title: In Vivo Evaluation of the Visual Pathway in Streptozotocin-Induced Diabetes by Diffusion Tensor MRI and Contrast Enhanced MRI.
abstract: Visual function has been shown to deteriorate prior to the onset of retinopathy in some diabetic patients and experimental animal models. This suggests the involvement of the brain's visual system in the early stages of diabetes. In this study, we tested this hypothesis by examining the integrity of the visual pathway in a diabetic rat model using in vivo multi-modal magnetic resonance imaging (MRI). Ten-week-old Sprague-Dawley rats were divided into an experimental diabetic group by intraperitoneal injection of 65 mg/kg streptozotocin in 0.01 M citric acid, and a sham control group by intraperitoneal injection of citric acid only. One month later, diffusion tensor MRI (DTI) was performed to examine the white matter integrity in the brain, followed by chromium-enhanced MRI of retinal integrity and manganese-enhanced MRI of anterograde manganese transport along the visual pathway. Prior to MRI experiments, the streptozotocin-induced diabetic rats showed significantly smaller weight gain and higher blood glucose level than the control rats. DTI revealed significantly lower fractional anisotropy and higher radial diffusivity in the prechiasmatic optic nerve of the diabetic rats compared to the control rats. No apparent difference was observed in the axial diffusivity of the optic nerve, the chromium enhancement in the retina, or the manganese enhancement in the lateral geniculate nucleus and superior colliculus between groups. Our results suggest that streptozotocin-induced diabetes leads to early injury in the optic nerve when no substantial change in retinal integrity or anterograde transport along the visual pathways was observed in MRI using contrast agent enhancement. DTI may be a useful tool for detecting and monitoring early pathophysiological changes in the visual system of experimental diabetes non-invasively.
authors: NeuroImaging Laboratory, University of Pittsburgh, Pittsburgh, PA, United States of America.|UPMC Eye Center, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America.
authors: Swarupa
authors: S
authors: Kancherla
authors: NeuroImaging Laboratory, University of Pittsburgh, Pittsburgh, PA, United States of America.|UPMC Eye Center, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America.
authors: William J
authors: WJ
authors: Kohler
authors: NeuroImaging Laboratory, University of Pittsburgh, Pittsburgh, PA, United States of America.|UPMC Eye Center, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America.|Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, United States of America.|McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America.|Louis J. Fox Center for Vision Restoration, University of Pittsburgh, Pittsburgh, PA, United States of America.
authors: Yolandi
authors: Y
authors: van der Merwe
authors: NeuroImaging Laboratory, University of Pittsburgh, Pittsburgh, PA, United States of America.|UPMC Eye Center, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America.|Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, United States of America.|McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America.|Louis J. Fox Center for Vision Restoration, University of Pittsburgh, Pittsburgh, PA, United States of America.|Center for the Neural Basis of Cognition, University of Pittsburgh and Carnegie Mellon University, Pittsburgh, PA, United States of America.|Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, China.
authors: Kevin C
authors: http://orcid.org/0000-0003-4012-7084
authors: KC
authors: Chan
mesh_terms: D000818:Animals; D003287:Contrast Media; D003921:Diabetes Mellitus, Experimental / Q000000981:diagnostic imaging*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D006801:Humans; D051381:Rats; D017207:Rats, Sprague-Dawley; D013311:Streptozocin; D014795:Visual Pathways / Q000473:pathology*
chemical_list: D003287:Contrast Media; D013311:Streptozocin