Kim Mulligan, left, an assistant professor of biological sciences, and Lillian Murphy, an award-winning student, are doing research with significant implications for dealing with brain disorders. (Sacramento State/Andrea Price)

Kim Mulligan’s close friend and roommate at Stanford University was brilliant and talented, beautiful and fun. Mental illness upended her life, ultimately driving her to suicide.

Mulligan, at the time a doctoral student of developmental biology, was haunted by questions about what happened to her friend.

What was the molecular basis of brain diseases such as bipolar disorder, the effects of which claimed a young woman who seemed to have such a bright future? What were the underlying forces responsible for the disease that led to her death?

The tragedy helped forge Mulligan’s career path. After earning her PhD at Stanford, she completed a fellowship at UC San Francisco focusing on the genetics of mental illness. Now an assistant professor of biological sciences at Sacramento State, Mulligan continues to research and teach the molecular and cellular underpinnings of disorders caused by abnormal brain development or brain damage early in life.

Mulligan's research laboratory uses the common fruit fly as a model organism to study how genes and environmental factors may converge to cause neurodevelopmental disorders including autism and Fragile X syndrome. The work recently earned student Lillian Murphy the 2019 Glenn Nagel Undergraduate Research Award, which supports student biotechnology research throughout the California State University system.

Joanna Mott, dean of the College of Natural Sciences and Mathematics (NSM), called Mulligan’s mentorship of students in her lab “simply outstanding.”

“Her efforts exemplify excellence in scholarly activity, and she illustrates the kind of successful research that can be accomplished on our campus,” said Mott.

Such studies could lead to better understanding of the origins of and treatments for terrible illnesses like the one that tormented her friend, Mulligan said in a recent interview.

“The big picture is to help inform preventive measures for these disorders,” she said. Those measures could include identifying products containing chemicals that might cause neurological damage to developing fetuses, Mulligan said. For a scientist, “that’s about as important as it gets.”

Mulligan, who grew up in the Sacramento area, credits her parents with fostering within her a sense of curiosity about the world and an appreciation for education. She has always had an interest in biology, she said, which she cultivated at an early age exploring tide pools at Dillon Beach in Marin County and collecting snails in her back yard in Rancho Cordova and Fair Oaks.

She fell in love with chemistry and biology as a student at American River College, she said, then earned her undergraduate degree at UC San Diego, where she majored in biochemistry and cell biology.

Conducting research in college was “transformational,” she said. “It seemed magnificent to me that we could ask these questions about science, and visualize molecules and cells.”

But it wasn’t until graduate school at Stanford – and her friend's death – that Mulligan’s career path became clear.

Mulligan and her housemate were part of a small group of doctoral candidates studying developmental biology, or the process by which organisms grow and mature. Both were excellent students and enjoyed sports and the outdoors.

During their fourth year at Stanford, Mulligan’s friend’s life began to deteriorate. She stopped attending class and gave up riding horses and jogging. She spent money indiscriminately. Her bubbly personality evaporated.

Not long after being diagnosed with bipolar disorder and beginning treatment, the friend drove to one of her favorite places, Lost Lake along the San Joaquin River northeast of Fresno, and injected herself with a fatal dose of laboratory chemicals. She left notes to close friends and relatives, blaming mental illness for her death and saying life was impossible to navigate “with a mind that is not my own,” Mulligan recalled.

As Mulligan’s grieved, she grappled for answers.

“It was part of what helped me heal,” she said. “I thought, ‘I can’t go back in time and change this. What can I do to understand these diseases of the mind?’ ”

After conducting three years of post-doctoral research at the University of California, San Francisco, on the origins of mental illness, Mulligan moved to Sacramento with her husband, Jack, a lawyer with deep roots in the capital. In January 2015 she accepted a position at Sac State, relishing the idea of mentoring another generation of scientists while continuing to research neurodevelopmental disorders.

“For me, it was the perfect mix of my two passions,” she said.

Mulligan and her students are investigating how certain chemicals interact with genes to harm brain development. Fruit flies are an ideal organism for such studies because they have many genes associated with human diseases. 

“Those genes have been sequenced, so we know a lot about them,” Mulligan said.

The flies also are less expensive and easier to work with than other species, such as mice.

Students in Mulligan's lab are studying the behaviors of flies and examining their brains to determine whether environmental factors increase the risk of neurodevelopmental disorders.

They are exposing the flies to chemicals suspected of causing or increasing the severity of certain brain disorders, then examining “innate” behaviors such as those associated with courtship.

When the scientists observe distinct differences in such behaviors, they perform cellular and molecular analyses of fly brains and neurons.

The work should lead to a better understanding of how genes linked to disorders such as autism work in human brain cells, said Mulligan and Murphy, her award-winning student.

“Since there are thousands of untested chemicals in the Environmental Protection Agency’s inventory, I hope this research will provide answers as to which chemicals impair neurodevelopment,” said Murphy, who is on track to graduate in Spring 2020 and plans to pursue a PhD in neurosciences. She said she hopes the research will lead to better awareness about neurobiological disorders and, ultimately, to better treatments.

The fruit fly research allows students such as Murphy to generate data that they can present at professional meetings, “preparing them to be competitive for careers in science,” said Mott, the NSM dean.

Mulligan also sees the work as a tribute to the friend whose death had such a profound impact.  

“These disorders are devastating,” she said. “The more evidence that we have in the world about what causes them, the better.” – Cynthia Hubert