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Seo S, Bharmauria V, Schütz A, Yan X, Wang H, Crawford JD. Multiunit Frontal Eye Field Activity Codes the Visuomotor Transformation, But Not Gaze Prediction or Retrospective Target Memory, in a Delayed Saccade Task. eNeuro 2024; 11:ENEURO.0413-23.2024. [PMID: 39054056 PMCID: PMC11373882 DOI: 10.1523/eneuro.0413-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 07/16/2024] [Accepted: 07/18/2024] [Indexed: 07/27/2024] Open
Abstract
Single-unit (SU) activity-action potentials isolated from one neuron-has traditionally been employed to relate neuronal activity to behavior. However, recent investigations have shown that multiunit (MU) activity-ensemble neural activity recorded within the vicinity of one microelectrode-may also contain accurate estimations of task-related neural population dynamics. Here, using an established model-fitting approach, we compared the spatial codes of SU response fields with corresponding MU response fields recorded from the frontal eye fields (FEFs) in head-unrestrained monkeys (Macaca mulatta) during a memory-guided saccade task. Overall, both SU and MU populations showed a simple visuomotor transformation: the visual response coded target-in-eye coordinates, transitioning progressively during the delay toward a future gaze-in-eye code in the saccade motor response. However, the SU population showed additional secondary codes, including a predictive gaze code in the visual response and retention of a target code in the motor response. Further, when SUs were separated into regular/fast spiking neurons, these cell types showed different spatial code progressions during the late delay period, only converging toward gaze coding during the final saccade motor response. Finally, reconstructing MU populations (by summing SU data within the same sites) failed to replicate either the SU or MU pattern. These results confirm the theoretical and practical potential of MU activity recordings as a biomarker for fundamental sensorimotor transformations (e.g., target-to-gaze coding in the oculomotor system), while also highlighting the importance of SU activity for coding more subtle (e.g., predictive/memory) aspects of sensorimotor behavior.
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Affiliation(s)
- Serah Seo
- Centre for Vision Research and Centre for Integrative and Applied Neuroscience, York University, Toronto, Ontario M3J 1P3, Canada
| | - Vishal Bharmauria
- Centre for Vision Research and Centre for Integrative and Applied Neuroscience, York University, Toronto, Ontario M3J 1P3, Canada
- Department of Neurosurgery and Brain Repair, Morsani College of Medicine, University of South Florida, Tampa, Florida 33606
| | - Adrian Schütz
- Department of Neurophysics, Philipps-Universität Marburg, 35032 Marburg, Germany
- Center for Mind, Brain, and Behavior - CMBB, Philipps-Universität Marburg, 35032 Marburg, and Justus-Liebig-Universität Giessen, Giessen, Germany
| | - Xiaogang Yan
- Centre for Vision Research and Centre for Integrative and Applied Neuroscience, York University, Toronto, Ontario M3J 1P3, Canada
| | - Hongying Wang
- Centre for Vision Research and Centre for Integrative and Applied Neuroscience, York University, Toronto, Ontario M3J 1P3, Canada
| | - J Douglas Crawford
- Centre for Vision Research and Centre for Integrative and Applied Neuroscience, York University, Toronto, Ontario M3J 1P3, Canada
- Departments of Psychology, Biology, Kinesiology & Health Sciences, York University, Toronto, Ontario M3J 1P3, Canada
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Wiesner D, Feldengut S, Woelfle S, Boeckers TM, Ludolph AC, Roselli F, Del Tredici K. Neuropeptide FF (NPFF)-positive nerve cells of the human cerebral cortex and white matter in controls, selected neurodegenerative diseases, and schizophrenia. Acta Neuropathol Commun 2024; 12:108. [PMID: 38943180 PMCID: PMC11212262 DOI: 10.1186/s40478-024-01792-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 05/02/2024] [Indexed: 07/01/2024] Open
Abstract
We quantified and determined for the first time the distribution pattern of the neuropeptide NPFF in the human cerebral cortex and subjacent white matter. To do so, we studied n = 9 cases without neurological disorders and n = 22 cases with neurodegenerative diseases, including sporadic amyotrophic lateral sclerosis (ALS, n = 8), Alzheimer's disease (AD, n = 8), Pick's disease (PiD, n = 3), and schizophrenia (n = 3). NPFF-immunopositive cells were located chiefly, but not exclusively, in the superficial white matter and constituted there a subpopulation of white matter interstitial cells (WMIC): Pyramidal-like and multipolar somata predominated in the gyral crowns, whereas bipolar and ovoid somata predominated in the cortex surrounding the sulci. Their sparsely ramified axons were unmyelinated and exhibited NPFF-positive bead-like varicosities. We found significantly fewer NPFF-immunopositive cells in the gray matter of the frontal, cingulate, and superior temporal gyri of both sporadic ALS and late-stage AD patients than in controls, and significantly fewer NPFF-positive cells in the subjacent as well as deep white matter of the frontal gyrus of these patients compared to controls. Notably, the number of NPFF-positive cells was also significantly lower in the hippocampal formation in AD compared to controls. In PiD, NPFF-positive cells were present in significantly lower numbers in the gray and white matter of the cingulate and frontal gyrii in comparison to controls. In schizophrenic patients, lower wNPFF cell counts in the neocortex were significant and global (cingulate, frontal, superior temporal gyrus, medial, and inferior gyri). The precise functions of NPFF-positive cells and their relationship to the superficial corticocortical white matter U-fibers are currently unknown. Here, NPFF immunohistochemistry and expression characterize a previously unrecognized population of cells in the human brain, thereby providing a new entry-point for investigating their physiological and pathophysiological roles.
