Clay M. Armstrong, MD, professor of physiology at the University of Pennsylvania School of Medicine, will share the 1999 Albert Lasker Basic Medical Research Award from the Albert and Mary Lasker Foundation. Armstrong was named with Bertil Hille, PhD, professor of physiology and biophysics at the University of Washington, and Roderick MacKinnon, MD, professor of molecular neurobiology and biophysics at The Rockefeller University. The researchers will receive their awards during a luncheon on October 1 in New York City.
The Lasker Award is often cited as a Nobel Prize predictor: 61 Lasker Award recipients have subsequently received the honor. Armstrong is being cited for pioneering research elucidating the physical processes underlying electrical signaling in and between cells. His work unveiled the mechanisms governing the behavior of ion channels. These basic components of all cells play a fundamental role in the conduction of electrical impulses in nerve, muscle, and heart, and control the central nervous system, including the brain, muscle contraction, cardiac rhythm, hormone secretion, and many other vital biological events.
Since the 19th century, scientists have known that nerve impulses were transmitted electrically. Exactly how they were propagated throughout the body, however, was still mysterious. During approximately the same era, engineers working on the first trans-Atlantic cables found that electronic signals would fade and be lost without the use of booster stations along the way. What Armstrong discovered years later was precisely how ion channels function as the nervous system's booster stations, responsible for receiving and reproducing signals as they travel along nerve fibers.
"Conveying nerve impulses through the body is like transmitting an electrical signal faithfully over a very long distance," Armstrong explains. "Both require the equivalent of amplifiers along the way. When a signal enters a cell, it doesn't simply pass through. The ion channels are needed to perfectly reproduce the message."
Clay Armstrong has been studying ion channels for nearly 40 years. Beginning in the early 1960s, building on the work of 1963 Nobelists A.L. Hodgkin and A.F. Huxley, Armstrong identified many of the fundamental properties of ion channels. Like Hodgkin and Huxley, Armstrong's studies used squid giant axons, which are 40 times larger in diameter than the corresponding nerve fibers of any vertebrate species, including humans. He described the channels as pores in the cell membrane which control the movement of ions - electrically charged atoms - into or out of the cell. These ions include sodium, potassium, calcium, and chloride, and their movement constitutes an electrical current. Many important drugs act by blocking ion channels. Examples include local anaesthetics and calcium channel blockers, which are used to restore the normal rhythms of the heart. Armstrong's research has contributed greatly to our understanding of the mechanisms by which drugs interact with ion channels.
In the 1970s, he delved deeper, gaining fundamental insights into the ion-channel structures responsible for sensing an incoming electrical signal, for opening the gate that controls ion passage, and, finally, for closing, or inactivating, the channel. He proposed the existence of a positively charged helix for detecting the electrical signal and opening, or "gating," the channel, and he first succeeded (with Francisco Bezanilla, now professor of physiology at the University of California, Los Angeles) in measuring the so-called gating current caused by the movement of that charged helix. He also postulated a "ball and chain" mechanism for inactivation of channels, in which a globular peptide attached to an amino acid chain can block the channel by becoming lodged in its inner mouth. In all of these areas, Armstrong anticipated recent structural insights gained from molecular biology and X-ray crystallography.
After earning his medical degree from Washington University in 1960, Armstrong completed a research fellowship in neurology there in 1961, and moved on to postdoctoral work at the NIH and the University College London, where he worked with A.F. Huxley. He was an assistant professor of physiology at Duke University from 1966 to 1969 and associate professor of physiology at the University of Rochester from 1969 to 1974, where he became a full professor in 1974. He came to Penn in 1975.
Editors: A photograph of Clay M. Armstrong, MD, is available on the web at three
different resolutions, 72 dpi, 100 dpi, and 600 dpi (please note that these URLs
are case sensitive):
http://mail.med.upenn.edu/~hokef/ARMSTRONG72.jpg
http://mail.med.upenn.edu/~hokef/ARMSTRONG100.jpg
http://mail.med.upenn.edu/~hokef/ARMSTRONG600.jpg
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