Prof. Emeritus Allan Rechtschaffen, a pioneer of modern sleep research and director of the University of Chicago Sleep Laboratory for more than 40 years, died Nov. 29. He was 93 years old.
Al, as he was affectionately known by his family, many friends and colleagues, was a seminal figure in our understanding of the biological functions and purpose of sleep, including the various stages of sleep and the detrimental effects of sleep deprivation. He also played a key role in establishing sleep research as an academic and clinical medical discipline in the 1960s.
“Al had a single-mindedness about his work. His whole career was devoted to understanding the function of sleep,” said Thomas Roth, director of the Sleep Disorders and Research Center at Henry Ford Hospital in Detroit. “He created the infrastructure and built the foundations that were necessary to create an environment where other people could expand the field into what it is today. If you ever needed to know anything about sleep, you just asked Al.”
The Professor Emeritus of Psychology, Psychiatry and the College, Rechtschaffen came to the University of Chicago in 1957—joining renowned faculty member Nathaniel Kleitman, who had established the world’s first sleep laboratory and is universally recognized as the father of sleep research.
A few years earlier, in 1953, Kleitman and one of his students, Eugene Aserinsky, had discovered rapid eye movements (REM) during sleep and first suggested that they were associated with dreaming. Rechtschaffen, taken by Kleitman’s work, began his own research on REM sleep and dreams, but his interests quickly led to the biological function and purpose of sleep, which preoccupied him for the next 44 years.
He was fixated on a fundamental question: “Why do we sleep?” All mammals, birds, and reptiles sleep in some form or another, whether it’s bundled up in a cozy bed, burrowed into a hole in the ground, or floating in the water. Sleep obviously serves an important biological purpose, but as Rechtschaffen once pointed out, it seems contrary to survival. “Sleep precludes hunting for and consuming food. It is incompatible with procreation. It produces vulnerability to attack from enemies. Sleep interferes with every voluntary adaptive motor act in the repertoire of coping mechanisms,” he said.
He pursued his research with characteristic intensity, studying the effects of sleep on various physiological functions, from exercise and mental stimulation to metabolism and stress. He worked primarily with animals, including rats and reptiles; Roth recalled once stumbling across a small alligator in a bathtub in Rechtschaffen’s lab on Drexel Avenue.
His research focused on what happens to animals when proper sleep is deprived or disrupted. In 1963, Rechtschaffen and UChicago colleague Gerry Vogel, working with William Dement of Stanford University, described narcolepsy—the first true sleep disorder—in a landmark paper. Later in 1968, Rechtschaffen and Anthony Kales of UCLA standardized the scoring system for human sleep stages, now known as the Rechtschaffen and Kales system, or simply R&K, which is still used by sleep laboratories worldwide today.
Rechtschaffen is perhaps best known for his landmark finding in 1983 that sleep is essential for survival. Researchers had long been trying to study the effects of sleep deprivation, primarily with rats, but the methods used to keep them awake, such as electrical shocks or dunking them in water, created additional stress and physical responses that confounded the intrinsic effects of lack of sleep.
Rechtschaffen, working with fellow UChicago faculty member Bernard Bergmann, devised a gentler apparatus called the disk-over-water method. An experimental rat would be placed on a round platform over a shallow pan of water, along with a control rat. When the experimental animal started to show signs of falling asleep, the disk began to slowly rotate. The animal had to walk to keep pace with it to avoid having its paws dipped into the water, thus staying awake. The control rat could continue sleeping whenever the experimental rat was awake.
Using this new technique, Rechtschaffen and collaborators showed that rats that were continuously deprived of sleep suffered severe health effects and died after about two weeks. Rats that were deprived of only REM sleep survived longer, but ultimately died as well. The rats also displayed a sharp drop in body temperature before they died. Rechtschaffen believed that this observation showed that sleep was essential for temperature regulation, although he never answered the question of the mechanisms underlying the lethal effect of sleep deprivation.
“If sleep does not serve an absolutely vital function,” he was fond of saying, “then it is the biggest mistake the evolutionary process has ever made.”
Rigorous, charismatic and intellectually generous
Rechtschaffen was born in New York City and grew up on the Lower East Side, later moving to the Bronx. He received his bachelor’s and master’s degrees from City College of New York and earned his Ph.D. in psychology from Northwestern University in 1956. He was initially hired by the University of Chicago as a clinician in the Department of Psychiatry, and was soon named director of the Sleep Research Laboratory.
Known as a rigorous, organized and charismatic researcher and teacher, Rechtschaffen’s work was supported by competitive grants from the National Institutes of Health for nearly his entire career. He trained 25 Ph.D. students, many of whom are still active in the field today.
—Prof. Jacqueline Stewart
