Leon Cooper is a Nobel Prize-winning physicist at Brown University and the director of its Institute for Brain and Neural Systems. Depending on whether you ask a physicist or a neuroscientist, you’ll get very different answers on why Cooper is famous. The former will argue it is because of his indispensable contribution to our understanding of matter; the latter, for his model of the way neurons work. So who is this great scientist, and how did he earn renown in such disparate fields?
Cooper embodies what one would hope a Nobel Laureate to be; wise and giving, pondering deep questions, walking the hallways in a tweed suit with the smell of excellent coffee wafting from his office. He carries himself with the quiet dignity and reserve of a bygone era, and is known for his perennial friendliness toward students and colleagues alike.
A native of New York, Cooper received his B.A., M.A., and Ph.D. from Columbia University, where he specialized in quantum field theory and nuclear physics. After he was a post-doctoral fellow at Princeton’s renowned Institute for Advanced Study, he began working with his colleague John Bardeen on the problem of superconductivity.
To better understand superconductivity, imagine stirring your coffee, and watching it spin in your cup forever. This is analogous to the nearly magical properties of superconductors, a class of materials that allows electricity to flow without losing any energy along the way. They have sparked the imagination of people working to transmit energy efficiently. Superconductors are now used in the powerful electromagnets inside MRI machines, magnetic-levitation trains, and particle accelerators. Although superconducting materials were first discovered in 1911, a coherent explanation for the phenomenon eluded the greatest minds for 50 years thereafter.
That is, until Cooper posited that electrons travel through superconducting materials in pairs, rather than singly, as in conventional conductors. An analogy is that one electron starts “drafting” off another, like NASCAR racers do behind each other’s cars. Cooper, along with Bardeen and Bardeen’s graduate student, John Robert Schrieffer, labored over what is now referred to as the “BCS” theory of superconductivity, for which they were awarded the Nobel Prize in Physics in 1972.
Leon Cooper, the year he won the Nobel Prize in Physics in 1972. (Courtesy of Emilio Segrè Visual Archives, American Institute of Physics)
Although Cooper had been working on his superconductor theory since he joined Brown’s physics faculty in 1958, after a time he says that the work became “very technical,” and his keen curiosity led him elsewhere.
Perhaps surprisingly, he became interested in the science of consciousness; specifically, the biological mechanisms that underlie learning and memory storage. He frames the problem in direct terms: “we knew lots about neurons” as cells, “but not much about how memory is stored.”
Of course, every reporter ushered into his sunny College Hill office has asked Cooper what led him to this change. With kindly patience and a wry smile, he quotes from a well-known film:
“ ‘I came to Casablanca for the waters.’
‘The waters? What waters? We’re in the desert!’
‘I was misinformed.’ ”
In fact, he recounts that “the ideas came rapidly” once he began collaborating with colleagues in neuroscience. His profound mathematical insight enabled the development of the highly successful ‘BCM’ model of synaptic plasticity in 1981. Named for its architects (Elie Bienenstock, Cooper, and Paul Munro), BCM theory provides an analytical model for observations of ‘long-term depression’ (persistent weakness in synaptic connections) or ‘long-term potentiation’ (persistent strengthening of the connections) in the visual cortex of the brain. Significantly, more recent experiments also confirmed this behavior in the hippocampus, which is the region of our brains responsible for the storage and formation of memories.
To develop this research, Cooper became the founding director of Brown’s Institute for Brain and Neural Systems in 1973. The center unites graduate students, post-doctoral fellows, and faculty from fields as diverse as mathematics, medicine, and linguistics to study neural networks and brain science. He collected many of his findings on the intersection of science and human consciousness in a fascinating book, “Science and Human Experience: Values, Culture and the Mind.”
Cooper’s transition from superconductivity to neuroscience is not surprising considering the questions he finds most interesting: “Where does our consciousness come from? How do we construct mental states? What is the circuitry of the brain?” These topics are arguably even more fundamental lines of inquiry than the foundation of matter itself.
To illustrate the point, Cooper cited a beautiful quote from 20th-century philosopher George Santayana: “All of our sorrows are real, but the atoms of which we are made are indifferent.” So how do we, as Cooper queries in his book, “construct real sorrow from indifferent atoms?” Although he concedes that “this is a very difficult question,” he maintains that he is a “scientific optimist — nothing in nature is unknowable.”
Ever the active mind, Cooper has recently turned his intellectual efforts towards understanding the effects of radiation on humans. Cooper is collaborating with a former graduate student, Michael Antosh, and fellow scientists at the Institute for Brain and Neural Systems to study gene expression in fruit flies. Their purpose is to show that there is a clear threshold in radiation tolerance before life expectancy and gene expression is affected. Their elegant experiment implies that the body can heal itself from consistent, low doses of radiation.
On the therapeutic side, he and a team of scientists from Brown and the University of Rhode Island have discovered that a class of compounds called pH Low-Insertion Peptides can be used to preferentially tether nanometer-sized gold particles to cancer cells. Since gold particles increase radiation damage to tumor cells, the use of pHLIP could enhance the effectiveness of a given dose of radiation in cancer treatment.
Both of these experiments are simple in design, with simple-to-understand conclusions, but they nonetheless have huge implications for society. Cooper is excited by these results and their potential to help people throughout the world. With a smile, he affirms, “that’s the kind of thing I like to do.”
A scientific optimist, indeed.
Jacqueline McCleary is a doctoral student in physics at Brown University, specializing in astrophysics.
(Courtesy of Leon Cooper) 
