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Milczarek MM, Gilani SIA, Lequin MH, Vann SD. Reduced mammillary body volume in individuals with a schizophrenia diagnosis: an analysis of the COBRE data set. SCHIZOPHRENIA (HEIDELBERG, GERMANY) 2023; 9:48. [PMID: 37528127 PMCID: PMC10394056 DOI: 10.1038/s41537-023-00376-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Accepted: 07/12/2023] [Indexed: 08/03/2023]
Abstract
While the frontal cortices and medial temporal lobe are well associated with schizophrenia, the involvement of wider limbic areas is less clear. The mammillary bodies are important for both complex memory formation and anxiety and are implicated in several neurological disorders that present with memory impairments. However, little is known about their role in schizophrenia. Post-mortem studies have reported a loss of neurons in the mammillary bodies but there are also reports of increased mammillary body volume. The findings from in vivo MRI studies have also been mixed, but studies have typically only involved small sample sizes. To address this, we acquired mammillary body volumes from the open-source COBRE dataset, where we were able to manually measure the mammillary bodies in 72 individuals with a schizophrenia diagnosis and 74 controls. Participant age ranged from 18 to 65. We found the mammillary bodies to be smaller in the patient group, across both hemispheres, after accounting for the effects of total brain volume and gender. Hippocampal volumes, but not subiculum or total grey matter volumes, were also significantly lower in patients. Given the importance of the mammillary bodies for both memory and anxiety, this atrophy could contribute to the symptomology in schizophrenia.
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Affiliation(s)
- Michal M Milczarek
- School of Psychology, Cardiff University, Tower Building, Cardiff, CF10 3AT, UK
- Neuroscience and Mental Health Innovation Institute, Hadyn Ellis Building, Cathays, Cardiff, CF24 4HQ, UK
| | - Syed Irtiza A Gilani
- School of Psychology, Cardiff University, Tower Building, Cardiff, CF10 3AT, UK
- CUBRIC, School of Psychology, Maindy Road, Cardiff, CF24 4HQ, UK
| | - Maarten H Lequin
- Division Imaging & Oncology, Department of Radiology & Nuclear Medicine, University Medical Center Utrecht & Princess Máxima Center for Pediatric Oncology, 3508 GA, Utrecht, The Netherlands
| | - Seralynne D Vann
- School of Psychology, Cardiff University, Tower Building, Cardiff, CF10 3AT, UK.
- Neuroscience and Mental Health Innovation Institute, Hadyn Ellis Building, Cathays, Cardiff, CF24 4HQ, UK.
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2
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Aggleton JP, Nelson AJD, O'Mara SM. Time to retire the serial Papez circuit: Implications for space, memory, and attention. Neurosci Biobehav Rev 2022; 140:104813. [PMID: 35940310 PMCID: PMC10804970 DOI: 10.1016/j.neubiorev.2022.104813] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 07/20/2022] [Accepted: 08/01/2022] [Indexed: 11/26/2022]
Abstract
After more than 80 years, Papez serial circuit remains a hugely influential concept, initially for emotion, but in more recent decades, for memory. Here, we show how this circuit is anatomically and mechanistically naïve as well as outdated. We argue that a new conceptualisation is necessitated by recent anatomical and functional findings that emphasize the more equal, working partnerships between the anterior thalamic nuclei and the hippocampal formation, along with their neocortical interactions in supporting, episodic memory. Furthermore, despite the importance of the anterior thalamic for mnemonic processing, there is growing evidence that these nuclei support multiple aspects of cognition, only some of which are directly associated with hippocampal function. By viewing the anterior thalamic nuclei as a multifunctional hub, a clearer picture emerges of extra-hippocampal regions supporting memory. The reformulation presented here underlines the need to retire Papez serially processing circuit.
