Related Experiment Video
Updated: Jun 13, 2025
05:49
Stress-Enhanced Fear Learning, a Robust Rodent Model of Post-Traumatic Stress Disorder
Published on: October 13, 2018
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Paraventricular Thalamus Hyperactivity Mediates Stress-Induced Sensitization of Unlearned Fear but Not
Kenji J Nishimura1, Denisse Paredes2, Nathaniel A Nocera1
1Center for Learning and Memory, Department of Neuroscience, University of Texas at Austin, Austin, TX, USA.
Biorxiv : the Preprint Server for Biology
|June 12, 2025
Summary
Stress can heighten unlearned fear responses, a process called fear sensitization. Researchers found the posterior paraventricular thalamus (pPVT) drives this sensitization, offering a new target for trauma disorder treatments.
Area of Science:
- Neuroscience
- Psychology
- Behavioral Science
Background:
- Stress exposure can lead to persistent enhancement of fear responses beyond original trauma cues.
- This phenomenon, known as fear sensitization, is implicated in trauma-related disorders.
- While stress-enhanced fear learning (SEFL) is studied, mechanisms of unlearned fear sensitization are less understood.
Purpose of the Study:
- Investigate neural mechanisms of stress-enhanced fear responding (SEFR), a model for unlearned fear sensitization.
- Identify brain regions mediating SEFR using c-Fos mapping and fiber photometry.
- Determine the role of the posterior paraventricular thalamus (pPVT) in SEFR.
Main Methods:
- Developed the Stress-Enhanced Fear Responding (SEFR) paradigm in mice.
- Utilized c-Fos mapping to identify stress-induced neural activity.
- Employed fiber photometry to monitor pPVT activity during SEFR and SEFL.
- Used chemogenetics to inhibit or stimulate pPVT activity.
Main Results:
- Footshock stress induced persistent pPVT hyperactivity correlating with SEFR.
- SEFR, but not SEFL, was associated with increased pPVT activity.
- pPVT inhibition blocked SEFR induction and expression; pPVT stimulation mimicked SEFR in naive mice.
- pPVT manipulation did not affect SEFL.
Conclusions:
- Stress-enhanced fear learning (SEFL) and stress-enhanced fear responding (SEFR) involve distinct neural mechanisms.
- pPVT hyperactivity is a key mechanism for stress-induced sensitization of unlearned fear (SEFR).
- The pPVT is a potential therapeutic target for arousal and reactivity symptoms in trauma and stressor-related disorders.
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