Seminare und Veranstaltungen

The passage of food through the alimentary canal generates a series of feedback signals that are sensed by the brain and used to control behavior. Many of these signals converge on the caudal brainstem, which contains the key neural circuits that drive meal termination.I will describe our work investigating the dynamics and function of these circuits during ingestion. A central theme is that these circuits integrate layers of signals from the mouth and gut, both during ingestion and over longer timescales through learning. [mehr]

A balanced intake of nutrients is a key determinant of health, wellbeing, and aging. To maintain homeostasis, animals adapt their foraging strategies, physiology, and metabolism to meet immediate and future demands. We aim to understand how animals decide what to eat and how their metabolism aligns with physiological needs, focusing on the interplay between brain-body interactions, metabolic processes, and the microbiome, a key player in shaping these adaptations. Our research uses Drosophila melanogaster as a model to investigate nutritional decision-making at the interface of behavior, metabolism, microbiome, and physiology. By leveraging tools such as automated behavioral analyses, metabolomics, connectomics, neuronal activity imaging, and precise nutritional and microbial manipulations, we explore how internal states and environmental factors influence dietary choices and metabolic responses. This integrative approach allows us to reveal how internal states and environmental contexts shape dietary decisions. Ultimately, our goal is to build a unified framework for understanding the principles of nutrient regulation, offering insights into metabolic resilience and fitness across species. [mehr]

Brain circuits that sense energy do far more than drive appetite. This talk explores how hypothalamic and brainstem networks orchestrate whole-body metabolism, managing a critical trade-off between immune readiness and energy conservation. This highlights an emerging framework of how the brain dynamically matches whole-body physiology to its perceived energy status and prioritizes tissue maintenance under changing nutritional states. [mehr]

Metabolic diseases such as obesity and type-2 diabetes (T2D) are among the most pressing health challenges of our time. Affecting over one-third of the world’s population, they are projected to become the leading cause of mortality by 2030. Discovering effective treatments is a global health priority.While long regarded as disorders of peripheral organs, mounting evidence reveals that the brain plays a central role in their development and progression. This seminar will explore how neural circuits regulate energy balance, glucose homeostasis, and insulin sensitivity, highlighting the dynamic two-way communication between the brain and peripheral tissues.Drawing on recent discoveries from AProf Dodd’s laboratory, we will examine how specific brain pathways act as potential therapeutic targets. By understanding and harnessing these mechanisms, new opportunities emerge to design treatments that more effectively combat obesity and T2D. [mehr]

Across mammalian species, new mothers undergo behavioural changes to nurture their offspring and meet the caloric demands of milk production. Although many neural circuits underlying feeding and parenting behaviours are well characterized, it is unclear how these different circuits interact and adapt during lactation. Here we performed transcriptomic profiling of the arcuate nucleus (ARC) and the medial preoptic area (MPOA) of the mouse hypothalamus in response to lactation and hunger. Furthermore, we showed that heightened appetite in lactating mice was accompanied by increased activity of hunger-promoting agouti-related peptide (AgRP) neurons in the ARC (ARC^AgRP neurons). To assess the strength of hunger versus maternal drives, we designed a conflict assay in which female mice chose between a food source or pups and nesting material. Although food-deprived lactating mothers prioritized parenting over feeding, hunger reduced the duration and disrupted the sequences of parenting behaviours in both lactating and virgin females. We found that ARC^AgRP neurons inhibit bombesin receptor subtype 3 (BRS3) neurons in the MPOA (MPOA^BRS3 neurons), which become more active postpartum and govern parenting and satiety. Activation of this ARC^AgRP-to-MPOA^BRS3 circuit shifted behaviours from parenting to food-seeking. Thus, hypothalamic networks are modulated by physiological states and work antagonistically during the prioritization of competing motivated behaviours. [mehr]

Most organisms exhibit circadian rhythms—approximately 24-hour cycles of physiological fluctuations—governed by a “central clock.” In mammals, this central clock resides in the hypothalamic suprachiasmatic nucleus (SCN). The SCN functions as an autonomous oscillator, generating near-24-hour rhythms through cellular transcription–translation feedback loops (TTFLs) and neuronal connections within the SCN. However, the neural outputs of the SCN and their role in driving circadian rhythms have long remained poorly understood. One of the many regions receiving projections from the SCN is the dorsomedial hypothalamic nucleus (DMH), which is critical for homeostatic regulation of body temperature, feeding, and metabolism. Our group investigates the role of the neural circuitry connecting the SCN and DMH in the regulation of behavioral and metabolic rhythms, and I will be presenting our latest findings on this topic. [mehr]

Sleep is vital for brain function, but how the brain senses the need for sleep—known as "sleep pressure"—is still not fully understood. In our recent studies, we explored the idea that the strength of connections between neurons may play a key role in this process. Combining mathematical modeling with experiments in cultured neurons, we found that stronger synaptic connections promote brain activity patterns associated with deep sleep. We also used a molecular tool to selectively boost synaptic strength in the prefrontal cortex of mice, which led to longer and deeper sleep. In this talk, I will present our latest findings suggesting that synaptic strength may serve as an internal signal for sleep need—and discuss what this means for how the brain regulates rest and recovery. [mehr]

[mehr]

Despite significant progress, the neuronal mechanisms that regulate body weight remain incompletely understood. In this presentation, I will highlight our past and ongoing efforts to leverage human genetics data alongside rodent single-cell analyses to uncover molecular processes in the mediobasal hypothalamus and hindbrain that regulate energy homeostasis. [mehr]

The majority of human diseases involve complex interactions of different cellular and organ systems. Traditional organ-centric pathophysiological models fail to capture these interactions. This talk outlines circuits of organ crosstalk in the gastrointestinal tract with a focus on the gut-liver-brain axis. Recently, we identified the impact of glucocorticoids on enteric glia and neurons and discovered the underlying mechanism that relays psychological stress to the exacerbation of gut inflammation.The talk will highlight new data on the emerging field of neuro-immune interactions and discuss potential implications for IBD. [mehr]