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Affiliation(s)
- John P Aggleton
- School of Psychology, Cardiff University, 70 Park Place, Cardiff CF10 3AT, Wales, UK.
| | - Andrew J D Nelson
- School of Psychology, Cardiff University, 70 Park Place, Cardiff CF10 3AT, Wales, UK
| | - Shane M O'Mara
- School of Psychology and Trinity College Institute of Neuroscience, Trinity College Dublin, The University of Dublin, Dublin D02 PN40, Ireland
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The anterior thalamic nuclei: core components of a tripartite episodic memory system. Nat Rev Neurosci 2022; 23:505-516. [PMID: 35478245 DOI: 10.1038/s41583-022-00591-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/25/2022] [Indexed: 12/13/2022]
Abstract
Standard models of episodic memory focus on hippocampal-parahippocampal interactions, with the neocortex supplying sensory information and providing a final repository of mnemonic representations. However, recent advances have shown that other regions make distinct and equally critical contributions to memory. In particular, there is growing evidence that the anterior thalamic nuclei have a number of key cognitive functions that support episodic memory. In this article, we describe these findings and argue for a core, tripartite memory system, comprising a 'temporal lobe' stream (centred on the hippocampus) and a 'medial diencephalic' stream (centred on the anterior thalamic nuclei) that together act on shared cortical areas. We demonstrate how these distributed brain regions form complementary and necessary partnerships in episodic memory formation.
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Kisel AA, Naumova AV, Yarnykh VL. Macromolecular Proton Fraction as a Myelin Biomarker: Principles, Validation, and Applications. Front Neurosci 2022; 16:819912. [PMID: 35221905 PMCID: PMC8863973 DOI: 10.3389/fnins.2022.819912] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 01/17/2022] [Indexed: 12/16/2022] Open
Abstract
Macromolecular proton fraction (MPF) is a quantitative MRI parameter describing the magnetization transfer (MT) effect and defined as a relative amount of protons bound to biological macromolecules with restricted molecular motion, which participate in magnetic cross-relaxation with water protons. MPF attracted significant interest during past decade as a biomarker of myelin. The purpose of this mini review is to provide a brief but comprehensive summary of MPF mapping methods, histological validation studies, and MPF applications in neuroscience. Technically, MPF maps can be obtained using a variety of quantitative MT methods. Some of them enable clinically reasonable scan time and resolution. Recent studies demonstrated the feasibility of MPF mapping using standard clinical MRI pulse sequences, thus substantially enhancing the method availability. A number of studies in animal models demonstrated strong correlations between MPF and histological markers of myelin with a minor influence of potential confounders. Histological studies validated the capability of MPF to monitor both demyelination and re-myelination. Clinical applications of MPF have been mainly focused on multiple sclerosis where this method provided new insights into both white and gray matter pathology. Besides, several studies used MPF to investigate myelin role in other neurological and psychiatric conditions. Another promising area of MPF applications is the brain development studies. MPF demonstrated the capabilities to quantitatively characterize the earliest stage of myelination during prenatal brain maturation and protracted myelin development in adolescence. In summary, MPF mapping provides a technically mature and comprehensively validated myelin imaging technology for various preclinical and clinical neuroscience applications.
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Affiliation(s)
- Alena A. Kisel
- Department of Radiology, University of Washington, Seattle, WA, United States
- Laboratory of Neurobiology, Tomsk State University, Tomsk, Russia
| | - Anna V. Naumova
- Department of Radiology, University of Washington, Seattle, WA, United States
| | - Vasily L. Yarnykh
- Department of Radiology, University of Washington, Seattle, WA, United States
- Laboratory of Neurobiology, Tomsk State University, Tomsk, Russia
- *Correspondence: Vasily L. Yarnykh,
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Coad BM, Ghomroudi PA, Sims R, Aggleton JP, Vann SD, Metzler-Baddeley C. Apolipoprotein ε4 modifies obesity-related atrophy in the hippocampal formation of cognitively healthy adults. Neurobiol Aging 2022; 113:39-54. [PMID: 35303671 PMCID: PMC9084919 DOI: 10.1016/j.neurobiolaging.2022.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 01/18/2022] [Accepted: 02/12/2022] [Indexed: 12/02/2022]
Abstract
Age-related inverted U-shaped curve of hippocampal myelin/neurite packing. Reduced hippocampal myelin/neurite packing and size/complexity in obesity. APOE modifies the effects of obesity on hippocampal size/complexity. Age-related slowing of spatial navigation but no risk effects on cognition. CA/DG predict episodic memory and subiculum predicts spatial navigation performance.
