Alan Lloyd Hodgkin Biography (1914-1998)
Alan Lloyd Hodgkin was best known for his work in defining the electrical andchemical characteristics of nerve impulses. Along with Andrew F. Huxley he performed experiments on the nerve fibers of squid and described the nerve impulses with a series of mathematical equations. For their research in this area, which resulted in the ionic theory of nerve impulses , the two menshared the 1963 Nobel Prize in physiology or medicine with John C. Eccles.
Hodgkin was born on February 5, 1914, in Banbury, Oxfordshire, England, to George L. and Mary Wilson Hodgkin. Hodgkin's father died in Baghdad during World War I, only a few years after his birth. Hodgkin was educated at the DownsSchool in Malvern and the Gresham School in Holt. In 1932, he entered TrinityCollege, Cambridge, where he first became interested in physiology. Hodgkinbecame a fellow at Trinity in 1936, serving as lecturer and later as assistant director of research at the physiological laboratory.
Hodgkin began studying the electrical properties of the nerve fibers in the shore crab while at Cambridge. He spent a year at the Rockefeller Institute inNew York City between 1937 and 1938, and while there he met scientists who had developed new methods for studying nerve fibers. Hodgkin brought these ideas back to Cambridge, where with Andrew Huxley he devised an experiment to test an hypothesis about nerve impulses first proposed by German physiologist Julius Bernstein .
Bernstein had hypothesized that nerve cells possess a resting or unstimulatedpotential and an action or stimulated potential. During the resting potential, he believed, the nerve cell membrane had an unequal distribution of positively and negatively charged ions, with more negative ones on the inside. During resting potential, the membrane was permeable to the positively charged ions, but the negatively charged ions could not permeate the cell membrane. When the cell was stimulated, Bernstein argued, the membrane "gates" were temporarily opened, allowing ions to pass in both directions. By using the nerve cells of the shore crab, Hodgkin was able to establish that the resting potential was due to an outward movement of potassium ions; during the action potential the cell membrane's gates allowed in the more concentrated sodium ions. He also discovered that the action potential was usually much larger than theresting potential.
Some of the researchers Hodgkin had met in the United States were working with squid, whose nerve fibers are larger than those of most organisms. Hodgkinand Huxley were able to develop a method to study these fibers using microelectrodes, and they were able to confirm the results of their earlier experiment. Their progress, however, came to a halt during World War II, when Hodgkinworked on radar systems for aircraft for the Air Ministry. Hodgkin and Huxleywere back in Cambridge in 1945, and they formed a small research group to pursue their pre-war investigations into nerve fibers.
In 1951, Hodgkin and his colleagues published the results of their research.They found that the membrane is permeable only to specific ions during the resting potential, because of the differing concentrations of potassium and sodium. The concentration of the positively charged sodium ions is greater on the outside of the membrane and the concentration of negative potassium ions higher on the inside during resting potential. During the action potential, thenegative and positive ions travel through the membrane, so that the interiorcharge becomes positive and the exterior negative. This is followed by an equilibrium charge, then a return to the resting potential charge state. All this happens in milliseconds.
The work done by Hodgkin and Huxley which was most responsible for bringing them to the attention of the Nobel Prize committee was the development of a series of mathematical formulae they published in 1952. The purpose of these equations was to synthesize the experimental information then available about the electrical and chemical nature of nerve transmissions. Their goal was to analyze and predict each stage in the passage of the nerve cell membrane fromresting to action potential. They were awarded the 1963 Nobel Prize in physiology or medicine, which they shared with John C. Eccles, an Australian who advanced the British team's findings by showing what happens to nerve impulsestransmitted across the synapses, or intersections, between nerve cells.
Hodgkin was appointed Foulerton Research Professor of the Royal Society in 1952, and was awarded the Royal Medal in 1958. He was John Humphrey Plummer Professor of Biophysics at Cambridge from 1970 to 1981, president of the MarineBiological Association from 1966 to 1976, and a master of Trinity College.
Hodgkin was married in 1944 to Marion Rous, the daughter of American Nobel Laureate Peyton Rous. The couple met during Hodgkin's year at the Rockefeller Institute in New York. They had four children Hodgkin died December 20,1998.