Mircea Steriade (August 20, 1924 – April 14, 2006), MD, DSc, was a prominent researcher in

systems neuroscience Systems neuroscience is a subdiscipline of neuroscience and systems biology that studies the structure and function of neural circuits and systems. Systems neuroscience encompasses a number of areas of study concerned with how nerve cells behave ...

. He was born in

Bucharest Bucharest ( , ; ro, București ) is the capital and largest city of Romania, as well as its cultural, industrial, and financial centre. It is located in the southeast of the country, on the banks of the Dâmbovița River, less than north of ...

Romania Romania ( ; ro, România ) is a country located at the crossroads of Central Europe, Central, Eastern Europe, Eastern, and Southeast Europe, Southeastern Europe. It borders Bulgaria to the south, Ukraine to the north, Hungary to the west, S ...

, and studied

medicine Medicine is the science and practice of caring for a patient, managing the diagnosis, prognosis, prevention, treatment, palliation of their injury or disease, and promoting their health. Medicine encompasses a variety of health care pract ...

University of Bucharest The University of Bucharest ( ro, Universitatea din București), commonly known after its abbreviation UB in Romania, is a public university founded in its current form on by a decree of Prince Alexandru Ioan Cuza to convert the former Princel ...

. He emigrated to

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

in 1968, where he became a professor of

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 ...

Université Laval Université Laval is a public research university in Quebec City, Quebec, Canada. The university was founded by royal charter issued by Queen Victoria in 1852, with roots in the founding of the Séminaire de Québec in 1663 by François de Montmo ...

Quebec Quebec ( ; )According to the Canadian government, ''Québec'' (with the acute accent) is the official name in Canadian French and ''Quebec'' (without the accent) is the province's official name in Canadian English is one of the thirtee ...

, a position he held for the rest of his life. He is the father of linguist, Donca Steriade.

Research

While at Laval University, he discovered that the slow oscillations of

NREM Non-rapid eye movement sleep (NREM), also known as quiescent sleep, is, collectively, sleep stages 1–3, previously known as stages 1–4. Rapid eye movement sleep (REM) is not included. There are distinct electroencephalographic and other char ...

sleep arise when groups of

neuron A neuron, neurone, or nerve cell is an electrically excitable cell that communicates with other cells via specialized connections called synapses. The neuron is the main component of nervous tissue in all animals except sponges and placozoa. N ...

s fire together for a little while (so-called "on periods"), then fall silent for about a fraction of a second ("off periods"), and then resume their synchronized firing. This was one of the fundamental discoveries in sleep research. After his discovery, scientists have also discovered that in birds and mammals, the slow waves are large if preceded by a long period of wakefulness and become smaller as sleep goes on. The majority of his research was on corticothalamic

oscillations Oscillation is the repetitive or periodic variation, typically in time, of some measure about a central value (often a point of equilibrium) or between two or more different states. Familiar examples of oscillation include a swinging pendulum ...

. He was among the first to study the dynamics of the

brain A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a v ...

during sleep, and one of his key discoveries was determining the role of thalamic reticular neurons as pacemakers in producing the

sleep spindle Sleep spindles are bursts of neural oscillatory activity that are generated by interplay of the thalamic reticular nucleus (TRN) and other thalamic nuclei during stage 2 NREM sleep in a frequency range of ~11 to 16 Hz (usually 12–14 Hz) ...

rhythm. He also discovered slow (<1 Hz) sleep rhythms associated with intracortical activity.

Honors

In 1998 he was the recipient of the Gloor-Award (American Clinical Neurophysiology Society).

References

Nature obituarySociety for Neuroscience obituaryNew Hypothesis Explains Why We Sleep (published in Scientific American)
Romanian emigrants to Canada 1924 births 2006 deaths University of Bucharest alumni Academic staff of Université Laval {{Med-bio-stub