Amygdala-Prefrontal in Fear Extinction

August 28, 2026 updated by: Washington University School of Medicine

Causal Dynamics of Human Amygdala-Prefrontal Circuits During Fear Extinction Learning

The goal of this clinical trial is to understand how brain circuits involving the amygdala and prefrontal cortex contribute to fear learning and extinction. Fear extinction is the process by which a fear response decreases when a threat is no longer present. The study will include participants with epilepsy who are undergoing stereoelectroencephalography (SEEG) monitoring as part of their clinical care. The main questions this study aims to answer are: How do the amygdala and prefrontal cortex interact during fear learning and extinction? Do different parts and hemispheres of the amygdala have different roles in fear learning and extinction? How does electrical stimulation of the amygdala affect these brain circuits and fear extinction? Participants will complete tasks involving fear learning and extinction while researchers record brain activity from clinically implanted electrodes. Researchers will also use electrical stimulation via these electrodes to study how amygdala activity affects other brain regions and fear extinction.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The ability to reduce fear responses through extinction when threats are no longer present is essential for mental health. Deficits in extinction underlie fear-related disorders such as post-traumatic stress disorder (PTSD). A critical gap remains in understanding the neural mechanisms underlying fear extinction, which poses a major barrier to developing more effective therapeutic interventions. The amygdala (AMY)-prefrontal circuits are critical in fear extinction. In animal models, the lateral nucleus of the amygdala (LA) receives sensory inputs and initiates fear learning, while the basal nucleus of the amygdala (BA) integrates regulatory inputs from the ventromedial prefrontal cortex (vmPFC) and dorsal anterior cingulate cortex (dACC) for appropriate fear response. However, due to species-specific differences between animal and human neurobiology, the nucleus-specific contributions of the amygdala and their interactions with the vmPFC and dACC in human fear extinction and regulation remain poorly understood. Clinically indicated stereoelectroencephalography (SEEG) electrodes, which allow direct recording and stimulation of amygdala-prefrontal circuits, provide a unique opportunity to address this gap. The objective of this study is to determine the causal dynamics of amygdala-prefrontal circuits involved in fear extinction learning in participants with epilepsy undergoing SEEG monitoring. The study will address three aims: (1) Determine the intrinsic and stimulation-induced dynamics of human amygdala-prefrontal circuits. The study will characterize cause pathways and circuit-level interactions in amygdala-vmPFC-dACC circuits using intracranial recordings and electrical stimulation. (2) Characterize nucleus-specific and hemispherical lateralized dynamics of amygdala-prefrontal circuits during fear extinction. The study will examine the neural dynamics of the LA, BA, and left and right amygdala-prefrontal circuits during fear extinction and regulation. (3) Determine the effects of theta-burst stimulation of amygdala nuclei on fear extinction. Theta-burst stimulation will be applied to the LA and BA during extinction learning to examine how targeted stimulation modulates fear-related neural circuits and behavior.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
40

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

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Study Contact Backup

Study Locations

  • United States
    • Missouri
      • St Louis, Missouri, United States, 63110-1010
        • Recruiting
        • Washington University School of Medicine
        • Contact:
        • Contact:
        • Principal Investigator:
          • Tao Xie, PhD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. At least 18 years of age.
  2. Able to understand the nature of the task.
  3. Able to provide informed consent themselves or provide consent through their legally authorized representative.
  4. Undergoing clinically indicated intracranial electrode implantation with coverage of at least one fear-related brain region, including the amygdala, hippocampus, cingulate cortex, insula, or prefrontal cortex.

Exclusion Criteria:

  1. Under the age of 18.
  2. Unable to understand the nature of the task.
  3. Unable to provide informed consent themselves or provide consent through their legally authorized representative.
  4. No clinically indicated intracranial electrode coverage in any fear-related brain region, including the amygdala, hippocampus, cingulate cortex, insula, or prefrontal cortex

