PET Whole Body Distribution Studies Using [11C]CUMI
| Status: | Archived |
|---|---|
| Conditions: | Anxiety, Depression, Major Depression Disorder (MDD) |
| Therapuetic Areas: | Psychiatry / Psychology, Pulmonary / Respiratory Diseases |
| Healthy: | No |
| Age Range: | Any |
| Updated: | 7/1/2011 |
| Start Date: | April 2010 |
PET Whole Body Distribution Studies Using the 5-HT1A Agonist, [11C]CUMI
Background:
- Researchers studying new treatments for major depressive disorder are looking at how
medications to treat depression act on the brain chemical serotonin, which interacts
with specific serotonin receptors on brain cells. New methods of studying serotonin
receptors in the brain may help provide a better understanding of depression and
treatment options.
- A new radioactive chemical called [11C]CUMI may be useful for studying serotonin
receptors in the brain. By using positron emission tomography (PET) scanning to see how
[11C]CUMI bonds with serotonin receptors, researchers will investigate whether
[11C]CUMI can be used to study depression and how antidepressant medications work.
Objectives:
- To determine the usefulness of [11C]CUMI as a method of studying serotonin receptors in
the brain.
Eligibility:
- Healthy individuals between 18 and 65 who have no history of psychiatric illness.
Design:
- This study requires 8 outpatient visits to the NIH clinic.
- Visit 1: Participants will have a full physical examination and medical history, as
well as a psychiatric evaluation and questions about alcohol and drug use. Other tests
will include blood and urine samples and an electrocardiogram (EKG). Testing will take
approximately 3 hours.
- Visit 2: Participants will have a magnetic resonance imaging (MRI) scan to evaluate
brain function and activity.
- Visit 3: Participants will have a PET scan, in which a small amount of the radioactive
chemical [11C]CUMI will be injected through an intravenous (IV) catheter, and will have
another IV line put in place to draw regular blood samples during the scan. The scan
will last approximately 4 hours.
- Visits 4-8: Participants will have regular blood tests after the scan between days 1-3
and at about weeks 1, 2, 3, and 4. The blood tests will check muscle, heart, and liver
function.
Eighteen million people in the United States are currently suffering from Major Depressive
Disorder, which is characterized by episodes of low mood, poor self attitude and poor
vitality. Of those suffering from Major Depressive Disorder (MDD), only one third
completely improve, but even among these cases, there is a waiting period of several weeks
or more during which antidepressants take effect. Our inability to adequately treat MDD is
evident in its being ranked number one in Disability Adjusted Life Years (DALY) among
persons aged 15-44. Given this profound burden, improving our understanding of the
molecular basis of MDD is of utmost importance in the development of novel antidepressant
medications.
Serotoninergic neurotransmission is implicated in MDD, as demonstrated by the relative
success of selective serotonin reuptake inhibitors (SSRIs). SSRIs block the reuptake of
serotonin through the serotonin transporter, which then increases serotonin at the synaptic
cleft. Serotonin then binds to 5-HT(1A) receptors, which are G-protein coupled receptors
that are present both presynaptically and postsynaptically. Presynaptically, these
receptors act as autoinhibitory receptors, triggering decreased firing rates and decreased
serotonin release. This autoinhibitory mechanism is believed to be the reason why patients
experience a delay in symptomatic improvement after initiation of SSRIs. Serotonin binding
to postsynaptic receptors mediates symptomatic improvement of depression. Multiple positron
emission tomography (PET) studies on 5-HT(1A) have been published. However, none of these
studies use 5-HT(1A) agonists, which are specific for the high affinity, G-protein coupled
and active state of the 5-HT(1A) receptor. We would therefore like to establish the use of
the 5-HT(1A) radiolabelled agonist, [(11)C]CUMI, here at NIH.
The purpose of this study is to perform whole body PET studies in healthy volunteers in
order to estimate radiation absorbed doses for [(11)C]CUMI. Future experiments will include
studies on Major Depressive Disorder.
We found this trial at
1
site
9000 Rockville Pike
Bethesda, Maryland 20892
Bethesda, Maryland 20892
301-496-2563
National Institutes of Health Clinical Center The National Institutes of Health (NIH) Clinical Center in...
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