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Zhang L, Li Y, Bian L, Luo Q, Zhang X, Zhao B. Cognitive Impairment of Patient With Neurological Cerebrovascular Disease Using the Artificial Intelligence Technology Guided by MRI. Front Public Health 2022; 9:813641. [PMID: 35310781 PMCID: PMC8927700 DOI: 10.3389/fpubh.2021.813641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 12/06/2021] [Indexed: 11/13/2022] Open
Abstract
This study was to explore the application of MRI based on artificial intelligence technology combined with neuropsychological assessment to the cognitive impairment of patients with neurological cerebrovascular diseases. A total of 176 patients were divided into a control group, a vascular cognitive impairment non-dementia (VCIND) group, a vascular dementia (VD) group, and an Alzheimer's disease (AD) group. All patients underwent MRI and neuropsychological evaluation and examination, and an improved fuzzy C-means (FCM) clustering algorithm was proposed for MRI processing. It was found that the segmentation accuracy (SA) and similarity (KI) data of the improved FCM algorithm used in this study were higher than those of the standard FCM algorithm, bias-corrected FCM (BCFCM) algorithm, and rough FCM (RFCM) algorithm (p < 0.05). In the activities of daily living (ADL), the values in the VCIND group (23.55 ± 6.12) and the VD group (28.56 ± 3.1) were higher than that in the control group (19.17 ± 3.67), so the hippocampal volume was negatively correlated with the ADL (r = −0.872, p < 0.01). In the VCIND group (52.4%), VD group (31%), and AD group (26.1%), the proportion of patients with the lacunar infarction distributed on both sides of the brain and the number of multiple cerebral infarction lesions (76.2, 71.4, and 71.7%, respectively) were significantly higher than those in the control group (23.9 and 50%). In short, the improved FCM algorithm showed a higher segmentation effect and SA for MRI of neurological cerebrovascular disease. In addition, the distribution, number, white matter lesions, and hippocampal volume of lacunar cerebral infarction were related to the cognitive impairment of patients with cerebrovascular diseases.
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Affiliation(s)
- Lifang Zhang
- Department of Neurology, Changzhi People's Hospital, Changzhi Medical College, Changzhi, China
- Department of Mental Health, Changzhi Medical College, Changzhi, China
- *Correspondence: Lifang Zhang
| | - Yanran Li
- Department of Radiology, First Affiliated Hospital of Xinjiang Medical University, Ürümqi, China
| | - Lin Bian
- Department of Neurology, Changzhi People's Hospital, Changzhi Medical College, Changzhi, China
| | - Qingrong Luo
- Department of Neurology, Changzhi People's Hospital, Changzhi Medical College, Changzhi, China
| | - Xiaoxi Zhang
- Department of Mental Health, Changzhi Medical College, Changzhi, China
| | - Bing Zhao
- Department of Neurology, Changzhi People's Hospital, Changzhi Medical College, Changzhi, China
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Qiu Y, Yu L, Ge X, Sun Y, Wang Y, Wu X, Xu Q, Zhou Y, Xu J. Loss of Integrity of Corpus Callosum White Matter Hyperintensity Penumbra Predicts Cognitive Decline in Patients With Subcortical Vascular Mild Cognitive Impairment. Front Aging Neurosci 2021; 13:605900. [PMID: 33679371 PMCID: PMC7930322 DOI: 10.3389/fnagi.2021.605900] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Accepted: 01/25/2021] [Indexed: 12/04/2022] Open
Abstract
Loss of white matter (WM) integrity contributes to subcortical vascular mild cognitive impairment (svMCI). Diffusion tensor imaging (DTI) has revealed damage beyond the area of WM hyperintensity (WMH) including in normal-appearing WM (NAWM); however, the functional significance of this observation is unclear. To answer this question, in this study we investigated the relationship between microstructural changes in the WMH penumbra (WMH-P) and cognitive function in patients with svMCI by regional tract-based analysis. A total of 111 patients with svMCI and 72 patients with subcortical ischemic vascular disease (SIVD) without cognitive impairment (controls) underwent DTI and neuropsychological assessment. WMH burden was determined before computing mean values of fractional anisotropy (FA) and mean diffusivity (MD) within WMHs and WMH-Ps. Pearson’s partial correlations were used to assess the relationship between measurements showing significant intergroup differences and composite Z-scores representing global cognitive function. Multiple linear regression analysis was carried out to determine the best model for predicting composite Z-scores. We found that WMH burden in the genu, body, and splenium of the corpus callosum (GCC, BCC, and SCC respectively); bilateral anterior, superior, and posterior corona radiata; left sagittal stratum was significantly higher in the svMCI group than in the control group (p < 0.05). The WMH burden of the GCC, BCC, SCC, and bilateral anterior corona radiata was negatively correlated with composite Z-scores. Among diffusion parameters showing significant differences across the 10 WM regions, mean FA values of WMH and WMH-P of the BCC were correlated with composite Z-scores in svMCI patients. The results of the multiple linear regression analysis showed that the FA of WMH-P of the BCC and WMH burden of the SCC and GCC were independent predictors of composite Z-score, with the FA of WMH-P of the BCC making the largest contribution. These findings indicate that disruption of the CC microstructure—especially the WMH-P of the BCC—may contribute to the cognitive deficits associated with SIVD.
