Andrew Huxley

Sir Andrew Huxley
Huxley in 1963
Born	Andrew Fielding Huxley (1917-11-22)22 November 1917 Hampstead, London, England
Died	30 May 2012(2012-05-30) (aged 94) Cambridge, England
Nationality	British
Citizenship	United Kingdom
Alma mater	M.A., Cambridge University (Trinity College)
Known for	nerve action potentials, theory of muscle contraction
Spouse(s)	J. Richenda G. Pease (1947–2003; her death)
Children	1 Son, 5 Daughters
Parent(s)	Leonard Huxley, Rosalind Bruce Huxley
Relatives	Aldous Huxley (Half-Brother), Julian Huxley (Half-Brother), T.H. Huxley (Grandfather), (See Huxley Family)
Awards	1963 Nobel Prize in Physiology or Medicine
Scientific career
Fields	physiologist and biophysicist

Sir Andrew Fielding Huxley, OM, PRS (22 November 1917 – 30 May 2012) was a Nobel Prize-winning British physiologist and biophysicist.

Early life and education

See also: Huxley family

Huxley was born in Hampstead, London, England, on 22 November 1917. He was the youngest son of the writer and editor Leonard Huxley by his second wife Rosalind Bruce, and hence half-brother of the writer Aldous Huxley and fellow biologist Julian Huxley, and grandson of the biologist T. H. Huxley.

When he was about 12, Andrew and his brother David were given a lathe by their parents. Andrew soon became proficient at designing, making and assembling mechanical objects of all kinds, from wooden candle sticks to a working internal combustion engine. He used these practical skills throughout his career, building much of the specialized equipment he needed for his research. It was also in his early teens that he formed his lifelong interest in microscopy.

He was educated at University College School and Westminster School in Central London, where he was a King's Scholar. He graduated and won a scholarship to Trinity College, Cambridge, to read natural sciences. He had intended to become an engineer but switched to physiology after taking the subject to fulfill an elective.

Career

Having entered Cambridge in 1935, Huxley graduated with a Bachelors degree in 1938. In 1939, Hodgkin returned from the USA to take up a fellowship at Trinity College, and Huxley became one of his postgraduates students. Hodgkin was interested in the transmission of electrical signals along nerve fibers. Beginning in 1935 in Cambridge, he had made preliminary measurements on frog sciatic nerves suggesting that the accepted view of the nerve as a simple, elongated battery was flawed. Hodgkin invited Huxley to join him researching the problem. The work was experimentally challenging. One major problem was that the small size of most neurons made it extremely difficult to study them using the techniques of the time. They overcame this by working at the Marine Biological Association laboratory in Plymouth using the giant axon of the Atlantic squid (Loligo pealei) which have the largest neurons known. The experiments were still extremely challenging as the nerve impulses only last a fraction of a millisecond, during which time they needed to measure the changing electrical potential at different points along the nerve. Using equipment largely of their own construction and design, including one of the earliest applications of a technique of electrophysiology known as the voltage clamp, they were able to record ionic currents. In 1939,they jointly published a short paper in Nature reporting on the work done in Plymouth and announcing their achievement of recording action potentials from inside a nerve fibre.

Then World War II broke out, and their research was abandoned. Huxley was recruited by the British Anti-Aircraft Command where he worked on radar control of anti-aircraft guns. Later he was transferred to the Admiralty to do work on naval gunnery, and worked in a team lead by Patrick Blackett. Hodgkin, meanwhile, was working on the development of radar at the Air Ministry. When he had a problem concerning a new type of gun sight, he contacted Huxley for advice. Huxley did a few sketches, borrowed a lathe and produced the necessary parts.

Huxley was elected to a research fellowship at Trinity College, Cambridge, in 1941. In 1946, with the war ended, he was able to take this up and to resume his collaboration with Hodgkin on understanding how nerves transmit signals. Continuing their work in Plymouth they were, within six years, able to solve the problem using equipment they built themselves. The solution was that nerve impulses, or action potentials, don't travel down the core of the fiber, but rather along the outer membrane of the fiber as cascading waves of sodium ions diffusing inward on a rising pulse and potassium ions diffusing out on a falling edge of a pulse. In 1952 they published their theory of how action potentials are transmitted in a joint paper, in which they also describe one of the earliest computational models in biochemistry. This model forms the basis of most of the models used in Neurobiology during the following four decades.

In 1952, having completed work on action potentials, Huxley was teaching physiology at Cambridge and became interested in another difficult, unsolved problem - how does muscle contract? To make progress on understanding the function of muscle, new ways of observing how the network of filaments behave during contraction were needed. Prior to the war, Huxley had been working on a preliminary design for interference microscopy, which at the time he believed to be original, though it turned out to have been tried 50 years before and abandoned. Huxley, however, was able to make interference microscopy work and to apply it to the problem of muscle contraction with great effect. Using microscopes of his own design, he was able to view muscle contraction with greater precision than conventional microscopes, and to distinguish types of fiber more easily. By 1954 he had begun to develop the sliding filament theory of muscle contractions. He synthesized his findings, and the work of colleagues into a detailed description of muscle structure and how muscle contraction occurs and generates force that he published in 1957. Although the details of Huxley's theory of muscle contraction have not been unequivocally proven, it remains the accepted explanation of how muscles function.

