Tulane Study Reveals Brain's Adjustments to Diminishing Threats

Research identifies neural circuits that shape fear responses from freezing to active escape.

Mar. 26, 2026 at 8:00am

Got story updates? Submit your updates here. ›

Researchers at Tulane University have identified brain circuits that help determine how fear responses change as perceived threats diminish, offering new insight into how the brain regulates defensive behavior and why those processes may break down in conditions such as post-traumatic stress disorder.

Why it matters

The findings suggest the brain organizes fear along a continuum, adjusting behavior based on perceived threat level rather than simply switching fear 'on' or 'off'. This more nuanced view of fear regulation may have implications for understanding psychiatric conditions like PTSD, where fear responses can be persistent and difficult to control.

The details

The study, led by neuroscientist Jonathan Fadok, examines how different populations of neurons in the central amygdala shape a range of fear responses - from freezing to active escape behaviors. The researchers found that fear does not simply disappear during extinction, but the brain gradually recalibrates how it responds to a perceived threat. Specifically, they identified distinct roles for CRF neurons, which supported higher-intensity escape-like responses, and SOM neurons, which promoted freezing and lower-intensity behaviors.

  • The study was published on March 26, 2026.

The players

Jonathan Fadok

Associate professor of psychology in Tulane University's School of Science and Engineering and the lead researcher on the study.

Tulane University

The institution where the research was conducted.

National Institutes of Health

The agency that provided funding support for the research.

U.S. Department of Veterans Affairs

The agency that provided funding support for the research.

Got photos? Submit your photos here. ›

What they’re saying

“For decades, most fear research has focused on freezing. That has been incredibly useful, but it captures only part of the picture. In real-world situations, fear can also produce more active responses like darting or trying to escape.”

— Jonathan Fadok, Associate professor of psychology

“At the neural level, extinction looks less like erasing fear and more like reshaping it. Different circuits help determine whether an animal responds with intense escape behavior, freezing or a lower-intensity defensive state.”

— Jonathan Fadok, Associate professor of psychology

“PTSD is often described as a disorder of persistent fear, but that persistence can look very different from person to person. Some individuals remain hypervigilant, while others experience more intense, panic-like reactions. Our work points to brain mechanisms that may contribute to those different expressions.”

— Jonathan Fadok, Associate professor of psychology

What’s next

The findings suggest that disruptions in the neural circuits identified in the study could help explain why fear remains so hard to regulate in conditions like PTSD, potentially serving as targets for future therapies aimed at improving fear extinction.

The takeaway

This research provides a more nuanced understanding of how the brain regulates fear responses, moving beyond the traditional focus on freezing behavior. The insights could have important implications for treating psychiatric disorders characterized by persistent and difficult-to-control fear, such as PTSD.