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Affiliation(s)
- Diana Wiesner
- Department of Neurology, Center for Biomedical Research, Ulm University, 89081, Ulm, Germany
- DZNE, Ulm Site, 89081, Ulm, Germany
| | - Simone Feldengut
- Clinical Neuroanatomy Section, Department of Neurology, Center for Biomedical Research, Ulm University, 89081, Ulm, Germany
| | - Sarah Woelfle
- Institute for Anatomy and Cell Biology, Ulm University, 89081, Ulm, Germany
| | - Tobias M Boeckers
- DZNE, Ulm Site, 89081, Ulm, Germany
- Institute for Anatomy and Cell Biology, Ulm University, 89081, Ulm, Germany
| | | | - Francesco Roselli
- Department of Neurology, Center for Biomedical Research, Ulm University, 89081, Ulm, Germany.
- DZNE, Ulm Site, 89081, Ulm, Germany.
| | - Kelly Del Tredici
- Clinical Neuroanatomy Section, Department of Neurology, Center for Biomedical Research, Ulm University, 89081, Ulm, Germany
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3
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He J, Wang Y. Superficial white matter microstructural imaging method based on time-space fractional-order diffusion. Phys Med Biol 2024; 69:065010. [PMID: 38394673 DOI: 10.1088/1361-6560/ad2ca1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Accepted: 02/23/2024] [Indexed: 02/25/2024]
Abstract
Objective. Microstructure imaging based on diffusion magnetic resonance signal is an advanced imaging technique that enablesin vivomapping of the brain's microstructure. Superficial white matter (SWM) plays an important role in brain development, maturation, and aging, while fewer microstructure imaging methods address the SWM due to its complexity. Therefore, this study aims to develop a diffusion propagation model to investigate the microstructural characteristics of the SWM region.Approach. In this paper, we hypothesize that the effect of cell membrane permeability and the water exchange between soma and dendrites cannot be neglected for typical clinical diffusion times (20 ms
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Affiliation(s)
- Jianglin He
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, People's Republic of China
| | - Yuanjun Wang
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, People's Republic of China
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Zouridakis A, Ayala I, Minogue G, Kawles A, Keszycki R, Macomber A, Bigio E, Geula C, Mesulam MM, Gefen T. Shades of gray in human white matter. J Comp Neurol 2023; 531:2109-2120. [PMID: 37376715 PMCID: PMC10751392 DOI: 10.1002/cne.25512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 05/22/2023] [Accepted: 05/31/2023] [Indexed: 06/29/2023]
Abstract
Anatomists have long expressed interest in neurons of the white matter, which is by definition supposed to be free of neurons. Hypotheses regarding their biochemical signature and physiological function are mainly derived from animal models. Here, we investigated 15 whole-brain human postmortem specimens, including cognitively normal cases and those with pathologic Alzheimer's disease (AD). Quantitative and qualitative methods were used to investigate differences in neuronal size and density, and the relationship between neuronal processes and vasculature. Double staining was used to evaluate colocalization of neurochemicals. Two topographically distinct populations of neurons emerged: one appearing to arise from developmental subplate neurons and the other embedded within deep, subcortical white matter. Both populations appeared to be neurochemically heterogeneous, showing positive reactivity to acetylcholinesterase (AChE) [but not choline acetyltransferase (ChAT)], neuronal nuclei (NeuN), nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d), microtubule-associated protein 2 (MAP-2), somatostatin (SOM), nonphosphorylated neurofilament protein (SMI-32), and calcium-binding proteins calbindin-D28K (CB), calretinin (CRT), and parvalbumin (PV). PV was more richly expressed in superficial as opposed to deep white matter neurons (WMNs); subplate neurons were also significantly larger than their deeper counterparts. NADPH-d, a surrogate for nitric oxide synthase, allowed for the striking morphological visualization of subcortical WMNs. NADPH-d-positive subcortical neurons tended to embrace the outer walls of microvessels, suggesting a functional role in vasodilation. The presence of AChE positivity in these neurons, but not ChAT, suggests that they are cholinoceptive but noncholinergic. WMNs were also significantly smaller in AD compared to control cases. These observations provide a landscape for future systematic investigations.
