Brain Receptors in Sympathetic Nervous System Regulation
Status:
Completed
Trial end date:
2004-12-01
Target enrollment:
Participant gender:
Summary
The purpose of this study is to investigate the role of brain receptors called
alpha2-adrenoreceptors in regulating the sympathetic nervous system, which maintains the
supply of blood and fuel to the body's organs in times of stress, fear, anger, or exercise.
Alpha(2)-adrenergic receptors (alpha(2)-AR) play a role in a variety of physiological
functions. There are three subtypes of alpha(2)-ARs, and their differences are unknown. This
study will examine the functional roles of these three subtypes by comparing the behavioral,
biochemical, psychophysiological, and autonomic function effects of the alpha(2)-AR drugs
clonidine and yohimbine.
Participants in this study will undergo a physical examination, electrocardiogram (ECG), and
blood, urine, and saliva tests. Women will have hormone tests to determine the time of their
last period and the time of their next ovulation. Participants will undergo
neuropsychological testing and other procedures.