Professor Oleh Hornykiewicz, who has died aged 93, was a biochemist who was the first to suggest a link between a lack of the chemical dopamine in the brain and the onset of Parkinson’s disease.
The fact that Hornykiewicz never received a Nobel Prize for his work was a cause of some outrage among neuroscientists. For it was thanks to his observations in the late 1950s and early 1960s that Arvid Carlsson, Paul Greengard and Eric Kandel – all Nobel recipients in 2000 – were able to map the signalling pathways that regulate some of the brain’s most important functions.
Hornykiewicz’s interest in the role of dopamine began when he joined the University Department of Pharmacology at Oxford. By experimenting on guinea pigs, he showed that dopamine – then considered a mere precursor to other neurotransmitters (chemicals governing brain function) such as adrenaline – caused a drop in blood pressure when administered in the laboratory.
Having left Oxford for his home town of Vienna, Hornykiewicz began studying patients who were dying of Parkinson’s. Autopsies revealed that their brains had very low dopamine levels.
This observation, made in 1959, became public a year later once Hornykiewicz and his assistant were confident that they had enough corroborating evidence. They also analysed the brains of patients with neurological disorders such as Huntington’s disease, finding that the lack of dopamine was specific to people with Parkinson’s.
At the same time, Arvid Carlsson and fellow Swedish researchers were exploring treatments. Levodopa (L-Dopa), unlike dopamine, can pass through the barrier of blood vessels that protects the brain from infection. Once in the brain, it is converted into dopamine: with, as Hornykiewicz put it, “spectacular” effects.
Bed-bound patients given L-Dopa from Hornykiewicz’s own laboratory began to move and walk; their speech improved, and some started “actually crying with joy” as the drug did its work. A film of the patients was aired at a meeting of the Medical Society of Vienna in 1961.
Though the initial response was sceptical, this footage is now considered a classic of its kind – and it had an inspiring effect upon the British neurologist Oliver Sacks. His “extraordinary summer” observing Parkinsonian patients’ responses to L-Dopa is recounted in Awakenings (1973) – later made into an acclaimed film starring Robert de Niro.
Oleh Hornykiewicz was born in Sychiv, Ukraine, on November 17 1926 – the third son of a Catholic Ukrainian priest, Theophilus, and his wife Anna. After the German invasion of Poland the family moved to Vienna, where, to help his family learn German, Theophilus would read aloud from a state-issued copy of Hitler’s Mein Kampf – breaking off only to deplore its ideology.
Oleh attended a predominantly Jewish school before studying Medicine at the University of Vienna. At Oxford he worked under Hermann Blaschko, a German émigré and a world expert on human enzymes.
In 1967 Hornykiewicz left Vienna for Toronto and a position at the Clarke Institute of Psychiatry. He became the University of Toronto’s professor in pharmacology and head of the department of psychopharmacology at the Clarke Institute, commuting between jobs in Vienna and Toronto for a full decade.
In later life much of his time was spent at the Brain Research Institute (now the Centre for Brain Research) at the Medical University of Vienna. He was still active, performing brain dissections by hand and discussing the latest neuroscientific ideas, into his tenth decade.
In 1979 Professor Oleh Hornykiewicz received the Wolf Prize in Medicine for his work on L-Dopa.
He and his wife Christina had four children.
Professor Oleh Hornykiewicz, born November 17 1926, died May 26 2020