title: Increased regional cerebral blood flow but normal distribution of GABAA receptor in the visual cortex of subjects with early-onset blindness.
abstract: Before the completion of visual development, visual deprivation impairs synaptic elimination in the visual cortex. The purpose of this study was to determine whether the distribution of central benzodiazepine receptor (BZR) is also altered in the visual cortex in subjects with early-onset blindness. Positron emission tomography was carried out with [(15)O]water and [(11)C]flumazenil on six blind subjects and seven sighted controls at rest. We found that the CBF was significantly higher in the visual cortex for the early-onset blind subjects than for the sighted control subjects. However, there was no significant difference in the BZR distribution in the visual cortex for the subject with early-onset blindness than for the sighted control subjects. These results demonstrated that early visual deprivation does not affect the distribution of GABA(A) receptors in the visual cortex with the sensitivity of our measurements. Synaptic elimination may be independent of visual experience in the GABAergic system of the human visual cortex during visual development.
authors.affiliation: Department of Neurology, Neurological Institute, Nippon Medical School Chiba-Hokusoh Hospital, Inba, Japan. mishina@nms.ac.jp
authors.forename: Masahiro
authors.initials: M
authors.lastname: Mishina
authors.forename: Michio
authors.initials: M
authors.lastname: Senda
authors.forename: Motohiro
authors.initials: M
authors.lastname: Kiyosawa
authors.forename: Kiichi
authors.initials: K
authors.lastname: Ishiwata
authors.forename: Anne G
authors.initials: AG
authors.lastname: De Volder
authors.forename: Hideki
authors.initials: H
authors.lastname: Nakano
authors.forename: Hinako
authors.initials: H
authors.lastname: Toyama
authors.forename: Kei-ichi
authors.initials: K
authors.lastname: Oda
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Kimura
authors.forename: Kenji
authors.initials: K
authors.lastname: Ishii
authors.forename: Touru
authors.initials: T
authors.lastname: Sasaki
authors.forename: Masashi
authors.initials: M
authors.lastname: Ohyama
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Komaba
authors.forename: Shirou
authors.initials: S
authors.lastname: Kobayashi
authors.forename: Shin
authors.initials: S
authors.lastname: Kitamura
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Katayama
mesh_terms: D000328:Adult; D017668:Age of Onset; D001766:Blindness / Q000453:epidemiology* / Q000503:physiopathology*; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D011963:Receptors, GABA-A / Q000378:metabolism*; D014055:Tomography, Emission-Computed; D014793:Visual Cortex / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology
chemical_list: D011963:Receptors, GABA-A