Sir Andrew Fielding Huxley shared the 1963 Nobel Prize for physiology or medicine with colleague Alan Lloyd Hodgkin for research which unlocked the secret of excitation and inhibition in nerve cells. Huxley theorized that the movement of sodium ions, and not just potassium ions, across the cell membrane was necessary to create an action potential. To test his hypothesis, in 1947, his colleagues Hodgkin and Bernard Katz manipulated the levels of sodium ions in the fluid outside the cell and discovered they could create or eliminate an action potential. This finding began the exciting road to discovering how neurons communicate.
Huxley was born in Hampstead, London. His father, Leonard Huxley, taught classics before becoming a writer, marrying Rosalind Bruce after his first wife died. Andrew, the youngest of their two sons, is half- brother to biologist Sir Julian Huxley and writer Aldous Huxley from his father's first marriage. His grandfather, Thomas Henry Huxley, was a writer and scientist whose work helped Charles Darwin establish his theory of natural selection.
Huxley attended University College School from 1925-1930 then Westminster School where became a King's Scholar. When he entered Trinity College, Cambridge on a scholarship in 1935, his interests lay in physics and engineering. However, a course in physiology excited him so much he transferred to medicine. He became a research assistant with Hodgkin at the Marine Biology Laboratory in Plymouth in 1939 studying electrical impulse transmission from neuron to neuron in squid giant axons. Earlier researchers, including Julius Bernstein, had already determined these impulses were action potentials and hypothesized (correctly) that a cell's resting potential was determined by the distribution of ions within and outside the cell. They knew the larger, positively charged sodium ions were more highly concentrated outside the cell, and the smaller, positively charged potassium ions were more highly concentrated inside the cell. They also believed that the tiny pores in the membrane allowed only the smaller ions to move in or out of the cell, and assumed the cell's resting potential was maintained solely by the movement of potassium ions down the concentration gradient--from inside to outside the cell. Bernstein believed that action potentials caused a temporary "breakdown" of the membrane, permitting ions from both inside and outside the cell to come into contact, thus shifting the resting potential from negative to neutral.
Huxley and Hodgkin decided to test this hypothesis. Using microscopic electrodes to stimulate an action potential in a neuron of a squid giant axon, they discovered that, during an action potential, the voltage was much greater than neutral and that the inside of the cell became positively charged while the outside became negatively charged. This meant that the direction of voltage was actually reversed. They decided that special "gates" or "channels" must penetrate the membrane, opening when subjected to voltage stimulation to allow larger sodium ions to move through the membrane. In 1947, Sir Bernard Katz, Huxley, and Hodgkin tested this theory. By inserting an electrode into cell membranes of squid giant axons and using a special voltage clamp to maintain the membrane at a particular voltage level, they watched the flow of ions with the aid of radioactive isotopes. Using these observations, Huxley created a mathematical model of an action potential using only a hand-cranked adding machine. The remarkable nature of this feat is even more remarkable considering modern biochemical methods of studying gates, channels, sodium-potassium exchange pumps, and the movement of ions across cell membranes, did not exist until the 1980s.
Huxley's research was interrupted by World War II. In 1940, he began conducting operational research in gunnery for the Anti-Aircraft Command and, later, the Admiralty. In 1946 he assumed a research fellowship awarded to him in 1941 by Trinity College, Cambridge and continued his former research while teaching in the Department of Physiology. Around 1952, Huxley began investigating muscle contraction, studying the striation pattern of isolated muscle fibers. He developed a special interference light microscope which allowed the observance of living, unstained muscle tissue. In 1960, he was named head of the physiology department and Jodrell Professor of Physiology at University College, London, and was appointed Royal Society Research Professor at the University of London in 1969 where he remains as professor emeritus. He has honorary degrees from universities in several countries, became a Fellow of the Royal Society in 1955, received the Copley Medal of the Royal Society in 1972, and was knighted in 1974.
Huxley married Jocelyn Richenda Gammell Pease, daughter of the Honorable H.B. Pease and M.S. Pease, a geneticist. Huxley's wife is a Justice of the Peace and extremely active in public work. The couple have five daughters and one son.
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