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Affiliation(s)
- Yage Qiu
- Department of Radiology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Ling Yu
- Department of Neurology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Xin Ge
- Department of Radiology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yawen Sun
- Department of Radiology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yao Wang
- Department of Radiology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Xiaowei Wu
- Department of Radiology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Qun Xu
- Department of Neurology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Department of Health Manage Center, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yan Zhou
- Department of Radiology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Jianrong Xu
- Department of Radiology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
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Ahmed HA, Ishrat T. The Brain AT2R-a Potential Target for Therapy in Alzheimer's Disease and Vascular Cognitive Impairment: a Comprehensive Review of Clinical and Experimental Therapeutics. Mol Neurobiol 2020; 57:3458-3484. [PMID: 32533467 PMCID: PMC8109287 DOI: 10.1007/s12035-020-01964-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 05/28/2020] [Indexed: 10/24/2022]
Abstract
Dementia is a potentially avertable tragedy, currently considered among the top 10 greatest global health challenges of the twenty-first century. Dementia not only robs individuals of their dignity and independence, it also has a ripple effect that starts with the inflicted individual's family and projects to the society as a whole. The constantly growing number of cases, along with the lack of effective treatments and socioeconomic impact, poses a serious threat to the sustainability of our health care system. Hence, there is a worldwide effort to identify new targets for the treatment of Alzheimer's disease (AD), the leading cause of dementia. Due to its multifactorial etiology and the recent clinical failure of several novel amyloid-β (Aβ) targeting therapies, a comprehensive "multitarget" approach may be most appropriate for managing this condition. Interestingly, renin angiotensin system (RAS) modulators were shown to positively impact all the factors involved in the pathophysiology of dementia including vascular dysfunction, Aβ accumulation, and associated cholinergic deficiency, in addition to tau hyperphosphorylation and insulin derangements. Furthermore, for many of these drugs, the preclinical evidence is also supported by epidemiological data and/or preliminary clinical trials. The purpose of this review is to provide a comprehensive update on the major causes of dementia including the risk factors, current diagnostic criteria, pathophysiology, and contemporary treatment strategies. Moreover, we highlight the angiotensin II receptor type 2 (AT2R) as an effective drug target and present ample evidence supporting its potential role and clinical applications in cognitive impairment to encourage further investigation in the clinical setting.
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Affiliation(s)
- Heba A Ahmed
- Department of Anatomy and Neurobiology, College of Medicine, University of Tennessee Health Science Center, 855 Monroe Avenue, Wittenborg Bldg, Room-231, Memphis, TN, 38163, USA
| | - Tauheed Ishrat
- Department of Anatomy and Neurobiology, College of Medicine, University of Tennessee Health Science Center, 855 Monroe Avenue, Wittenborg Bldg, Room-231, Memphis, TN, 38163, USA.
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, TN, USA.
- Neuroscience Institute, University of Tennessee Health Science Center, Memphis, TN, USA.
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Pietzuch M, King AE, Ward DD, Vickers JC. The Influence of Genetic Factors and Cognitive Reserve on Structural and Functional Resting-State Brain Networks in Aging and Alzheimer's Disease. Front Aging Neurosci 2019; 11:30. [PMID: 30894813 PMCID: PMC6414800 DOI: 10.3389/fnagi.2019.00030] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 02/01/2019] [Indexed: 01/22/2023] Open
Abstract
Magnetic resonance imaging (MRI) offers significant insight into the complex organization of neural networks within the human brain. Using resting-state functional MRI data, topological maps can be created to visualize changes in brain activity, as well as to represent and assess the structural and functional connections between different brain regions. Crucially, Alzheimer's disease (AD) is associated with progressive loss in this connectivity, which is particularly evident within the default mode network. In this paper, we review the recent literature on how factors that are associated with risk of dementia may influence the organization of the brain network structures. In particular, we focus on cognitive reserve and the common genetic polymorphisms of APOE and BDNF Val66Met.
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Affiliation(s)
- Manuela Pietzuch
- Wicking Dementia Research and Education Centre, College of Health and Medicine, University of Tasmania, Hobart, TAS, Australia
| | - Anna E. King
- Wicking Dementia Research and Education Centre, College of Health and Medicine, University of Tasmania, Hobart, TAS, Australia
| | - David D. Ward
- Population Health Sciences, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - James C. Vickers
- Wicking Dementia Research and Education Centre, College of Health and Medicine, University of Tasmania, Hobart, TAS, Australia
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Koundal S, Liu X, Sanggaard S, Mortensen K, Wardlaw J, Nedergaard M, Benveniste H, Lee H. Brain Morphometry and Longitudinal Relaxation Time of Spontaneously Hypertensive Rats (SHRs) in Early and Intermediate Stages of Hypertension Investigated by 3D VFA-SPGR MRI. Neuroscience 2019; 404:14-26. [PMID: 30690138 DOI: 10.1016/j.neuroscience.2019.01.030] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Revised: 01/15/2019] [Accepted: 01/18/2019] [Indexed: 02/03/2023]
Abstract
Cerebral small vessel disease(s) (SVD) results from pathological changes of the small blood vessels in the brain and is common in older people. The diagnostic features by which SVD manifests in brain includes white matter hyperintensities, lacunes, dilated perivascular spaces, microbleeds, and atrophy. In the present study, we use in vivo magnetic resonance imaging (MRI) to characterize brain morphometry and longitudinal relaxation time (T1) of spontaneously hypertensive rats (SHRs) to study the contribution of chronic hypertension to SVD relevant pathology. Male SHR and Wistar-Kyoto (WKY) rats underwent 3D variable flip angle spoiled gradient echo brain MRI at 9.4 T at early (seven weeks old) and established (19 weeks old) stages of hypertension. The derived proton density weighted and T1 images were utilized for morphometry and to characterize T1 properties in gray matter (GM), white matter (WM) and cerebrospinal fluid (CSF). Custom tissue probability maps were constructed for accurate computerized whole brain tissue segmentations and voxel-wise analyses. Characteristic morphological differences between the two strains included enlarged ventricles, smaller corpus callosum (CC) volumes and general 'thinning' of CC in SHR compared to WKY rats at both age groups. While we did not observe parenchymal T1 differences, the T1 of CSF was elevated in SHR compared to controls. Collectively these findings indicate that SHRs develop WM atrophy which is a clinically robust MRI biomarker associated with WM degeneration.
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Affiliation(s)
- Sunil Koundal
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, United States of America
| | - Xiaodan Liu
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, United States of America
| | - Simon Sanggaard
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, United States of America
| | - Kristian Mortensen
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Joanna Wardlaw
- Center for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, UK; UK Dementia Research Institute at The University of Edinburgh, The University of Edinburgh, Edinburgh, UK; Row Fogo Centre for Research into Ageing and the Brain, The University of Edinburgh, Edinburgh, UK
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Division of Glia Disease and Therapeutics, Center for Translational Neuromedicine, University of Rochester Medical School, Rochester, NY, USA
| | - Helene Benveniste
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, United States of America
| | - Hedok Lee
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, United States of America.
