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King-Robson J, Wilson H, Politis M. Associations Between Amyloid and Tau Pathology, and Connectome Alterations, in Alzheimer's Disease and Mild Cognitive Impairment. J Alzheimers Dis 2021; 82:541-560. [PMID: 34057079 DOI: 10.3233/jad-201457] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND The roles of amyloid-β and tau in the degenerative process of Alzheimer's disease (AD) remain uncertain. [18F]AV-45 and [18F]AV-1451 PET quantify amyloid-β and tau pathology, respectively, while diffusion tractography enables detection of their microstructural consequences. OBJECTIVE Examine the impact of amyloid-β and tau pathology on the structural connectome and cognition, in mild cognitive impairment (MCI) and AD. METHODS Combined [18F]AV-45 and [18F]AV-1451 PET, diffusion tractography, and cognitive assessment in 28 controls, 32 MCI, and 26 AD patients. RESULTS Hippocampal connectivity was reduced to the thalami, right lateral orbitofrontal, and right amygdala in MCI; alongside the insula, posterior cingulate, right entorhinal, and numerous cortical regions in AD (all p < 0.05). Hippocampal strength inversely correlated with [18F]AV-1451 SUVr in MCI (r = -0.55, p = 0.049) and AD (r = -0.57, p = 0.046), while reductions in hippocampal connectivity to ipsilateral brain regions correlated with increased [18F]AV-45 SUVr in those same regions in MCI (r = -0.33, p = 0.003) and AD (r = -0.31, p = 0.006). Cognitive scores correlated with connectivity of the right temporal pole in MCI (r = -0.60, p = 0.035) and left hippocampus in AD (r = 0.69, p = 0.024). Clinical Dementia Rating Scale scores correlated with [18F]AV-1451 SUVr in multiple areas reflecting Braak stages I-IV, including the right (r = 0.65, p = 0.004) entorhinal cortex in MCI; and Braak stages III-VI, including the right (r = 0.062, p = 0.009) parahippocampal gyrus in AD. CONCLUSION Reductions in hippocampal connectivity predominate in the AD connectome, correlating with hippocampal tau in MCI and AD, and with amyloid-β in the target regions of those connections. Cognitive scores correlate with microstructural changes and reflect the accumulation of tau pathology.
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Affiliation(s)
- Josh King-Robson
- Neurodegeneration Imaging Group, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London, London, UK
| | - Heather Wilson
- Neurodegeneration Imaging Group, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London, London, UK.,Neurodegeneration Imaging Group, University of Exeter Medical School, London, UK
| | - Marios Politis
- Neurodegeneration Imaging Group, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London, London, UK.,Neurodegeneration Imaging Group, University of Exeter Medical School, London, UK
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Brémond Martin C, Simon Chane C, Clouchoux C, Histace A. Recent Trends and Perspectives in Cerebral Organoids Imaging and Analysis. Front Neurosci 2021; 15:629067. [PMID: 34276279 PMCID: PMC8283195 DOI: 10.3389/fnins.2021.629067] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 05/20/2021] [Indexed: 01/04/2023] Open
Abstract
Purpose: Since their first generation in 2013, the use of cerebral organoids has spread exponentially. Today, the amount of generated data is becoming challenging to analyze manually. This review aims to overview the current image acquisition methods and to subsequently identify the needs in image analysis tools for cerebral organoids. Methods: To address this question, we went through all recent articles published on the subject and annotated the protocols, acquisition methods, and algorithms used. Results: Over the investigated period of time, confocal microscopy and bright-field microscopy were the most used acquisition techniques. Cell counting, the most common task, is performed in 20% of the articles and area; around 12% of articles calculate morphological parameters. Image analysis on cerebral organoids is performed in majority using ImageJ software (around 52%) and Matlab language (4%). Treatments remain mostly semi-automatic. We highlight the limitations encountered in image analysis in the cerebral organoid field and suggest possible solutions and implementations to develop. Conclusions: In addition to providing an overview of cerebral organoids cultures and imaging, this work highlights the need to improve the existing image analysis methods for such images and the need for specific analysis tools. These solutions could specifically help to monitor the growth of future standardized cerebral organoids.
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Affiliation(s)
- Clara Brémond Martin
- ETIS Laboratory UMR 8051, CY Cergy Paris Université, ENSEA, CNRS, Cergy, France
- WITSEE, Paris, France
| | - Camille Simon Chane
- ETIS Laboratory UMR 8051, CY Cergy Paris Université, ENSEA, CNRS, Cergy, France
| | | | - Aymeric Histace
- ETIS Laboratory UMR 8051, CY Cergy Paris Université, ENSEA, CNRS, Cergy, France
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Aghjayan SL, Lesnovskaya A, Esteban-Cornejo I, Peven JC, Stillman CM, Erickson KI. Aerobic exercise, cardiorespiratory fitness, and the human hippocampus. Hippocampus 2021; 31:817-844. [PMID: 34101305 PMCID: PMC8295234 DOI: 10.1002/hipo.23337] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 04/22/2021] [Accepted: 04/25/2021] [Indexed: 01/27/2023]
Abstract
The hippocampus is particularly susceptible to neurodegeneration. Physical activity, specifically increasing cardiorespiratory fitness via aerobic exercise, shows promise as a potential method for mitigating hippocampal decline in humans. Numerous studies have now investigated associations between the structure and function of the hippocampus and engagement in physical activity. Still, there remains continued debate and confusion about the relationship between physical activity and the human hippocampus. In this review, we describe the current state of the physical activity and exercise literature as it pertains to the structure and function of the human hippocampus, focusing on four magnetic resonance imaging measures: volume, diffusion tensor imaging, resting-state functional connectivity, and perfusion. We conclude that, despite significant heterogeneity in study methods, populations of interest, and scope, there are consistent positive findings, suggesting a promising role for physical activity in promoting hippocampal structure and function throughout the lifespan.
