Bruce McEwen, 1938–2020

The pioneering neuroscientist Bruce McEwen died on January 2, 2020 at the age of 81 following a brief illness. He was the Alfred E. Mirsky Professor and head of the Harold and Margaret Millikin Hatch Laboratory of Neuroendocrinology at The Rockefeller University. Born in Fort Collins, Colorado, Bruce grew up in Ann Arbor, Michigan, in an academic household; his father George was a Professor of English in the University of Michigan’s Engineering School. After graduating from Oberlin College, Bruce started graduate study at The Rockefeller University in 1959 and, after a postdoctorate in Sweden and a brief appointment at the University of Minnesota, served on The Rockefeller University’s faculty for 54 years until his death. He and his wife, the neuroimmunologist Karen Bulloch, collaborated in research and writing. Bruce remained active scientifically until the very end, with a paper published on the day of his death. His friend and coauthor on that paper, Huda Akil, and his brother, Craig McEwen, remember him.

Bruce McEwen with Kobe and Buber on the coast of Maine. Image courtesy of Karen Bulloch McEwen (The Rockefeller University, New York, NY).

Huda

Bruce has been a major force in neuroscience. He conducted groundbreaking research and inspired many of us to think differently about how we create science and how we use it for the greater good. The central theme of his research—the brain biology of stress—lends itself to every level of exploration, from the molecular and cellular, to the neural and behavioral, to the societal and global, and Bruce explored them all. In a seminal 1968 Nature paper (1), Bruce demonstrated for the first time the binding of glucocorticoids in the brain, specifically in the hippocampus. This was very surprising as the hippocampus had been thought to be primarily relevant to memory. That discovery led to the unexpected notion that the response to stress is not simply a peripheral event related to “fight or flight” but rather was integral to many functions of the brain, affecting our cognition, memory, and perception.

Bruce also knew cell biology and understood that glucocorticoids have both rapid and long-lasting effects, even though this predated the characterization of steroid receptors as ligand-activated transcription factors. This led Bruce and colleagues to consider how steroid hormones might remodel the brain at the structural and functional level, literally changing the shapes of neurons and their connectivity. This dynamic view of the brain was revolutionary for the time but was entirely in line with Bruce’s views of the brain as an organ for adapting, coping, and integrating information from various sources: its social setting, the rest of the body, and other ongoing neural functions. He underscored that as the arc of our lives moves forward, our experiences (positive and negative) are written in the structure of our brains and become part of its fabric.

“We can never go back,” Bruce emphasized, but adaptive mechanisms could counterbalance, compensate, and induce resilience to environmental demands. He pointed to factors that stretch these adaptive mechanisms to their extreme, be they genetic vulnerability, an unhealthy body, or a toxic environment, increasing the “allostatic load” to the point where it could lead to depression, dementia, and other brain disorders. But this plethora of convergent factors is also a source of hope; there are many ways to reset the system, lighten the load, and call upon the remarkable neuroplasticity of the brain to rewire itself and bounce back.

But beyond this reframing of our thinking about our own minds, Bruce was also ahead of the curve in thinking about science as a team sport, not an ego trip. Many of my clearest memories of him are in my living room in Ann Arbor during the late 1980s or early 1990s. My husband Stanley Watson and I, along with members of our laboratories, are brainstorming with Bruce. We have a flip chart on an easel, and a postdoctorate is telling Bruce about his latest studies, not only the good stuff but also the challenges. Bruce listens attentively, has very specific and helpful suggestions, and points us to various relevant papers in the literature. We eat sandwiches from Zingerman’s deli and make a party of it.

This scene was to repeat itself over several years, as Bruce’s mother was still living in Ann Arbor, and he visited her on a regular basis. During these gatherings, we told Bruce about our progress, and he updated us about work ongoing in his laboratory. We discussed neuroscience more broadly: Gaps, challenges and exciting questions for the future. We also got to know each other’s families, including Bruce’s wonderful mom and her love of Gilbert and Sullivan; and his wife Karen Bulloch and his brother Craig McEwen, with whom we celebrated the University of Michigan Honorary Doctorate that Bruce received in 2005.