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Ménard B, Chazalviel L, Roussel S, Bernaudin M, Touzani O. Two-kidney one-clip is a pertinent approach to integrate arterial hypertension in animal models of stroke: Serial magnetic resonance imaging studies of brain lesions before and during cerebral ischemia. J Cereb Blood Flow Metab 2018; 38:1769-1780. [PMID: 28617154 PMCID: PMC6168912 DOI: 10.1177/0271678x17715813] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Although chronic arterial hypertension (CAH) represents the major comorbid factor in stroke, it is rarely integrated in preclinical studies of stroke. The majority of those investigations employ spontaneously hypertensive rats (SHR) which display a susceptibility to ischemic damage independent of hypertension. Here, we used a renovascular model of hypertension (RH) to examine, with magnetic resonance imaging (MRI), brain alterations during the development of hypertension and after brain ischemia. We also examined whether MRI-derived parameters predict the extent of ischemia-induced brain damage. RH was induced according to the two-kidney one-clip model and multiparametric MRI was performed at 3, 6, 9, and 12 weeks after hypertension and also at 10, 50, and 60 min following stroke. Blood pressure values increased progressively and reached a plateau at 6 weeks after RH induction. At 12 weeks, all hypertensive animals displayed spontaneous brain lesions (hemorrhages, deep and cortical lesions, ventricular dilatation), increased apparent diffusion coefficient (ADC) values in the corpus callosum and higher fractional anisotropy in the cortex. Following ischemia, these animals showed larger brain lesions (406 ± 82 vs. 179 ± 36 mm3, p < 0.002) which correlated with ADC values at chronic stage of hypertension. This model of hypertension displays many characteristics of the neuropathology of human CAH. The use of this model in stroke studies is relevant and desirable.
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Affiliation(s)
- Benjamin Ménard
- Normandie Univ, UNICAEN, CNRS, CEA, ISTCT/CERVOxy group, Caen, France
| | | | - Simon Roussel
- Normandie Univ, UNICAEN, CNRS, CEA, ISTCT/CERVOxy group, Caen, France
| | - Myriam Bernaudin
- Normandie Univ, UNICAEN, CNRS, CEA, ISTCT/CERVOxy group, Caen, France
| | - Omar Touzani
- Normandie Univ, UNICAEN, CNRS, CEA, ISTCT/CERVOxy group, Caen, France
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Ahmed HA, Ishrat T, Pillai B, Fouda AY, Sayed MA, Eldahshan W, Waller JL, Ergul A, Fagan SC. RAS modulation prevents progressive cognitive impairment after experimental stroke: a randomized, blinded preclinical trial. J Neuroinflammation 2018; 15:229. [PMID: 30103772 PMCID: PMC6090822 DOI: 10.1186/s12974-018-1262-x] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 07/29/2018] [Indexed: 01/08/2023] Open
Abstract
Background With the aging population, the prevalence and incidence of cerebrovascular disease will continue to rise, as well as the number of individuals with vascular cognitive impairment/dementia (VCID). No specific FDA-approved treatments for VCID exist. Although clinical evidence supports that angiotensin receptor blockers (ARBs) prevent cognitive decline in older adults, whether ARBs have a similar effect on VCID after stroke is unknown. Moreover, these agents reduce BP, which is undesirable in the acute stroke period, so we believe that giving C21 in this acute phase or delaying ARB administration would enable us to achieve the neurovascular benefits without the risk of unintended and potentially dangerous, acute BP lowering. Methods The aim of our study was to determine the impact of candesartan (ARB) or compound-21 (an angiotensin type 2 receptor––AT2R––agonist) on long-term cognitive function post-stroke, in spontaneously hypertensive rats (SHRs). We hypothesized that AT2R stimulation, either directly with C21, or indirectly by blocking the angiotensin type 1 receptor (AT1R) with candesartan, initiated after stroke, would reduce cognitive impairment. Animals were subjected to a 60-min transient middle cerebral artery occlusion and randomly assigned to either saline/C21 monotherapy, for the full study duration (30 days), or given sequential therapy starting with saline/C21 (7 days) followed by candesartan for the remainder of the study (21 days). Outcome measures included sensorimotor/cognitive-function, amyloid-β determination, and histopathologic analyses. Results Treatment with RAS modulators effectively preserved cognitive function, reduced cytotoxicity, and prevented chronic-reactive microgliosis in SHRs, post-stroke. These protective effects were apparent even when treatment was delayed up to 7 days post-stroke and were independent of blood pressure and β-amyloid accumulation. Conclusion Collectively, our findings demonstrate that RAS modulators effectively prevent cognitive impairment after stroke, even when treatment is delayed. Electronic supplementary material The online version of this article (10.1186/s12974-018-1262-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Heba A Ahmed
- Program in Clinical and Experimental Therapeutics, Charlie Norwood VA Medical Center and University of Georgia College of Pharmacy, HM Bldg., 1120 15th St, Augusta, GA, 30912, USA
| | - Tauheed Ishrat
- Department of Anatomy and Neurobiology, College of Medicine, Neuroscience Institute, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Bindu Pillai
- Program in Clinical and Experimental Therapeutics, Charlie Norwood VA Medical Center and University of Georgia College of Pharmacy, HM Bldg., 1120 15th St, Augusta, GA, 30912, USA
| | - Abdelrahman Y Fouda
- Program in Clinical and Experimental Therapeutics, Charlie Norwood VA Medical Center and University of Georgia College of Pharmacy, HM Bldg., 1120 15th St, Augusta, GA, 30912, USA
| | - Mohammed A Sayed
- Program in Clinical and Experimental Therapeutics, Charlie Norwood VA Medical Center and University of Georgia College of Pharmacy, HM Bldg., 1120 15th St, Augusta, GA, 30912, USA
| | - Wael Eldahshan
- Program in Clinical and Experimental Therapeutics, Charlie Norwood VA Medical Center and University of Georgia College of Pharmacy, HM Bldg., 1120 15th St, Augusta, GA, 30912, USA
| | - Jennifer L Waller
- Department of Biostatistics and Epidemiology, Augusta University, Augusta, GA, USA
| | - Adviye Ergul
- Program in Clinical and Experimental Therapeutics, Charlie Norwood VA Medical Center and University of Georgia College of Pharmacy, HM Bldg., 1120 15th St, Augusta, GA, 30912, USA.,Department of Physiology, Augusta University, Augusta, GA, USA
| | - Susan C Fagan
- Program in Clinical and Experimental Therapeutics, Charlie Norwood VA Medical Center and University of Georgia College of Pharmacy, HM Bldg., 1120 15th St, Augusta, GA, 30912, USA. .,Department of Neurology, Augusta University, Augusta, GA, USA.
