Background:
- Dopamine is a chemical signal linked to the rewarding effects of drugs. Certain genes make
these effects sensitive to the time of day they are taken. Cocaine can affect these genes in
the brain. Researchers want to measure brain dopamine at different times of day.
Objectives:
- To look for changes to a person s biological clock in the function of the dopamine reward
system. To test if cocaine disrupts this.
Eligibility:
- Adults age 21-55 with a cocaine use disorder.
- Healthy volunteers age 21-55.
Design:
- Participants will be screened with medical history, physical exam, interview, and blood
and urine tests. Their breath will be tested for alcohol and recent smoking.
- Participants will have 3 overnight clinic visits.
- Visit 1: They will have blood and urine collected and a heart test.
- A plastic tube (catheter) will be placed into a vein in each arm by needle.
- Participants will have a PET scan in a donut-shaped machine. They will lie on a bed that
slides in and out of it, wearing a cap. A radiotracer (measures dopamine) and a drug
(blocks dopamine removal) will be injected via catheter. Vital signs will be measured
and blood will be drawn throughout.
- Visit 2: repeats Visit 1, except at night.
- Visit 3, participants will have urine collected.
- They will have MRI scans in a metal cylinder surrounded by a magnetic field. They will
lie on a table that slides in and out of it, with a coil over their head.
- Participants may answer questions, take computer or paper tests, and perform simple
actions.
- For 1 week, participants will wear a wrist device that measures daily activity.
Phase:
Early Phase 1
Details
Lead Sponsor:
National Institute on Alcohol Abuse and Alcoholism (NIAAA)