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Affiliation(s)
- Antonia Zouridakis
- Mesulam Center for Cognitive Neurology and Alzheimer’s Disease, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Ivan Ayala
- Mesulam Center for Cognitive Neurology and Alzheimer’s Disease, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Grace Minogue
- Mesulam Center for Cognitive Neurology and Alzheimer’s Disease, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Allegra Kawles
- Mesulam Center for Cognitive Neurology and Alzheimer’s Disease, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Rachel Keszycki
- Mesulam Center for Cognitive Neurology and Alzheimer’s Disease, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Alyssa Macomber
- Mesulam Center for Cognitive Neurology and Alzheimer’s Disease, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Eileen Bigio
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Changiz Geula
- Mesulam Center for Cognitive Neurology and Alzheimer’s Disease, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
- Department of Cell and Developmental Biology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - M.-Marsel Mesulam
- Mesulam Center for Cognitive Neurology and Alzheimer’s Disease, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Tamar Gefen
- Mesulam Center for Cognitive Neurology and Alzheimer’s Disease, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
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5
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Dienel SJ, Dowling KF, Barile Z, Bazmi HH, Liu A, Vespoli JC, Fish KN, Lewis DA. Diagnostic Specificity and Association With Cognition of Molecular Alterations in Prefrontal Somatostatin Neurons in Schizophrenia. JAMA Psychiatry 2023; 80:1235-1245. [PMID: 37647039 PMCID: PMC10469307 DOI: 10.1001/jamapsychiatry.2023.2972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 06/14/2023] [Indexed: 09/01/2023]
Abstract
Importance Individuals with schizophrenia (SZ) exhibit pronounced deficits in somatostatin (SST) messenger RNA (mRNA) levels in the dorsolateral prefrontal cortex (DLPFC). Molecularly distinct subtypes of SST neurons, located in the superficial and deep zones of the DLPFC, are thought to contribute to different functional processes of this region; understanding the specificity of SST alterations in SZ across these zones could inform the functional consequences of those alterations, including cognitive impairments characteristic of SZ. Objective To quantify mRNA levels of SST and related neuropeptides in the DLPFC in individuals with SZ, bipolar disorder (BPD), or major depressive disorder (MDD) and unaffected comparison individuals. Design, Setting, and Participants This case-control study, conducted from January 20, 2020, to March 30, 2022, used postmortem brain tissue specimens previously obtained from individuals with SZ, MDD, or BPD and unaffected individuals from a community population through 2 medical examiners' offices. Demographic, clinical, and educational information was ascertained through psychological autopsies. Exposures Diagnosis of SZ, BPD, or MDD. Main Outcome and Measures The main outcome was levels of SST and related neuropeptide mRNA in 2 DLPFC zones, examined using laser microdissection and quantitative polymerase chain reaction or fluorescent in situ hybridization (FISH). Findings were compared using educational attainment as a proxy measure of premorbid cognition. Results A total of 200 postmortem brain specimens were studied, including 65 from unaffected comparison individuals (42 [65%] male; mean [SD] age, 49.2 [14.1] years); 54 from individuals with SZ (37 [69%] male; mean [SD] age, 47.5 [13.3] years); 42 from individuals with MDD (24 [57%] male; mean [SD] age, 45.6 [12.1] years); and 39 from individuals with BPD (23 [59%] male; mean (SD) age, 46.2 [12.5] years). Compared with unaffected individuals, levels of SST mRNA were lower in both superficial (Cohen d, 0.68; 95% CI, 0.23-1.13; P = .004) and deep (Cohen d, 0.60; 95% CI, 0.16-1.04; P = .02) DLPFC zones in individuals with SZ; findings were confirmed using FISH. Levels of SST were lower only in the superficial zone in the group with MDD (Cohen d, 0.58; 95% CI, 0.14-1.02; P = .12), but the difference was not significant; SST levels were not lower in either zone in the BPD group. Levels of neuropeptide Y and tachykinin 1 showed similar patterns. Neuropeptide alterations in the superficial, but not deep, zone were associated with lower educational attainment only in the group with SZ (superficial: adjusted odds ratio, 1.71 [95% CI, 1.11-2.69]; P = .02; deep: adjusted odds ratio, 1.08 [95% CI, 0.64-1.84]; P = .77). Conclusions and Relevance The findings revealed diagnosis-specific patterns of molecular alterations in SST neurons in the DLPFC, suggesting that distinct disease processes are reflected in the differential vulnerability of SST neurons in individuals with SZ, MDD, and BPD. In SZ, alterations specifically in the superficial zone may be associated with cognitive dysfunction.