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Affiliation(s)
- Sarah L Aghjayan
- Department of Psychology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.,Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Alina Lesnovskaya
- Department of Psychology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.,Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Irene Esteban-Cornejo
- PROFITH "PROmoting FITness and Health Through Physical Activity" Research Group, Sport and Health University Research Institute (iMUDS), Department of Physical Education and Sports, Faculty of Sport Sciences, University of Granada, Granada, Spain.,College of Science, Health, Engineering, and Education, Murdoch University, Perth, Western Australia
| | - Jamie C Peven
- Department of Psychology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.,Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Chelsea M Stillman
- Department of Psychology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Kirk I Erickson
- Department of Psychology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.,Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.,College of Science, Health, Engineering, and Education, Murdoch University, Perth, Western Australia
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54
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Harini C, Yuskaitis CJ, Libenson MH, Yang E, DeLeo M, Zhang B, Mysak K, Marti C, Peters JM, Bergin AM, Pearl PL, Prabhu SP. Hippocampal Involvement With Vigabatrin-Related MRI Signal Abnormalities in Patients With Infantile Spasms: A Novel Finding. J Child Neurol 2021; 36:575-582. [PMID: 33432856 DOI: 10.1177/0883073820985395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND In a subset of infants exhibiting typical vigabatrin-related magnetic resonance imaging (MRI) changes, the authors observed additional hippocampal signal abnormalities. The authors investigated occurrence and significance of additional signal abnormalities. METHODS A retrospective review of infantile spasms patients with typical vigabatrin-related MRI abnormalities was performed. Atypical features included signal changes unilaterally or at previously unreported sites. Comparisons were made between patients with and without atypical features. RESULTS In all, 26/55 (47%) exhibited typical vigabatrin-related MRI changes, with additional signal abnormalities in the hippocampi in 6 of 26. On follow-up, evolution of hippocampal signal changes paralleled changes at typical locations in 4 patients. Two patients, clinically well, without follow-up MRI. Patients with and without additional hippocampal signal changes did not differ with respect to clinical factors, including seizure status. One patient had unilateral thalamic/cerebral peduncle signal abnormality along with typical vigabatrin changes. CONCLUSIONS Hippocampal changes seen in subset of patients with typical vigabatrin-related changes may be attributable to vigabatrin exposure in the appropriate circumstance.
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Affiliation(s)
- Chellamani Harini
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, 1862Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Christopher J Yuskaitis
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, 1862Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Mark H Libenson
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, 1862Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Edward Yang
- Neuroradiology Division, Department of Radiology, 1862Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Michelle DeLeo
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, 1862Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Bo Zhang
- Department of Neurology and ICCTR Biostatistics and Research Design Center, 1862Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Kate Mysak
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, 1862Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Candice Marti
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, 1862Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jurriaan M Peters
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, 1862Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Ann Marie Bergin
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, 1862Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Phillip L Pearl
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, 1862Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Sanjay P Prabhu
- Neuroradiology Division, Department of Radiology, 1862Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
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55
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Mizuochi-Endo T, Itou K, Makuuchi M, Kato B, Ikeda K, Nakamura K. Graphomotor memory in Exner's area enhances word learning in the blind. Commun Biol 2021; 4:443. [PMID: 33824412 PMCID: PMC8024258 DOI: 10.1038/s42003-021-01971-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 03/05/2021] [Indexed: 01/11/2023] Open
Abstract
Handwriting is thought to impede vocabulary learning in sighted adults because the motor execution of writing interferes with efficient audiovisual processing during encoding. However, the motor memory of writing may facilitate adult word learning when visual sensory inputs are severely restricted. Using functional MRI, we show that late-blind participants, but not sighted participants, learned novel words by recruiting the left dorsal premotor cortex known as Exner’s writing area and its functional coupling with the left hippocampus. During later recall, the phonological and semantic contents of these words are represented in the activation patterns of the left hippocampus as well as in those of left frontotemporal language areas. These findings suggest that motor codes of handwriting help blind participants maintain word-form representations during learning and retrieval. We propose that such reliance on the motor system reflects a broad architecture of the cerebral language network which encompasses the limb motor system as a hardwired component. Mizuochi-Endo et al. conduct a fMRI study, which reveals that in blind participants, unlike sighted participants, learning new words is associated with increased activity in Exner’s area—a part of the brain known to play a crucial role in handwriting motor memory. This demonstrates the importance of writing motor memory in vocabulary learning in the blind.
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Affiliation(s)
| | - Kazuyuki Itou
- National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan
| | - Michiru Makuuchi
- National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan
| | - Baku Kato
- National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan
| | - Kazuhisa Ikeda
- National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan
| | - Kimihiro Nakamura
- National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan.
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56
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Rocchi F, Oya H, Balezeau F, Billig AJ, Kocsis Z, Jenison RL, Nourski KV, Kovach CK, Steinschneider M, Kikuchi Y, Rhone AE, Dlouhy BJ, Kawasaki H, Adolphs R, Greenlee JDW, Griffiths TD, Howard MA, Petkov CI. Common fronto-temporal effective connectivity in humans and monkeys. Neuron 2021; 109:852-868.e8. [PMID: 33482086 PMCID: PMC7927917 DOI: 10.1016/j.neuron.2020.12.026] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 10/02/2020] [Accepted: 12/30/2020] [Indexed: 01/24/2023]
Abstract
Human brain pathways supporting language and declarative memory are thought to have differentiated substantially during evolution. However, cross-species comparisons are missing on site-specific effective connectivity between regions important for cognition. We harnessed functional imaging to visualize the effects of direct electrical brain stimulation in macaque monkeys and human neurosurgery patients. We discovered comparable effective connectivity between caudal auditory cortex and both ventro-lateral prefrontal cortex (VLPFC, including area 44) and parahippocampal cortex in both species. Human-specific differences were clearest in the form of stronger hemispheric lateralization effects. In humans, electrical tractography revealed remarkably rapid evoked potentials in VLPFC following auditory cortex stimulation and speech sounds drove VLPFC, consistent with prior evidence in monkeys of direct auditory cortex projections to homologous vocalization-responsive regions. The results identify a common effective connectivity signature in human and nonhuman primates, which from auditory cortex appears equally direct to VLPFC and indirect to the hippocampus. VIDEO ABSTRACT.
