Denis Aristide Baylor (January 30, 1940 – March 16, 2022) was an American neurobiologist. He was professor emeritus of neurobiology at Stanford University. He is known for his research on nerve cells in the retina of the eye. He developed a widely-used method for observing the electrical activity of single rod and cone photoreceptor cells and described how they encode light stimuli. Baylor’s work has been recognized by his election to the

American Academy of Arts and Sciences The American Academy of Arts and Sciences (abbreviation: AAA&S) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, a ...

, the National Academy of Sciences, and the

Royal Society of London The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, re ...

Early life and education

Baylor was born on January 30, 1940, in

Oskaloosa, Iowa Oskaloosa is a city in, and the county seat of, Mahaska County, Iowa, United States. In the late nineteenth and early twentieth century, Oskaloosa was a national center of bituminous coal mining. The population was 11,558 in the 2020 U.S. Ce ...

.Baylor, Denis "Curriculum Vitae" via https://profiles.stanford.edu/denis-baylor Baylor received his BA in chemistry from Knox College in 1961, where he graduated magna cum laude and was elected to Phi Beta Kappa. In 1965, Baylor received his M.D. from

Yale School of Medicine The Yale School of Medicine is the graduate medical school at Yale University, a private research university in New Haven, Connecticut. It was founded in 1810 as the Medical Institution of Yale College and formally opened in 1813. The primary te ...

, where he was elected to

Alpha Omega Alpha Alpha Omega Alpha Honor Medical Society () is an honor society in the field of medicine. Alpha Omega Alpha currently has active Chapters in 132 LCME- accredited medical schools in the United States and Lebanon. It annually elects over 4,000 new ...

medical honor society and graduated cum laude. At Yale, he was a postdoctoral fellow in

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 ...

with John Nicholls from 1965 and 1968. He then joined the

United States Public Health Service The United States Public Health Service (USPHS or PHS) is a collection of agencies of the Department of Health and Human Services concerned with public health, containing nine out of the department's twelve operating divisions. The Assistant ...

and worked at the

National Institutes of Health The National Institutes of Health, commonly referred to as NIH (with each letter pronounced individually), is the primary agency of the United States government responsible for biomedical and public health research. It was founded in the late ...

for two years in the laboratory of M.G.F. Fuortes. From 1970 to 1972 he was a Special Fellow of the USPHS in the laboratory of

Alan Hodgkin Sir Alan Lloyd Hodgkin (5 February 1914 – 20 December 1998) was an English physiologist and biophysicist who shared the 1963 Nobel Prize in Physiology or Medicine with Andrew Huxley and John Eccles. Early life and education Hodgkin was bo ...

in Cambridge, England.

Research and career

Academic posts

In 1972 Baylor joined the faculty of the University of Colorado Medical School,where he was associate 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 ...

. In 1974 he moved to Stanford University, where he was an associate professor of physiology up to 1975. Baylor was then an associate professor of

neurobiology Neuroscience is the scientific study of the nervous system (the brain, spinal cord, and peripheral nervous system), its functions and disorders. It is a multidisciplinary science that combines physiology, anatomy, molecular biology, developme ...

between 1975 and 1978. In 1978, he became a professor of neurobiology at Stanford and chaired the Department from 1992-1995. He became Emeritus in 2001. During his career, Baylor has served on the editorial board for ''

The Journal of Physiology ''The Journal of Physiology'' is a biweekly peer-reviewed scientific journal that was established in 1878 and is published by Wiley-Blackwell on behalf of The Physiological Society. It covers research on all aspects of physiology, with an emphasi ...

'', ''

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. ...

'', ''

Journal of Neurophysiology The ''Journal of Neurophysiology'' is a monthly peer-reviewed scientific journal established in 1938. It is published by the American Physiological Society with Jan "Nino" Ramirez as its editor-in-chief. Ramirez is the Director for the Center fo ...

'', '' Visual Neuroscience'', and ''

The Journal of Neuroscience ''The Journal of Neuroscience'' is a weekly peer-reviewed scientific journal published by the Society for Neuroscience. It covers empirical research on all aspects of neuroscience. Its editor-in-chief is Marina Picciotto (Yale University). According ...

''. He served on the Scientific Advisory and Medical Advisory Boards of the Howard Hughes Medical Institute, where he was also a Senior Scientific Officer. He was a member of the Lasker Awards Jury and was on the Visiting Committee at

Harvard Medical School Harvard Medical School (HMS) is the graduate medical school of Harvard University and is located in the Longwood Medical Area of Boston, Massachusetts. Founded in 1782, HMS is one of the oldest medical schools in the United States and is consi ...

. He served on the Visual Sciences Study Section of the NIH, which he chaired, as well as the advisory boards of multiple other foundations.

Research interests and selected publications

Denis Baylor is known for work on early steps in vision, in particular the mechanism in which light energy is converted to neural signals within the rod and cone photoreceptor cells of the eye. He provided a quantitative description of the laws that govern the process. Using a new method for recording the electrical currents of individual cells he recorded for the first time the response of retinal rods to single photons of light and showed that the response is remarkably reproducible. He also described and defined the molecular mechanism of two components of intrinsic photoreceptor noise that limit our ability to detect very dim light. His work revealed how light and color are initially encoded in the primate retina, providing a physiological basis for psychophysical results of Stiles on human vision. He also helped to elucidate the molecular mechanism of a number of the steps that mediate and control the photoreceptor’s electrical response to light.

Awards and honors

Baylor's work has been honored by various awards, including election to the

(1992), the National Academy of Sciences (1993), and the

(2003).

Death

Baylor died of cardiac arrhythmia at the Stanford Golf Course on March 16, 2022, at the age of 82.

References

{{DEFAULTSORT:Baylor, Denis 1940 births 2022 deaths Members of the United States National Academy of Sciences Fellows of the Royal Society Fellows of the American Academy of Arts and Sciences Yale School of Medicine alumni Knox College (Illinois) alumni People from Oskaloosa, Iowa Stanford University School of Medicine faculty