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Seiler S, Fletcher E, Hassan-Ali K, Weinstein M, Beiser A, Himali JJ, Satizabal CL, Seshadri S, DeCarli C, Maillard P. Cerebral tract integrity relates to white matter hyperintensities, cortex volume, and cognition. Neurobiol Aging 2018; 72:14-22. [PMID: 30172922 PMCID: PMC6242702 DOI: 10.1016/j.neurobiolaging.2018.08.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Revised: 07/19/2018] [Accepted: 08/03/2018] [Indexed: 01/09/2023]
Abstract
We examined the relationship among white matter (WM) tract integrity, WM hyperintensities (WMH), lobar gray matter (GM) volumes, and cognition in the cross-sectional Framingham Offspring Study. Six hundred eighty participants (71.7 ± 7.7 years) completed cognitive testing and magnetic resonance imaging. Diffusion tensor imaging probabilistic tractography was used to reconstruct major WM tracts. We computed tract-specific mean fractional anisotropy (FA) and tract-specific WMH ratio. Linear regressions identified relations between tracts and lobar GM volumes. Partial least squares regression examined associations between integrity of combined tracts, lobar GM volumes and cognition, including scores of memory and processing speed. Five tracts were particularly vulnerable to WMH, and tract-specific WMH volumes were inversely associated with tract-specific FA (p values < 0.05). Tract-specific FA related to lobar GM volumes. Memory was associated with lobar GM, while processing speed related to both tract integrity and lobar GM volumes. We conclude that subtle microstructural WM tract degeneration relates to specific lobar GM atrophy. The integrity of associated WM tracts and GM lobes differentially impacts memory and processing speed.
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Affiliation(s)
- Stephan Seiler
- Department of Neurology, Center for Neurosciences, University of California at Davis, Davis, CA, USA; Imaging of Dementia and Aging (IDeA) Laboratory, University of California at Davis, Davis, CA, USA; Department of Neurology, Medical University Graz, Graz, Austria.
| | - Evan Fletcher
- Department of Neurology, Center for Neurosciences, University of California at Davis, Davis, CA, USA; Imaging of Dementia and Aging (IDeA) Laboratory, University of California at Davis, Davis, CA, USA
| | - Kinsy Hassan-Ali
- Department of Neurology, Center for Neurosciences, University of California at Davis, Davis, CA, USA; Imaging of Dementia and Aging (IDeA) Laboratory, University of California at Davis, Davis, CA, USA
| | - Michelle Weinstein
- Department of Neurology, Center for Neurosciences, University of California at Davis, Davis, CA, USA; Imaging of Dementia and Aging (IDeA) Laboratory, University of California at Davis, Davis, CA, USA
| | - Alexa Beiser
- The Framingham Heart Study, Framingham, MA, USA; Department of Neurology, Boston University School of Medicine, Boston, MA, USA; Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - Jayandra J Himali
- The Framingham Heart Study, Framingham, MA, USA; Department of Neurology, Boston University School of Medicine, Boston, MA, USA; Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - Claudia L Satizabal
- The Framingham Heart Study, Framingham, MA, USA; Department of Neurology, Boston University School of Medicine, Boston, MA, USA
| | - Sudha Seshadri
- The Framingham Heart Study, Framingham, MA, USA; Department of Neurology, Boston University School of Medicine, Boston, MA, USA
| | - Charles DeCarli
- Department of Neurology, Center for Neurosciences, University of California at Davis, Davis, CA, USA; Imaging of Dementia and Aging (IDeA) Laboratory, University of California at Davis, Davis, CA, USA
| | - Pauline Maillard
- Department of Neurology, Center for Neurosciences, University of California at Davis, Davis, CA, USA; Imaging of Dementia and Aging (IDeA) Laboratory, University of California at Davis, Davis, CA, USA
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Takakura H, Nishijo H, Ishikawa A, Shojaku H. Cerebral Hemodynamic Responses During Dynamic Posturography: Analysis with a Multichannel Near-Infrared Spectroscopy System. Front Hum Neurosci 2015; 9:620. [PMID: 26635574 PMCID: PMC4647449 DOI: 10.3389/fnhum.2015.00620] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 10/29/2015] [Indexed: 11/13/2022] Open
Abstract
To investigate cortical roles in standing balance, cortical hemodynamic activity was recorded from the right hemisphere using near-infrared spectroscopy (NIRS) while subjects underwent the sensory organization test (SOT) protocol that systematically disrupts sensory integration processes (i.e., somatosensory or visual inputs or both). Eleven healthy men underwent the SOT during NIRS recording. Group statistical analyses were performed based on changes in oxygenated hemoglobin concentration in 10 different cortical regions of interest and on a general linear analysis with NIRS statistical parametric mapping. The statistical analyses indicated significant activation in the right frontal operculum (f-Op), right parietal operculum (p-Op), and right superior temporal gyrus (STG), right posterior parietal cortex (PPC), right dorsal and ventral premotor cortex (PMC), and the supplementary motor area (SMA) under various conditions. The activation patterns in response to specific combinations of SOT conditions suggested that (1) f-Op, p-Op, and STG are essential for sensory integration when standing balance is perturbed; (2) the SMA is involved in the execution of volitional action and establishment of new motor programs to maintain postural balance; and (3) the PPC and PMC are involved in the updating and computation of spatial reference frames during instances of sensory conflict between vestibular and visual information.
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Affiliation(s)
- Hiromasa Takakura
- Department of Otorhinolaryngology, Head and Neck Surgery, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama , Toyama , Japan
| | - Hisao Nishijo
- System Emotional Science, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama , Toyama , Japan
| | - Akihiro Ishikawa
- R&D Department, Medical Systems Division, Shimadzu, Co., Ltd. , Kyoto , Japan
| | - Hideo Shojaku
- Department of Otorhinolaryngology, Head and Neck Surgery, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama , Toyama , Japan
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Abstract
Spatial priority maps are real-time representations of the behavioral salience of locations in the visual field, resulting from the combined influence of stimulus driven activity and top-down signals related to the current goals of the individual. They arbitrate which of a number of (potential) targets in the visual scene will win the competition for attentional resources. As a result, deployment of visual attention to a specific spatial location is determined by the current peak of activation (corresponding to the highest behavioral salience) across the map. Here we report a behavioral study performed on healthy human volunteers, where we demonstrate that spatial priority maps can be shaped via reward-based learning, reflecting long-lasting alterations (biases) in the behavioral salience of specific spatial locations. These biases exert an especially strong influence on performance under conditions where multiple potential targets compete for selection, conferring competitive advantage to targets presented in spatial locations associated with greater reward during learning relative to targets presented in locations associated with lesser reward. Such acquired biases of spatial attention are persistent, are nonstrategic in nature, and generalize across stimuli and task contexts. These results suggest that reward-based attentional learning can induce plastic changes in spatial priority maps, endowing these representations with the "intelligent" capacity to learn from experience.
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