What Fuels Our Cravings for Food and Drink? Key Role May Be Played by Amygdala Neurons

To make sure our bodies receive adequate calories and fluids, the brain depends on an intricate system of cells, signals, and pathways to direct us toward eating, drinking, or stopping. Nevertheless, many aspects of how the brain interprets bodily requirements and transforms these into actions remain mysterious.

In a new study published in Nature Communications Researchers from the Max Planck Institute for Biological Intelligence, working alongside colleagues at the University of Regensburg and Stanford University, have pinpointed particular groups of neurons within the amygdala—a region central to emotions and motivation—that are crucial for this function.

These specific "thirst" and "hunger" nerve cells function via separate pathways, affecting the urge to consume food or fluids. Conducted with mice, this research illuminates the amygdala’s part in managing our dietary requirements and could provide understanding into eating disorders and addiction issues.

In the core of the brain's emotional region

The amygdala, a part of the brain commonly associated with emotions and decision-making, significantly influences our cravings for food and drinks. Research conducted by Rüdiger Klein’s team at the Max Planck Institute for Biological Cybernetics demonstrated that cells within the central nucleus of the amygdala link eating experiences to emotional responses—associating delicious meals with pleasant sensations, connecting poor-quality food with negative reactions, and reducing hunger when feeling nauseous.

The team showed that altering the activity of these neurons can change behaviors, causing mice to consume food despite being satiated or not feeling well.

Expanding upon those discoveries, the latest study has identified separate clusters of neurons within the same core area of the amygdala that react uniquely to feelings of thirst and different ones that address sensations of hunger. These neuron responses are orchestrated by an intricate network of biochemical signals.

Federica Fermani, who headed the research, notes that one group of neurons exclusively manages the urge to consume liquids; this marks the initial 'thirst neuron' discovered within the amygdala. Activating these cells resulted in increased water intake among the mice, whereas inhibiting them decreased such behavior.

We additionally pinpointed another set of neurons within the same area of the amygdala that triggers thirst yet also contributes to managing appetite. This discovery underscores how certain neurons exhibit distinct specificity towards particular actions, whereas others possess broader functions in steering decisions related to eating and drinking.

In order to investigate how neurons within the central nucleus of the amygdala control drinking and eating behaviors, scientists employed sophisticated genetic techniques to examine neural activity in mice under conditions of hunger, thirst, and satiety with adequate hydration. A technique known as optogenetics enabled this group to stimulate particular neuron types through light-activated proteins activated by a finely calibrated laser designed specifically for triggering these cell groups.

They employed techniques to deactivate the neurons, studying how their inhibition affected the mice’s inclination towards eating or drinking. This was coupled with novel methodologies allowing for the tracking of single neurons across various parts of the brain. Through this approach, the scientists were able to trace where these neurons received input from and pinpoint which other areas of the brain they interacted with.

Raising new questions

The mapping of the routes these neurons take to interact with other parts of the brain uncovered connections to zones responsible for handling sensory data related to food and water, like the parabrachial complex.

The research further examined how the brain integrates various elements like taste when influencing actions. Specifically, by associating an undesirable beverage flavor with selective activation of cells within the central amygdala, scientists discovered they were able to alter the rodents' preferences, turning a formerly shunned taste into one they favored anew.

Given the similarity in the amygdala’s structure between mice and humans, the researchers propose that these discoveries might enhance our comprehension of how emotions and motivations affect our personal eating and drinking behaviors.

As basic urges such as thirst and hunger drive us to consume food and water at appropriate intervals, they provide essential nourishment and sustenance required for survival," says Rüdiger Klein, who directs the Max Planck Institute for Biological Intelligence. "However, these very neurological pathways may lead to excessive eating or insufficient intake based on the various signals processed within the brain.

Through revealing these mechanisms, we achieve a deeper comprehension of how the brain assesses food and beverages from an emotional standpoint, acquires associations between them and enjoyment or dislike, and how neural growth influences both inherent and acquired behaviors.

This research paves the way for exploring new inquiries, such as understanding how the brain manages hunger, thirst, and emotions; determining when we have consumed adequate food and drink versus excessive amounts; examining how various demands are concurrently balanced; and investigating alterations in these neural pathways under circumstances like obesity, anorexia, or alcohol dependency.

More information: Federica Fermani and colleagues found that food and water consumption are controlled by separate neural pathways within the central amygdala through the use of intersecting genetic techniques. Nature Communications (2025). DOI: 10.1038/s41467-025-58144-3

Furnished by the Max Planck Society

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