title: In vivo molecular imaging of the GABA/benzodiazepine receptor complex in the aged rat brain.
abstract: The GABA-ergic system, known to regulate neural tissue genesis during cortical development, has been postulated to play a role in cerebral aging processes. Using in vivo molecular imaging and voxel-wise quantification, we aimed to assess the effects of aging on the benzodiazepine (BDZ) recognition site of the GABA(A) receptor. To visualize BDZ site availability, [(11)C]-flumazenil microPET acquisitions were conducted in young and old rats. The data were analyzed and region of interest analyses were applied to validate the voxel-wise approach. We observed decreased [(11)C]-flumazenil binding in the aged rat brains in comparison with the young control group. More specifically, clusters of reduced radioligand uptake were detected in the bilateral hippocampus, cerebellum, midbrain, and bilateral frontal and parieto-occipital cortex. Our results support the pertinence of voxel-wise quantification in the analysis of microPET data. Moreover, these findings indicate that the aging process involves declines in neural BDZ recognition site availability, proposed to reflect alterations in GABA(A) receptor subunit polypeptide expression.
authors.affiliation: Department de Psiquiatria i Medicina Legal, Universitat Autònoma de Barcelona, 08192, Bellaterra, Barcelona, Spain.
authors.forename: Elseline
authors.initials: E
authors.lastname: Hoekzema
authors.forename: Santiago
authors.initials: S
authors.lastname: Rojas
authors.forename: Raúl
authors.initials: R
authors.lastname: Herance
authors.forename: Deborah
authors.initials: D
authors.lastname: Pareto
authors.forename: Sergio
authors.initials: S
authors.lastname: Abad
authors.forename: Xavier
authors.initials: X
authors.lastname: Jiménez
authors.forename: Francisca P
authors.initials: FP
authors.lastname: Figueiras
authors.forename: Foteini
authors.initials: F
authors.lastname: Popota
authors.forename: Alba
authors.initials: A
authors.lastname: Ruiz
authors.forename: Núria
authors.initials: N
authors.lastname: Flotats
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Fernández
authors.forename: Milagros
authors.initials: M
authors.lastname: Rocha
authors.forename: Mariana
authors.initials: M
authors.lastname: Rovira
authors.forename: Víctor M
authors.initials: VM
authors.lastname: Víctor
authors.forename: Juan D
authors.initials: JD
authors.lastname: Gispert
mesh_terms: D000375:Aging / Q000378:metabolism* / Q000473:pathology; D000818:Animals; D001921:Brain / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D008297:Male; D057054:Molecular Imaging / Q000379:methods*; D011485:Protein Binding / Q000502:physiology; D051381:Rats; D011963:Receptors, GABA-A / Q000378:metabolism*
chemical_list: D011963:Receptors, GABA-A