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Nicotinic Modulation of the Default Network of Resting Brain Function

2018年7月3日 更新者：National Institute on Drug Abuse (NIDA)

Background:

- A brain circuit called the default network is the brain circuit that is active when the brain is at rest; that is, when individuals are not concentrating on specific tasks. Previous research has shown that the default network functions differently in people with schizophrenia and Alzheimer s disease, and may contribute to the problems with memory and concentration that can affect people who have these conditions. Studies have also shown that nicotine affects the default network, but more research is needed on the ways in which nicotinic receptors may change activity in these regions and thereby affect individuals ability to concentrate on specific tasks.

Objectives:

- To determine whether and how nicotine and mecamylamine, a drug that blocks nicotinic receptors, affect the default network in nonsmokers in ways that improve thinking and concentration.

Eligibility:

  • Healthy, right-handed volunteers between 21 and 50 years of age.
  • Volunteers must not have used any kind of tobacco product in the past 2 years.

Design:

  • This study involves an initial screening visit, a training visit, and three testing visits.
  • Participants will be screened with a medical history and physical examination, as well as blood and urine samples and questions about smoking history.
  • Participants will have an initial training session to practice the tasks that will be done during magnetic resonance imaging scans at the testing visits. These tasks will test participants concentration and memory.
  • Participants will have three test sessions with the following combinations of study drugs: (1) a nicotine patch and a placebo capsule, (2) a placebo patch and a capsule of mecamylamine, or (3) a placebo patch and capsule. Different combinations will be given at each visit, and participants will not know which one they receive.
  • Participants will perform the same concentration and memory tasks at each testing visit, and will provide a blood sample after each visit to determine levels of nicotine and mecamylamine.

研究概览

地位

完全的

条件

详细说明

Objective: To evaluate the potential of manipulating activity in the so-called default network of resting brain function by nicotinic ligands. Default network activity modulates cognitive functioning, and effects of nicotine thereon may motivate smoking behavior. In the future, this mechanism could become a novel approach to improving cognition in disease populations that show dysfunction of this network, such as schizophrenia or Alzheimer s disease.

Study population: 27 healthy non-smokers.

Design: A double-blind, placebo-controlled, within-subject fMRI study, evaluating regional brain activation and cognitive functions under conditions of transdermal nicotine (7 mg/day), oral mecamylamine (a nicotinic antagonist, 7.5 mg), and placebo.

Outcome measures: Activity and functional connectivity of default regions during cognitive task performance, measures of cognitive task performance, measures of subjective state, and plasma concentrations of nicotine, nicotine metabolites and mecamylamine.

研究类型

观察性的

注册 (实际的)

43

联系人和位置

本节提供了进行研究的人员的详细联系信息，以及有关进行该研究的地点的信息。

学习地点

  • 美国
    • Maryland
      • Baltimore、Maryland、美国、21224
        • National Institute on Drug Abuse, Biomedical Research Center (BRC)
      • Catonsville、Maryland、美国、21228
        • University of Maryland at Baltimore/MPRC

参与标准

研究人员寻找符合特定描述的人，称为资格标准。这些标准的一些例子是一个人的一般健康状况或先前的治疗。

资格标准

适合学习的年龄

21年 至 55年 (成人)

接受健康志愿者

是的

有资格学习的性别

全部

描述

  • INCLUSION CRITERIA:

    1. Age 21 through 55. We want to avoid exposing a maturing brain to centrally active substances that it has not previously been exposed to (non-smokers), and to increase sensitivity for measuring drug effects by minimizing population inhomogeneity related to both cognitive decline with normal aging (Verhaeghen and Salthouse 1997, De Luca et al. 2003) and to ongoing brain maturation.
    2. Did not consume cigarettes, cigarillos, cigars, or other tobacco or nicotine-containing products more than 20 times in lifetime, and did not use any nicotine-containing product at all within the last two years.
    3. Normal or corrected to normal vision (at least 20/80).

EXCLUSION CRITERIA:

  1. Presence of metal objects in the body, implanted electronic devices, or any other counter indication for MRI.
  2. Claustrophobia.
  3. Major psychiatric disorders including mood, anxiety or psychotic disorders.
  4. Cardiovascular or cerebrovascular disease, such as history of myocardial infarction, heart failure, angina, stroke, severe arrhythmias, or EKG abnormalities as specified under Screening methods .
  5. Kidney or liver disease.
  6. Hypertension (resting systolic BP above 140 or diastolic above 85 mm Hg).
  7. Hypotension (resting systolic BP below 95 or diastolic below 60).
  8. Use of any prescription or over-the-counter drug other than supplements and birth control.
  9. History of or current neurological illnesses, such as stroke, seizures, dementia or organic brain syndrome.
  10. Learning disability, attention deficit disorder, or any other condition that impedes memory and attention.
  11. Glaucoma, organic pyloric stenosis, uremia or renal insufficiency (see Mecamylamine-related risks).
  12. Prostatic hypertrophy, bladder neck obstruction or urethral stricture (see Mecamylamine-related risks).
  13. Left-handed or ambidextrous.
  14. Pregnant as determined by urine test, or breast-feeding.
  15. History or current diagnosis of drug or alcohol abuse or dependence.
  16. IQ < 85 as estimated by the WASI vocabulary subtest.
  17. Strong disposition to get car sick.

学习计划

本节提供研究计划的详细信息，包括研究的设计方式和研究的衡量标准。

研究是如何设计的？

设计细节

研究衡量的是什么？

主要结果指标

结果测量
Activity and functional connectivity of default regions during cognitive task performance, measures of cognitive task performance, measures of subjective state, and plasma concentrations of nicotine, nicotine metabolites and mecamylamine.

合作者和调查者

在这里您可以找到参与这项研究的人员和组织。

赞助

National Institute on Drug Abuse (NIDA)

出版物和有用的链接

负责输入研究信息的人员自愿提供这些出版物。这些可能与研究有关。

一般刊物

研究记录日期

这些日期跟踪向 ClinicalTrials.gov 提交研究记录和摘要结果的进度。研究记录和报告的结果由国家医学图书馆 (NLM) 审查，以确保它们在发布到公共网站之前符合特定的质量控制标准。

研究主要日期

学习开始

2010年10月24日

研究完成

2014年12月24日

研究注册日期

首次提交

2010年11月11日

首先提交符合 QC 标准的

2010年11月11日

首次发布 (估计)

2010年11月15日

研究记录更新

最后更新发布 (实际的)

2018年7月5日

上次提交的符合 QC 标准的更新

2018年7月3日

最后验证

2014年12月24日

更多信息

与本研究相关的术语

关键字

其他相关的 MeSH 术语

其他研究编号

  • 999911461
  • 11-DA-N461

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