., an NIEHS RIVER Award recipient, to be independent and forge her own path in life. This tendency has served her well in a research career marked by following her own curiosity, making valuable discoveries, creating innovative experimental techniques, and helping younger scientists blaze their own trails.

Now at the University of Rochester, Cory-Slechta studies how air pollutant exposure early in life can contribute to neurodevelopmental disorders and neurodegenerative diseases.

A Shift to Behavioral Toxicology

After completing bachelor’s and master’s degrees in psychology at Western Michigan, Cory-Slechta moved to the University of Minnesota. There, she earned her Ph.D. in psychology and completed a postdoctoral fellowship under the mentorship of Travis Thompson, Ph.D., who helped establish the behavioral pharmacology field.

In Thompson’s lab, Cory-Slechta studied methadone abuse, using both rodent/mouse and human behavioral testing. This work primed her to consider how chemicals in a person’s environment may affect their behavior. When she came across a study linking lead exposure to behavioral changes in mice, she was fascinated and wanted to dive deeper.

Her mentor encouraged her to pursue her interests, and Cory-Slechta began her early work in behavioral toxicology.

A Pioneer of Lead Exposure Studies

Wanting to stick with this new field of research, Cory-Slechta started postdoctoral work at the University of Rochester, which hosted one of the few behavioral toxicology labs in the nation. There, she continued her lead exposure studies using mice, as well as designing a human epidemiology study in collaboration with pediatrician and lead expert, Bruce Lanphear, M.D. Together, they examined data from a cohort study of children and recruited more families for data collection, searching for links between blood lead concentrations and cognitive outcomes in children. They found lead exposure lowered children’s IQ scores, even at concentrations below the Centers for Disease Control and Prevention (CDC) level of concern.

Cory-Slechta used her mouse model to investigate how lead exposure might cause the neurological outcomes they observed in children. It soon became clear, though, their mouse studies had a major flaw.

“Mothers would come in and say, ‘I can’t afford to pay rent or buy groceries. Now, I have to worry about lead exposure?’” Cory-Slechta recalled. “I went back to my lab and looked at my rats, thinking, ‘What am I modeling? This isn’t anything like what’s going on in the human environment.’ It started me thinking about how to make more translationally relevant models of exposures.”

Cory-Slechta redesigned her mouse model to simulate the stress of a human experiencing deprivation. She trained mice to perform tasks for rewards, then began to reward only one mouse, while another mouse watched but did not receive a reward, causing the deprived mouse stress. When Cory-Slechta added lead exposure to this experiment, the data confirmed what she suspected — the effects of lead are more pronounced when combined with stress, providing a better understanding of real-world toxicity.

A New Research Direction

With a growing appreciation of the importance of replicating real-life conditions holistically in the lab, Cory-Slechta leaped on a new opportunity to explore the effects of contaminants from a different source.

Fellow researchers at the University of Rochester were already studying how air pollution affects the heart and lungs, but few had considered the brain. In 2010, a group of colleagues approached her to examine mouse tissue samples for particulate matter damage. She was astonished to find air pollution affected every area of the brain. From that experience, she began to study the interplay between air pollution and brain health.

Using an inhalation facility that can expose mice to different types of air pollution, Cory-Slechta began looking at the effects of specific components of air pollution on the brain. She started considering metals in air pollution, such as iron and copper, because excess amounts can damage the brain. Her research showed that exposure to all these substances during development via air pollution led mice to display behaviors and characteristics resembling human neurodevelopmental disorders, like autism, and neurodegenerative diseases, such as schizophrenia.

Unlocking the Secrets of Wastesomes

Cory-Slechta’s drive to understand air pollution’s effects on behavior led her to zoom in on a specific component of the brain, corpora amylacea, sometimes called wasteosomes. These small, sponge-like structures are thought to help clean waste out of the brain. Above-average concentrations of wasteosomes, however, are associated with neurodevelopmental and neurodegenerative diseases. Cory-Slechta hypothesizes that when too many wasteosomes cluster near blood vessels, they collapse, releasing their loads of toxins and waste products back into the brain.

Her team found excess wasteosomes in all the pollution-exposed brain tissues they examined, both human and mouse, suggesting the structures could serve as biomarkers for air pollution damage. The team also discovered nano wasteosomes, which are as small as 10 nanometers long, while previously known wasteosomes range from 50 nanometers to a micrometer. The discovery of these nano wasteosomes has opened new avenues of research into their role in brain health and disease. Multiple journal articles on the topic are in process.

“Research is addicting,” Cory-Slechta admitted. “Every time you learn one thing, suddenly there are 10 new questions.”

In 2021, NIEHS presented Cory-Slechta with the RIVER Award, allowing her to pursue new research directions, including the study of wasteosomes and air pollution, with stable funding.

“The RIVER Award has opened doors for my research, allowing me to ask new questions, pursue the answers to related questions, and build collaborations,” she explained. “It has been an extraordinary resource.”

Making a Difference at the Bench

Cory-Slechta attributes part of her success to the crucial support of mentors throughout her career. She, in turn, strives to support early career researchers as they establish themselves. She advises junior faculty and postdocs, particularly working mothers like herself, on how to navigate career challenges, balance work and family demands, and develop fruitful research career.

“Being able to mentor junior faculty has been one of the most rewarding things for me,” she said. “It's very reinforcing to see their progress.”

She also emphasized the importance of translating research into action, to benefit all people affected by air pollution. She works with various organizations, including the U.S. Environmental Protection Agency and the CDC, to advance environmental health research and inform public policy.

“I want to see children grow up without these harmful exposures,” Cory-Slechta said. “Ultimately, that’s where I want to make a difference.”