It was during these scientific exchanges that I discovered how Bruce’s personality played into his science. He had a deep and up-to-date knowledge of the field and a prodigious memory to use it maximally. Bruce saw connections that were not at all obvious that formed the basis of his new conceptual frameworks. And he made it all seem easy, probably because it came easily to him. But more importantly, I began to perceive how remarkable he was as a person: His humility, integrity, and generosity. Bruce always gave full credit to others. He never spoke down to anyone. His ego was never, ever, in the way. He made us feel like we were all in this together, on a fantastic adventure to discover important truths. Needless to say, we trusted him completely, with our early data, our discoveries, our successes, and our failures.

It is this remarkable combination of passion, intellectual power, bone-deep integrity, and love of humanity that explains why Bruce is such an inspirational figure. His science blended seamlessly with his essential goodness and his life made it clear that knowledge is a gift to be shared, not just among those who create it, but also with those who need it most.

Craig

Sharing his vast knowledge and insights with students, the public, policymakers, and practitioners was a central feature of Bruce’s later career. A small sampling includes two books for the lay public—The Hostage Brain (2) and The End of Stress as We Know It (3)—collaborating with researchers and practitioners of mindfulness and meditation, sharing the stage with the Dalai Lama as part of a Mind and Life Dialogue, meeting with policymakers to deepen their understanding of posttraumatic stress disorder, lecturing to medical students about brain research and its clinical implications, supporting the RockEDU Science Outreach to K–12 science educators and students, and Rockefeller’s Parents and Science Initiative. He believed deeply in science, science education, and the potential of science to change lives for the better.

Bruce’s family, as well as friends, graduate students, postdoctorates, and colleagues were all beneficiaries of Bruce’s willingness and ability to share his knowledge. We were familiar with what his former students called his Big Mac attacks: Times when in response to a question about a scientific question, he would pause, roll his eyes, and then download a coherent rendition of research across disciplines, complete with citations. I experienced early indications of this capacity for encyclopedic knowledge. In his teens he seemed to know extensive details about every airplane ever built and spent many hours assembling plastic and wooden models.

Over the last decade, Bruce came to describe himself as a molecular sociologist. He developed that identity over several decades, starting in the MacArthur Network on Determinants and Consequences of Health-Promoting and Disease-Preventing Behavior and continuing with the MacArthur Network on Socioeconomic Status and Health. That engagement led to active participation on the National Scientific Council on the Developing Child. These and other commitments, such as membership in the Hope for Depression Research Foundation Task Force, reflected Bruce’s wide-ranging interests and commitment to putting science to work for the common good.

Bruce’s view of himself as a molecular sociologist may have been influenced a bit by my career as a sociologist. Bruce was my older brother by almost 8 years, so our lives and careers diverged early on. Nonetheless, we talked often and learned from each other. Although I was in awe of Bruce’s extraordinary accomplishments, he was not. He followed my career with loving encouragement and openly admired my hands-on engagement in local communities, including work with the United Way of Mid Coast Maine to strengthen supports for early childhood development.

An invitation for the two of us to provide the keynote at the 2011 Annual Meeting of the United Way deepened our conversations about early childhood and the impact of social inequality on life chances. This began an unusual and immensely rewarding professional collaboration, as I came to understand through Bruce that social processes and structures help shape and reshape the brain, with consequences for behavior and life trajectories. After several coauthored articles, our partnership culminated in a joint lecture on the 111th anniversary of our father’s birth, shortly before Bruce’s death. That talk on Inequality and Early Childhood Adversity: Toxic Stress and Its Epigenetic Effects at the University of Pennsylvania’s Andrea Mitchell Center was part of their Reverberations of Inequality Series and represented well Bruce’s extraordinary interdisciplinary reach, intellectual openness, and deep commitment to science and to social justice. He was a beloved brother and a cherished intellectual partner.