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Affiliation(s)
- Francesca Rocchi
- Biosciences Institute, Newcastle University Medical School, Newcastle upon Tyne, UK.
| | - Hiroyuki Oya
- Department of Neurosurgery, The University of Iowa, Iowa City, IA, USA; Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA, USA.
| | - Fabien Balezeau
- Biosciences Institute, Newcastle University Medical School, Newcastle upon Tyne, UK
| | | | - Zsuzsanna Kocsis
- Biosciences Institute, Newcastle University Medical School, Newcastle upon Tyne, UK; Department of Neurosurgery, The University of Iowa, Iowa City, IA, USA
| | - Rick L Jenison
- Department of Neuroscience, University of Wisconsin - Madison, Madison, WI, USA
| | - Kirill V Nourski
- Department of Neurosurgery, The University of Iowa, Iowa City, IA, USA; Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA, USA
| | | | - Mitchell Steinschneider
- Departments of Neurology and Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Yukiko Kikuchi
- Biosciences Institute, Newcastle University Medical School, Newcastle upon Tyne, UK
| | - Ariane E Rhone
- Department of Neurosurgery, The University of Iowa, Iowa City, IA, USA
| | - Brian J Dlouhy
- Department of Neurosurgery, The University of Iowa, Iowa City, IA, USA; Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA, USA
| | - Hiroto Kawasaki
- Department of Neurosurgery, The University of Iowa, Iowa City, IA, USA
| | - Ralph Adolphs
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Jeremy D W Greenlee
- Department of Neurosurgery, The University of Iowa, Iowa City, IA, USA; Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA, USA
| | - Timothy D Griffiths
- Biosciences Institute, Newcastle University Medical School, Newcastle upon Tyne, UK; Department of Neurosurgery, The University of Iowa, Iowa City, IA, USA; Wellcome Centre for Human Neuroimaging, University College London, London, UK
| | - Matthew A Howard
- Department of Neurosurgery, The University of Iowa, Iowa City, IA, USA; Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA, USA; Pappajohn Biomedical Institute, The University of Iowa, Iowa City, IA, USA
| | - Christopher I Petkov
- Biosciences Institute, Newcastle University Medical School, Newcastle upon Tyne, UK.
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57
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Plachti A, Kharabian S, Eickhoff SB, Maleki Balajoo S, Hoffstaedter F, Varikuti DP, Jockwitz C, Caspers S, Amunts K, Genon S. Hippocampus co-atrophy pattern in dementia deviates from covariance patterns across the lifespan. Brain 2021; 143:2788-2802. [PMID: 32851402 DOI: 10.1093/brain/awaa222] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 04/29/2020] [Accepted: 05/21/2020] [Indexed: 12/22/2022] Open
Abstract
The hippocampus is a plastic region and highly susceptible to ageing and dementia. Previous studies explicitly imposed a priori models of hippocampus when investigating ageing and dementia-specific atrophy but led to inconsistent results. Consequently, the basic question of whether macrostructural changes follow a cytoarchitectonic or functional organization across the adult lifespan and in age-related neurodegenerative disease remained open. The aim of this cross-sectional study was to identify the spatial pattern of hippocampus differentiation based on structural covariance with a data-driven approach across structural MRI data of large cohorts (n = 2594). We examined the pattern of structural covariance of hippocampus voxels in young, middle-aged, elderly, mild cognitive impairment and dementia disease samples by applying a clustering algorithm revealing differentiation in structural covariance within the hippocampus. In all the healthy and in the mild cognitive impaired participants, the hippocampus was robustly divided into anterior, lateral and medial subregions reminiscent of cytoarchitectonic division. In contrast, in dementia patients, the pattern of subdivision was closer to known functional differentiation into an anterior, body and tail subregions. These results not only contribute to a better understanding of co-plasticity and co-atrophy in the hippocampus across the lifespan and in dementia, but also provide robust data-driven spatial representations (i.e. maps) for structural studies.
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Affiliation(s)
- Anna Plachti
- Institute of Systems Neuroscience, Heinrich Heine University Düsseldorf, Düsseldorf 40225, Germany.,Institute of Neuroscience and Medicine (INM-1, INM-7), Research Centre Jülich, Jülich, Germany
| | - Shahrzad Kharabian
- Institute of Systems Neuroscience, Heinrich Heine University Düsseldorf, Düsseldorf 40225, Germany.,Institute of Neuroscience and Medicine (INM-1, INM-7), Research Centre Jülich, Jülich, Germany
| | - Simon B Eickhoff
- Institute of Systems Neuroscience, Heinrich Heine University Düsseldorf, Düsseldorf 40225, Germany.,Institute of Neuroscience and Medicine (INM-1, INM-7), Research Centre Jülich, Jülich, Germany
| | - Somayeh Maleki Balajoo
- Institute of Neuroscience and Medicine (INM-1, INM-7), Research Centre Jülich, Jülich, Germany
| | - Felix Hoffstaedter
- Institute of Neuroscience and Medicine (INM-1, INM-7), Research Centre Jülich, Jülich, Germany
| | - Deepthi P Varikuti
- Institute of Neuroscience and Medicine (INM-1, INM-7), Research Centre Jülich, Jülich, Germany
| | - Christiane Jockwitz
- Institute of Neuroscience and Medicine (INM-1, INM-7), Research Centre Jülich, Jülich, Germany.,Department of Psychiatry, Psychotherapy and Psychosomatics, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Svenja Caspers
- Institute of Neuroscience and Medicine (INM-1, INM-7), Research Centre Jülich, Jülich, Germany.,JARA-BRAIN, Jülich-Aachen Research Alliance, Jülich, Germany.,Institute for Anatomy I, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
| | - Katrin Amunts
- Institute of Neuroscience and Medicine (INM-1, INM-7), Research Centre Jülich, Jülich, Germany.,JARA-BRAIN, Jülich-Aachen Research Alliance, Jülich, Germany.,C. & O. Vogt Institute for Brain Research, Heinrich Heine University, Düsseldorf, Germany
| | - Sarah Genon
- Institute of Neuroscience and Medicine (INM-1, INM-7), Research Centre Jülich, Jülich, Germany.,GIGA-CRC In vivo Imaging, University of Liege, Liege, Belgium