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Affiliation(s)
- Samuel J. Dienel
- Medical Scientist Training Program, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
- Translational Neuroscience Program, Department of Psychiatry, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
- Department of Neuroscience, Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania
- Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, Pennsylvania
| | - Kevin F. Dowling
- Medical Scientist Training Program, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
- Translational Neuroscience Program, Department of Psychiatry, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
- Department of Neuroscience, Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Zackery Barile
- Translational Neuroscience Program, Department of Psychiatry, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - H. Holly Bazmi
- Translational Neuroscience Program, Department of Psychiatry, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Amy Liu
- Translational Neuroscience Program, Department of Psychiatry, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Julia C. Vespoli
- Translational Neuroscience Program, Department of Psychiatry, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Kenneth N. Fish
- Translational Neuroscience Program, Department of Psychiatry, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - David A. Lewis
- Translational Neuroscience Program, Department of Psychiatry, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
- Department of Neuroscience, Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania
- Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, Pennsylvania
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6
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Woelfle S, Deshpande D, Feldengut S, Braak H, Del Tredici K, Roselli F, Deisseroth K, Michaelis J, Boeckers TM, Schön M. CLARITY increases sensitivity and specificity of fluorescence immunostaining in long-term archived human brain tissue. BMC Biol 2023; 21:113. [PMID: 37221592 PMCID: PMC10207789 DOI: 10.1186/s12915-023-01582-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 03/29/2023] [Indexed: 05/25/2023] Open
Abstract
BACKGROUND Post mortem human brain tissue is an essential resource to study cell types, connectivity as well as subcellular structures down to the molecular setup of the central nervous system especially with respect to the plethora of brain diseases. A key method is immunostaining with fluorescent dyes, which allows high-resolution imaging in three dimensions of multiple structures simultaneously. Although there are large collections of formalin-fixed brains, research is often limited because several conditions arise that complicate the use of human brain tissue for high-resolution fluorescence microscopy. RESULTS In this study, we developed a clearing approach for immunofluorescence-based analysis of perfusion- and immersion-fixed post mortem human brain tissue, termed human Clear Lipid-exchanged Acrylamide-hybridized Rigid Imaging / Immunostaining / In situ hybridization-compatible Tissue-hYdrogel (hCLARITY). hCLARITY is optimized for specificity by reducing off-target labeling and yields very sensitive stainings in human brain sections allowing for super-resolution microscopy with unprecedented imaging of pre- and postsynaptic compartments. Moreover, hallmarks of Alzheimer's disease were preserved with hCLARITY, and importantly classical 3,3'-diaminobenzidine (DAB) or Nissl stainings are compatible with this protocol. hCLARITY is very versatile as demonstrated by the use of more than 30 well performing antibodies and allows for de- and subsequent re-staining of the same tissue section, which is important for multi-labeling approaches, e.g., in super-resolution microscopy. CONCLUSIONS Taken together, hCLARITY enables research of the human brain with high sensitivity and down to sub-diffraction resolution. It therefore has enormous potential for the investigation of local morphological changes, e.g., in neurodegenerative diseases.