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Amygdala-prefrontal in Fear Extinction
Participants will undergo direct intracranial electrical stimulation and complete a Pavlovian fear conditioning and extinction task while neural activity is recorded through clinically implanted stereoelectroencephalography (SEEG) electrodes. Electrical stimulation, including single-pulse and/or high-frequency stimulation, will be delivered through the intracranial electrodes to investigate amygdala-prefrontal circuit dynamics. Participants may also receive theta-burst stimulation of the amygdala during extinction learning.
Other: Direct intracranial electrical stimulation
During a resting state and extinction learning phase, participants will receive electrical stimulation (single-pulse and/or high-frequency stimulation) through the intracranial electrodes while recording local field potentials from the neural networks. Direct electrical stimulation will be accomplished using FDA-approved equipment and stimulation protocols that are consistent with those used routinely for clinical purposes.
Behavioral: Fear conditioning
Participants will be involved in a Pavlovian fear conditioning/extinction experiment while recording local field potential signals from the neural networks. During the experiment, neutral stimuli will be paired with an aversive but not painful electric shock (via the surface skin of the hand/foot) or screeching sound.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Broadband high-frequency power (70-170 Hz) in amygdala-prefrontal circuits
Time Frame: During research sessions, up to 2 hours per day for up to 4 days during the participant's hospital stay.
Broadband high-frequency power (70-170 Hz) will be quantified from local field potentials recorded through clinically implanted stereoelectroencephalography (SEEG) electrodes in the amygdala and prefrontal cortex. Broadband high-frequency power will be assessed during fear processing and during intracranial electrical stimulation to characterize local neural activity within amygdala-prefrontal circuits. For stimulation recordings, stimulation artifacts will be removed using appropriate artifact-removal methods, for example, MPARRM (matching pursuit-based artifact reconstruction and removal method) for single-pulse stimulation and LIBRA (linear baseline-integrated removal of artifacts) for high-frequency stimulation.
During research sessions, up to 2 hours per day for up to 4 days during the participant's hospital stay.
Oscillatory power at the stimulation frequency during intracranial electrical stimulation
Time Frame: During research sessions, up to 2 hours per day for up to 4 days during the participant's hospital stay.
Oscillatory power at the stimulation frequency will be quantified from local field potentials recorded through clinically implanted stereoelectroencephalography (SEEG) electrodes in the amygdala and prefrontal cortex. Power at the stimulation frequency will be assessed during intracranial electrical stimulation to quantify stimulation-induced oscillatory entrainment within amygdala-prefrontal circuits. For theta-burst stimulation, theta-band activity (4-8 Hz) will be assessed.
During research sessions, up to 2 hours per day for up to 4 days during the participant's hospital stay.
Amplitude of cortico-cortical evoked potentials in amygdala-prefrontal circuits
Time Frame: During research sessions, up to 2 hours per day for up to 4 days during the participant's hospital stay.
Cortico-cortical evoked potential (CCEP) amplitude will be quantified from local field potentials recorded through clinically implanted stereoelectroencephalography (SEEG) electrodes following single-pulse intracranial electrical stimulation. CCEP amplitude will be used to assess effective connectivity between the amygdala and prefrontal cortex.
During research sessions, up to 2 hours per day for up to 4 days during the participant's hospital stay.
Theta/gamma band power in amygdala-prefrontal circuits
Time Frame: During research sessions, up to 2 hours per day for up to 4 days during the participant's hospital stay.
Theta (4-8 Hz) and gamma (30-50 Hz) band power will be quantified from local field potentials recorded through clinically implanted stereoelectroencephalography (SEEG) electrodes in the amygdala and prefrontal cortex. Theta/gamma-band power will be assessed during fear conditioning and extinction to characterize oscillatory neural activity within amygdala-prefrontal circuits.
During research sessions, up to 2 hours per day for up to 4 days during the participant's hospital stay.
Cross-frequency coupling in amygdala-prefrontal circuits
Time Frame: During research sessions, up to 2 hours per day for up to 4 days during the participant's hospital stay.
Cross-frequency coupling will be quantified from local field potentials recorded through clinically implanted stereoelectroencephalography (SEEG) electrodes in the amygdala and prefrontal cortex. Coupling between neural activity across different frequency bands, including phase-amplitude coupling between lower-frequency oscillations and high-frequency activity, will be assessed during resting state and fear processing to characterize cross-frequency neural interactions within amygdala-prefrontal circuits.
During research sessions, up to 2 hours per day for up to 4 days during the participant's hospital stay.
Skin conductance response amplitude during fear conditioning and extinction
Time Frame: During research sessions, up to 2 hours per day for up to 4 days during the participant's hospital stay.
Skin conductance response (SCR) amplitude will be quantified during fear conditioning and extinction to assess autonomic responses to conditioned stimuli.
During research sessions, up to 2 hours per day for up to 4 days during the participant's hospital stay.
Pupil diameter during fear conditioning and extinction
Time Frame: During research sessions, up to 2 hours per day for up to 4 days during the participant's hospital stay.
Pupil diameter will be quantified from eye-tracking recordings during fear conditioning and extinction to assess autonomic responses to conditioned stimuli.
During research sessions, up to 2 hours per day for up to 4 days during the participant's hospital stay.
Button press reaction time during fear conditioning and extinction
Time Frame: During research sessions, up to 2 hours per day for up to 4 days during the participant's hospital stay.
Button press reaction time will be quantified during fear conditioning and extinction to assess behavioral responses to conditioned stimuli.
During research sessions, up to 2 hours per day for up to 4 days during the participant's hospital stay.
Subjective unpleasantness rating during fear conditioning and extinction
Time Frame: During research sessions, up to 2 hours per day for up to 4 days during the participant's hospital stay.
Participants will rate the unpleasantness of the conditioned stimuli during fear conditioning and extinction. Ratings will be used to quantify subjective emotional responses to the conditioned stimuli.
During research sessions, up to 2 hours per day for up to 4 days during the participant's hospital stay.

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Heart rate during fear conditioning and extinction
Time Frame: During research sessions, up to 2 hours per day for up to 4 days during the participant's hospital stay.
Heart rate will be quantified during fear conditioning and extinction to assess autonomic responses to conditioned stimuli.
During research sessions, up to 2 hours per day for up to 4 days during the participant's hospital stay.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Washington University School of Medicine

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
National Institute of Mental Health (NIMH)

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Tao Xie, PhD, Washington University School of Medicine

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 15, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
July 31, 2031

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
July 31, 2032

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
August 18, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 28, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
September 2, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 2, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 28, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 202507143
  • K99MH144521 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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