BRAIN blood flow is important to two distinct areas of medicine. Brain blood f low is the basis for modern functional brain imaging. Disruption of blood flow to the brain is the integral event in stroke and cerebrovascular disease. For two decades in the 1970s and 1980s, the group in Glasgow University directed by Professor Murray Harper led the world in research into the regulation of brain blood f low.

Alexander Murray Harper was born in Mansewood in 1933 and was the elder son of the Rev Dr Thomas Harper, who was the minister of Eastwood Parish Church, and Mrs Margaret Harper (nee Ross).

He was educated at Belmont House and Hutchesons' Grammar School in Glasgow, and entered Glasgow University to study medicine in 1951. After completing his MBChB and his house officer posts in 1958, he gained the McIntyre Fellowship, which he held in the department of surgery of the Royal Infirmary in Glasgow.

This fellowship allowed him to spend two years in full-time medical research and it changed the direction of Murray Harper's life. Medical research, rather than direct patient care, was to be the major focus of Murray's academic life for the next 40 years.

The first major scientific achievement of Murray Harper was technological innovation.

A new technique for measuring brain blood flow with radioactive inert gases was developed. This was such a major advance that in 1966, Tomorrow's World, the BBC science programme, showed Murray and his neurosurgical colleagues measuring blood flow in a patient in the old hospital at Killearn. The inert gas clearance method transformed the entire field of research, which had been in the scientific doldrums for the past decade.

The technology was employed by Niels Lassen and others in Scandinavia to perform the first functional brain mapping studies in man.

Murray himself employed this technique to characterise how blood pressure and carbon dioxide interacted in the regulation of blood flow. These seminal studies were the basis of his doctorate in medicine (MD) which was awarded with honours (a rare distinction for higher degrees like MD).

Over the next decade, Murray Harper and his team elucidated when the nerves around brain blood vessels modulated blood flow. Murray received the H G Wolff award of the American Headache Association and the Gold Medal of the British Migraine Association because of the importance of these discoveries to the understanding of migraine.

In 1981, the pre-eminent investigators in the field (who included Murray Harper) created a new professional society and a new scientific journal (the Journal of Cerebral Blood Flow and Metabolism). Murray was the unanimous choice to be the founding editor-in-chief.

Within two years, the journal was the top in the field (which it remains) and was profitable (and remains the financial pillar of the International Society).

Alongside Murray's seminal contribution to brain blood flow, his lasting legacy is the research environment he created on the Garscube campus of Glasgow University. The Wellcome Surgical Institute, which he established, was a department where multidisciplinary research was encouraged (groundbreaking 30 years ago but commonplace today).

Research had to be rigorous, innovative and fun.

More than 40 individuals whose research had been performed at the Wellcome progressed to become full professors. Murray enjoyed being a mentor and always provided tremendous support to young scientists.

He was generous - excessively generous - in giving credit to his colleagues. It was a source of quiet professional pride that this department which Murray had created and led was ranked as "world class" in Research Assessment Exercise of 1992.

Glasgow University promoted Murray to senior lecturer in 1968, reader in 1969 and professor in 1981. He was an honorary consultant clinical physiologist to the Royal and Western Infirmaries and to the Southern General Hospital. He published more than 200 scientific papers.

Murray came from a highachieving family: his brother is Ross Harper the celebrated lawyer, and his daughter is the oustanding Scottish artist Alison Harper, one of the Glasgow Girls. Like his brother, Murray's compelling and sustaining hobby was angling.

Starting at the age of seven, he fished, often in company with Ross , most of the great salmon rivers of Scotland. He was an energetic and successful angler and nothing gave him greater pleasure than catching a salmon on a fly he designed.

Latterly, his back problem forced him to quit river fishing but he still found enjoyment, until a year or so ago, from fishing for trout, in which he was equally successful and adept. In his final year he enjoyed listening to classical music and admiring his daughter's artwork.

In 1958 he married Charlotte Fossleitnier, a young nurse from Austria who supported him throughout his life and who survives him. Charlotte and Murray had three children - Peter, Alison and Murray - and three grandchildren.

Professor Emeritus A M Harper; born May 31, 1933, died July 26 2005.