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Brain Imaging in Elderly People and Individuals With Alzheimer's Disease

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: NCT00001917
Recruitment Status : Completed
First Posted : November 4, 1999
Last Update Posted : March 4, 2008
Information provided by:
National Institutes of Health Clinical Center (CC)

Brief Summary:

The purpose of this study is to use brain imaging technology to study the effects of aging and Alzheimer's Disease (AD) on a specific type of brain receptor.

The brain is made up of cells called neurons. The neurons communicate with one another and secrete chemicals called neurotransmitters. The neurotransmitters bind to specific sites on other neurons called receptors. Acetylcholine (ACh) is a neurotransmitter that binds to ACh receptors. In both aging and AD, the number of neurons that secrete ACh decreases and the function of some ACh receptors changes. This study will use positron emission tomography (PET) scans of the brain to study the effects of age and AD on muscarinic type 2 [M2], a type of ACh receptor.

Participants in this study will be injected with a radioactive tracer (ligand [F-18] FP-TZTP) which binds to [M2] receptors. Participants will then undergo a PET scan in order for the density and function of [M2] receptors to be studied.

Condition or disease Intervention/treatment
Alzheimer's Disease Healthy Drug: O15 Drug: [F-18] FP-TZTP

Detailed Description:
The Geriatric Psychiatry Branch (GPB) of the National Institute of Mental Health (NIMH) proposes to study the effect of aging and Alzheimer's Disease (AD) on muscarinic type 2 (M2) receptor density and function using the ligand [F-18] FP-TZTP. M2 receptors are primarily autoreceptors found on acetylcholine (ACh) neurons, and are lost along with ACh neurons in aging and AD, particularly in the cerebral cortex. As we near completion of the study of the young versus the old, we would like to add a few more healthy subjects to achieve better gender balance, continue the accrual of Alzheimer's patients and expand the Protocol to include its natural scientific progression. Quantification of M2 receptors with a single FP-TZTP scan as we are currently performing with 99-M-0073 provides a measure of the number of cholinergic receptors in the brain, but not their capacity to release acetylcholine into the synapse. To test this capacity requires a second TZTP scan and the use of an agent that alters acetylcholine concentrations in the synapse. Non-human primate studies performed here (1) have found PET scans with FP-TZTP to be sensitive to changes in acetylcholine synapse concentrations, as a result of competition, in response to the adminstration of the acetylinesterase inhibitor physostigmine. We would like to use physostigmine in all groups; young, older normal, and Alzheimer's patients to infer differences in capacity to release acetylcholine.

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Study Type : Observational
Enrollment : 150 participants
Official Title: M2 Receptor Measurements in Aging and in Alzheimer's Disease
Study Start Date : April 1999
Study Completion Date : April 2005

Resource links provided by the National Library of Medicine

Information from the National Library of Medicine

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Ages Eligible for Study:   Child, Adult, Older Adult
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes


Healthy males and females between 20-100 years old and volunteers with AD.

AD volunteers must meet the NINCDS-ADRDA criteria for possible, probable, or definite AD.

All subjects will be required to be off all prescription medications which could effect the PET scan, such as medications with anticholinergic effects, for two weeks to one month prior to the PET scan, and off psychotropic medication for one month.

Subjects will be cautioned not to consume alcohol, marijuana, or psychotropic drugs while on the study, nor to smoke, use caffeinated beverages, or take over-the-counter medications such as cold medications (ie: Benadryl, Sudafed) for at least 12 hours prior to the PET scan.


Patients withe significant cardiovascular disease, history of alcoholism, significant head trauma, uncontrolled hypertension, diabetes, bleeding disorders or other medical conditions which would make it medically unsafe to perform any part of the PET scan or would confound data analysis.

Subjects with evidence of significant chronic disease to be accepted into the healthy control group.

Subjects must not be pregnant.

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): NCT00001917

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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: NCT00001917     History of Changes
Other Study ID Numbers: 990073
First Posted: November 4, 1999    Key Record Dates
Last Update Posted: March 4, 2008
Last Verified: April 2005
Keywords provided by National Institutes of Health Clinical Center (CC):
Positron Emission Tomography
Visual Stimulation
Cholinergic Stimulation
[F-18] FP-TZIP
Alzheimer's Disease
Visual Activation
Additional relevant MeSH terms:
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Alzheimer Disease
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Neurodegenerative Diseases
Neurocognitive Disorders
Mental Disorders