06 November 2025
It is quite intuitive to think that the brain is controlling our body, but less clear to grasp that the body is also influencing the brain. This essay by Champalimaud Foundation’s principal investigators Carlos Ribeiro and Albino J. Oliveira-Maia guides us through some of the brain-body interactions that are crucial for the normal functioning of all living organisms.
Historically, scientists studying the brain, like neuroscientists and psychologists, worked separately from those studying the body, such as endocrinologists and physiologists. Research on how the nervous system interacts with the body has been growing, but “it kind of stops there, rarely making it past the neck to reach the brain again”, as Carlos Ribeiro puts it. Neuroscientists, meanwhile, often focus on higher brain functions without considering how body signals might influence them.
In a recent Current Biology essay, Carlos Ribeiro, a biologist and neuroscientist, and Albino J. Oliveira-Maia, a psychiatrist and also a neuroscientist, teamed up to discuss why this brain-body dialogue is essential for an organism’s function, helping us stay well and cope when we’re not.
Taking advantage of their interdisciplinary backgrounds and interests, Oliveira-Maia and Ribeiro draw from studies in fruit flies, mice, and humans to explore how body signals shape brain responses and behaviour.
“Different systems have different strengths,” says Ribeiro. “You can play the different strengths and also identify what’s common and that’s normally the strongest lever to pull when you want a view of the mechanisms at work and how to apply it later, namely in the clinic.” As Oliveira-Maia adds, “we always humanise the research we do, even if we're researching with flies, so having these different models and perspectives is something I value.”
For Ribeiro, invertebrates like fruit flies offer clear advantages: “You can do many different experiments and be extremely precise mechanistically.”
To illustrate this, the authors use a cascading logic. In their essay, they start off by describing how a fly’s nutritional state influences what it eats and where it searches for food. Hungry flies tend to revisit places where they’ve found food before rather than exploring new locations, indicating that cues from the body shape how the brain retrieves memories and makes decisions, influencing the fly's foraging strategies.
Comparative studies then allow scientists to move to more complex organisms, such as mice, and test similar ideas. Like flies, mice show changes in brain activity when hungry or thirsty. These animals can also learn to associate flavours with higher sugar intake, again showing how body signals drive behavioural preferences.
Humans bring a different advantage to the table: they can describe what they feel. Oliveira-Maia explains that ideas tested in flies or mice can offer insight into human behaviour. A fly’s foraging, for example, can be compared to “some elements of risk taking and decision-making in humans, which are linked both to the control of eating and to the development of disorders such as obesity or anorexia.”
To Oliveira-Maia, these parallels offer some reassurance, “I'm looking at this phenomenon that exists in flies and then there are conceptual elements there that translate well to humans which is a great source of comfort. Is this going to solve all of the problems in the world? I don't think so. But it provides a very interesting framework for advancement that requires collaboration and collective thinking”. Plus, as Ribeiro sums up, “No matter what you do, you will always need to compare, and I think it’s also conceptually interesting to do it.”
Although the field of brain-body interactions was once overlooked, interest in it is now rapidly growing. Its interdisciplinary nature makes it both exciting and challenging, particularly when it comes to funding or publishing, since it bridges multiple scientific domains. Technology is another challenge to consider. Neuroscience tools have made tremendous progress in studying the brain, but extending that same level of precision to the rest of the nervous system, namely the body’s signals outside the brain, remains far more complex.
Besides, as Oliveira-Maia explains, “the external sensory systems [vision, audition, touch] have been the traditional focus in neuroscience” because they’re easy to observe and describe. But internal sensations, what he calls “the interoceptive perspective of sensation and sensory signals”, are harder to articulate. Although we can’t easily describe how we sense blood pressure or energy levels, these signals constantly inform the brain, helping to keep the body functioning. Understanding this processing is especially important when things go wrong. “As a psychiatrist, I'm very much interested in the circumstances where things don't seem to be working as seamlessly as they do in a healthy state”, says Oliveira-Maia.
Brain-body interactions can influence both physical and mental health. Depression, for instance, can alter behaviour and increase risk-taking, which in turn may potentially increase the risk of heart disease or diabetes. Conversely, diseases like cancer can trigger emotional disorders such as depression. Growing evidence points to “biologically measurable elements, especially those linked to the immune system” that could serve as a bridge between these conditions.
More investment in this area could help researchers untangle these links and deepen our understanding of the brain-body interactions.
Similarly to the link between the brain and the body, this essay is a result of collaboration. Ribeiro, a biologist working with fruit flies, and Oliveira-Maia, a psychiatrist studying humans, come from very different backgrounds, yet share a common goal: understanding how the body influences the brain and vice versa.
Oliveira-Maia recalls that the project began when Ribeiro challenged him to co-write it. “I was very happy he did so,” he says, as it sparked deep conversations and revealed an unexpected common ground. “It took us a month just to decide what we were actually going to write about because we kept discussing different perspectives,” Ribeiro says.
Their friendship helped. “I'm very happy to call Carlos a friend,” says Oliveira-Maia, “and that makes the conversation easier. It's not just about finding common ground in a document like this, or about the science and the language, it's also about the people”. Despite differences in terminology, their shared curiosity made collaboration feel natural. Over lunches and runs, they realised they were “interested in the same questions, but trying to answer them in very different ways”.
Ribeiro sees these collaborations as essential, comparing them to a continuous loop: human studies inspire questions for animal models, and animal findings often inform clinical research. “It’s a network that you need to build on,” he says. “You need discussion, and you need everybody working together. You need to think interdisciplinarily and be bold in embracing areas where you might not consider yourself an expert in”.
Oliveira-Maia agrees that real collaboration does not come without effort. “We have to take that extra step, devote the time and mental energy to create something that becomes a shared space reflecting both of our individual perspectives,” he says. He uses the example of a Venn diagram, “you not only need to find the intersection, but also actively use it and help it expand”.
This collaboration has been mutually inspiring for Ribeiro and Oliveira-Maia, shaping both their research directions. They plan to continue working together, namely on a project connecting the culinary world and basic research, exploring how protein-rich foods affect the human brain.
Reflecting on the writing process, Ribeiro notes that true progress comes “not from the clinician or the scientist alone, but from working together with mutual respect for each other’s know-how.” As Oliveira-Maia adds, it’s “the opportunity to work and think together” that makes their partnership successful.
This partnership embodies the Champalimau Foundation’s essence and perfectly illustrates how collaboration between fundamental and clinical researchers can advance our understanding of how organisms function. Creating bridges between different fields and approaches is crucial to uncover new insights into brain-body interactions and to develop better approaches to treating disorders linked to them.
Original paper: here
