Association Between Serum and Neuroimaging Measurements of the GABAergic System

February 13, 2025 updated by: Francois Corbin

The GABAergic System: Study of the Association Between Serum Measurements and Those Obtained Through Neuroimaging in Healthy Human Adults

The goal of this study is to better understand the relationship between peripheral and central nervous system measurements of the gamma-aminobutyric acid (GABA) system in otherwise healthy individuals. the main questions it aims to answer are:

  1. Does GABA cross the blood-brain barrier?
  2. Can peripheral measurements of the GABAergic system be used to study GABA in the brain?

Participants will receive oral GABA and Placebo and undergo blood draws, MRI scans and transcranial magnetic stimulation sessions.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet 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

Although gamma-aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the central nervous system in humans, and various pharmacological compounds and natural products aim to modulate it, it is still unknown whether GABA can cross the blood-brain barrier. The present project aims to clarify this issue by comparing measurements obtained in the central nervous system (the brain) with peripheral measurements (serum) following oral administration of the amino acid GABA. This will help determine if peripheral concentrations of GABA in the blood reflect levels in the brain. This would facility studying the GABAergic system in vulnerable clinical populations (such as children or patients with intellectual disabilities) to participate in without resorting to expensive neuroimaging exams and the inclusion of individuals who cannot undergo neuroimaging exams (e.g., claustrophobia, presence of metal in the body). To achieve this, GABA measurements (serum and neuroimaging) will be obtained before and after the oral intake of 1800mg of GABA or a placebo in 30 healthy adults participating in a cross-over, single-blind study with repeated measures.

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.
30

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

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

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

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Be between 18 and 35 years old
  • Be of right manual dominance
  • In good health

Exclusion Criteria:

  • Have an implant or pacemaker,
  • Having tinnitus,
  • Have a history of fainting,
  • Have already had an epileptic seizure or have a family history of epilepsy,
  • Have a known neurological disease,
  • Have a diagnosis of diabetes
  • Be under psychotropic medication,
  • Have suffered from substance abuse or dependence in the last 6 months,
  • Have a neurostimulator,
  • Have a splinter or metallic implant in the head or the rest of the body,
  • Have a cochlear implant,
  • Have an automated injection system implanted (insulin pump),
  • Have a transdermal patch,
  • Have tattoos in the area to be studied,
  • Be pregnant or breastfeeding,
  • Being claustrophobic or having other reasons that would prevent the volunteer from tolerating the imaging exam.

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: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Double

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: GABA Start Group
Participants who are randomly assigned to the GABA start group. These participants receive GABA at the first experimental visit and the placebo at the second experimental visit.
Other: Acute Oral gamma-aminobutyric acid (Natural Health Product in Canada)
1800 mg (3 capsules of 600mg) of GABA taken at the research center under the supervision of the research team.
Other Names:
  • GABA
Other: Acute Placebo
A capsule filled with powdered sugar taken under the supervision of the research team.
Experimental: Placebo Start Group
Participants who are randomly assigned to the Placebo start group. These participants will receive a placebo at the first experimental visit and GABA at the second experimental visit.
Other: Acute Oral gamma-aminobutyric acid (Natural Health Product in Canada)
1800 mg (3 capsules of 600mg) of GABA taken at the research center under the supervision of the research team.
Other Names:
  • GABA
Other: Acute Placebo
A capsule filled with powdered sugar taken under the supervision of the research team.

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
Impact of Acute GABA consumption on short intracortical inhibition
Time Frame: Pre-GABA, 40 minutes after acute administration of GABA, Pre-Placebo, 40 minutes after acute administration of Placebo
TMS-derived measure of Intracortical inhibition: The degree of decrease of peak-to-peak motor evoked potential (MEP) amplitude induced by the administration of a conditioning stimulus (set at 70% of resting motor threshold) 2-4 ms before the test stimulus (stimulation intensity required to produce an MEP of 1 millivolt (mV), approximately 120% of resting motor threshold)
Pre-GABA, 40 minutes after acute administration of GABA, Pre-Placebo, 40 minutes after acute administration of Placebo
Impact of Acute GABA consumption on peripheral serum GABA concentrations
Time Frame: Pre-GABA, 40 minutes after acute administration of GABA, Pre-Placebo, 40 minutes after acute administration of Placebo
Serum GABA concentration will be measured before and after acute administration of GABA and placebo.
Pre-GABA, 40 minutes after acute administration of GABA, Pre-Placebo, 40 minutes after acute administration of Placebo

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
Impact of Acute GABA consumption on short intracortical facilitation
Time Frame: Pre-GABA, 40 minutes after acute administration of GABA, Pre-Placebo, 40 minutes after acute administration of Placebo
Transcranial magnetic stimulation (TMS) -derived measure of Intracortical facilitation: The degree of increase of peak-to-peak motor evoked potential (MEP) amplitude induced by the administration of a conditioning stimulus (set at 80% of resting motor threshold) 12-24 ms before the test stimulus (stimulation intensity required to produce an MEP of 1 mV, approximately 120% of resting motor threshold).
Pre-GABA, 40 minutes after acute administration of GABA, Pre-Placebo, 40 minutes after acute administration of Placebo
Impact of Acute GABA consumption on GABA concentrations in the brain
Time Frame: Pre-GABA, 40 minutes after acute administration of GABA, Pre-Placebo, 40 minutes after acute administration of Placebo
Estimation of GABA concentrations in the brain from magnetic resonance spectroscopy
Pre-GABA, 40 minutes after acute administration of GABA, Pre-Placebo, 40 minutes after acute administration of Placebo
Impact of Acute GABA consumption on subjective alertness
Time Frame: Pre-GABA, 40 minutes after acute administration of GABA, Pre-Placebo, 40 minutes after acute administration of Placebo
Subjective alertness will be measured using the Biphasic Alcohol Alertness Scale (BAES). This scale which measures alertness and sedation and is comprised of 6 items, for each item participants rate how they feel from 1 (not at all) to 10 (extremely)
Pre-GABA, 40 minutes after acute administration of GABA, Pre-Placebo, 40 minutes after acute administration of Placebo
Impact of Acute GABA consumption on objective alertness
Time Frame: Pre-GABA, 40 minutes after acute administration of GABA, Pre-Placebo, 40 minutes after acute administration of Placebo
Objective alertness will be measured using the psychomotor vigilance task (PVT). This computerised task measures alertness, participants will have to respond to visual cues that are presented at random intervals on the screen.
Pre-GABA, 40 minutes after acute administration of GABA, Pre-Placebo, 40 minutes after acute administration of Placebo

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.
Francois Corbin

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.
May 5, 2025

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.
May 1, 2026

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 1, 2026

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).
June 10, 2024

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.
June 17, 2024

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.
June 18, 2024

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.
March 25, 2025

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.
February 13, 2025

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.
February 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

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.
  • 2024-5398 (Other Identifier: CÉR CIUSSS Estrie - CHUS)

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

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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