Characterizing age- and risk-related hippocampal vulnerabilities may inform about the neural underpinnings of cognitive decline. We studied the impact of three risk-factors, Apolipoprotein (APOE)-ε4, a family history of dementia, and central obesity, on the CA1, CA2/3, dentate gyrus and subiculum of 158 cognitively healthy adults (38-71 years). Subfields were labelled with the Automatic Segmentation of Hippocampal Subfields and FreeSurfer (version 6) protocols. Volumetric and microstructural measurements from quantitative magnetization transfer and Neurite Orientation Density and Dispersion Imaging were extracted for each subfield and reduced to three principal components capturing apparent myelin/neurite packing, size/complexity, and metabolism. Aging was associated with an inverse U-shaped curve on myelin/neurite packing and affected all subfields. Obesity led to reductions in myelin/neurite packing and size/complexity regardless of APOE and family history of dementia status. However, amongst individuals with a healthy Waist-Hip-Ratio, APOE ε4 carriers showed lower size/complexity than non-carriers. Segmentation protocol type did not affect this risk pattern. These findings reveal interactive effects between APOE and central obesity on the hippocampal formation of cognitively healthy adults.
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Clarke H, Messaritaki E, Dimitriadis SI, Metzler-Baddeley C. Dementia Risk Factors Modify Hubs but Leave Other Connectivity Measures Unchanged in Asymptomatic Individuals: A Graph Theoretical Analysis. Brain Connect 2022; 12:26-40. [PMID: 34030485 PMCID: PMC8867081 DOI: 10.1089/brain.2020.0935] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Background: Alzheimer's disease (AD) is the most common form of dementia with genetic and environmental risk contributing to its development. Graph theoretical analyses of brain networks constructed from structural and functional magnetic resonance imaging (MRI) measurements have identified connectivity changes in AD and individuals with mild cognitive impairment. However, brain connectivity in asymptomatic individuals at risk of AD remains poorly understood. Methods: We analyzed diffusion-weighted MRI data from 161 asymptomatic individuals (38-71 years) from the Cardiff Ageing and Risk of Dementia Study (CARDS). We calculated white matter tracts and constructed whole-brain, default mode network (DMN) and visual structural brain networks that incorporate multiple structural metrics as edge weights. We then calculated the relationship of three AD risk factors, namely Apolipoprotein-E ɛ4 (APOE4) genotype, family history of dementia (FH), and central obesity (Waist-Hip-Ratio [WHR]), on graph theoretical measures and hubs. Results: We observed no risk-related differences in clustering coefficients, characteristic path lengths, eccentricity, diameter, and radius across the whole-brain, DMN or visual system. However, a hub in the right paracentral lobule was present in all the high-risk groups (FH, APOE4, obese), but absent in low-risk groups (no FH, APOE4-ve, healthy WHR). Discussion: We identified no risk-related effects on graph theoretical metrics in the structural brain networks of cognitively healthy individuals. However, high risk was associated with a hub in the right paracentral lobule, a medial fronto-parietal cortical area with motor and sensory functions. This finding is consistent with accumulating evidence for right parietal cortex contributions in AD. If this phenotype is shown to predict symptom development in longitudinal studies, it could be used as an early biomarker of AD. Impact statement Alzheimer's disease (AD) is a common form of dementia that to date has no cure. Identifying early biomarkers will aid the discovery and development of treatments that may slow AD progression in the future. In this article, we report that asymptomatic individuals at heightened risk of dementia due to their family history, Apolipoprotein-E ɛ4 genotype, and central adiposity have a hub in the right paracentral lobule, which is absent in low-risk groups. If this phenotype were to predict the development of symptoms in a longitudinal study of the same cohort, it could provide an early biomarker of disease progression.
