Advanced Functional and Structural MRI Techniques for Neuropharmacological Imaging

Overview

Background: \- Functional and structural magnetic resonance imaging (MRI) techniques have allowed researchers to map and study how the brain works when at rest and when engaged in specific tasks. MRI scans have provided more information about how drugs affect the brain, and about how drug addiction changes the brain and influences behavior, mood, and thinking processes. To better understand the underlying mechanism of drug addiction and to develop strategies for more effective treatment, researchers are interested in developing new MRI techniques to study the effects of addiction on the brain. Objectives: \- To develop new functional and structural MRI techniques, and to evaluate their potential use in brain imaging studies related to addiction. Eligibility: * Individuals between 18 and 80 years of age. * Participants may be smokers or nonsmokers, and may use drugs or not use drugs. Design: * During the initial screening, participants will complete questionnaires about family and personal history, drug use, and other information as required by the researchers. Participants who will be asked to complete tasks during the MRI scan will be shown how to perform these tasks before the scanning session. * Before each study session, participants may be asked to complete some or all of the following: questions about their drug use during the last week, a breathalyzer test, a urine drug-use assessment, a urine pregnancy test, or a measure of carbon monoxide. Participants will also provide blood samples before the start of the scan. * For each scanning session, participants will have an MRI scan that will last approximately 2 hours. * MRI scans may include specific tasks to be performed during the scan, or an experiment that studies the brain's response to carbon dioxide.

Objective: Functional and structural magnetic resonance imaging techniques have proven essential for noninvasive mapping of brain physiology and pathology. The primary objective of this protocol is to develop advanced magnetic resonance imaging and spectroscopy (MRI and MRS) techniques for neuroimaging studies related to addiction. These neuroimaging techniques will be used in other studies to better understand the underlying mechanism of drug addiction and to potentially develop strategies for more effective treatment. Study population: Healthy controls and drug users will participate in the study. Technical developments of MRI/MRS will be performed on healthy controls, while the evaluation of the applicability of these techniques to addiction related neuroimaging studies will be performed using drug users and healthy controls. Design: Based on the fundamental principle of the biophysical transduction of physiological signals to magnetic resonance (MR) imaging and spectroscopic signals, advanced techniques will be developed to measure the activity, metabolism, structure, and biochemistry of the brain. The development of these techniques typically includes the following steps: 1) proof-of-concept computer simulations, 2) implementation of the imaging concept with an MRI scanner and phantoms, 3) feasibility testing on control subjects, and 4) evaluation of the sensitivity and specificity of these techniques in detecting functional changes modulated by task performance, CO2 (5%)administration, or non-invasive neuromodulation techniques (e.g.: transcranial magnetic stimulation (TMS), and transcranial rotating permanent magnet stimulation (TRPMS), 5) evaluation of these techniques in detecting functional and/or structural alterations of the brain related to a specific disease. Outcome measures: Advanced neuroimaging techniques developed from this protocol will demonstrate the ability to distinguish between drug using and control populations. Successful techniques will then be incorporated into hypothesis driven studies in the Neuroimaging Research Branch at NIDA-IRP. These techniques will also be useful, through publications and technology transfer, to the entire neuroimaging society.