Nathaniel Kleitman (April 26, 1895 – August 13, 1999) was an American physiologist and

sleep Sleep is a sedentary state of mind and body. It is characterized by altered consciousness, relatively inhibited sensory activity, reduced muscle activity and reduced interactions with surroundings. It is distinguished from wakefulness by a de ...

researcher who served as

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Physiology Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a sub-discipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out the chemical ...

at the

University of Chicago The University of Chicago (UChicago, Chicago, U of C, or UChi) is a private research university in Chicago, Illinois. Its main campus is located in Chicago's Hyde Park neighborhood. The University of Chicago is consistently ranked among the b ...

. He is recognized as the father of modern sleep research, and is the author of the seminal 1939 book ''Sleep and Wakefulness''.

Biography

Early life

Nathaniel Kleitman was born in

Chișinău Chișinău ( , , ), also known as Kishinev (russian: Кишинёв, r=Kishinjóv ), is the Capital city, capital and largest city of the Republic of Moldova. The city is Moldova's main industrial and commercial center, and is located in the ...

, also known as Kishinev, the capital of the province of

Bessarabia Bessarabia (; Gagauz: ''Besarabiya''; Romanian: ''Basarabia''; Ukrainian: ''Бессара́бія'') is a historical region in Eastern Europe, bounded by the Dniester river on the east and the Prut river on the west. About two thirds of Be ...

(now

Moldova Moldova ( , ; ), officially the Republic of Moldova ( ro, Republica Moldova), is a Landlocked country, landlocked country in Eastern Europe. It is bordered by Romania to the west and Ukraine to the north, east, and south. The List of states ...

), in 1895 to a Jewish family. He was deeply interested in consciousness and reasoned that he could get insight in consciousness by studying the unconsciousness of sleep.

Pogrom A pogrom () is a violent riot incited with the aim of massacring or expelling an ethnic or religious group, particularly Jews. The term entered the English language from Russian to describe 19th- and 20th-century attacks on Jews in the Russia ...

s drove him to

Palestine __NOTOC__ Palestine may refer to: * State of Palestine, a state in Western Asia * Palestine (region), a geographic region in Western Asia * Palestinian territories, territories occupied by Israel since 1967, namely the West Bank (including East ...

, and in 1915 he emigrated to the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

as a result of

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

. At the age of twenty, he landed in

New York City New York, often called New York City or NYC, is the List of United States cities by population, most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the L ...

penniless; in 1923, at age twenty-eight, he had worked his way through

City College of New York The City College of the City University of New York (also known as the City College of New York, or simply City College or CCNY) is a public university within the City University of New York (CUNY) system in New York City. Founded in 1847, Cit ...

and earned a PhD from the

's Department of Physiology. His thesis was "Studies on the physiology of sleep." Soon after, in 1925, he joined the faculty there. An early sponsor of Kleitman's sleep research was the Wander Company, which manufactured

Ovaltine Ovaltine (also known by its original name Ovomaltine) is a brand of milk flavoring product made with malt extract (except in the blue packaging in the United States), sugar (except in Switzerland), and whey. Some flavors also have cocoa. Ovalt ...

and hoped to promote it as a remedy for

insomnia Insomnia, also known as sleeplessness, is a sleep disorder in which people have trouble sleeping. They may have difficulty falling asleep, or staying asleep as long as desired. Insomnia is typically followed by daytime sleepiness, low energy, ...

REM sleep

Eugene Aserinsky Eugene Aserinsky (May 6, 1921 – July 22, 1998), a pioneer in sleep research, was a graduate student at the University of Chicago in 1953 when he discovered REM sleep. He was the son of a dentist of Russian–Jewish descent. He made the dis ...

, one of Kleitman's graduate students, decided to hook sleepers up to an early version of an

electroencephalogram Electroencephalography (EEG) is a method to record an electrogram of the spontaneous electrical activity of the brain. The biosignals detected by EEG have been shown to represent the postsynaptic potentials of pyramidal neurons in the neocortex ...

machine, which scribbled across of paper each night. In the process, Aserinsky noticed that several times each night the sleepers went through periods when their eyes darted wildly back and forth. Kleitman insisted that the experiment be repeated yet again, this time on his daughter, Esther. In 1953, he and Aserinsky introduced the world to " rapid-eye movement," or REM sleep. Kleitman and Aserinsky demonstrated that REM sleep was correlated with dreaming and brain activity. Another of Kleitman's graduate students,

William C. Dement William Charles Dement (July 29, 1928 – June 17, 2020) was an American sleep researcher and founder of the Sleep Research Center at Stanford University. He was a leading authority on sleep, sleep deprivation and the diagnosis and treatment of s ...

, who was a professor of psychiatry at the

Stanford medical school Stanford University School of Medicine is the medical school of Stanford University and is located in Stanford, California. It traces its roots to the Medical Department of the University of the Pacific, founded in San Francisco in 1858. This ...

, described this as the year that "the study of sleep became a true scientific field."

Rest activity cycle

Kleitman made countless additional contributions to the field of sleep research and was especially interested in "rest-activity" cycles, leading to many fundamental findings on

circadian A circadian rhythm (), or circadian cycle, is a natural, internal process that regulates the sleep–wake cycle and repeats roughly every 24 hours. It can refer to any process that originates within an organism (i.e., endogenous) and responds to ...

and

ultradian rhythm In chronobiology, an ultradian rhythm is a recurrent period or cycle repeated throughout a 24-hour day. In contrast, circadian rhythms complete one cycle daily, while infradian rhythms such as the human menstrual cycle have periods longer than ...

s. Kleitman proposed the existence of a

Basic rest activity cycle BASIC (Beginners' All-purpose Symbolic Instruction Code) is a family of General-purpose programming language, general-purpose, high-level programming languages designed for ease of use. Dartmouth BASIC, The original version was created by John ...

, or BRAC, during both sleep and wakefulness.

Other experiments

Renowned for his personal and experimental rigor, he conducted well-known sleep studies underground in

Mammoth Cave Mammoth Cave National Park is an American national park in west-central Kentucky, encompassing portions of Mammoth Cave, the longest cave system known in the world. Since the 1972 unification of Mammoth Cave with the even-longer system under F ...

Kentucky Kentucky ( , ), officially the Commonwealth of Kentucky, is a state in the Southeastern region of the United States and one of the states of the Upper South. It borders Illinois, Indiana, and Ohio to the north; West Virginia and Virginia to ...

and lesser-known studies underwater in submarines during

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

and above the

Arctic Circle The Arctic Circle is one of the two polar circles, and the most northerly of the five major circles of latitude as shown on maps of Earth. Its southern equivalent is the Antarctic Circle. The Arctic Circle marks the southernmost latitude at w ...

References

External links

Guide to the Nathaniel Kleitman Papers 1896-2001
at th
University of Chicago Special Collections Research Center
{{DEFAULTSORT:Kleitman, Nathaniel 1895 births 1999 deaths Scientists from Chișinău People from Kishinyovsky Uyezd Moldovan Jews Emigrants from the Russian Empire to the Ottoman Empire Emigrants from the Russian Empire to the United States American people of Moldovan-Jewish descent American physiologists Sleep researchers American centenarians Men centenarians Chronobiologists University of Chicago alumni University of Chicago faculty Jewish neuroscientists American neuroscientists