What drives our desires to eat and drink: key neurons in the brain found

Scientists from the Max Planck Institute for Biological Intelligence, in collaboration with the Universities of Regensburg and Stanford, have taken a step towards understanding these processes. In a new study published in Nature Communications, they have discovered specialised neurons in the brain responsible for hunger and thirst.

Details: Federica Fermani et al, Food and water intake are regulated by distinct central amygdala circuits revealed using intersectional genetics, Nature Communications (2025). DOI: 10.1038/s41467-025-58144-3

The amygdala, an area of the brain known primarily for its connection to emotion and decision-making, plays a major role. However, recent findings show that it is also involved in regulating our basic needs, such as nutrition and water balance.

The researchers focused on the central part of the amygdala. This is where groups of neurons are located that are activated in response to the need for water or food. Some neurons turned out to be specialised: some are responsible solely for thirst, while others are responsible for both signals at once. It is important that when these cells are activated in laboratory mice sharply increased interest in water or food. When "switching off" these neurons thirst and appetite sharply decreased.

To achieve these results, scientists used modern methods, including optogenetics - a technique in which certain neurons can be activated or inhibited by light. The researchers also monitored the activity of individual brain cells in different areas of the brain to understand how hunger and thirst signals are transmitted and processed.

It turned out that amygdala neurons are connected to other areas of the brain that process taste information and control behaviour. One of the interesting findings: if stimulation of thirst neurons was combined with the presentation of an unpleasant taste, the mice began to prefer this taste, although they had previously avoided it. This proves that the brain can rewrite taste preferences if strong internal cues are behind it.

According to the study authors, the structure of the amygdala in humans is similar to that in mice, so the findings could help us understand how emotions and needs affect our eating habits. This could be useful when studying conditions such as obesity, eating disorders or alcohol dependence.

These basic desires - to eat and drink - shape behaviours necessary for survival. But they can also lead to overeating or refusal to eat if brain signals are disrupted," explains Rüdiger Klein, director of the institute and one of the authors of the paper.

The study opens up new questions: how does the brain determine whether we need more food or water? How does it manage competing needs? Why do we find some flavours pleasurable and others repulsive? The answers to these questions will help us better understand not only everyday behaviour, but also important medical and psychological conditions.