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Diffusion kurtosis imaging detects subclinical white matter abnormalities in Phenylketonuria. NEUROIMAGE-CLINICAL 2021; 29:102555. [PMID: 33461111 PMCID: PMC7814191 DOI: 10.1016/j.nicl.2020.102555] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 12/02/2020] [Accepted: 12/29/2020] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Phenylketonuria (PKU) is an autosomal recessive disorder whereby deficiencies in phenylalanine metabolism cause progressive neurological dysfunction. Managing PKU is challenging, with disease monitoring focussed on short-term phenylalanine control rather than measures of neuronal damage. Conventional imaging lacks sensitivity, however diffusion kurtosis imaging (DKI), a new MRI method may reveal subclinical white matter structural changes in PKU. METHODS This cohort study involved adults with PKU recruited during routine clinical care. MRI, neurocognitive assessment and historical phenylalanine (Phe) levels were collected. A hypothesis-generating case study comparing diet-compliant and non-compliant siblings confirmed that DKI metrics are sensitive to dietary adherence and prompted a candidate metric (Krad/KFA ratio). We then tested this metric in a Replication cohort (PKU = 20; controls = 43). RESULTS Both siblings scored outside the range of controls for all DKI-based metrics, with severe changes in the periventricular white matter and a gradient of severity toward the cortex. Krad/KFA provided clear separation by diagnosis in the Replication cohort (p < 0.001 in periventricular, deep and pericortical compartments). The ratio also correlated negatively with attention (r = -0.51 & -0.50, p < 0.05) and positively with 3-year mean Phe (r = 0.45 & 0.58, p < 0.01). CONCLUSION DKI reveals regionally-specific, progressive abnormalities of brain diffusion characteristics in PKU, even in the absence of conspicuous clinical signs or abnormalities on conventional MRI. A DKI-based marker derived from these scores (Krad/KFA ratio) was sensitive to cognitive impairment and PKU control over the medium term and may provide a meaningful subclinical biomarker of end-organ damage.
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59
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Lin YH, Dhanaraj V, Mackenzie AE, Young IM, Tanglay O, Briggs RG, Chakraborty AR, Hormovas J, Fonseka RD, Kim SJ, Yeung JT, Teo C, Sughrue ME. Anatomy and White Matter Connections of the Parahippocampal Gyrus. World Neurosurg 2021; 148:e218-e226. [PMID: 33412321 DOI: 10.1016/j.wneu.2020.12.136] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 12/23/2020] [Accepted: 12/24/2020] [Indexed: 10/22/2022]
Abstract
BACKGROUND The parahippocampal gyrus is understood to have a role in high cognitive functions including memory encoding and retrieval and visuospatial processing. A detailed understanding of the exact location and nature of associated white tracts could significantly improve postoperative morbidity related to declining capacity. Through diffusion tensor imaging-based fiber tracking validated by gross anatomic dissection as ground truth, we have characterized these connections based on relationships to other well-known structures. METHODS Diffusion imaging from the Human Connectome Project for 10 healthy adult controls was used for tractography analysis. We evaluated the parahippocampal gyrus as a whole based on connectivity with other regions. All parahippocampal gyrus tracts were mapped in both hemispheres, and a lateralization index was calculated with resultant tract volumes. RESULTS We identified 2 connections of the parahippocampal gyrus: inferior longitudinal fasciculus and cingulum. Lateralization of the cingulum was detected (P < 0.05). CONCLUSIONS The parahippocampal gyrus is an important center for memory processing. Subtle differences in executive functioning following surgery for limbic tumors may be better understood in the context of the fiber-bundle anatomy highlighted by this study.
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Affiliation(s)
- Yueh-Hsin Lin
- Centre for Minimally Invasive Neurosurgery Prince of Wales Private Hospital, Sydney, Australia
| | - Vukshitha Dhanaraj
- Centre for Minimally Invasive Neurosurgery Prince of Wales Private Hospital, Sydney, Australia
| | - Alana E Mackenzie
- Centre for Minimally Invasive Neurosurgery Prince of Wales Private Hospital, Sydney, Australia
| | | | - Onur Tanglay
- Centre for Minimally Invasive Neurosurgery Prince of Wales Private Hospital, Sydney, Australia
| | - Robert G Briggs
- Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Arpan R Chakraborty
- Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Jorge Hormovas
- Centre for Minimally Invasive Neurosurgery Prince of Wales Private Hospital, Sydney, Australia
| | - R Dineth Fonseka
- Centre for Minimally Invasive Neurosurgery Prince of Wales Private Hospital, Sydney, Australia
| | - Sihyong J Kim
- Centre for Minimally Invasive Neurosurgery Prince of Wales Private Hospital, Sydney, Australia
| | - Jacky T Yeung
- Centre for Minimally Invasive Neurosurgery Prince of Wales Private Hospital, Sydney, Australia
| | - Charles Teo
- Centre for Minimally Invasive Neurosurgery Prince of Wales Private Hospital, Sydney, Australia
| | - Michael E Sughrue
- Centre for Minimally Invasive Neurosurgery Prince of Wales Private Hospital, Sydney, Australia.
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Borghammer P. The α-Synuclein Origin and Connectome Model (SOC Model) of Parkinson's Disease: Explaining Motor Asymmetry, Non-Motor Phenotypes, and Cognitive Decline. JOURNAL OF PARKINSON'S DISEASE 2021; 11:455-474. [PMID: 33682732 PMCID: PMC8150555 DOI: 10.3233/jpd-202481] [Citation(s) in RCA: 74] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Accepted: 02/10/2021] [Indexed: 12/12/2022]
Abstract
A new model of Parkinson's disease (PD) pathogenesis is proposed, the α-Synuclein Origin site and Connectome (SOC) model, incorporating two aspects of α-synuclein pathobiology that impact the disease course for each patient: the anatomical location of the initial α-synuclein inclusion, and α-synuclein propagation dependent on the ipsilateral connections that dominate connectivity of the human brain. In some patients, initial α-synuclein pathology occurs within the CNS, leading to a brain-first subtype of PD. In others, pathology begins in the peripheral autonomic nervous system, leading to a body-first subtype. In brain-first cases, it is proposed that the first pathology appears unilaterally, often in the amygdala. If α-synuclein propagation depends on connection strength, a unilateral focus of pathology will disseminate more to the ipsilateral hemisphere. Thus, α-synuclein spreads mainly to ipsilateral structures including the substantia nigra. The asymmetric distribution of pathology leads to asymmetric dopaminergic degeneration and motor asymmetry. In body-first cases, the α-synuclein pathology ascends via the vagus to both the left and right dorsal motor nuclei of the vagus owing to the overlapping parasympathetic innervation of the gut. Consequently, the initial α-synuclein pathology inside the CNS is more symmetric, which promotes more symmetric propagation in the brainstem, leading to more symmetric dopaminergic degeneration and less motor asymmetry. At diagnosis, body-first patients already have a larger, more symmetric burden of α-synuclein pathology, which in turn promotes faster disease progression and accelerated cognitive decline. The SOC model is supported by a considerable body of existing evidence and may have improved explanatory power.
