In Memoriam: Arne Schousboe 1944–2024

Our dear friend, colleague, and mentor professor Arne Schousboe has passed away. Arne leaves behind a legacy that will forever be etched into the annals of neurochemistry and pharmacology. But even more so, he will be etched into the scientists whose careers he helped shape and support. Born in 1944, Arne embarked on a lifelong journey that would see him become one of the most influential figures in the study of the brain's chemical processes. After earning his degree in biochemistry from the University of Copenhagen in 1968, Arne immersed himself into the world of academic science. This took him across the globe time and time again (and how he loved to travel!) beginning with a post-doctoral research stay at the City of Hope National Medical Center, California, with Dr. Eugene Roberts. During this stay, Arne contributed to the purification and characterization of GABA transaminase being the initial degrading enzyme of the principal inhibitory neurotransmitter γ-aminobutyric acid (GABA). However, to obtain enough biological material, Arne and his colleagues had to start out with 9000 (!) mouse brains. This number of experimental animals is completely unimaginable today, but it was what science demanded at the time. Upon his return to Denmark, Arne, together with his wife Inger, further demonstrated that GABA transaminase is strictly localized in the mitochondria (luckily, they had turned to ox brain!). Arne had by then started his lifelong study of GABA forming the foundation of his research career. Arne was deeply devoted to understanding how neurons and astrocytes work in concert to maintain GABA homeostasis and how this is linked to brain energy metabolism. In 1990, Arne was appointed Professor at the Royal Danish School of Pharmaceutical Sciences, which later became part of the University of Copenhagen. Arne's prolific career saw him publish close to 600 scientific publications, and his ability to draft near-perfect manuscripts by hand (yes, writing with a pen on real paper) was legendary, truly reflecting a bygone era of skills. He once drafted an entire manuscript by hand on a plane ride from Mexico to Denmark and handed it to a hopeful PhD student upon his return: “If the student would please transfer the manuscript draft to a computer.” Arne was a pillar in the scientific community, serving (among much more) as secretary and president of the International Society of Neurochemistry and as Editor-in-Chief of Neurochemical Research since 2010. He managed to stay academically relevant to the very end, organizing and traveling to meetings. At scientific meetings, Arne was in his element, clearly making a difference with his smile, laughter, and characteristic way of greeting with a great hug. He was always active during seminars, offering intriguing comments and questions. For his protégés, it was a gift to accompany him to meetings and learn from his exceptional “meeting skills,” where his scientific capacity and warm personality combined perfectly. Attendance at meetings often led to collaborations with colleagues around the world, whom Arne loved to invite for wonderful food and excellent wines. For Arne, this was the only civilized way to conclude a day of hard work—and he indeed loved to work hard. To those who believed in glial cells during the long, dark period when the neuron concept dominated brain science. For us left behind, Arne was more than just a scientist; he was a mentor and an inspiration to both peers and protégés. He believed in lifting others, guiding young scientists through the intricate labyrinths of the academic world, and he created a trustful and safe space for young scientists in spe. It is hard to express in writing what he meant for us, whose careers and lives he touched. There are so many memories, too many to express here. Arne was deeply invested in the International Conference on Brain Energy Metabolism (ICBEM); a meeting series held biannually since 1993. Here, Arne is flanked by his former students Lasse K. Bak & Helle S. Waagepetersen at the 11th ICBEM meeting held in Helsinge, Denmark (2014) Arne together with Mary C. McKenna and L. Felipe Barros at the opening reception of the 13th ICBEM meeting held in Valdivia, Chile (2018). The NeuroMet group from the University of Copenhagen at a group seminar in Abbekås, Sweden (2014). Back row (left to right): Malin H. Stridh, Helle S. Waagepetersen, George Gegelashvili (Gogi), Amaia de Diego Ajenjo, Ann-Kathrin Reuschlein & Jens V. Andersen. Front row (left to right): Sofie C. Lange, Arne Schousboe, Emil Jakobsen, Blanca I. Aldana, Anne B. Walls, Michaela C. Hohnholt, Laura F. McNair & Lasse K. Bak. Out of frame: Caroline C. Voss & Rasmus Kornfelt.