Klaus Miczek was born in Germany and earned his BA degree at the Padagogische Hochschule-Berlin in 1966. He completed his graduate training at the University of Chicago, Illinois, where he began studying aggressive behavior and operant models of conditioned aversion under the mentorship of Sebastian P. Grossman. After receiving his PhD in 1972, he accepted a faculty position at Carnegie-Mellon University in Pittsburgh, Pennsylvania, where he was an Assistant and then Associate Professor. In 1979, he accepted a position at Tufts University, Massachusetts, in the Department of Psychology and was promoted to Professor in 1984. Klaus remained at Tufts for the duration of his career, becoming the Moses Hunt Professor of Psychology, Psychiatry, Pharmacology and Neuroscience. He was 79 years old when he died. He is survived by his beloved wife Christiane and son Nikolai Miczek.

Credit: Anna Miller/Tufts University

Klaus was a world-renowned leader in behavioral pharmacology and neuropsychopharmacology research. Over the course of his career, he focused on understanding the pharmacological and brain mechanisms underlying aggression, social stress, and drug and alcohol misuse. He was prolific, publishing more than 270 research articles, 50 reviews and numerous book chapters, and he was highly successful at maintaining federal funding. Klaus was awarded multiple R01 grants funded by the National Institute on Drug Abuse (NIDA) and the National Institute on Alcohol Abuse and Alcoholism (NIAAA), including a NIDA grant with sustained funding for 29 years. He was also the recipient of an NIAAA MERIT award, which is the highest individual award given to provide long-term support to outstanding, experienced investigators.

Klaus at the first joint meeting of the Behavioral Pharmacology Society and the European Behavioral Pharmacology Society in Boston with some of his former mentees. Shown (left to right) are Lisa Gold, Margaret Haney, Klaus Miczek, James Winslow, Jeffrey Vivian and an attendee. Klaus served as President of the Behavioral Pharmacology Society. Credit: Lisa Gold

Klaus was most known for his research on aggressive behavior and was a pioneer in developing social-stress paradigms based on ethologically relevant behaviors. Early on, he developed the resident–intruder paradigm to study aggression in rodents1. The aggressive response of the resident to defend its territory or offspring results in a stress response in the intruder opponent. An important feature of the resident–intruder test is that it enables researchers to study the effects of drugs on both aggressive behavior (that of the resident) and social defeat behavior (that of the intruder). An early finding was the demonstration that social defeat stress can result in opioid-like analgesia via the release of endogenous opioid peptides in the CNS, and that with repeated exposure and subsequent development of ‘social defeat’ behaviors, opioid tolerance develops and changes in opioid receptors occur2. His research also demonstrated that chronic social stress exposure results in an anxiety- or fear-like state3 as well as long-term impairment of autonomic circadian rhythm and high levels of defensive behaviors that do not habituate over time4. Klaus’s research also provided insight into individual differences in aggressive behaviors, behavioral phenotypes, and the distinct effects of alcohol, anxiolytic and stimulant drugs on patterns of aggressive behaviors5,6. Importantly, social defeat and chronic social stress have acute and long-lasting effects on brain neurochemistry and behavior that increase self-administration of drugs such as cocaine, opioids and alcohol7,8,9,10.

For his profound achievements, Klaus received numerous awards, including the Tufts University Distinguished Scholar Award, the Distinguished Scientist Award of the European Behavioral Pharmacology Society, the highly prestigious Brady–Shuster Award from the American Psychological Association (Division 28 in Psychopharmacology), and the Solvay Duphar Award. He was awarded Silver Medals from the Charles University in the Czech Republic, was named the Boerhaave Professor at the medical faculty of Leiden University in the Netherlands, and received the Japan International Science & Technology Fellowship twice, at the Universities of Tokyo and Tsukuba. Klaus also received a Knight’s Cross Order of Merit from the President of the Federal Republic of Germany for his scholarly achievements.

In addition to his passion for science, Klaus loved opera, art and poetry. He and Christiane were members of the Metropolitan Opera House, and he also was a member of a German poetry club. Some may remember his inclusion of different works of art in his talks at scientific conferences. He also was a keen cyclist, often riding his bike to work.

On a personal note, Klaus was our PhD mentor at Tufts University. As many know, a graduate school mentor is like one’s scientific parent. You come to graduate school with enthusiasm but little else, so a mentor has enormous influence in shaping the scientist you become. Klaus had an unwavering commitment to scientific rigor and a deep and abiding fascination for science. He taught us to critically evaluate evidence and to work hard. Klaus had exacting standards and was not effusive with praise. As a result, when he delivered positive feedback, it could lift you up for days. That variable reinforcer schedule maintained high rates of behavior from his students. Klaus was very supportive of his mentees throughout their careers, sponsoring them for awards and a range of scientific opportunities. He fostered long-term connections with his mentees over decades, which included large dinners for current and prior trainees at the Society for Neuroscience meetings, and our celebration (and gentle roasting) at his 70th birthday. Many of his mentees have gone on to have successful careers in academia and industry, a testament to Klaus’ extraordinary influence and guidance. We are endlessly grateful for the foundational impact Klaus has had on our lives. He will be missed deeply.