Microglia meet metabolism: Microglia as drivers of brain and metabolic health

Invited speaker: Agnès Nadjar 

University of Bordeaux, INSERM, Neurocentre Magendie, Bordeaux, France 

Biography of the speaker: 

Agnes Nadjar is a Professor of Neuroscience and leads the research group ‘Neuroimmunology of metabolic health and disease’ (NOMAD) at the Institute of Neurodegenerative Diseases at the University of Bordeaux. Her research aims at understanding how the immune system and the central nervous system communicate, both under healthy conditions and during disease. She is particularly interested in how this two-way “neuroimmune” dialogue shapes whole-body metabolism, in both males and females. A major focus of her research is the interaction between microglia—the brain’s resident immune cells—and neurons. She explores how these interactions are influenced by diet, with a special emphasis on the role of lipids in regulating microglial physiology. Beyond microglia, she also investigates how other types of immune cells contribute to metabolic regulation. To address these questions, she combines a broad range of approaches, from cell and molecular physiology to in vivo models and behavioral studies. Ultimately, by uncovering the mechanisms of neuroimmune communication, she aims to understand how lifestyle and diet influence whole-body metabolism, and to open new avenues for preventing or treating metabolic and neurological diseases. 

Agnes Nadjar got a PhD in neuroscience from the University of Bordeaux in 2004, followed by two post-docs on neurodegeneration and on glial cells. In 2011, she was appointed Associate Professor at the University of Bordeaux to study the effects of the nutritional environment on microglia–neuron interactions and their role in mood and cognitive disorders. In 2019, she was promoted to Full Professor, and since 2020, she has focused on neuroimmune mechanisms regulating metabolism. In 2021, she became junior member of the 'Institut Universitaire de France' and in 2025, she was promoted to the rank of 'Professeur classe exceptionelle'.  

Description of the general focus of the symposium:  

The symposium explores the interplay of brain immune cells, microglia, with metabolic cascades across the lifespan that shape vulnerability and resilience to metabolic, neurodevelopmental, and neuropsychiatric conditions. Microglia have quintessential roles in the central nervous system, both in maintaining brain homeostasis and during development and activity-dependent synaptic remodeling. Concrete research during the past two decades further reveals microglial involvement in nearly all neurodegenerative and neuroinflammatory diseases. Therefore, understanding the molecular processes that shift microglial states from adaptive to pathological has become a considerable priority in neuroscience. This symposium integrates multi-modality research efforts revealing the convergence of microglia and systemic metabolic factors to influence brain health - from prenatal development to aging. The symposium will kickstart with a leading discussion on sex-specific regulation of systemic metabolism in mice focused on combinatorial refinement of hypothalamic circuits by hormonal, neuronal, and immune cues. Extending this theme to early development, the second talk will examine how maternal perinatal metabolic insults in mice alter retinal microglia and Müller cells in the offspring. The third talk will discuss ongoing translational studies in humans demonstrating how adverse childhood experiences shape adult mental health via lipid-mediated microglial signaling. The symposium will conclude with a discussion on the mediating role of microglial metabolism in driving synaptic loss in neurodegenerative disorders. Together, these perspectives will highlight the intricate relationship between systemic influences and microglia dynamics in determining brain and metabolic health. Furthermore, by elucidating the factors that shift microglia toward protective or pathological states, molecular cascades that are amenable to enhancing resilience against brain and metabolic diseases will be brought to focus. 

Role of brain immunity in the regulation of metabolism 

Brief description of the talk: 

Across evolution, female mammals have developed exceptional metabolic flexibility. Hormonal and innate genetic factors enable them to sustain reproduction during periods of food scarcity and efficiently allocate energy while supporting energetically demanding fetuses. This evolutionary advantage gives females a remarkable capacity to maintain energy balance under a wide range of physiological conditions, from handling a calorie-rich meal to withstanding fasting. Central to this regulation is the hypothalamus, which integrates hormonal, neuronal, and nutritional cues. Within this structure, diverse cell populations interact to precisely coordinate whole-body metabolism, including food intake and energy expenditure. Our research aims to uncover the neuroimmune mechanisms that underlie the heightened metabolic resilience seen in females. In my presentation, I will share data demonstrating how microglia and a subpopulation of lymphocytes collaborate to regulate hypothalamus activity and related metabolic function.