Australian physiologist who was awarded the 1963 Nobel Prize for Physiology or Medicine for his discovery of the chemical changes that bring about the transmission or inhibition of impulses by nerve cells. He was knighted in 1959 and was created a Companion of the Order of Australia in 1990.
Eccles graduated from the University of Melbourne and subsequently spent many years researching at Oxford University (1925–37) before returning to Australia as director of the Kanematsu Memorial Institute of Pathology in Sydney (1937–43). By 1952, when he had become professor of physiology at the Australian National University at Canberra (1951–66), he was able to demonstrate that a nerve impulse is transmitted when a substance (acetylcholine) is released from the ending of a nerve cell. The substance causes the pores of the cell membrane to expand and allows sodium ions to cross into the neighbouring cell, causing the polarity of the electric charge on this cell to change. This proceeds from cell to cell causing a wave of electrical charge along the nerve, which constitutes the impulse. He also found that there are nerve endings of a second, inhibitory, type. If the cell induces this ending to release a substance into the neighbouring cells, potassium ions move across the membrane and reinforce the existing electrical charge, preventing transmission of the impulse.
Subjects: Biological Sciences — Contemporary History (Post 1945).