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Chen HJ, Gao YQ, Che CH, Lin H, Ruan XL. Diffusion Tensor Imaging With Tract-Based Spatial Statistics Reveals White Matter Abnormalities in Patients With Vascular Cognitive Impairment. Front Neuroanat 2018; 12:53. [PMID: 29997482 PMCID: PMC6028522 DOI: 10.3389/fnana.2018.00053] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Accepted: 06/04/2018] [Indexed: 11/26/2022] Open
Abstract
Purpose: The aim of this study was to evaluate microstructural changes of major white matter (WM) tracts in patients with vascular cognitive impairment (VCI). Method: Diffusion tensor imaging (DTI) data were obtained from 24 subjects with subcortical ischemic vascular disease (SIVD), including 13 subjects with VCI-no dementia (VCIND) and 11 subjects with normal cognition (as a control group). A tract-based spatial statistics approach was performed to investigate WM microstructure in VCIND by integrating multiple indices including fractional anisotropy (FA) and mean diffusivity (MD), which are intra-voxel metrics, and local diffusion homogeneity (LDH), which is an inter-voxel metric. Results: The VCIND group had decreased FA and increased MD values throughout widespread WM areas predominately in the corpus callosum, bilateral internal capsule/corona radiata/posterior thalamic radiation/inferior fronto-occipital fasciculus and right inferior/superior longitudinal fasciculus. There was a slight discrepancy between the distribution of areas with decreased FA and LDH. The FA, MD and LDH values were significantly correlated with cognitive test results. According to a WM tract atlas, 10 major tracts were identified as tracts of interest in which three diffusion metrics simultaneously differed between groups, including bilateral anterior thalamic radiation, forceps minor, right corticospinal tract, bilateral inferior fronto-occipital fasciculus, left inferior and superior longitudinal fasciculus, and bilateral uncinate fasciculus. Receiver operating characteristic (ROC) analysis demonstrated the feasibility of using diffusion metrics along the forceps minor and left anterior thalamic radiation for separating two groups. Conclusion: The results suggest WM microstructural abnormalities contribute to cognitive impairments in SIVD patients. DTI parameters may be potential biomarkers for detecting VCIND from SIVD.
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Affiliation(s)
- Hua-Jun Chen
- Department of Radiology, Fujian Medical University Union Hospital, Fuzhou, China
| | - Yong-Qing Gao
- Department of Radiology, Fujian Medical University Union Hospital, Fuzhou, China.,Department of Radiology, Fuqing City Hospital, Fuqing, China
| | - Chun-Hui Che
- Department of Neurology, Fujian Medical University Union Hospital, Fuzhou, China
| | - Hailong Lin
- Department of Radiology, Fujian Medical University Union Hospital, Fuzhou, China
| | - Xin-Lin Ruan
- Department of Geriatrics, Fujian Medical University Union Hospital, Fuzhou, China
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Vemuri P, Knopman DS, Jack CR, Lundt ES, Weigand SD, Zuk SM, Thostenson KB, Reid RI, Kantarci K, Slinin Y, Lakshminarayan K, Davey CS, Murray A. Association of Kidney Function Biomarkers with Brain MRI Findings: The BRINK Study. J Alzheimers Dis 2018; 55:1069-1082. [PMID: 27767995 DOI: 10.3233/jad-160834] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Chronic kidney disease (CKD) studies have reported variable prevalence of brain pathologies, in part due to low inclusion of participants with moderate to severe CKD. OBJECTIVE To measure the association between kidney function biomarkers and brain MRI findings in CKD. METHODS In the BRINK (BRain IN Kidney Disease) study, MRI was used to measure gray matter volumes, cerebrovascular pathologies (white matter hyperintensity (WMH), infarctions, microhemorrhages), and microstructural changes using diffusion tensor imaging (DTI). We performed regression analyses with estimated glomerular filtration rate (eGFR) and urine albumin to creatinine ratio (UACR) as primary predictors, and joint models that included both predictors, adjusted for vascular risk factors. RESULTS We obtained 240 baseline MRI scans (150 CKD with eGFR <45 in ml/min/1.73 m2; 16 mild CKD: eGFR 45-59; 74 controls: eGFR≥60). Lower eGFR was associated with greater WMH burden, increased odds of cortical infarctions, and worsening diffusion changes throughout the brain. In eGFR models adjusted for UACR, only cortical infarction associations persisted. However, after adjusting for eGFR, higher UACR provided additional information related to temporal lobe atrophy, increased WMH, and whole brain microstructural changes as measured by increased DTI mean diffusivity. CONCLUSIONS Biomarkers of kidney disease (eGFR and UACR) were associated with MRI brain changes, even after accounting for vascular risk factors. UACR adds unique additional information to eGFR regarding brain structural and diffusion biomarkers. There was a greater impact of kidney function biomarkers on cerebrovascular pathologies and microstructural brain changes, suggesting that cerebrovascular etiology may be the primary driver of cognitive impairment in CKD.