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Affiliation(s)
- Per Borghammer
- Department of Nuclear Medicine & PET, Aarhus University Hospital, Aarhus, Denmark
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61
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Roelofs EF, Bas-Hoogendam JM, van Ewijk H, Ganjgahi H, van der Werff SJA, Barendse MEA, Westenberg PM, Vermeiren RRJM, van der Wee NJA. Investigating microstructure of white matter tracts as candidate endophenotypes of Social Anxiety Disorder - Findings from the Leiden Family Lab study on Social Anxiety Disorder (LFLSAD). NEUROIMAGE-CLINICAL 2020; 28:102493. [PMID: 33395984 PMCID: PMC7691726 DOI: 10.1016/j.nicl.2020.102493] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 10/29/2020] [Accepted: 11/01/2020] [Indexed: 12/16/2022]
Abstract
BACKGROUND Social anxiety disorder (SAD) is a mental illness with a complex, partially genetic background. Differences in characteristics of white matter (WM) microstructure have been reported in patients with SAD compared to healthy controls. Also, WM characteristics are moderately to highly heritable. Endophenotypes are measurable characteristics on the road from genotype to phenotype, putatively reflective of genetically based disease mechanisms. In search of candidate endophenotypes of SAD we used a unique sample of SAD patients and their family members of two generations to explore microstructure of WM tracts as candidate endophenotypes. We focused on two endophenotype criteria: co-segregation with social anxiety within the families, and heritability. METHODS Participants (n = 94 from 8 families genetically vulnerable for SAD) took part in the Leiden Family Lab Study on Social Anxiety Disorder (LFLSAD). We employed tract-based spatial statistics to examine structural WM characteristics, being fractional anisotropy (FA), axial diffusivity (AD), mean diffusivity (MD) and radial diffusivity (RD), in three a-priori defined tracts of interest: uncinate fasciculus (UF), superior longitudinal fasciculus (SLF) and inferior longitudinal fasciculus (ILF). Associations with social anxiety symptoms and heritability were estimated. RESULTS Increased FA in the left and right SLF co-segregated with symptoms of social anxiety. These findings were coupled with decreased RD and MD. All characteristics of WM microstructure were estimated to be at least moderately heritable. CONCLUSION These findings suggest that alterations in WM microstructure in the SLF could be candidate endophenotypes of SAD, as they co-segregated within families genetically vulnerable for SAD and are heritable. These findings further elucidate the genetic susceptibility to SAD and improve our understanding of the overall etiology.
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Affiliation(s)
- Eline F Roelofs
- Curium-LUMC, Department of Child and Adolescent Psychiatry, Leiden University Medical Center, Leiden, The Netherlands; Department of Psychiatry, Leiden University Medical Center, Leiden, The Netherlands; Leiden Institute for Brain and Cognition, Leiden, The Netherlands.
| | - Janna Marie Bas-Hoogendam
- Department of Psychiatry, Leiden University Medical Center, Leiden, The Netherlands; Leiden Institute for Brain and Cognition, Leiden, The Netherlands; Developmental and Educational Psychology, Institute of Psychology, Leiden University, Leiden, The Netherlands.
| | - Hanneke van Ewijk
- Curium-LUMC, Department of Child and Adolescent Psychiatry, Leiden University Medical Center, Leiden, The Netherlands; Department of Psychiatry, Leiden University Medical Center, Leiden, The Netherlands.
| | - Habib Ganjgahi
- Department of Statistics, University of Oxford, Oxford, United Kingdom.
| | - Steven J A van der Werff
- Department of Psychiatry, Leiden University Medical Center, Leiden, The Netherlands; Leiden Institute for Brain and Cognition, Leiden, The Netherlands.
| | | | - P Michiel Westenberg
- Leiden Institute for Brain and Cognition, Leiden, The Netherlands; Developmental and Educational Psychology, Institute of Psychology, Leiden University, Leiden, The Netherlands.
| | - Robert R J M Vermeiren
- Curium-LUMC, Department of Child and Adolescent Psychiatry, Leiden University Medical Center, Leiden, The Netherlands; Leiden Institute for Brain and Cognition, Leiden, The Netherlands.
| | - Nic J A van der Wee
- Department of Psychiatry, Leiden University Medical Center, Leiden, The Netherlands; Leiden Institute for Brain and Cognition, Leiden, The Netherlands.
