- ICH GCP
- US Clinical Trials Registry
- Klinisk utprøving NCT00357409
GABA Levels in the Brains of Blind People
GABA Levels in the Occipital Cortex of Blind Human Subjects
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.
Studieoversikt
Detaljert beskrivelse
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
Subjects 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. 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.
Studietype
Registrering
Kontakter og plasseringer
Studiesteder
-
-
Maryland
-
Bethesda, Maryland, Forente stater, 20892
- National Institutes of Health Clinical Center, 9000 Rockville Pike
-
-
Deltakelseskriterier
Kvalifikasjonskriterier
Alder som er kvalifisert for studier
Tar imot friske frivillige
Kjønn som er kvalifisert for studier
Beskrivelse
- INCLUSION CRITERIA:
All subjects must be between 18 and 55 years of age.
Healthy sighted volunteers. Legally blind subjects with blindness secondary to retinal lesions or eye removal acquired at ages earlier than 4 years old (EARLY) and after 13 years of age (LATE). The rationale for the distinction is based in our previous studies that indicate different magnitude of brain plasticity depending on the age of acquisition of blindness.
EXCLUSION CRITERIA:
Exclusion criteria will be those of MRI procedures:
Pregnant women tested after urine pregnancy test.
Subjects with metal in the cranium except mouth.
Subjects with metal fragments from occupational exposure or surgical clips in or near the brain.
Subjects with blood vessel, cochlear or eye implants.
Subjects with increased intracranial pressure as evaluated by clinical means.
Subjects with cardiac or neural pacemakers.
Subjects with intracardiac lines and implanted medication pumps.
Studieplan
Hvordan er studiet utformet?
Samarbeidspartnere og etterforskere
Publikasjoner og nyttige lenker
Studierekorddatoer
Studer hoveddatoer
Studiestart
Studiet fullført
Datoer for studieregistrering
Først innsendt
Først innsendt som oppfylte QC-kriteriene
Først lagt ut (Anslag)
Oppdateringer av studieposter
Sist oppdatering lagt ut (Faktiske)
Siste oppdatering sendt inn som oppfylte QC-kriteriene
Sist bekreftet
Mer informasjon
Denne informasjonen ble hentet direkte fra nettstedet clinicaltrials.gov uten noen endringer. Hvis du har noen forespørsler om å endre, fjerne eller oppdatere studiedetaljene dine, vennligst kontakt register@clinicaltrials.gov. Så snart en endring er implementert på clinicaltrials.gov, vil denne også bli oppdatert automatisk på nettstedet vårt. .
Kliniske studier på Syn
-
Indiana UniversityKing Systems CorporationFullførtPediatrisk anestesi | King Vision Video Laryngoscope IntubasjonForente stater
-
Northeastern State UniversityAktiv, ikke rekrutterendeBakre kapselopacification obscuring visionForente stater
-
Zhongshan Ophthalmic Center, Sun Yat-sen UniversityHar ikke rekruttert ennåAksial forlengelse | Ungdom og barn | Naked Eye 3D Vision Training | Visuell funksjon