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Affiliation(s)
| | | | | | - Emily S Lundt
- Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA
| | - Stephen D Weigand
- Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA
| | - Samantha M Zuk
- Department of Radiology, Mayo Clinic, Rochester, MN, USA
| | | | - Robert I Reid
- Department of Radiology, Mayo Clinic, Rochester, MN, USA
| | - Kejal Kantarci
- Department of Radiology, Mayo Clinic, Rochester, MN, USA
| | - Yelena Slinin
- Department of Internal Medicine, Nephrology Division, University of Minnesota, Minneapolis, MN, USA.,Veteran's Affairs Medical Center, Minneapolis, MN, USA
| | - Kamakshi Lakshminarayan
- Department of Neurology, University of Minnesota, Minneapolis, MN, USA.,Division of Epidemiology & Community Health, University of Minnesota School of Public Health, Minneapolis, MN, USA
| | - Cynthia S Davey
- Biostatistical Design and Analysis Center, University of Minnesota Clinical and Translational Science Institute, Minneapolis, MN, USA
| | - Anne Murray
- Berman Center for Clinical Research and Outcomes, Minneapolis Medical Research Foundation, Minneapolis, MN, USA.,Department of Internal Medicine, Geriatrics Division, Hennepin County Medical Center, Minneapolis, MN, USA.,Department of Medicine, University of Minnesota, Minneapolis, MN, USA
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Muñoz-Moreno E, Tudela R, López-Gil X, Soria G. Early brain connectivity alterations and cognitive impairment in a rat model of Alzheimer's disease. Alzheimers Res Ther 2018; 10:16. [PMID: 29415770 PMCID: PMC5803915 DOI: 10.1186/s13195-018-0346-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 01/22/2018] [Indexed: 02/05/2023]
Abstract
BACKGROUND Animal models of Alzheimer's disease (AD) are essential to understanding the disease progression and to development of early biomarkers. Because AD has been described as a disconnection syndrome, magnetic resonance imaging (MRI)-based connectomics provides a highly translational approach to characterizing the disruption in connectivity associated with the disease. In this study, a transgenic rat model of AD (TgF344-AD) was analyzed to describe both cognitive performance and brain connectivity at an early stage (5 months of age) before a significant concentration of β-amyloid plaques is present. METHODS Cognitive abilities were assessed by a delayed nonmatch-to-sample (DNMS) task preceded by a training phase where the animals learned the task. The number of training sessions required to achieve a learning criterion was recorded and evaluated. After DNMS, MRI acquisition was performed, including diffusion-weighted MRI and resting-state functional MRI, which were processed to obtain the structural and functional connectomes, respectively. Global and regional graph metrics were computed to evaluate network organization in both transgenic and control rats. RESULTS The results pointed to a delay in learning the working memory-related task in the AD rats, which also completed a lower number of trials in the DNMS task. Regarding connectivity properties, less efficient organization of the structural brain networks of the transgenic rats with respect to controls was observed. Specific regional differences in connectivity were identified in both structural and functional networks. In addition, a strong correlation was observed between cognitive performance and brain networks, including whole-brain structural connectivity as well as functional and structural network metrics of regions related to memory and reward processes. CONCLUSIONS In this study, connectivity and neurocognitive impairments were identified in TgF344-AD rats at a very early stage of the disease when most of the pathological hallmarks have not yet been detected. Structural and functional network metrics of regions related to reward, memory, and sensory performance were strongly correlated with the cognitive outcome. The use of animal models is essential for the early identification of these alterations and can contribute to the development of early biomarkers of the disease based on MRI connectomics.
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Affiliation(s)
- Emma Muñoz-Moreno
- Experimental 7T MRI Unit, Institut d’Investigacions Biòmediques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Raúl Tudela
- Consorcio Centro de Investigación Biomédica en Red (CIBER) de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Group of Biomedical Imaging, University of Barcelona, Barcelona, Spain
| | - Xavier López-Gil
- Experimental 7T MRI Unit, Institut d’Investigacions Biòmediques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Guadalupe Soria
- Experimental 7T MRI Unit, Institut d’Investigacions Biòmediques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
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11
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Role of angiotensin system modulation on progression of cognitive impairment and brain MRI changes in aged hypertensive animals - A randomized double- blind pre-clinical study. Behav Brain Res 2017; 346:29-40. [PMID: 29229547 DOI: 10.1016/j.bbr.2017.12.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 12/05/2017] [Accepted: 12/07/2017] [Indexed: 01/10/2023]
Abstract
Growing evidence suggests that renin angiotensin system (RAS) modulators support cognitive function in various animal models. However, little is known about their long-term effects on the brain structure in aged hypertensive animals with chronic cerebral hypoperfusion as well as which specific domains of cognition are most affected. Therefore, in the current study we examined the effects of Candesartan and Compound 21 (C21) (RAS modulators) on aspects of cognition known to diminish with advanced age and accelerate with hypertension and vascular disease. Outcome measures for sensorimotor and cognitive function were performed using a sequence of tests, all blindly conducted and assessed at baseline and after 4 and 8 weeks of chronic hypoxic hypoperfusion and treatment. Magnetic resonance imaging (MRI) was performed at the end of the 8 week study period followed by animal sacrifice and tissue collection. Both Candesartan and C21 effectively preserved cognitive function and prevented progression of vascular cognitive impairment (VCI) but only candesartan prevented loss of brain volume in aged hypertensive animals. Collectively, our findings demonstrate that delayed administration of RAS modulators effectively preserve cognitive function and prevent the development / progression of VCI in aged hypertensive animals with chronic cerebral hypoperfusion.
