PET Scanning of Brain Dopaminergic Signal Transduction Involving Arachidonic Acid in Adults With Attention Deficit Hyperactivity Disorder (ADHD)
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 16
- 试验地点
- 1
研究概览
简要总结
This study will explore the brain in men with and without attention deficit hyperactivity disorder (ADHD). It will use positron emission tomography (PET) and magnetic resonance imaging (MRI) to study brain function and nerve cell communication involving phospholipids (fatty molecules that make up the covering of nerve cell fibers in the brain and are involved in communication between the cells). It will also look at how nerve cell communication is related to blood flow. In particular, the study will explore communication through the dopamine system, which is one of the main neurotransmitter systems in the brain involved in ADHD.
Healthy men and men with ADHD between 18 and 55 years of age may be eligible for this study.
Participants undergo the following procedures:
"<TAB>Medical history and psychiatric and medical evaluation, including blood and urine tests.
"<TAB>MRI scan. This test uses a strong magnetic field and radio waves to obtain images of the brain. The subject lies still on a table that slides into the scanner (a metal cylinder) during the scanning.
"<TAB>PET scanning. The subject lies on the scanner bed with his head held still using a special facemask. A catheter (plastic tube or needle) is placed in an artery to collect blood samples and in a vein to inject radioactive isotopes for measuring blood flow and phospholipid metabolism. Scans are done after an injection of a saline solution and again after injection of apomorphine, a medication that turns on dopamine receptors in the brain. The injections are given under the skin of the abdomen, about one and a half hours apart....
详细描述
A. Objective
Attention deficit hyperactivity disorder (ADHD) is a heritable neurodevelopmental disorder with a reported male predominance that persists into adulthood and leads to significant morbidity in affected individuals. ADHD is currently hypothesized to reflect central dopaminergic dysfunction. Evaluation of human dopaminergic dysfunction using in vivo neuroimaging has been limited to studies of receptor localization and quantification, and dopamine synthesis, rather than direct measurement of the functional status of receptor signaling. There exists a need to thoroughly elucidate mechanisms underlying aberrant dopaminergic neurotransmission downstream of receptor activation in signaling processes. We have developed an in vivo method to measure neuroreceptor-initiated signal transduction involving activation of phospholipase A(2) to release the second messenger, arachidonic acid (AA). We propose to use positron emission tomography (PET) to quantitatively image dopamine-initiated signal transduction via AA in ADHD patients and healthy volunteers, in subjects administered the dopaminergic agonist, apomorphine, and to measure regional cerebral blood flow (rCBF) as well. We hypothesize that signaling and flow responses to apomorphine will be elevated, demonstrating hypersensitivity of the dopamine signaling mechanism.
B. Study population
18 healthy male volunteers between the ages of 18 and 55, will be recruited for this study (see justification for recruitment of males only in Study Design and Methods).
C. Design
研究设计
- 研究类型
- Observational
- 时间视角
- Other
入排标准
- 年龄范围
- 18 Years 至 55 Years（Adult）
- 性别
- Male
- 接受健康志愿者
- 否
入选标准
- 未提供
排除标准
- 未提供