title: In vivo evaluation of optic nerve aging in adult rhesus monkey by diffusion tensor imaging.
abstract: Aging of the optic nerve can result in reduced visual sensitivity or vision loss. Normal optic nerve aging has been investigated previously in tissue specimens but poorly explored in vivo. In the present study, the normal aging of optic nerve was evaluated by diffusion tensor imaging (DTI) in non-human primates. Adult female rhesus monkeys at the ages of 9 to 13 years old (young group, n=8) and 21 to 27 years old (old group, n=7) were studied using parallel-imaging-based DTI on a clinical 3T scanner. Compared to young adults, the old monkeys showed 26% lower fractional anisotropy (P<0.01), and 44% greater radial diffusivity, although the latter difference was of marginal statistical significance (P=0.058). These MRI findings are largely consistent with published results of light and electron microscopic studies of optic nerve aging in macaque monkeys, which indicate a loss of fibers and degenerative changes in myelin sheaths.
authors.affiliation: 1 Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329, USA ; 2 Marcus Autism Center, Children's Healthcare of Atlanta, Emory University, Atlanta, Georgia 30322, USA ; 3 Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329, USA ; 4 The Wallace H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, Georgia 30322, USA.
authors.forename: Yumei
authors.initials: Y
authors.lastname: Yan
authors.affiliation: 1 Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329, USA ; 2 Marcus Autism Center, Children's Healthcare of Atlanta, Emory University, Atlanta, Georgia 30322, USA ; 3 Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329, USA ; 4 The Wallace H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, Georgia 30322, USA.
authors.forename: Longchuan
authors.initials: L
authors.lastname: Li
authors.affiliation: 1 Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329, USA ; 2 Marcus Autism Center, Children's Healthcare of Atlanta, Emory University, Atlanta, Georgia 30322, USA ; 3 Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329, USA ; 4 The Wallace H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, Georgia 30322, USA.
authors.forename: Todd M
authors.initials: TM
authors.lastname: Preuss
authors.affiliation: 1 Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329, USA ; 2 Marcus Autism Center, Children's Healthcare of Atlanta, Emory University, Atlanta, Georgia 30322, USA ; 3 Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329, USA ; 4 The Wallace H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, Georgia 30322, USA.
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Hu
authors.affiliation: 1 Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329, USA ; 2 Marcus Autism Center, Children's Healthcare of Atlanta, Emory University, Atlanta, Georgia 30322, USA ; 3 Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329, USA ; 4 The Wallace H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, Georgia 30322, USA.
authors.forename: James G
authors.initials: JG
authors.lastname: Herndon
authors.affiliation: 1 Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329, USA ; 2 Marcus Autism Center, Children's Healthcare of Atlanta, Emory University, Atlanta, Georgia 30322, USA ; 3 Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329, USA ; 4 The Wallace H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, Georgia 30322, USA.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhang
keywords: GRAPPA; Optic nerve aging; fractional anisotropy (FA); mean diffusivity (MD); non-human primate; parallel imaging; white matter