Mechanisms of Human Plasticity in the Human System

March 3, 2008 updated by: National Institute of Neurological Disorders and Stroke (NINDS)

Mechanisms of Plasticity in the Human Motor System

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.

Study Overview

Status

Completed

Conditions

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.

Study Type

Observational

Enrollment

260

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

United States
- Maryland
  - Bethesda, Maryland, United States, 20892
    - National Institute of Neurological Disorders and Stroke (NINDS)

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

Child
Adult
Older Adult

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

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.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

National Institute of Neurological Disorders and Stroke (NINDS)

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

December 1, 1996

Study Completion

March 1, 2002

Study Registration Dates

First Submitted

November 3, 1999

First Submitted That Met QC Criteria

November 3, 1999

First Posted (Estimate)

November 4, 1999

Study Record Updates

Last Update Posted (Estimate)

March 4, 2008

Last Update Submitted That Met QC Criteria

March 3, 2008

Last Verified

March 1, 2002

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

970048
97-N-0048

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.