Max Planck Institute for Metabolism Research

According to the WHO, over 64 million adults and 300,000 children and adolescents in Europe are currently living with diabetes. In 90 percent of cases, excess weight is the primary trigger. At the Max Planck Institute for Metabolism Research in Cologne, Jens Brüning is investigating the mechanisms through which obesity leads to insulin resistance.

A complex network of electrical and chemical signals ensures that the body and brain work in unison on matters of nutrition. Marc Tittgemeyer and his team at the Max Planck Institute for Metabolism Research in Cologne are exploring the implications of these intricate 'agreements.'

Adapting sugar metabolism starts in the brain

Many publications by Max Planck scientists in 2023 were of great social relevance or met with a great media response. We have selected 12 articles to present you with an overview of some noteworthy research of the year

Liraglutide benefits brain activity in people with obesity

Feel hungry, grab a pudding, enjoy it, and have another. Many different electrical and chemical signals ensure that the body and the brain cooperate in the area of nutrition. Marc Tittgemeyer and his team at the Max Planck Institute for Metabolism Research in Cologne are studying the implications of such coordination.

Single-cell RNA sequencing (scRNA-seq) allows the analysis of gene expression patterns in individual cells, enabling the characterisation of cell types based on their molecular identity. This allows to precisely describe the heterogeneity of different neurons in the brain in an unbiased manner. We built a comprehensive atlas of cell types of the hypothalamus, a brain region which plays a central role in the regulation of metabolism, by integrating published and novel data sets.

Through learning processes, sensory signals gain a motivational force and enable the brain to direct actions and adapt our behaviour to maintain physiological needs. To that end, sensory computations in the brain must be regulated by the body's momentary metabolic state, taking into account external sensory cues. We investigate physiological pathways by which bodily metabolic signals are communicated through the brain to interact with sensory perception and learning processes to guide motivated behaviour.

The hypothalamus is an area in the brain that regulates metabolism. It consists of neuronal groups, one of which is the Pro-opiomelanocortin- expressing group. POMC neurons drive satiety and use of stored energy in the body. Studying this neuronal group has led us to find different subgroups within a population that was thought to be uniform. We are studying in detail how they influence metabolism.

Our understanding of how our brain governs food intake has recently been revolutionized by the discovery that key hunger neurons are switched off within a few seconds upon detection of food cues that signal to the brain food vicinity, like sight or smell. Following on these seminal discoveries and building upon the challenge of better characterizing the critical mechanism by which our brain orchestrates feeding behavior, our group is keen on elucidating the influence of our senses on brain circuits governing appetite and metabolism. 

The hypothalamus works as a key regulatory center of food intake. Since many different neurons are involved in this regulation, it has so far been virtually impossible to understand the underlying neural circuits of this brain area and their connections. Using cell-type-specific genetic, electrophysiological and optical approaches, we identified previously unknown „satiety neurons“ and uncovered which neurotransmitter mediates the communication of hunger neurons.