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12
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Hosseini AA, Meng D, Simpson RJ, Auer DP. Mesiotemporal atrophy and hippocampal diffusivity distinguish amnestic from non-amnestic vascular cognitive impairment. Eur J Neurol 2017; 24:902-911. [PMID: 28547878 PMCID: PMC5518192 DOI: 10.1111/ene.13299] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2016] [Accepted: 03/21/2017] [Indexed: 01/24/2023]
Abstract
Background and purpose The role of clinical factors, cerebral infarcts and hippocampal damage in vascular cognitive impairment (VCI) subtypes remains unclear. Methods Non‐demented patients with carotid stenosis and recent transient ischemic attack/stroke had cognitive assessment and brain magnetic resonance imaging (MRI). Amnestic VCI was defined as memory impairment; non‐amnestic VCI was any other subdomain impairment. Associations of MRI metrics [log‐transformed total ischemic lesion load (log TILL), mesiotemporal atrophy (MTA) score, hippocampal mean diffusivity (hipMD)] with cognitive performance were assessed. Results A hundred and eight patients, 47 with amnestic VCI and 21 with non‐amnestic VCI, were assessed. A higher MTA (odds ratio 12.89, P = 0.001) and left hipMD (odds ratio 4.43, P = 0.003) contributed to amnestic VCI versus normal. Age‐adjusted fluency correlated with log TILL (P = 0.002). Age‐adjusted memory was associated with left hipMD (P = 0.001), MTA (P < 0.001) but not log TILL (P = 0.14). Left hipMD, MTA and smoking showed classification potential between amnestic VCI versus normal (area 0.859, P < 0.001). Conclusions Neuroimaging assists stratification in amnestic VCI characterized by hippocampal changes and in non‐amnestic VCI by higher ischemic burden. MTA and hippocampal diffusivity show diagnostic biomarker potential.
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Affiliation(s)
- A A Hosseini
- Sir Peter Mansfield Imaging Centre, School of Medicine, University of Nottingham, Nottingham, UK.,Division of Clinical Neuroscience, Radiological Sciences, University of Nottingham, Nottingham, UK
| | - D Meng
- Sir Peter Mansfield Imaging Centre, School of Medicine, University of Nottingham, Nottingham, UK.,Division of Clinical Neuroscience, Radiological Sciences, University of Nottingham, Nottingham, UK
| | - R J Simpson
- Sir Peter Mansfield Imaging Centre, School of Medicine, University of Nottingham, Nottingham, UK.,Division of Clinical Neuroscience, Radiological Sciences, University of Nottingham, Nottingham, UK
| | - D P Auer
- Sir Peter Mansfield Imaging Centre, School of Medicine, University of Nottingham, Nottingham, UK.,Division of Clinical Neuroscience, Radiological Sciences, University of Nottingham, Nottingham, UK
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13
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Tudela R, Muñoz-Moreno E, López-Gil X, Soria G. Effects of Orientation and Anisometry of Magnetic Resonance Imaging Acquisitions on Diffusion Tensor Imaging and Structural Connectomes. PLoS One 2017; 12:e0170703. [PMID: 28118397 PMCID: PMC5261617 DOI: 10.1371/journal.pone.0170703] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 01/09/2017] [Indexed: 11/19/2022] Open
Abstract
Diffusion-weighted imaging (DWI) quantifies water molecule diffusion within tissues and is becoming an increasingly used technique. However, it is very challenging as correct quantification depends on many different factors, ranging from acquisition parameters to a long pipeline of image processing. In this work, we investigated the influence of voxel geometry on diffusion analysis, comparing different acquisition orientations as well as isometric and anisometric voxels. Diffusion-weighted images of one rat brain were acquired with four different voxel geometries (one isometric and three anisometric in different directions) and three different encoding orientations (coronal, axial and sagittal). Diffusion tensor scalar measurements, tractography and the brain structural connectome were analyzed for each of the 12 acquisitions. The acquisition direction with respect to the main magnetic field orientation affected the diffusion results. When the acquisition slice-encoding direction was not aligned with the main magnetic field, there were more artifacts and a lower signal-to-noise ratio that led to less anisotropic tensors (lower fractional anisotropic values), producing poorer quality results. The use of anisometric voxels generated statistically significant differences in the values of diffusion metrics in specific regions. It also elicited differences in tract reconstruction and in different graph metric values describing the brain networks. Our results highlight the importance of taking into account the geometric aspects of acquisitions, especially when comparing diffusion data acquired using different geometries.
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Affiliation(s)
- Raúl Tudela
- CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona, Spain
| | | | | | - Guadalupe Soria
- CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona, Spain
- Experimental MRI 7T Unit, IDIBAPS, Barcelona, Spain
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14
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Boehm-Sturm P, Füchtemeier M, Foddis M, Mueller S, Trueman RC, Zille M, Rinnenthal JL, Kypraios T, Shaw L, Dirnagl U, Farr TD. Neuroimaging Biomarkers Predict Brain Structural Connectivity Change in a Mouse Model of Vascular Cognitive Impairment. Stroke 2017; 48:468-475. [PMID: 28070001 PMCID: PMC5266417 DOI: 10.1161/strokeaha.116.014394] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 11/01/2016] [Accepted: 11/28/2016] [Indexed: 12/11/2022]
Abstract
BACKGROUND AND PURPOSE Chronic hypoperfusion in the mouse brain has been suggested to mimic aspects of vascular cognitive impairment, such as white matter damage. Although this model has attracted attention, our group has struggled to generate a reliable cognitive and pathological phenotype. This study aimed to identify neuroimaging biomarkers of brain pathology in aged, more severely hypoperfused mice. METHODS We used magnetic resonance imaging to characterize brain degeneration in mice hypoperfused by refining the surgical procedure to use the smallest reported diameter microcoils (160 μm). RESULTS Acute cerebral blood flow decreases were observed in the hypoperfused group that recovered over 1 month and coincided with arterial remodeling. Increasing hypoperfusion resulted in a reduction in spatial learning abilities in the water maze that has not been previously reported. We were unable to observe severe white matter damage with histology, but a novel approach to analyze diffusion tensor imaging data, graph theory, revealed substantial reorganization of the hypoperfused brain network. A logistic regression model from the data revealed that 3 network parameters were particularly efficient at predicting group membership (global and local efficiency and degrees), and clustering coefficient was correlated with performance in the water maze. CONCLUSIONS Overall, these findings suggest that, despite the autoregulatory abilities of the mouse brain to compensate for a sudden decrease in blood flow, there is evidence of change in the brain networks that can be used as neuroimaging biomarkers to predict outcome.
