Try the modernized beta website. Learn more about the modernization effort.
Working… Menu

The Effect of Acetylcholine on Memory and Attention

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00001977
Recruitment Status : Completed
First Posted : December 10, 2002
Last Update Posted : March 4, 2008
Information provided by:
National Institutes of Health Clinical Center (CC)

Brief Summary:

This study will examine whether enhancing the chemical acetylcholine in the brain can improve memory and attention. It will identify changes in brain function that occur during these cognitive tasks. Animal and human studies have shown that a decrease in acetylcholine may be responsible for some of the cognition deficits in Alzheimer's disease. Conversely, patients taking medications that slow the breakdown of this neurotransmitter have experienced improvements in memory.

Normal volunteers and patients with Alzheimer's disease may be eligible for this study of functional brain imaging using positron emission tomography (PET) and magnetic resonance imaging (MRI). These techniques can measure brain activity and identify brain regions involved in memory and attention. Candidates for this study will be screened with a medical and psychiatric history and a physical examination including blood tests, urinalysis, chest X-ray, and electrocardiogram (ECG). Those enrolled will perform memory and attention tasks during PET and MRI studies. The cognition tasks will be repeated twice-once during infusion of saline (a fluid with no drug effect) through a catheter inserted into a blood vessel and again during infusion of physostigmine, a drug that delays the breakdown of acetylcholine. The PET procedure will be completed in one day; the MRI procedure will be done on two different days.

During imaging, attention and memory tasks will be presented in short blocks of about 4-minutes duration. They will be repeated in sequence up to 10 times with a few minutes separation. Subjects will be shown pictures of faces or other visual stimuli and asked to decide whether the pictures are the same or different.

Information gained from this study may increase knowledge about how acetylcholine affects the brain's response to memory and attention tasks and perhaps lead to better treatments for the cognitive deficits in Alzheimer's disease.

Condition or disease
Alzheimer's Disease Healthy

Detailed Description:
The goal of this research project is to determine the role of cholinergic neuromodulation in the functional organization of memory and attention in humans, using functional neuroimaging techniques. The study of human cognition with functional brain imaging in conjunction with pharmacologic probes that alter cognitive processes provides an opportunity to examine another dimension of the organization of human neural systems. In addition to identifying the anatomical structures that participate in specific cognitive functions, this approach can reveal how different neuromodulators can influence processing in those structures. Additionally, the combined use of functional brain imaging and pharmacological manipulation can be used to evaluate the role of neurotransmitter dysfunction in disease states that produce cognitive impairment and may direct us to potential therapeutic approaches.

Layout table for study information
Study Type : Observational
Enrollment : 70 participants
Official Title: Cholinergic Modulation of Human Memory and Attention: Functional Neuroimaging Studies
Study Start Date : January 2000
Study Completion Date : April 2001

Resource links provided by the National Library of Medicine

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Layout table for eligibility information
Ages Eligible for Study:   Child, Adult, Older Adult
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Three groups of subjects will be enrolled:

Subjects with Alzheimer's Disease (AD) 45-100 years of age;

Healthy controls 20-50 years of age;

Healthy controls 50-90 years of age.

No evidence of, or history of, any medical, neurological or psychiatric condition (other than dementia in the AD patient group) which may affect brain function and metabolism and/or represent a contraindication to the study; including learning disability, psychiatric condition, head trauma with loss of consciousness, seizures or other neurological conditions, alcoholism or substance abuse, hypertension, cardiovascular disease, diabetes and other endocrine diseases, malignancy.

No subjects with vision and/or hearing problems severe enough to interfere with testing.

No females with a positive pregnancy test.

No subjects with contraindications to magnetic resonance imaging (MRI), including pacemakers, cochlear implants, surgical clips or metal fragments in their eyes or body parts.

Only subjects with good health and without evidence of significant chronic disease will be accepted into the healthy control groups.

Only patients without evidence of significant chronic disease who meet standard clinical criteria for the diagnosis of dementia of Alzheimer's disease type will be accepted into the study in the AD group.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00001977

Layout table for location information
United States, Maryland
National Institute of Mental Health (NIMH)
Bethesda, Maryland, United States, 20892
Sponsors and Collaborators
National Institute of Mental Health (NIMH)
Layout table for additonal information Identifier: NCT00001977    
Other Study ID Numbers: 000056
First Posted: December 10, 2002    Key Record Dates
Last Update Posted: March 4, 2008
Last Verified: January 2000
Keywords provided by National Institutes of Health Clinical Center (CC):
Alzheimer's Disease
Functional Magnetic Resonance Imaging
Positron Emission Tomography
Working Memory
Additional relevant MeSH terms:
Layout table for MeSH terms
Alzheimer Disease
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Neurodegenerative Diseases
Neurocognitive Disorders
Mental Disorders