- ICH GCP
- Yhdysvaltain kliinisten tutkimusten rekisteri
- Kliininen tutkimus 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.
Tutkimuksen yleiskatsaus
Yksityiskohtainen kuvaus
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.
Opintotyyppi
Ilmoittautuminen
Yhteystiedot ja paikat
Opiskelupaikat
-
-
Maryland
-
Bethesda, Maryland, Yhdysvallat, 20892
- National Institutes of Health Clinical Center, 9000 Rockville Pike
-
-
Osallistumiskriteerit
Kelpoisuusvaatimukset
Opintokelpoiset iät
Hyväksyy terveitä vapaaehtoisia
Sukupuolet, jotka voivat opiskella
Kuvaus
- 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.
Opintosuunnitelma
Miten tutkimus on suunniteltu?
Yhteistyökumppanit ja tutkijat
Julkaisuja ja hyödyllisiä linkkejä
Opintojen ennätyspäivät
Opi tärkeimmät päivämäärät
Opiskelun aloitus
Opintojen valmistuminen
Opintoihin ilmoittautumispäivät
Ensimmäinen lähetetty
Ensimmäinen toimitettu, joka täytti QC-kriteerit
Ensimmäinen Lähetetty (Arvio)
Tutkimustietojen päivitykset
Viimeisin päivitys julkaistu (Todellinen)
Viimeisin lähetetty päivitys, joka täytti QC-kriteerit
Viimeksi vahvistettu
Lisää tietoa
Nämä tiedot haettiin suoraan verkkosivustolta clinicaltrials.gov ilman muutoksia. Jos sinulla on pyyntöjä muuttaa, poistaa tai päivittää tutkimustietojasi, ota yhteyttä register@clinicaltrials.gov. Heti kun muutos on otettu käyttöön osoitteessa clinicaltrials.gov, se päivitetään automaattisesti myös verkkosivustollemme .
Kliiniset tutkimukset Näkemys
-
Rigshospitalet, DenmarkValmisStereoskooppinen visioTanska
-
Medical University of ViennaValmisStereoskooppinen visioItävalta
-
ChampionsEdge, LLCValmisVisio, Kiikarit | UrheilulääketiedeYhdysvallat
-
Ocuphire Pharma, Inc.Ophthalmic Consultants of Long IslandValmisPimeänäön väheneminen | Häiriö; Visio, menetysYhdysvallat
-
University of GeorgiaDSM Nutritional Products, Inc.Valmis
-
Ocuphire Pharma, Inc.ValmisPimeänäkövalitukset | Pimeänäön väheneminen | Häiriö; Visio, menetysYhdysvallat
-
Stanford UniversityValmisKipu | Visio likinäköinenYhdysvallat
-
VA Office of Research and DevelopmentValmis
-
Osaka City UniversityNihon University; Kurume University; Miyata Eye Hospital; Fukuoka Kinen Hospital ja muut yhteistyökumppanitValmis
-
Medical University of South CarolinaSouth Carolina School for the Deaf and the BlindValmis