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Affiliation(s)
- Hannah Clarke
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff, United Kingdom
- School of Medicine, UK Dementia Research Institute, Cardiff University, Cardiff, United Kingdom
| | - Eirini Messaritaki
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff, United Kingdom
- BRAIN Biomedical Research Unit, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Stavros I. Dimitriadis
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff, United Kingdom
- Neuroinformatics Group, Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, Cardiff, United Kingdom
- Division of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, Cardiff, United Kingdom
- School of Psychology, Cardiff University, Cardiff, United Kingdom
- Neuroscience and Mental Health Research Institute, School of Medicine, Cardiff University, Cardiff, United Kingdom
- MRC Centre for Neuropsychiatric Genetics and Genomics, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Claudia Metzler-Baddeley
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff, United Kingdom
- Neuroscience and Mental Health Research Institute, School of Medicine, Cardiff University, Cardiff, United Kingdom
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Srisaikaew P, Wongpakaran N, Anderson ND, Chen JJ, Kothan S, Varnado P, Unsrisong K, Mahakkanukrauh P. Fornix Integrity Is Differently Associated With Cognition in Healthy Aging and Non-amnestic Mild Cognitive Impairment: A Pilot Diffusion Tensor Imaging Study in Thai Older Adults. Front Aging Neurosci 2020; 12:594002. [PMID: 33343334 PMCID: PMC7745667 DOI: 10.3389/fnagi.2020.594002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 11/02/2020] [Indexed: 02/05/2023] Open
Abstract
Damage to the fornix leads to significant memory impairment and executive dysfunction and is associated with dementia risk. We sought to identify if fornix integrity and fiber length are disrupted in mild cognitive impairment (MCI) and how they associate with cognition. Data from 14 healthy older adult controls (HCs) and 17 subjects with non-amnestic MCI (n-aMCI) were analyzed. Diffusion tensor imaging (DTI) at 1.5 Tesla MRI was performed to enable manual tracing of the fornix and calculation of DTI parameters. Higher fractional anisotropy of body and column of the fornix was associated with better executive functioning and memory, more strongly in the HC than in the n-aMCI group. Fornix fiber tract length (FTL) was associated with better executive function, more strongly in the n-aMCI than in the HC group, and with better memory, more strongly in the HC than in the n-aMCI group. These results highlight a decline in the contributions of the fornix to cognition in n-aMCI and suggest that maintenance of fornix FTL is essential for sustaining executive functioning in people with n-aMCI.
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Affiliation(s)
- Patcharaporn Srisaikaew
- Ph.D. Program in Anatomy, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
- Department of Anatomy, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Nahathai Wongpakaran
- Geriatric Psychiatry Unit, Department of Psychiatry, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Nicole D. Anderson
- Rotman Research Institute, Baycrest Health Science, Toronto, ON, Canada
- Department of Psychology and Psychiatry, University of Toronto, Toronto, ON, Canada
| | - J. Jean Chen
- Rotman Research Institute, Baycrest Health Science, Toronto, ON, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - Suchart Kothan
- Department of Radiologic Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
| | - Pairada Varnado
- Geriatric Psychiatry Unit, Department of Psychiatry, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Kittisak Unsrisong
- Department of Radiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Pasuk Mahakkanukrauh
- Department of Anatomy, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
- Excellence in Osteology Research and Training Center (ORTC), Chiang Mai University, Chiang Mai, Thailand
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8
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Mole JP, Fasano F, Evans J, Sims R, Kidd E, Aggleton JP, Metzler-Baddeley C. APOE-ε4-related differences in left thalamic microstructure in cognitively healthy adults. Sci Rep 2020; 10:19787. [PMID: 33188215 PMCID: PMC7666117 DOI: 10.1038/s41598-020-75992-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 10/15/2020] [Indexed: 01/05/2023] Open
Abstract
APOE-ε4 is a main genetic risk factor for developing late onset Alzheimer's disease (LOAD) and is thought to interact adversely with other risk factors on the brain. However, evidence regarding the impact of APOE-ε4 on grey matter structure in asymptomatic individuals remains mixed. Much attention has been devoted to characterising APOE-ε4-related changes in the hippocampus, but LOAD pathology is known to spread through the whole of the Papez circuit including the limbic thalamus. Here, we tested the impact of APOE-ε4 and two other risk factors, a family history of dementia and obesity, on grey matter macro- and microstructure across the whole brain in 165 asymptomatic individuals (38-71 years). Microstructural properties of apparent neurite density and dispersion, free water, myelin and cell metabolism were assessed with Neurite Orientation Density and Dispersion (NODDI) and quantitative magnetization transfer (qMT) imaging. APOE-ε4 carriers relative to non-carriers had a lower macromolecular proton fraction (MPF) in the left thalamus. No risk effects were present for cortical thickness, subcortical volume, or NODDI indices. Reduced thalamic MPF may reflect inflammation-related tissue swelling and/or myelin loss in APOE-ε4. Future prospective studies should investigate the sensitivity and specificity of qMT-based MPF as a non-invasive biomarker for LOAD risk.
