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Mechanisms of Human Plasticity in the Human System

This study has been completed.
Information provided by:
National Institutes of Health Clinical Center (CC) Identifier:
First received: November 3, 1999
Last updated: March 3, 2008
Last verified: March 2002

The purpose of this study is to investigate the physiology associated with plasticity of the motor system. Plasticity refers to the process by which neighboring brain cells assume the responsibilities of damaged or diseased brain cells.

The mechanisms behind this process are unknown. However, researchers have several theories about how plastic changes take place. Possible explanations include the growth of new connections between brain cells and the use of previously unused connections.

Researchers plan to use transcranial magnetic stimulation and drug intervention in order to determine the mechanisms responsible for specific types of plasticity.

Previous studies have shown that certain drugs can affect the mechanisms involved in these changes. By using one drug at a time, researchers plan to evaluate the role of each of several different mechanisms in brain reorganization.

Cerebrovascular Accident
Spinal Cord Injury

Study Type: Observational
Official Title: Mechanisms of Plasticity in the Human Motor System

Further study details as provided by National Institutes of Health Clinical Center (CC):

Estimated Enrollment: 260
Study Start Date: December 1996
Estimated Study Completion Date: March 2002
Detailed Description:

The purpose of this study is to investigate the physiology associated with plasticity of the motor system seen in a number of different circumstances. Techniques used will involve the combination of transcranial magnetic stimulation (TMS) and pharmacologic interventions. We propose to use drugs judged to be safe, that either potentiate GABA related intracortical inhibition, change presynaptic release of excitatory aminoacids like glutamate, or decrease the activity of the NMDA receptors (mostly antiepileptic drugs). If plastic changes expressed as larger motor maps or motor evoked potentials (MEP) to TMS are secondary to intracortical disinhibition, administration of a drug that potentiates intracortical inhibition may result in decreased plasticity and smaller motor maps or MEP. This finding would then identify intracortical disinhibition as the mechanism responsible for this type of plasticity. Similarly, if plastic changes decrease with a drug that inhibits release of excitatory aminoacids, or that antagonize the action of NMDA receptors, the mechanism underlying plasticity is likely to be mediated by modulation in the release of excitatory aminoacids or activity in NMDA-receptors.

Results from this study will then provide information about the relative involvement of intracortical disinhibition, modulation in the release of excitatory aminoacids, and role of NMDA receptors in different settings of human plasticity.


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

Must be over 18 years of age.

Must not have personal history of seizures, loss of consciousness, hypertension, psychosis, heart conditions or allergies to any of the drugs.

Women must not be nursing or pregnant.

Patients may have amputations, spinal cord injuries, blindness or large hemispheric lesions from stroke.

  Contacts and Locations
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Please refer to this study by its identifier: NCT00001661

United States, Maryland
National Institute of Neurological Disorders and Stroke (NINDS)
Bethesda, Maryland, United States, 20892
Sponsors and Collaborators
National Institute of Neurological Disorders and Stroke (NINDS)
  More Information

Publications: Identifier: NCT00001661     History of Changes
Other Study ID Numbers: 970048
Study First Received: November 3, 1999
Last Updated: March 3, 2008

Keywords provided by National Institutes of Health Clinical Center (CC):
Spinal Cord Injury
Intracortical Inhibition

Additional relevant MeSH terms:
Spinal Cord Injuries
Spinal Cord Diseases
Central Nervous System Diseases
Nervous System Diseases
Trauma, Nervous System
Wounds and Injuries
Cerebrovascular Disorders
Brain Diseases
Vascular Diseases
Cardiovascular Diseases
Vision Disorders
Sensation Disorders
Neurologic Manifestations
Eye Diseases
Signs and Symptoms processed this record on May 25, 2017