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Affiliation(s)
- Philipp Boehm-Sturm
- From the Department of Experimental Neurology, Center for Stroke Research Berlin (CSB) (P.B.-S., M.F., M.F., S.M., M.Z., U.D., T.D.F.), Charité Core Facility 7T Experimental MRIs (P.B.-S., S.M.), Department of Neuropathology (J.L.R.), and German Centre for Neurodegenerative Diseases (DZNE), Berlin site (M.F., U.D.), Charité University Medicine Berlin, Germany; and School of Life Sciences (R.C.T., T.D.F.) and School of Mathematics (T.K., L.S.), University of Nottingham, United Kingdom
| | - Martina Füchtemeier
- From the Department of Experimental Neurology, Center for Stroke Research Berlin (CSB) (P.B.-S., M.F., M.F., S.M., M.Z., U.D., T.D.F.), Charité Core Facility 7T Experimental MRIs (P.B.-S., S.M.), Department of Neuropathology (J.L.R.), and German Centre for Neurodegenerative Diseases (DZNE), Berlin site (M.F., U.D.), Charité University Medicine Berlin, Germany; and School of Life Sciences (R.C.T., T.D.F.) and School of Mathematics (T.K., L.S.), University of Nottingham, United Kingdom
| | - Marco Foddis
- From the Department of Experimental Neurology, Center for Stroke Research Berlin (CSB) (P.B.-S., M.F., M.F., S.M., M.Z., U.D., T.D.F.), Charité Core Facility 7T Experimental MRIs (P.B.-S., S.M.), Department of Neuropathology (J.L.R.), and German Centre for Neurodegenerative Diseases (DZNE), Berlin site (M.F., U.D.), Charité University Medicine Berlin, Germany; and School of Life Sciences (R.C.T., T.D.F.) and School of Mathematics (T.K., L.S.), University of Nottingham, United Kingdom
| | - Susanne Mueller
- From the Department of Experimental Neurology, Center for Stroke Research Berlin (CSB) (P.B.-S., M.F., M.F., S.M., M.Z., U.D., T.D.F.), Charité Core Facility 7T Experimental MRIs (P.B.-S., S.M.), Department of Neuropathology (J.L.R.), and German Centre for Neurodegenerative Diseases (DZNE), Berlin site (M.F., U.D.), Charité University Medicine Berlin, Germany; and School of Life Sciences (R.C.T., T.D.F.) and School of Mathematics (T.K., L.S.), University of Nottingham, United Kingdom
| | - Rebecca C Trueman
- From the Department of Experimental Neurology, Center for Stroke Research Berlin (CSB) (P.B.-S., M.F., M.F., S.M., M.Z., U.D., T.D.F.), Charité Core Facility 7T Experimental MRIs (P.B.-S., S.M.), Department of Neuropathology (J.L.R.), and German Centre for Neurodegenerative Diseases (DZNE), Berlin site (M.F., U.D.), Charité University Medicine Berlin, Germany; and School of Life Sciences (R.C.T., T.D.F.) and School of Mathematics (T.K., L.S.), University of Nottingham, United Kingdom
| | - Marietta Zille
- From the Department of Experimental Neurology, Center for Stroke Research Berlin (CSB) (P.B.-S., M.F., M.F., S.M., M.Z., U.D., T.D.F.), Charité Core Facility 7T Experimental MRIs (P.B.-S., S.M.), Department of Neuropathology (J.L.R.), and German Centre for Neurodegenerative Diseases (DZNE), Berlin site (M.F., U.D.), Charité University Medicine Berlin, Germany; and School of Life Sciences (R.C.T., T.D.F.) and School of Mathematics (T.K., L.S.), University of Nottingham, United Kingdom
| | - Jan Leo Rinnenthal
- From the Department of Experimental Neurology, Center for Stroke Research Berlin (CSB) (P.B.-S., M.F., M.F., S.M., M.Z., U.D., T.D.F.), Charité Core Facility 7T Experimental MRIs (P.B.-S., S.M.), Department of Neuropathology (J.L.R.), and German Centre for Neurodegenerative Diseases (DZNE), Berlin site (M.F., U.D.), Charité University Medicine Berlin, Germany; and School of Life Sciences (R.C.T., T.D.F.) and School of Mathematics (T.K., L.S.), University of Nottingham, United Kingdom
| | - Theodore Kypraios
- From the Department of Experimental Neurology, Center for Stroke Research Berlin (CSB) (P.B.-S., M.F., M.F., S.M., M.Z., U.D., T.D.F.), Charité Core Facility 7T Experimental MRIs (P.B.-S., S.M.), Department of Neuropathology (J.L.R.), and German Centre for Neurodegenerative Diseases (DZNE), Berlin site (M.F., U.D.), Charité University Medicine Berlin, Germany; and School of Life Sciences (R.C.T., T.D.F.) and School of Mathematics (T.K., L.S.), University of Nottingham, United Kingdom
| | - Laurence Shaw
- From the Department of Experimental Neurology, Center for Stroke Research Berlin (CSB) (P.B.-S., M.F., M.F., S.M., M.Z., U.D., T.D.F.), Charité Core Facility 7T Experimental MRIs (P.B.-S., S.M.), Department of Neuropathology (J.L.R.), and German Centre for Neurodegenerative Diseases (DZNE), Berlin site (M.F., U.D.), Charité University Medicine Berlin, Germany; and School of Life Sciences (R.C.T., T.D.F.) and School of Mathematics (T.K., L.S.), University of Nottingham, United Kingdom
| | - Ulrich Dirnagl
- From the Department of Experimental Neurology, Center for Stroke Research Berlin (CSB) (P.B.-S., M.F., M.F., S.M., M.Z., U.D., T.D.F.), Charité Core Facility 7T Experimental MRIs (P.B.-S., S.M.), Department of Neuropathology (J.L.R.), and German Centre for Neurodegenerative Diseases (DZNE), Berlin site (M.F., U.D.), Charité University Medicine Berlin, Germany; and School of Life Sciences (R.C.T., T.D.F.) and School of Mathematics (T.K., L.S.), University of Nottingham, United Kingdom
| | - Tracy D Farr
- From the Department of Experimental Neurology, Center for Stroke Research Berlin (CSB) (P.B.-S., M.F., M.F., S.M., M.Z., U.D., T.D.F.), Charité Core Facility 7T Experimental MRIs (P.B.-S., S.M.), Department of Neuropathology (J.L.R.), and German Centre for Neurodegenerative Diseases (DZNE), Berlin site (M.F., U.D.), Charité University Medicine Berlin, Germany; and School of Life Sciences (R.C.T., T.D.F.) and School of Mathematics (T.K., L.S.), University of Nottingham, United Kingdom.
