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Brain Imaging of Serotonin Transporters in the Brain

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00059046
Recruitment Status : Completed
First Posted : April 16, 2003
Last Update Posted : March 4, 2008
Information provided by:
National Institutes of Health Clinical Center (CC)

Brief Summary:

Serotonin is a chemical involved in the regulation of emotions, anxiety, sleep, stress, and other body functions. The purpose of this study is to use brain imaging technology to study how serotonin works in the brain.

The serotonin transporter (SERT) regulates the release of sertonin throughout the body. Until recently, radioactive chemicals called tracers were not suitable for viewing SERT activity. However, a newly developed tracer called [11C]DASB can be used with positron emission tomography (PET) imaging to view the parts of the brain that use serotonin.

Participants in this study will be screened with medical and psychiatric examinations, an electrocardiogram (EKG), and blood and urine tests. This study comprises two parts. During Part 1, participants will undergo a whole-body PET scan. During Part 2, participants will undergo a magnetic resonance imaging (MRI) scan of the brain. At the next study visit, participants will have one or two PET head scans. If not is not possible to perform both scans on the same day, an additional visit will be scheduled for the second PET scan.

Condition or disease
Healthy Serotonin Transporter

Detailed Description:

The serotonin transporter (SERT) modulates the activity of the central serotonergic system and SERT is also the primary target of the widely prescribed specific serotonin reuptake inhibitors. Until recently, suitable radioligands for in vivo imaging of SERT have not been available. However, a recently developed PET radioligand, [11C]DASB, appears suitable for quantifying SERT in humans. In the two protocols that have been approved by the CSRP for submission to the IRB, we planned to use [11C]DASB PET to study the pathophysiology of SERT in Parkinson's disease and OCD. This protocol was created to address criticisms raised by the NIH RDRC committee and the external scientific review.

  1. The NIH RDRC (Radioactive Drug Research Committee) review of this protocol asked that we obtain human biodistribution data to confirm the expected low levels of radiation exposure, based upon our prior studies in monkeys.
  2. To address one of the criticisms raised by the CSRP review, namely 1) to quantify SERT binding parameters with [11C]DASB in up to 10 normal subjects and 2) to determine the reliability and reproducibility of SERT binding parameter measurements by performing a second retest [11C]DASB PET study in the same subjects, because such data are not available for this radioligand. PET scanning will be performed with an intravenous injection of 20 mCi of [11C]DASB for 2 h, during which multiple arterial blood samples will also be obtained. The reproducibility of SERT binding parameters will be assessed by calculating the variability as well as the intraclass correlation coefficient between test/retest measurements. We expect that 1) we can accurately quantify SERT binding parameters using [11C]DASB PET imaging and 2) [11C]DASB PET measurements of SERT binding will be reliable and reproducible.

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Study Type : Observational
Enrollment : 20 participants
Official Title: Kinetic Studies in Whole Body and Brain of [11C]DASB PET Imaging of Serotonin Transporters
Study Start Date : April 2003
Study Completion Date : January 2005

Information from the National Library of Medicine

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Ages Eligible for Study:   Child, Adult, Older Adult
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes


Diagnosis: Healthy

Ages: 18-50 years


History of psychiatric disease, substance dependence or traumatic brain injury, severe systemic disease, poor vision or hearing.

History of substance abuse within 6 months

Abnormal laboratory tests, including HIV test

Any prior participation in other research protocols involving radiation exposure within the past year

Prior participation in other research protocols within the past year such that a radiation exposure together with the present study would exceed the annual limits

Pregnancy and Breast Feeding

Positive HIV test


Age: 18-50 y

Male or female

Consent given


DSM-IV Axis I diagnostic criteria such as history of, or current diagnosis ADHD, mood/anxiety disorder, alcohol or psychoactive substance abuse/dependence. All subjects must meet none of the Axis I diagnoses.

Psychotropic medication or other drugs that may cross the blood brain barrier. Drug free period must be greater than 4 weeks (antidepressants and benzodiazepine) and greater than 6 weeks (fluoxetine, antipsychotics, anticonvulsants).

Pregnancy or breastfeeding

Abnormal MRI other than minor atrophy

Abnormal laboratory tests, including HIV test


Pregnancy or breast feeding. Women with child bearing potential will a pregnancy test to exclude pregnancy

Prior participation in other research protocols within the past year such that a radiation exposure together with the present study would exceed the annual limits. Limits: A total effective dose or 5.0 rem in a year.

Any condition that increases risk for MRI (e.g., pacemaker, metallic foreign body in the eye, etc.)

Traumatic brain injury, severe systemic disease, poor vision or hearing

Major medical conditions or neurological disorders

Single radial and ulnar arterial circulation. This will be determined during physical examination (A simple wrist compression test)

Individuals who recently donated blood.

Unable to lay on one's back for PET/MRI scans. PET and MRI scans take approximately 2 and 1 hours, respectively.

Novacaine allergy - yes - Local anesthetic used for insertion of arterial and venous catheters.

Positive HIV test

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00059046

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United States, Maryland
National Institute of Mental Health (NIMH)
Bethesda, Maryland, United States, 20892
Sponsors and Collaborators
National Institute of Mental Health (NIMH)
Layout table for additonal information Identifier: NCT00059046    
Other Study ID Numbers: 030159
First Posted: April 16, 2003    Key Record Dates
Last Update Posted: March 4, 2008
Last Verified: January 2005
Keywords provided by National Institutes of Health Clinical Center (CC):
PET Measurements
Kinetic Analysis
Healthy Volunteer