In 1953, Huxley worked at Woods Hole, Massachusetts, as a Lalor Scholar. He gave the Herter Lectures at Johns Hopkins Medical School in 1959 and the Jesup Lectures at Columbia University in 1964. In 1961 he lectured on Neurophysiology at Kiev University as part of an exchange scheme between British and Russian professors.

He was an editor of the Journal of Physiology from 1950 to 1957 and also of the Journal of Molecular Biology. In 1955, he was elected a Fellow of the Royal Society and served on the Council of the Royal Society from 1960 to 1962.

He continued to hold college and university posts in Cambridge until 1960, when he became head of the Department of Physiology at University College London. In 1963 he was jointly awarded the Nobel Prize in Physiology or Medicine for his part in discoveries concerning the ionic mechanisms of the nerve cell. In 1969 he was appointed to a Royal Society Research Professorship which he holds in the Department of Physiology at University College London.

In 1980, Sir Andrew was elected as President of the Royal Society, a post he held until 1985. In his Presidential Address in 1981, he chose to defend the Darwinian explanation of evolution, as his ancestor, T. H. Huxley had in 1860. Where as T. H. Huxley was defying the Bishops of his day, Sir Andrew as countering new theories of periods of accelerated change. In 1983 he defended the Society’s decision to elect Margaret Thatcher as a fellow on the ground of her support for science even after 44 fellows had signed a letter of protest.

In 1984, he was elected Master of Trinity, following his long time collaborator, Sir Alan Hodgkin. His appointment broke the tradition that the Master of Trinity alters between a man of science and an arts man.

He remained Master until 1990, and was fond of reminding everyone that Trinity had more Nobel Prize winners than the whole of France.

He maintained up to his death his position as a fellow at Trinity College, Cambridge, teaching in physiology, natural sciences and medicine. He was also a fellow of Imperial College London in 1980.

From his experimental work with Hodgkin, Huxley developed a set of differential equations that provided a mathematical explanation for nerve impulses—the "action potential". This work provided the foundation for the all of the current work on voltage-sensitive membrane channels, which are responsible for the functioning of animal nervous systems. Quite separately, he developed the mathematical equations for the operation of myosin "cross-bridges" that generate the sliding forces between actin and myosin filaments, which cause the contraction of skeletal muscles. These equations presented an entirely new paradigm for understanding muscle contraction, which has been extended to provide our understanding of almost all of the movements produced by cells above the level of bacteria.

Awards

He won the 1963 Nobel Prize in Physiology or Medicine for his experimental and mathematical work with Alan Hodgkin on the basis of nerve action potentials, the electrical impulses that enable the activity of an organism to be coordinated by a central nervous system. Hodgkin and Huxley shared the prize that year with John Eccles, who was cited for research on synapses. Hodgkin and Huxley's findings led the pair to hypothesize the existence of ion channels, which were isolated only decades later. Together with the Swiss physiologist Robert Stämpfli he evidenced the existence of saltatory conduction in myelinated nerve fibres.

Huxley was elected a Fellow of the Royal Society on 17 March 1955, and was awarded the Copley Medal in 1973 "in recognition of his outstanding studies on the mechanisms of the nerve impulse and of activation of muscular contraction." He was knighted by Queen Elizabeth II on 12 November 1974. Sir Andrew was then appointed to the Order of Merit on 11 November 1983. In 1976–77, he was President of the British Science Association and from 1980 to 1985 he served as President of the Royal Society.

Personal life

In 1947, he married Jocelyn "Richenda" Gammell (née Pease) (1925–2003), the daughter of the geneticist Michael Pease (a son of Edward R. Pease) and his wife Helen Bowen Wedgwood, eldest daughter of the first Lord Wedgwood (see also Darwin-Wedgwood family). They had one son and five daughters:

• Janet Rachel Huxley (born 20 April 1948)
• Stewart Leonard Huxley (born 19 December 1949)
• Camilla Rosalind Huxley (born 12 March 1952)
• Eleanor Bruce Huxley (born 21 February 1959)
• Henrietta Catherine Huxley (born 25 December 1960)
• Clare Marjory Pease Huxley (born 4 November 1962)

See also

• Hodgkin-Huxley model
• Huxley family

Further reading

• Huxley, A. F., 1980. Reflections on muscle. The Sherrington Lectures XIV. Liverpool.

External links

• Biography of Andrew Huxley
• Andrew Huxley interviewed by Alan Macfarlane, 5 October 2007 (film)
• Sir Andrew Huxley obituary The Guardian, 31 May 2012.
• Physicist discovered key to brain science The Sydney Morning Herald, 6 June 2012, reprinted from The New York Times.