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Affiliation(s)
- Jilu P Mole
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Maindy Road, Cathays, Cardiff, CF24 4HQ, UK
| | - Fabrizio Fasano
- Siemens Healthcare, Henkestrasse 127, 91052, Erlangen, Germany
| | - John Evans
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Maindy Road, Cathays, Cardiff, CF24 4HQ, UK
| | - Rebecca Sims
- Division of Psychological Medicine and Clinical Neuroscience, School of Medicine, Cardiff University, Haydn Ellis Building, Maindy Road, Cathays, Cardiff, CF24 4HQ, UK
| | - Emma Kidd
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Redwood Building, King Edward VII Avenue,, Cardiff, CF10 3NB, UK
| | - John P Aggleton
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Maindy Road, Cathays, Cardiff, CF24 4HQ, UK
| | - Claudia Metzler-Baddeley
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Maindy Road, Cathays, Cardiff, CF24 4HQ, UK.
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Mole JP, Fasano F, Evans J, Sims R, Hamilton DA, Kidd E, Metzler-Baddeley C. Genetic risk of dementia modifies obesity effects on white matter myelin in cognitively healthy adults. Neurobiol Aging 2020; 94:298-310. [PMID: 32736120 DOI: 10.1016/j.neurobiolaging.2020.06.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 06/19/2020] [Accepted: 06/20/2020] [Indexed: 01/05/2023]
Abstract
APOE-ε4 is a major genetic risk factor for late-onset Alzheimer's disease that interacts with other risk factors, but the nature of such combined effects remains poorly understood. We quantified the impact of APOE-ε4, family history (FH) of dementia, and obesity on white matter (WM) microstructure in 165 asymptomatic adults (38-71 years old) using quantitative magnetization transfer and neurite orientation dispersion and density imaging. Microstructural properties of the fornix, parahippocampal cingulum, and uncinate fasciculus were compared with those in motor and whole-brain WM regions. Widespread interaction effects between APOE, FH, and waist-hip ratio were found in the myelin-sensitive macromolecular proton fraction from quantitative magnetization transfer. Among individuals with the highest genetic risk (FH+ and APOE-ε4), obesity was associated with reduced macromolecular proton fraction in the right parahippocampal cingulum, whereas no effects were present for those without FH. Risk effects on apparent myelin were moderated by hypertension and inflammation-related markers. These findings suggest that genetic risk modifies the impact of obesity on WM myelin consistent with neuroglia models of aging and late-onset Alzheimer's disease.
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Affiliation(s)
- Jilu P Mole
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff, UK
| | | | - John Evans
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff, UK
| | - Rebecca Sims
- Division of Psychological Medicine and Clinical Neuroscience, School of Medicine, Cardiff University, Cardiff, UK
| | - Derek A Hamilton
- Department of Psychology, The University of New Mexico, Albuquerque, NM, USA
| | - Emma Kidd
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK
| | - Claudia Metzler-Baddeley
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff, UK.
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