NCT00357409

GABA Levels in the Brains of Blind People

Completed Last updated 2 July 2017

What this trial tests

trial in Vision in 39 participants. Completed in 3 March 2008.

Timeline

11 February 2002

3 March 2008

Quick facts

Lead sponsor	National Institute of Neurological Disorders and Stroke (NINDS)
Status	Completed
Study type	OBSERVATIONAL
Enrollment	39
Start date	11 February 2002
Estimated completion	3 March 2008
Sites	1 location across United States

Conditions studied

• Vision — all drugs for Vision →
• Blind — all drugs for Blind →

Sponsor

National Institute of Neurological Disorders and Stroke (NINDS)

Who can join

Adults 18 to 55, any sex, with Vision or Blind. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

In blind individuals, the occipital cortex becomes capable of processing tactile and auditory information, a phenomenon described as crossmodal plasticity. GABA is the major inhibitory neurotransmitter in the brain and a possible candidate to mediate this form of human plasticity. We intend to use magnetic resonance spectroscopy (MRS) to measure GABA and hypothesize that GABA levels in the occipital cortex of blind humans will be lower than in sighted controls. Such decrease could possibly mediate compensatory changes in the occipital cortex of the blind.

Objective

Early blind subjects exhibit better tactile acuity than late blinds or sighted individuals. The purpose of the study is the determine GABA levels in the human occipital cortex after long-term light deprivation (blindness).

Study Population

Our experiments will make use of early blind, late blind, and sighted control subjects.

Design

Subject will be identified and will receive clinical and neurological examinations at the NIH. MRS studies will be performed at NIH MRI Center with 3Tesla Magnet. Each subject head will be positioned in an adjustable holder (designed for minimal motion and maximal comfort) such that a flat coil lay just below the occipital cortex. The sequence has been described before \[33\]. The individuals who perform the data analysis will be blind to the purpose of the experiments.

Outcome measures

The concentration of GABA from the 14 ml voxel over the visual cortex will be measured. Edited proton spectrum of GABA will be compared with the edited sub spectrum of creatine for a concentration reference.

Publications & conference data

No peer-reviewed publications indexed yet for this trial. Completed trials usually publish results within 12-18 months.