Born to a Viennese mother and Hungarian-Jewish Father in 1924 in Timisoara, Romania, Marianne Fillenz and her family moved to New Zealand in 1939 to avoid the rise of Nazism in Eastern Europe.

It was in New Zealand that Marianne met the most important influence in her life, Jack Eccles FRS, Professor of Physiology at Otago (recipient of the Nobel Prize in 1963 in Physiology or Medicine) a previous research student and colleague of Sir Charles Sherrington PRS in Oxford. He inspired her to focus her research on physiology during her pre-clinical medical studies at the University of Otago, and consequentially to move to Oxford to undertake a DPhil in Physiology. Fittingly, her last paper, published in 2012, remembers his life and work.

She came to Somerville College in 1950 and remained in Oxford for the rest of her life. Her DPhil in the Laboratory of Physiology with Sybil Cooper and David Whitteridge studied receptors responding to stretch of the eye muscles. Her work showed clearly that an eye muscle length signal is indeed supplied to the brain in the cat, a fact later confirmed in humans. This is demonstrated in her classic 1955 Journal of Physiology paper “Responses in the brainstem of the cat to stretch of extrinsic ocular muscles”.

After her DPhil, Marianne spent nine years as a College Lecturer at St Hilda’s and as a University Demonstrator in the Laboratory of Physiology, alongside leading independent research in a large suite of labs in the Sherrington Building. While her work across the 1950s was mainly devoted to motor physiology and eye muscles, years later her research interests evolved to focus on the anatomy and physiology of the autonomic nervous system, and she became the local expert on the subject. Marianne was one of the first people to use and develop the technique of voltammetry (electrochemical scanning of transmitters that transport signals from one neuron to another) to measure catecholamine release deep in the brain. Her landmark paper on this subject, published in Neuroscience in 1982, is entitled “Linear sweep voltammetry with carbon paste electrodes in the rat striatum”. Her technique of linear sweep voltammetry to measure dopamine release in the rat striatum in still much in use today. She went onto work closely with John Albery FRS, a Distinguished Chemist at Oxford, to develop voltammetry electrodes for conveniently measuring many other substances, such as glucose, alcohol, amino acids, oxygen, CO2 and N2O. Consequently, her lab was positioned at the forefront of the application of measuring chemicals that could be detected directly at the electrode.

In 1963, Fillenz won a Tutorial Fellowship at St Anne’s College, remaining a loyal member of St Anne’s for the rest of her life. She was particularly keen to encourage her female students not to feel that family commitments would inevitably reduce their scientific productivity; Marianne herself brought up three children alongside a successful career with help from her husband John Clarke, a Rhodes Scholar from Western Australia whom she met during her first term at Oxford. She revelled in her students’ successes when they came and is fondly remembered by her former undergraduate student Dame Fiona Caldicott, who was first female President of the Royal College of Psychiatrists, Principal of Somerville College, now National Data Guardian for Health and Social Care: “She was the archetypal personal tutor and a fantastic role model, combining her teaching and research duties with her family responsibilities, always without apparent difficulty. She was supportive even when challenging and I valued Marianne’s opinions increasingly as my undergraduate days receded. Without her I would not ultimately have come to Somerville, in an unexpected role, to fulfil the aspiration that I had had as a schoolgirl when I applied to read medicine.”

In her spare time Marianne enjoyed philosophy, playing the piano and regularly attending musical concerts. She was also a keen Member of The Physiological Society – most of her early publications were originally in the form of Physiological Society Proceedings.

In 1990, she published an important book, “Noradrenergic Neurons”, which examines the mechanisms regulating the release and synthesis of the neurotransmitter noradrenaline, which plays an important role in response to stress and the development of resistance to stress, as well as psychological mood itself. On her retirement from her University Lectureship in September 1992, she received the title of Senior Research Fellow in recognition of her ongoing work. In 1999, she applied for a Doctor of Science based on her research output, and this was awarded by the Board of the Faculty of Physiological Sciences in June 2000.

After her death, she was remembered by John Stein, whom Fillenz taught while he was studying at New College: “We will miss her exceptional friendliness, her interest in everything from local gossip to the place of humanity in the universe, her positive outlook and her quizzical responses to incautious remarks.”