Scientists Uncover Brain Circuit Behind Fear Without Physical Experience (Image supported by ChatGPT)
DAEJEON, May 16 (Korea Bizwire) — A research team at the Korea Advanced Institute of Science and Technology (KAIST) has identified a specific brain circuit responsible for forming fear memories induced solely by visual threats—without any physical pain—offering new insights into the neurological basis of PTSD, anxiety disorders, and depression.
In findings published May 9 in Science Advances, the team led by Prof. Jin-Hee Han of the Department of Biological Sciences revealed that a neural pathway connecting the posterior insular cortex (pIC) to the parabrachial nucleus (PBN) in the brain plays a central role in encoding emotionally traumatic experiences based on psychological—rather than physical—stimuli.
The study, conducted on mice, simulated predator attacks using looming shadows to trigger visual fear responses. Despite the absence of physical harm, the mice formed strong fear memories.
Using chemogenetics and optogenetics techniques, the researchers identified that when the pIC-to-PBN circuit was artificially suppressed, visual-threat-induced fear memory was significantly diminished, while pain-based fear learning remained unaffected.
Activation of the Psychological Fear Memory Circuit in Mice. (Image courtesy of KAIST)
“This provides clear evidence that emotional and physical pain are processed by distinct brain circuits,” the researchers noted.
Dr. Junho Han, the study’s lead author, emphasized the broader implications: “People can develop PTSD even without directly experiencing trauma—just by witnessing an event or being exposed to intense media coverage.
Until now, most studies on fear memory have focused on physical pain. This study shifts the focus to neural responses to psychological threat.”
Prof. Jin-Hee Han added, “Understanding this brain circuitry brings us closer to developing targeted therapies for mental illnesses rooted in emotional trauma, such as PTSD, panic disorder, and generalized anxiety.”
The discovery is expected to contribute to the development of more precise, circuit-level treatments for emotional disorders that originate from psychologically induced fear.
M. H. Lee (mhlee@koreabizwire.com)