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Grünblatt E, Bartl J, Iuhos DI, Knezovic A, Trkulja V, Riederer P, Walitza S, Salkovic-Petrisic M. Characterization of cognitive deficits in spontaneously hypertensive rats, accompanied by brain insulin receptor dysfunction. J Mol Psychiatry 2015; 3:6. [PMID: 26110057 PMCID: PMC4479234 DOI: 10.1186/s40303-015-0012-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 05/29/2015] [Indexed: 01/05/2023] Open
Abstract
Background The spontaneously hypertensive rat (SHR) has been used to model changes in the central nervous system associated with cognitive-related disorders. Recent human and animal studies indicate a possible relationship between cognitive deficits, insulin resistance and hypertension. We aimed to investigate whether cognitively impaired SHRs develop central and/or peripheral insulin resistance and how their cognitive performance is influenced by the animal’s sex and age as well as strains used for comparison (Wistar and Wistar-Kyoto/WKY). Methods Three and seven-month-old SHR, Wistar, and WKY rats were studied for their cognitive performance using Morris Water Maze (MWM) and Passive Avoidance tests (PAT). Plasma glucose and insulin were obtained after oral glucose tolerance tests. Cerebral cortex, hippocampus, and striatum status of insulin-receptor (IR) β-subunit and glycogen synthase kinase-3β (GSK3β) and their phosphorylated forms were obtained via ELISA. Results SHRs performed poorly in MWM and PAT in comparison to both control strains but more pronouncedly compared to WKY. Females performed poorer than males and 7-month-old SHRs had poorer MWM performance than 3-month-old ones. Although plasma glucose levels remained unchanged, plasma insulin levels were significantly increased in the glucose tolerance test in 7-month-old SHRs. SHRs demonstrated reduced expression and increased activity of IRβ-subunit in cerebral cortex, hippocampus, and striatum with different regional changes in phospho/total GSK3β ratio, as compared to WKYs. Conclusion Results indicate that cognitive deficits in SHRs are accompanied by both central and peripheral insulin dysfunction, thus allowing for the speculation that SHRs might additionally be considered as a model of insulin resistance-induced type of dementia. Electronic supplementary material The online version of this article (doi:10.1186/s40303-015-0012-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Edna Grünblatt
- University Clinics of Child and Adolescent Psychiatry, University of Zurich, Neumuensterallee 9, 8032 Zurich, Switzerland ; Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland ; University Hospital, Clinic and Policlinic for Psychiatry, Psychosomatic and Psychotherapy, University of Würzburg, Füchsleinstr. 15, D-97080 Würzburg, Germany ; University Clinics of Child and Adolescent Psychiatry, University of Zurich, Wagistrasse 12, CH-8952 Schlieren, Switzerland
| | - Jasmin Bartl
- University Clinics of Child and Adolescent Psychiatry, University of Zurich, Neumuensterallee 9, 8032 Zurich, Switzerland
| | - Diana-Iulia Iuhos
- University Hospital, Clinic and Policlinic for Psychiatry, Psychosomatic and Psychotherapy, University of Würzburg, Füchsleinstr. 15, D-97080 Würzburg, Germany
| | - Ana Knezovic
- Department of Pharmacology and Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Salata 11, 10 000 Zagreb, Croatia
| | - Vladimir Trkulja
- Department of Pharmacology and Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Salata 11, 10 000 Zagreb, Croatia
| | - Peter Riederer
- University Hospital, Clinic and Policlinic for Psychiatry, Psychosomatic and Psychotherapy, University of Würzburg, Füchsleinstr. 15, D-97080 Würzburg, Germany
| | - Susanne Walitza
- University Clinics of Child and Adolescent Psychiatry, University of Zurich, Neumuensterallee 9, 8032 Zurich, Switzerland ; Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Melita Salkovic-Petrisic
- Department of Pharmacology and Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Salata 11, 10 000 Zagreb, Croatia
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Vascular change and opposing effects of the angiotensin type 2 receptor in a mouse model of vascular cognitive impairment. J Cereb Blood Flow Metab 2015; 35:476-84. [PMID: 25492118 PMCID: PMC4348389 DOI: 10.1038/jcbfm.2014.221] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 11/03/2014] [Accepted: 11/10/2014] [Indexed: 01/16/2023]
Abstract
Our aims were to assess the spatiotemporal development of brain pathology in a mouse model of chronic hypoperfusion using magnetic resonance imaging (MRI), and to test whether the renin-angiotensin system (RAS) can offer therapeutic benefit. For the first time, different patterns of cerebral blood flow alterations were observed in hypoperfused mice that ranged from an immediate and dramatic to a delayed decrease in cerebral perfusion. Diffusion tensor imaging revealed increases in several quantitative parameters in different brain regions that are indicative of white-matter degeneration; this began around 3 weeks after induction of hypoperfusion. While this model may be more variable than previously reported, neuroimaging tools represent a promising way to identify surrogate markers of pathology. Vascular remodelling was observed in hypoperfused mice, particularly in the anterior part of the Circle of Willis. While the angiotensin II receptor type 2 agonist, Compound 21 (C21), did not influence this response, it did promote expansion of the basilar artery in microcoil animals. Furthermore, C21-treated animals exhibited increased brain lymphocyte infiltration, and importantly, C21 had opposing effects on spatial reference memory in hypoperfused and sham mice. These results suggest that the RAS may have a role in vascular cognitive impairment.
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