Hodgkin and action potential

Alan Lloyd Hodgkin was born on 5 February 1914 in Banbury, Oxfordshire, into a family of Quakers. He won a scholarship to Trinity College, Cambridge, to study zoology, chemistry and mathematics, graduating in 1936.

During the 1939–45 war, Hodgkin volunteered to work on aviation medicine, but was sent to the Telecommunications Research Establishment, where he worked on developing the centrimetric radar system for use in aircraft.

After the war, along with one of his former undergraduate students, Andrew Huxley, he resumed his study of membrane potentials in the axons of giant squid, work that was started in 1939, but abandoned at the outbreak of war.

The species was chosen because of the large size of its axons, up to 1mm in diameter, 10 times that of humans. This allowed easy observation of the cells using conventional microscopes available at the time. They studied the movement of ions along the length of the axon following stimulation of the nerve, describing the change in electrical potential along the cell.

They found that changing the concentration of ions inside the cell affects the permeability of the cell membrane, and that on stimulation, sodium ions flow into the cell, and potassium ions out, altering the electrical potential across the cell membrane. When the internal sodium ion concentration reaches a threshold level, neighbouring ion channels open, causing the membrane, or action potential, to move along the neurone.

In 1952 the pair published five papers describing their experimental results, which led to the development of a mathematical model for an action potential. In 1963 they were awarded the Nobel Prize in Physiology or Medicine for their work. Alan Hodgkin was knighted in 1972, and appointed to the Order of Merit in 1973. He died on 20 December 1998, aged 84.