Young, J(ohn) Z(achary) (1907–1997)

English zoologist who discovered and studied the giant nerve fibres in squids, contributing greatly to knowledge of nerve structure and function. He also did research on the central nervous system of octopuses, demonstrating that memory stores are located in the brain.

Young was born in Bristol and studied at Oxford and the zoological station in Naples, Italy. He set up a unit at Oxford to study nerve regeneration in mammals. In 1945 he became the first nonmedical scientist in Britain to hold a professorship in anatomy, at London.

Young discovered that certain nerve fibres of squids are about 100 times the diameter of mammalian neurons and are covered with a relatively thin myelin sheath (unlike mammalian nerve fibres, which have thick sheaths). These properties make them easy to experiment on and to obtain intracellular nerve material.

Turning his attention to the central nervous system, Young showed that octopuses can learn to discriminate between different orientations of the same object. When presented with horizontal and vertical rectangles, for example, the octopuses attacked one but avoided the other. He also demonstrated that octopuses can learn to recognize objects by touch. In addition, Young proposed a model to explain the processes involved in memory.

He published the textbooks The Life of Vertebrates (1950) and The Life of Mammals (1957).