Scientists launch a $14.2 million project to map the body’s “hidden sixth sense.”

Now, a collaborative team from Scripps Research and the Allen Institute has received a National Institutes of Health (NIH) Director’s Translational Research Award to develop the first comprehensive atlas of this internal sensory system.

Significant investment in brain and body research

The project is led by Nobel Prize-winning neuroscientist Ardem Patapoutyan, and is joined by Li Yi, head of the Department of Chemistry and Chemical Biology at the Scripps Research Institute, and Bosiljka Tasic, director of molecular genetics at the Allen Institute. Shen Jin, associate professor at Scripps Research Institute, will serve as co-investigator and direct the genome and cell type profiling work.

The National Institutes of Health awarded the team $14.2 million over five years to implement this ambitious project.

“My team is honored by NIH’s support for the kind of collaborative science needed to study such a complex system,” says Patapoutian, the Presidential Endowed Chair for Neurobiology at Scripps Research.

Patapoutian, who shared the 2021 Nobel Prize in Physiology or Medicine for his discovery of cellular sensors that detect touch, will now apply his expertise to understanding internal interoception.

“We hope our findings will help other scientists ask new questions about how internal organs and the nervous system stay in sync,” Ye adds. Like Patapoutian, he is also an investigator at the Howard Hughes Medical Institute.

Established in 2009, the Translational Research Prize funds pioneering, interdisciplinary projects that transcend traditional scientific boundaries. It is part of the High-Risk-Reward Research Program of the NIH Common Fund, which is designed to support innovative ideas that could reshape our understanding of human health but may struggle to obtain funding through traditional mechanisms.

What makes the objection unique

Unlike the classical senses – such as smell, sight and hearing – which rely on specialized sensory organs that detect stimuli from the outside world, interoception involves a vast network of neurons that sense what is happening inside the body. These neural circuits track vital processes including circulation, digestion, and immune activity.

Because intercepted signals originate deep within the body and are often processed unconsciously, scientists often describe this system as our “hidden sixth sense.”

Despite its essential role, the objection has received little scholarly attention. The signals they produce are complex, overlapping, and difficult to measure. The sensory neurons they carry are distributed throughout organs such as the heart, lungs, stomach and kidneys, making them difficult to isolate and map accurately.

Mapping brain-body connectivity

With support from the National Institutes of Health, Scripps and Allen researchers plan to map how sensory neurons connect to a wide range of internal organs, including the heart and digestive system. Their goal is to create a detailed anatomical and molecular atlas that reveals how these neural pathways are regulated.

To achieve this, one part of the project will label sensory neurons and use whole-body imaging to trace their paths from the spinal cord to various organs, producing a high-resolution 3D map. The second part will use genetic profiling to distinguish between different cell types, such as neurons that send signals from the intestine, bladder, or adipose tissue.

Together, these datasets will form the first unified reference for understanding the body’s internal sensory wiring.

Why is interoception important for health?

By deciphering how internal interoception works, scientists hope to uncover basic principles of brain-body communication that could lead to new treatments for diseases. Disturbances in these intrinsic sensory pathways have been linked to a range of conditions, including autoimmune disorders, chronic pain, neurodegenerative diseases, and high blood pressure.

“Interoceptivity is fundamental to almost every aspect of health, but it remains a largely unexplored frontier in neuroscience,” says Jain, a Howard Hughes Medical Institute researcher Freeman Hrabowski. “By creating the first atlas of this system, we aim to lay the foundation for a better understanding of how the brain maintains homeostasis in the body, how this homeostasis can be disrupted in disease and how we can restore it.”