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De Luca A, Guo F, Froeling M, Leemans A. Spherical deconvolution with tissue-specific response functions and multi-shell diffusion MRI to estimate multiple fiber orientation distributions (mFODs). Neuroimage 2020; 222:117206. [DOI: 10.1016/j.neuroimage.2020.117206] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Revised: 07/20/2020] [Accepted: 07/23/2020] [Indexed: 12/18/2022] Open
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Gabrieli D, Schumm SN, Vigilante NF, Parvesse B, Meaney DF. Neurodegeneration exposes firing rate dependent effects on oscillation dynamics in computational neural networks. PLoS One 2020; 15:e0234749. [PMID: 32966291 PMCID: PMC7510994 DOI: 10.1371/journal.pone.0234749] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 06/01/2020] [Indexed: 12/26/2022] Open
Abstract
Traumatic brain injury (TBI) can lead to neurodegeneration in the injured circuitry, either through primary structural damage to the neuron or secondary effects that disrupt key cellular processes. Moreover, traumatic injuries can preferentially impact subpopulations of neurons, but the functional network effects of these targeted degeneration profiles remain unclear. Although isolating the consequences of complex injury dynamics and long-term recovery of the circuit can be difficult to control experimentally, computational networks can be a powerful tool to analyze the consequences of injury. Here, we use the Izhikevich spiking neuron model to create networks representative of cortical tissue. After an initial settling period with spike-timing-dependent plasticity (STDP), networks developed rhythmic oscillations similar to those seen in vivo. As neurons were sequentially removed from the network, population activity rate and oscillation dynamics were significantly reduced. In a successive period of network restructuring with STDP, network activity levels returned to baseline for some injury levels and oscillation dynamics significantly improved. We next explored the role that specific neurons have in the creation and termination of oscillation dynamics. We determined that oscillations initiate from activation of low firing rate neurons with limited structural inputs. To terminate oscillations, high activity excitatory neurons with strong input connectivity activate downstream inhibitory circuitry. Finally, we confirm the excitatory neuron population role through targeted neurodegeneration. These results suggest targeted neurodegeneration can play a key role in the oscillation dynamics after injury.
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Affiliation(s)
- David Gabrieli
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Samantha N. Schumm
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Nicholas F. Vigilante
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Brandon Parvesse
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - David F. Meaney
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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64
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Tanaka M, Osada T, Ogawa A, Kamagata K, Aoki S, Konishi S. Dissociable Networks of the Lateral/Medial Mammillary Body in the Human Brain. Front Hum Neurosci 2020; 14:228. [PMID: 32625073 PMCID: PMC7316159 DOI: 10.3389/fnhum.2020.00228] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Accepted: 05/22/2020] [Indexed: 12/20/2022] Open
Abstract
The mammillary body (MB) has been thought to implement mnemonic functions. Although recent animal studies have revealed dissociable roles of the lateral and medial parts of the MB, the dissociable roles of the lateral/medial MB in the human brain is still unclear. Functional connectivity using resting-state functional magnetic resonance imaging (fMRI) provides a unique opportunity to noninvasively inspect the intricate functional organization of the human MB with a high degree of spatial resolution. The present study divided the human MB into lateral and medial parts and examined their functional connectivity with the hippocampal formation, tegmental nuclei, and anterior thalamus. The subiculum of the hippocampal formation was more strongly connected with the medial part than with the lateral part of the MB, whereas the pre/parasubiculum was more strongly connected with the lateral part than with the medial part of the MB. The dorsal tegmental nucleus was connected more strongly with the lateral part of the MB, whereas the ventral tegmental nucleus showed an opposite pattern. The anterior thalamus was connected more strongly with the medial part of the MB. These results confirm the extant animal literature on the lateral/medial MB and provide evidence on the parallel but dissociable systems involving the MB that ascribe mnemonic and spatial-navigation functions to the medial and lateral MBs, respectively.
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Affiliation(s)
- Masaki Tanaka
- Department of Neurophysiology, Juntendo University School of Medicine, Tokyo, Japan
| | - Takahiro Osada
- Department of Neurophysiology, Juntendo University School of Medicine, Tokyo, Japan
| | - Akitoshi Ogawa
- Department of Neurophysiology, Juntendo University School of Medicine, Tokyo, Japan
| | - Koji Kamagata
- Department of Radiology, Juntendo University School of Medicine, Tokyo, Japan
| | - Shigeki Aoki
- Department of Radiology, Juntendo University School of Medicine, Tokyo, Japan
| | - Seiki Konishi
- Department of Neurophysiology, Juntendo University School of Medicine, Tokyo, Japan.,Research Institute for Diseases of Old Age, Juntendo University School of Medicine, Tokyo, Japan.,Sportology Center, Juntendo University School of Medicine, Tokyo, Japan.,Advanced Research Institute for Health Science, Juntendo University School of Medicine, Tokyo, Japan
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65
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Characterizing the gradients of structural covariance in the human hippocampus. Neuroimage 2020; 218:116972. [PMID: 32454206 DOI: 10.1016/j.neuroimage.2020.116972] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 04/29/2020] [Accepted: 05/17/2020] [Indexed: 11/23/2022] Open
Abstract
The hippocampus is a plastic brain structure that has been associated with a range of behavioral aspects but also shows vulnerability to the most frequent neurocognitive diseases. Different aspects of its organization have been revealed by studies probing its different neurobiological properties. In particular, histological work has shown a pattern of differentiation along the proximal-distal dimension, while studies examining functional properties and large-scale functional integration have primarily highlighted a pattern of differentiation along the anterior-posterior dimension. To better understand how these organizational dimensions underlie the pattern of structural covariance (SC) in the human hippocampus, we here applied a non-linear decomposition approach, disentangling the major modes of variation, to the pattern of gray matter volume correlation of hippocampus voxels with the rest of the brain in a sample of 377 healthy young adults. We additionally investigated the consistency of the derived gradients in an independent sample of life-span adults and also examined the relationships between these major modes of variations and the patterns derived from microstructure and functional connectivity mapping. Our results showed that similar major modes of SC-variability are identified across the two independent datasets. The major dimension of variation found in SC runs along the hippocampal anterior-posterior axis and followed closely the principal dimension of functional differentiation, suggesting an influence of network level interaction in this major mode of morphological variability. The second main mode of variability in the SC showed a gradient along the dorsal-ventral axis, and was moderately related to variability in hippocampal microstructural properties. Thus our results depicting relatively reliable patterns of SC-variability within the hippocampus show an interplay between the already known organizational principles on the pattern of variability in hippocampus' macrostructural properties. This study hence provides a first insight on the underlying organizational forces generating different co-plastic modes within the human hippocampus that may, in turn, help to better understand different vulnerability patterns of this crucial structure in different neurological and psychiatric diseases.
