Have you ever wondered how your brain knows when to take a breath, regulate your blood pressure, or alert you when you're getting sick? The answer lies in interoception, a remarkable biological system powered by certain proteins in your body called 'Piezo'. It was identified by Nobel Prize-winning neuroscientist Dr. Ardem Patapoutian at Scripps Research, an American medical research facility. Piezo protein acts as your body's internal sensory network and act as pressure-sensing molecules that make interoception possible. This system of interoception acts as our body’s sixth sense.
While most people are familiar with the traditional five senses, namely sight, hearing, touch, taste, and smell, interoception represents a "hidden sixth sense." It constantly monitors what’s happening inside our bodies. Unlike external senses that detect stimuli from the outside world, interoception involves a vast network of neurons tracking internal processes. These include various internal activities like circulation, digestion, and immune responses.
This internal awareness system is responsible for everyday sensations and we often take it for granted. These aren't just abstract feelings. They are the result of specialized sensors called Piezo proteins.
These proteins are present throughout your body and communicate with your brain.
The molecular basis of interoception was uncovered by Dr. Ardem Patapoutian at Scripps Research, who won the 2021 Nobel Prize in Physiology or Medicine for identifying Piezo proteins. Piezo proteins are pressure-sensing molecules that make interoception possible. This groundbreaking discovery revealed how our cells detect mechanical stimuli in both the skin and internal organs.
Piezo proteins function through mechanotransduction, the conversion of mechanical force into biological signals, and play crucial roles in physiology. 2
Patapoutian's team identified 73 candidates that might be the pressure sensor. Using a technique called siRNA knockdown, they began turning off each gene one by one to see if the cell would stop responding to pressure.
After more than a year of testing, the breakthrough came with the 73rd and final candidate. The protein was named Piezo, derived from the Greek word for pressure.
Piezo proteins are fundamental to numerous bodily functions. These molecular sensors enable your body to perform various functions, including monitoring blood pressure and cardiovascular function, detecting lung expansion during breathing, and sensing mechanical pressure throughout internal organs.
Much of interoception relies on the vagus nerve, which is a massive cable of around 100,000 nerve fibers connecting your brain to nearly every organ. This critical nerve contains the majority of Piezo proteins and acts as the body's vital sign reader.
The vagus nerve constantly transmits information about pressure, temperature, acidity, glucose levels, and even signals related to gut microbes back to the brain. This allows your nervous system to make continuous adjustments to maintain homeostasis. The system is remarkably sophisticated.
Recognizing the importance of understanding this system, the National Institutes of Health awarded Dr. Patapoutian and his collaborators $14.2 million over five years through the NIH Director’s Transformative Research Award. The team aims to create the first comprehensive atlas of interoception, mapping how sensory neurons connect with internal organs.
The research team includes:
Dr. Ardem Patapoutian (Nobel Prize winner, Scripps Research)
Dr. Li Ye (N. Paul Whittier Chair in Chemistry, Scripps Research)
Dr. Bosiljka Tasic (Director of Molecular Genetics, Allen Institute)
Dr. Xin Jin (Associate Professor, Scripps Research)
“My team is honored that the NIH is supporting the kind of collaborative science needed to study such a complex system,” says Patapoutian.
The project used whole-body imaging to trace neural pathways from the spinal cord to different organs, creating a high-resolution 3D map. Genetic profiling distinguishes between different cell types, such as neurons signaling from the gut, bladder, or fat tissue.
Perhaps the most exciting aspect of interoception research is its potential to revolutionize mental health treatment. Emerging research suggests psychiatric conditions, from anxiety to depression, may be caused in part by disruptions in interoception.
Dr. Harini Bhat, PharmD, aptly describes the link between interoception and mental health through her Instagram reel.
“There’s a growing body of research to suggest psychiatric conditions, from anxiety to depression, may be caused in part by issues with perceiving our internal environment,” explains Dr. Bhat. “Meaning one day it might be possible to treat these conditions by restoring a person's internal sense.”
Dr. Camilla Nord at Cambridge University has found that individuals with psychiatric disorders show unusual activity in the mid-insula, a brain region that interprets internal signals from interoceptors. Her team is testing whether focused ultrasound targeting this area could help treat mental health conditions by restoring proper signal interpretation.
Disruptions in interoceptive pathways have been linked to numerous health conditions, including:
Autoimmune disorders
Chronic pain syndromes
Neurodegenerative diseases
High blood pressure (hypertension)
As Dr. Jin notes, “Interoception is fundamental to nearly every aspect of health, but it remains a largely unexplored frontier of neuroscience. By creating the first atlas of this system, we aim to lay the foundation for better understanding how the brain keeps the body in balance, how that balance can be disrupted in disease, and how we might restore it.”
References:
1. NobelPrize.org. “Press Release.” Nobel Prize Outreach 2026, January 9, 2026. https://www.nobelprize.org/prizes/medicine/2021/press-release/
2. Coste B, Mathur J, Schmidt M, et al. Piezo1 and Piezo2 are essential components of distinct mechanically activated cation channels. Science. 2010;330(6000):55-60. doi:10.1126/science.1193270
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