Neural Circuits, Microbes, and Behavioral Evolution
Philipp Brand receives an ERC Starting Grant
Microbial symbionts are widespread across the animal kingdom and can profoundly influence the biology and evolution of their hosts. Some microbes can even alter mating behavior, changing the preferences of who to court and mate with – sometimes over many generations. However, the mechanisms behind these effects remain poorly understood. Philipp Brand, research group leader at the Max Planck Institute for Brain Research, and his team aim to uncover how microbes influence mating behavior and evolution with the “SIMBIO” project. To support this work, the European Research Council (ERC) has awarded Brand a 1.5 million Euro Starting Grant over the next five years.
The Brand Lab uses Drosophila fruit flies as model organism to investigate how genetic changes shape neural circuits and, ultimately, behavior during evolution. The diversity of closely related Drosophila species, combined with powerful genetic tools, allows the researchers to compare how different species process social and environmental cues and how these differences influence behaviors such as courtship and mate choice. The ERC Starting Grant will enable Brand and his team to investigate how microbial symbionts interfere with these processes and contribute to mate choice. To this end, the researchers will combine behavioral experiments and genetic approaches with methods for studying the structure and activity of neural circuits, including brain imaging, neuroanatomy and optogenetics.
Philipp Brand says: “I am truly excited about this opportunity to study how microbial symbionts infecting the brain alter their host’s mating behavior. This will allow us to better understand not only the mechanisms underlying microbe-brain interactions but also how the resulting changes in the nervous system alter the choice of mating partners. The symbioses we study are inherited from mothers to their offspring, spanning many generations, which means that such behavioral modifications can persistently restrict reproduction between different populations that previously mated freely, thereby profoundly influencing the hosts’ evolutionary trajectories. These processes are not well understood, and I am grateful for the support provided by the ERC to investigate them.”
About Philipp Brand
Philipp Brand received his MSc in Genetics and Evolutionary Biology from Heinrich Heine University Düsseldorf and Ruhr University Bochum, and his PhD in Population Biology from the University of California, Davis. As a postdoctoral fellow, Brand worked with Vanessa Ruta at The Rockefeller University in New York. In 2025, he joined the Max Planck Institute for Brain Research in Frankfurt, Germany, where he leads the “Evolutionary Neuroscience and Behavior” research group. His work focuses on understanding how environmental factors influence genetic variation and changes in neural circuits, and how these mechanisms contribute to behavioral diversity and evolution, using Drosophila fruit flies as a model system.
About the ERC
The European Research Council (ERC), set up by the European Union in 2007, is the premier European funding organization for excellent frontier research. It funds creative researchers of any nationality and age, to run projects based across Europe. The ERC’s Starting Grants support cutting-edge research in a wide range of fields and aim to help researchers at the beginning of their careers to launch their own projects, build their teams and pursue their most promising ideas. The funding for the ERC Starting Grants - totaling nearly €705 million - is part of the EU's Horizon Europe program. The latest call received a record of 4,807 proposals of which 8,8 % (421) were selected for funding. Brand is one of nine 2026 Starting Grant recipients currently affiliated with the Max Planck Society.
