Effects of Adolescent Synaptic Pruning (SPA PET)

May 4, 2026 updated by: Beatriz Luna
The study will use a PET-based measure of brain cell (neuron) connections (synapses) in young adults who have also obtained an MRI, to assess how the loss of brain cell connections (synaptic pruning) is captured by MRI-based measures. This will inform youth MRI studies to understand neurotypical brain development that can help identify abnormal trajectories as in mental illness.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Enrolling by invitation

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 loss of brain cell (neuron) connections (synapses) through human development, known as synaptic pruning, has been characterized in postmortem studies but how this proceeds in live humans as they age into adulthood is not well understood. This study will use the PET tracer [11C]UCB-J which provides a direct measure of synaptic density, in conjunction with previously acquired ultra-high field MRI, in a group of young adults in order to understand how standard MRI-based measures reflect changes in the density of synapses. PET [11C]UCB-J is known to measure the density of synaptic connections by measuring a protein (SV2A) present in synapses. A comparison of results from the current study with MRI-based measures of byproducts of synaptic membrane breakdown from childhood to early adulthood will allow assessment of how non-invasive MRI reflects synaptic pruning through development, facilitating studies of how the brain changes through adolescence and into adulthood, which is needed to identify patterns of development associated with the emergence of mental illness.

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.
60

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 Locations

  • United States
    • Pennsylvania
      • Pittsburgh, Pennsylvania, United States, 15213
        • Laboratory of Neurocognitive Development

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

Yes

Description

Inclusion Criteria:

  • Males or females between 18-26 years of age, AND currently enrolled in the Parent Project (R01MH067924)

Exclusion Criteria: (these exclusion criteria are outlined in the Parent Project)

  • Head injury with loss of consciousness over an hour.
  • A vision problem or eye movement problem (such as lazy eye, double vision, blurred vision, or color blindness).
  • A learning disability and/or ever had an Individualized Education Plan (IEP) in school.
  • Significant neurological or metabolic illness: Epilepsy, Meningitis, Encephalitis, Diabetes, Huntington's disease.
  • Diagnosed with a psychiatric disorder.
  • Participants with, or with a first degree relative, having a DSM IV Axis l psychiatricdisorder.
  • Metal implants or ferromagnetic objects contained within the body which may interfere with the MRI scan (but not limited to, those with a pacemaker, presence of metallic fragments near the eyes or spinal cord, or cochlear implant.) Dental fillings do not present a risk for MRI. If there is a possibility of metal being present in the participant's body, the participant will be excluded from the study.
  • Weight more than 250 pounds.
  • Claustrophobia or uncomfortable in small spaces.
  • <70% on the Achenbach scale (either from Youth Self Report (YSR) or Adult Self Report (ASR)).
  • IQ < 80 or IQ > 130.
  • Pregnancy or lactation, lack of effective birth control during 15 days before the scans.
  • Currently employed as radiation worker; or participation in radioactive drug research protocols within the previous year such that the total cumulative annual radiation dose (i.e., from participation in the previous radioactive drug study [studies] and this study) would exceed the radiation dose limits specified in the FDA regulations (i.e., 21 CFR 361.1) that govern the research use of [C-11]UCB-J
  • History of drug or alcohol abuse (from parent study eligibility).

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: PET Imaging Supplemental Component
Adult participants enrolled in the parent study, will be given the option to be a part of the PET imaging supplemental project. Maximum enrollment is 60 adult participants. Interested participants will be consented into the PET portion, and will have a single PET scan (as outlined in the Study Description section).
Radiation: PET Imaging Scan using [11C]UCB-J
[11C]UCB-J (~ 15 mCi and ≤ 6μg) will be injected as a slow intravenous bolus. Following an intravenous bolus injection of [11C]UCB-J, the participants will be positioned in the scanner for a low dose CT scan (for attenuation correction) fifty-five minutes after the [11C]UCB-J injection, and emission data will be collected.

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
Non-invasive quantification of synaptic pruning
Time Frame: The PET-CT scan will be within approximately 30 days of the parent study MRI.

1. Age-related changes in synaptic density through young adulthood

o Cross-sectional age-related (18-26 years of age) changes in synaptic density via SUVR quantified within the dorsolateral prefrontal cortex.
The PET-CT scan will be within approximately 30 days of the parent study MRI.
Non-invasive quantification of synaptic pruning
Time Frame: The PET-CT scan will be within approximately 30 days of the parent study MRI.

2. Within-subject associations of synapse density to MRI-derived measures of brain membrane byproducts

o Synaptic density, based on SUVR modeling of [11C]UCB-J acquisitions, will be compared to ultra-high field (7 Tesla) [31P]MRSI measurement of membrane phospholipid levels obtained from the same participants.
The PET-CT scan will be within approximately 30 days of the parent study MRI.

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.
Beatriz Luna

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: Beatriz Luna, PhD, University of Pittsburgh

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 (Actual)

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.
January 9, 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.
June 30, 2028

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.
June 30, 2028

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).
April 27, 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.
May 4, 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.
May 6, 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.
May 6, 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.
May 4, 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.
May 1, 2026

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.
  • STUDY24060023
  • 3R01MH067924-19S1 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Individual [11C]UCB-J SUVR maps will be shared via the NIH Data Archive (NDA), along with basic corresponding demographic data (age, sex).

IPD Sharing Time Frame

Upon completion of the study.

IPD Sharing Access Criteria

Access of shared IPD is managed by the NIH Data Archive.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL

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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