Obituary: George Gray

GEORGE GRAY was a pioneer in the study of brain ultrastructure. He was Professor of Cytology in the anatomy department at University College London from 1967 to 1977 and then headed the Laboratory of Biological Ultrastructure at the National Institute for Medical Research.

He had an unusual background for an academic. Born Edward George Gray in 1924 in South Wales, he left school at 15, was a bank clerk for three years, then served in the Navy for four years, and saw military action during the Second World War. After the war he was able to take a boyhood passion for microscopy of pond life to a new level by studying Zoology at university (Aberystwyth) followed by a PhD on the nervous control of fish melanophores (pigment-containing cells in the skin).

The eminent zoologist J.Z. Young, then Professor of Anatomy at UCL, was the external examiner for Gray's thesis in 1955 and recruited him as a research assistant that same year. Soon after he arrived at UCL, Young also recruited J.D. Robertson from Boston to set up an electron microscope laboratory. This was at a time when advances in techniques were beginning to unlock the potential of the electron microscope, with its spectacular resolving power, to unravel the mysteries of biological ultrastructure.

Within a few months of setting up shop Robertson discovered the basic structure of the cell membrane, Gray had begun to use the new techniques to look at frog muscle spindles and the insect ear and the laboratory was on its way to becoming one of the world's leading centres for ultrastructural studies.

In 1957-58 Gray turned his attention to the brain, especially the cerebral cortex, and a series of notable discoveries followed. He showed that dendritic spines - or thorns - are major targets for synaptic input (the incoming messages from other nerve cells) and described the still incompletely understood organelle, the spine apparatus. Most notably, he was the first to recognise that there are two types of synaptic contact with different features and different distributions, one chiefly on spines and small dendrites, with a thick postsynaptic density and wide cleft, and another type found mainly on cell bodies and large dendrites, with a narrow cleft and thin postsynaptic density.

Within a few years these "type 1" and "type 2" synapses were being confidently equated with excitatory and inhibitory synapses, respectively, as the microelectrode, in the hands of John Eccles and others, was able to determine the physiological characteristics of the type 1 and type 2 synapses. These insights provided researchers with a powerful tool for interpreting the ultrastructural organisation of the brain in functional terms.

In this same period, a study of spinal cord provided the first description of the probable anatomical substrate for the physiological phenomenon of presynaptic inhibition, and Gray's collaboration with the biochemist V.P. Whittaker led to the characterisation of "synaptosomes", pinched- off nerve endings produced by homogenising and centrifuging brain tissue, which seal up, retain their content of synaptic vesicles, and provide a major and still current tool for the biochemical study of synapses.

Recognition was swift. Gray became internationally renowned, his name today still linked to that of the type 1 and type 2 synapse classification. He made frequent trips to international meetings (which he did not enjoy), and rose swiftly from 1957 through the academic ranks at UCL: Assistant Lecturer, Lecturer, Reader, and Professor in 1967. He was elected FRS in 1976.

The late Fifties and early Sixties were Gray's golden days. Although he continued to make contributions to our understanding of normal and abnormal synaptic ultrastructure, his work never thereafter reached comparable heights. Ill-health, including severe depressions, about which he wrote in a highly personal but analytical article in the British Journal of Psychiatry in 1983, progressively impaired his ability to maintain front- line research. He retired from the NIMR in 1983 but continued, for so long as his health permitted, to pursue studies of human neurodegenerative disease, first at the Institute of Neurology, then back at UCL.

George Gray was a quiet, introverted and shy man who felt comfortable with a few close friends and colleagues but avoided socialising and was never happy as a teacher, especially when he had to demonstrate to medical students in the dissecting room. In his forties he took up the challenge of learning to play the violin (which he would practice daily after lunch in his office). This and painting (water-colours) sustained him in his retirement.

A. R. Lieberman

Edward George Gray, anatomist: born Pontypool, Monmouthshire 11 January 1924; Assistant Lecturer, Department of Anatomy, University College London 1957-59, Lecturer 1959-61, Reader 1961-67, Professor of Cytology 1967- 77; FRS 1976; Head of the Laboratory of Biological Ultrastructure, National Institute for Medical Research 1977-83; married 1953 May Rautiainen (two sons); died Welwyn Garden City, Hertfordshire 14 August 1999.