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66
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Kim HJ, Song C, Bang M, Lee SH. Early sexual trauma is related with the tapetum in patients with panic disorder. J Affect Disord 2020; 267:107-113. [PMID: 32063561 DOI: 10.1016/j.jad.2020.02.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 02/04/2020] [Accepted: 02/06/2020] [Indexed: 02/09/2023]
Abstract
BACKGROUND Early trauma exposure is suggested to confer a greater risk for the development of panic disorder (PD) by altering neurodevelopmental processes. A body of studies have shown that white matter microstructures, particularly in the fronto-limbic and callosal regions, could be affected by a history of early trauma in patients with PD. The tapetum, the extended posterior part of the corpus callosum connecting the bilateral temporal lobes, has not yet been studied regarding its relationship with early trauma, especially sexual one. METHODS Seventy participants with PD, sixty age- and sex-matched healthy controls were enrolled. The Early Trauma Inventory Self Report-Short Form (ETISR-SF), Neuroticism Scale, and Panic Disorder Severity Scale (PDSS) were administered. Voxel-wise statistical analysis of diffusion tensor imaging data was performed within the bilateral tapetum regions using Tract-Based Spatial Statistics (TBSS). RESULTS In participants with PD, higher levels of sexual trauma were significantly associated with the increased fractional anisotropies (FAs) in a cluster of the right tapetum. Exploratory correlation analysis revealed that FAs in this cluster were significantly correlated with higher neuroticism and poorer treatment response after one year of pharmacotherapy. No significant correlation was found between FAs of the right tapetum cluster and the PDSS scores. LIMITATIONS The possibility of retrospective recall bias for early trauma cannot be completely ruled out. CONCLUSIONS The findings of this study suggest that the right tapetum may serve as a potential neural marker of early sexual trauma in patients with PD and contribute to personal vulnerability and poorer treatment outcome after pharmacotherapy.
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Affiliation(s)
- Hyun-Ju Kim
- Department of Psychiatry, CHA Bundang Medical Center, CHA University School of Medicine, Seongnam, South Korea
| | - Chaerim Song
- Department of Psychiatry, CHA Bundang Medical Center, CHA University School of Medicine, Seongnam, South Korea; Clinical Counseling Psychology Graduate School, CHA University, Seongnam, South Korea
| | - Minji Bang
- Department of Psychiatry, CHA Bundang Medical Center, CHA University School of Medicine, Seongnam, South Korea
| | - Sang-Hyuk Lee
- Department of Psychiatry, CHA Bundang Medical Center, CHA University School of Medicine, Seongnam, South Korea; Department of Clinical Pharmacology and Therapeutics, CHA Bundang Medical Center, CHA University School of Medicine, Seongnam, South Korea.
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67
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Dietary Fructose Intake and Hippocampal Structure and Connectivity during Childhood. Nutrients 2020; 12:nu12040909. [PMID: 32224933 PMCID: PMC7230400 DOI: 10.3390/nu12040909] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 03/21/2020] [Accepted: 03/24/2020] [Indexed: 01/06/2023] Open
Abstract
In rodent literature, there is evidence that excessive fructose consumption during development has a detrimental impact on hippocampal structure and function. In this study of 103 children ages 7–11 years old, we investigated whether dietary fructose intake was related to alterations in hippocampal volume and connectivity in humans. To examine if these associations were specific to fructose or were related to dietary sugars intake in general, we explored relationships between dietary intake of added sugars and the monosaccharide, glucose, on the same brain measures. We found that increased dietary intake of fructose, measured as a percentage of total calories, was associated with both an increase in the volume of the CA2/3 subfield of the right hippocampus and increased axial, radial, and mean diffusivity in the prefrontal connections of the right cingulum. These findings are consistent with the idea that increased fructose consumption during childhood may be associated with an inflammatory process, and/or decreases or delays in myelination and/or pruning. Increased habitual consumption of glucose or added sugar in general were associated with an increased volume of right CA2/3, but not with any changes in the connectivity of the hippocampus. These findings support animal data suggesting that higher dietary intake of added sugars, particularly fructose, are associated with alterations in hippocampal structure and connectivity during childhood.
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68
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Welton T, Indja BE, Maller JJ, Fanning JP, Vallely MP, Grieve SM. Replicable brain signatures of emotional bias and memory based on diffusion kurtosis imaging of white matter tracts. Hum Brain Mapp 2019; 41:1274-1285. [PMID: 31773802 PMCID: PMC7268065 DOI: 10.1002/hbm.24874] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 11/11/2019] [Accepted: 11/12/2019] [Indexed: 12/31/2022] Open
Abstract
Diffusion MRI (dMRI) is sensitive to anisotropic diffusion within bundles of nerve axons and can be used to make objective measurements of brain networks. Many brain disorders are now recognised as being caused by network dysfunction or are secondarily associated with changes in networks. There is therefore great potential in using dMRI measures that reflect network integrity as a future clinical tool to help manage these conditions. Here, we used dMRI to identify replicable, robust and objective markers that meaningfully reflect cognitive and emotional performance. Using diffusion kurtosis analysis and a battery of cognitive and emotional tests, we demonstrated strong relationships between white matter structure across networks of anatomically and functionally specific brain regions with both emotional bias and emotional memory performance in a large healthy cohort. When the connectivity of these regions was examined using diffusion tractography, the terminations of the identified tracts overlapped precisely with cortical loci relating to these domains, drawn from an independent spatial meta‐analysis of available functional neuroimaging literature. The association with emotional bias was then replicated using an independently acquired healthy cohort drawn from the Human Connectome Project. These results demonstrate that, even in healthy individuals, white matter dMRI structural features underpin important cognitive and emotional functions. Our robust cross‐correlation and replication supports the potential of structural brain biomarkers from diffusion kurtosis MRI to characterise early neurological changes and risk in individuals with a reduced threshold for cognitive dysfunction, with further testing required to demonstrate clinical utility.
