Exploring Learning and Unlearning of Fear

Not Applicable

Withdrawn

• Conditions: Healthy Individuals
• Interventions: Drug: Lactose pill; Drug: d-Cycloserine; Genetic: Saliva sample; Other: Functional neuroimaging (fMRI)

• Registration Number: NCT01512316
• Lead Sponsor: Universitaire Ziekenhuizen KU Leuven

Brief Summary

The present study investigates the effect of d-cycloserine on learning and unlearning of fear in healthy humans and its underlying effect on the amygdala.

As a second objective, the effect of genotype on fear learning will be studied.

Detailed Description

A growing body of evidence suggests that the extinction of fear is mediated by the N-methyl-D-aspartate (NMDA) receptor activity in the basolateral amygdala. Intra-amygdala infusions of antagonists of this glutamate receptor in small animals (eg: rats, mice) have demonstrated a blockage of fear acquisition and extinction. Agonists, on the other hand, facilitate conditioned fear extinction.

The animal studies are all based on the simple fear learning paradigm of conditioning. However, it is not clear that human anxiety disorders are based on prior conditioning encounter. Therefore it is important to disentangle the effect of DCS on acquisition and extinction in the context of a simple learning paradigm, particular its effect on the human amygdala.

Study Timeline

• Study First Submitted: 2011-12-22
• Study First Submitted QC: 2012-01-13
• Study First Posted: 2012-01-19
• Status Verified: 2016-05
• Last Update Submitted: 2023-01-27
• Last Update Posted: 2023-01-31

Recruitment & Eligibility

• Status: WITHDRAWN
• Sex: All
• Target Recruitment: Not specified

Inclusion Criteria

• No axis I diagnosis compatible with the DSM-IV by means of a structured diagnostic interview
• Right-handed

Exclusion Criteria

• Current psychopharmacological or psychological treatment.
• The presence of a physical/medical condition that may interfere with the study.
• A contraindication for the use of DCS
• Pacemaker, medication pump (such as insulin pump), hearing aid, removable prosthodontics
• Metal in or on body (such as acupuncture needles, artificial limbs, stents, metal splints, clips, implanted electrodes, tattoos, or piercings)

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
d-Cycloserine Acquisition	Saliva sample	d-Cycloserine will be given on day1, before acquisition
Placebo	Lactose pill	A placebo pill will be administered on day1 and 2
d-Cycloserine Acquisition	Functional neuroimaging (fMRI)	d-Cycloserine will be given on day1, before acquisition
d-Cycloserine Extinction	Saliva sample	d-Cycloserine will be administered on day2, before extinction
d-Cycloserine Extinction	Functional neuroimaging (fMRI)	d-Cycloserine will be administered on day2, before extinction
Placebo	Saliva sample	A placebo pill will be administered on day1 and 2
Placebo	Functional neuroimaging (fMRI)	A placebo pill will be administered on day1 and 2
d-Cycloserine Acquisition	d-Cycloserine	d-Cycloserine will be given on day1, before acquisition
d-Cycloserine Extinction	d-Cycloserine	d-Cycloserine will be administered on day2, before extinction

Primary Outcome Measures

Name	Time	Method
change in BOLD-signal during a fear conditioning task	t0, t+24, t+48	Subjects will participate in a 3-day experiment. Day1 (t0): Acquisition Day2 (T+24): extinction Day3 (T+48): re-exposure

Trial Locations

Locations (1)

Catholic University Leuven, Departement of Radiology; 🇧🇪 Leuven, Belgium