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Affiliation(s)
- Thomas Welton
- Sydney Translational Imaging Laboratory, Heart Research Institute, The University of Sydney, Camperdown, New South Wales, Australia
| | - Ben E Indja
- Sydney Medical School, The University of Sydney, Camperdown, New South Wales, Australia
| | - Jerome J Maller
- Sydney Translational Imaging Laboratory, Heart Research Institute, The University of Sydney, Camperdown, New South Wales, Australia.,GE Healthcare, Richmond, Victoria, Australia
| | - Jonathon P Fanning
- Faculty of Medicine, The University of Queensland, Brisbane, New South Wales, Australia.,The Critical Care Research Group, The Prince Charles Hospital, Brisbane, New South Wales, Australia
| | - Michael P Vallely
- Sydney Medical School, The University of Sydney, Camperdown, New South Wales, Australia.,Department of Cardiothoracic Surgery, The Northern Beaches Hospital, Sydney, New South Wales, Australia
| | - Stuart M Grieve
- Sydney Translational Imaging Laboratory, Heart Research Institute, The University of Sydney, Camperdown, New South Wales, Australia.,Department of Radiology, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
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69
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Shen KK, Welton T, Lyon M, McCorkindale AN, Sutherland GT, Burnham S, Fripp J, Martins R, Grieve SM. Structural core of the executive control network: A high angular resolution diffusion MRI study. Hum Brain Mapp 2019; 41:1226-1236. [PMID: 31765057 PMCID: PMC7267982 DOI: 10.1002/hbm.24870] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 10/27/2019] [Accepted: 11/05/2019] [Indexed: 12/28/2022] Open
Abstract
Executive function (EF) is a set of cognitive capabilities considered essential for successful daily living, and is negatively affected by ageing and neurodegenerative conditions. Underpinning EF performance are functional nodes in the executive control network (ECN), while the structural connectivity underlying this network is not well understood. In this paper, we evaluated the structural white matter tracts that interconnect the ECN and investigated their relationship to the EF performance. Using high‐angular resolution diffusion MRI data, we performed tractography analysis of structural connectivity in a cognitively normal cohort (n = 140), specifically targeting the connectivity between ECN nodes. Our data revealed the presence of a strongly‐connected “structural core” of the ECN comprising three components: interhemispheric frontal connections, a fronto‐parietal subnetwork and fronto‐striatal connections between right dorsolateral prefrontal cortex and right caudate. These pathways were strongly correlated with EF performance (p = .003). Post‐hoc analysis of subregions within the significant ECN connections showed that these effects were driven by a highly specific subset of interconnected cortical regions. The structural core subnetwork of the functional ECN may be an important feature crucial to a better future understanding of human cognition and behaviour.
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Affiliation(s)
- Kai-Kai Shen
- Australian eHealth Research Centre, CSIRO, Floreat, Western Australia, Australia.,Department of Biomedical Sciences, Macquarie University, Sydney, New South Wales, Australia.,Sydney Translational Imaging Laboratory, Heart Research Institute, Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia
| | - Thomas Welton
- Sydney Translational Imaging Laboratory, Heart Research Institute, Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia
| | - Matthew Lyon
- Sydney Translational Imaging Laboratory, Heart Research Institute, Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia
| | - Andrew N McCorkindale
- Sydney Translational Imaging Laboratory, Heart Research Institute, Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia
| | - Greg T Sutherland
- Faculty of Medicine and Health, Charles Perkins Centre and School of Medical Sciences, University of Sydney, Sydney, New South Wales, Australia
| | - Samantha Burnham
- Australian eHealth Research Centre, CSIRO, Floreat, Western Australia, Australia
| | - Jurgen Fripp
- Australian eHealth Research Centre, CSIRO, Floreat, Western Australia, Australia
| | - Ralph Martins
- Department of Biomedical Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Stuart M Grieve
- Sydney Translational Imaging Laboratory, Heart Research Institute, Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia.,Department of Radiology, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
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Freedberg M, Toader AC, Wassermann EM, Voss JL. Competitive and cooperative interactions between medial temporal and striatal learning systems. Neuropsychologia 2019; 136:107257. [PMID: 31733236 DOI: 10.1016/j.neuropsychologia.2019.107257] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 09/13/2019] [Accepted: 11/06/2019] [Indexed: 01/20/2023]
Abstract
The striatum and medial temporal lobes (MTL) exhibit dissociable roles during learning. Whereas the striatum and its network of thalamic relays and cortical nodes are necessary for nondeclarative learning, the MTL and associated network are required for declarative learning. Several studies have suggested that these networks are functionally competitive during learning. Since these discoveries, however, evidence has accumulated that they can operate in a cooperative fashion. In this review, we discuss evidence for both competition and cooperation between these systems during learning, with the aim of reconciling these seemingly contradictory findings. Examples of cooperation between the striatum and MTL have been provided, especially during consolidation and generalization of knowledge, and do not appear to be precluded by differences in functional specialization. However, whether these systems cooperate or compete does seem to depend on the phase of learning and cognitive or motor aspects of the task. The involvement of other regions, such as midbrain dopaminergic nuclei and the prefrontal cortex, may promote and mediate cooperation between the striatum and the MTL during learning. Building on this body of research, we propose a model for striatum-MTL interactions in learning and memory and attempt to predict, in general terms, when cooperation or competition will occur.
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Affiliation(s)
- Michael Freedberg
- National Institute of Neurological Disorders and Stroke, 9000 Rockville Pike, 10 Center Drive, Bethesda, MD 20892, USA; Henry M. Jackson Foundation for the Advancement of Military Medicine, 6720A Rockledge Drive, Bethesda, MD 20892, USA.
| | - Andrew C Toader
- National Institute of Neurological Disorders and Stroke, 9000 Rockville Pike, 10 Center Drive, Bethesda, MD 20892, USA; Weill Cornell/Rockefeller/Sloan-Kettering Tri-Institutional MD-PhD Program, New York, NY 20892, USA.
| | - Eric M Wassermann
- National Institute of Neurological Disorders and Stroke, 9000 Rockville Pike, 10 Center Drive, Bethesda, MD 20892, USA.
| | - Joel L Voss
- Department of Medical Social Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA; Ken and Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA; Department of Psychiatry and Behavioral Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA; Northwestern University Interdepartmental Neuroscience Program, Northwestern University, Chicago, IL, USA.
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Quantification of thalamic nuclei in patients diagnosed with temporal lobe epilepsy and hippocampal sclerosis. Neuroradiology 2019; 62:185-195. [DOI: 10.1007/s00234-019-02299-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 10/01/2019] [Indexed: 12/23/2022]
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