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Affiliation(s)
- Sarah Woelfle
- Institute for Anatomy and Cell Biology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
- International Graduate School in Molecular Medicine Ulm, IGradU, 89081, Ulm, Germany
| | - Dhruva Deshpande
- Institute of Biophysics, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
- Chemical and Systems Biology Department, Stanford School of Medicine, 269 Campus Drive, Stanford, CA, 94305, USA
| | - Simone Feldengut
- Clinical Neuroanatomy Section/Department of Neurology, Center for Biomedical Research, Ulm University, Helmholtzstraße 8/1, 89081, Ulm, Germany
| | - Heiko Braak
- Clinical Neuroanatomy Section/Department of Neurology, Center for Biomedical Research, Ulm University, Helmholtzstraße 8/1, 89081, Ulm, Germany
| | - Kelly Del Tredici
- Clinical Neuroanatomy Section/Department of Neurology, Center for Biomedical Research, Ulm University, Helmholtzstraße 8/1, 89081, Ulm, Germany
| | - Francesco Roselli
- Department of Neurology, Ulm University, 89081, Ulm, Germany
- Deutsches Zentrum für Neurodegenerative Erkrankungen, DZNE, Ulm Site, 89081, Ulm, Germany
| | - Karl Deisseroth
- Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, 94305, USA
- Howard Hughes Medical Institute, Stanford, CA, 94305, USA
| | - Jens Michaelis
- Institute of Biophysics, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Tobias M Boeckers
- Institute for Anatomy and Cell Biology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
- Deutsches Zentrum für Neurodegenerative Erkrankungen, DZNE, Ulm Site, 89081, Ulm, Germany
| | - Michael Schön
- Institute for Anatomy and Cell Biology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany.
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Schilling KG, Archer D, Rheault F, Lyu I, Huo Y, Cai LY, Bunge SA, Weiner KS, Gore JC, Anderson AW, Landman BA. Superficial white matter across development, young adulthood, and aging: volume, thickness, and relationship with cortical features. Brain Struct Funct 2023; 228:1019-1031. [PMID: 37074446 PMCID: PMC10320929 DOI: 10.1007/s00429-023-02642-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 04/08/2023] [Indexed: 04/20/2023]
Abstract
Superficial white matter (SWM) represents a significantly understudied part of the human brain, despite comprising a large portion of brain volume and making up a majority of cortico-cortical white matter connections. Using multiple, high-quality datasets with large sample sizes (N = 2421, age range 5-100) in combination with methodological advances in tractography, we quantified features of SWM volume and thickness across the brain and across development, young adulthood, and aging. We had four primary aims: (1) characterize SWM thickness across brain regions (2) describe associations between SWM volume and age (3) describe associations between SWM thickness and age, and (4) quantify relationships between SWM thickness and cortical features. Our main findings are that (1) SWM thickness varies across the brain, with patterns robust across individuals and across the population at the region-level and vertex-level; (2) SWM volume shows unique volumetric trajectories with age that are distinct from gray matter and other white matter trajectories; (3) SWM thickness shows nonlinear cross-sectional changes across the lifespan that vary across regions; and (4) SWM thickness is associated with features of cortical thickness and curvature. For the first time, we show that SWM volume follows a similar trend as overall white matter volume, peaking at a similar time in adolescence, leveling off throughout adulthood, and decreasing with age thereafter. Notably, the relative fraction of total brain volume of SWM continuously increases with age, and consequently takes up a larger proportion of total white matter volume, unlike the other tissue types that decrease with respect to total brain volume. This study represents the first characterization of SWM features across the large portion of the lifespan and provides the background for characterizing normal aging and insight into the mechanisms associated with SWM development and decline.
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Affiliation(s)
- Kurt G Schilling
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA.
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA.
| | - Derek Archer
- Vanderbilt Memory and Alzheimer's Center, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Genetics Institute, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Francois Rheault
- Department of Electrical Engineering and Computer Engineering, Vanderbilt University, Nashville, TN, USA
| | - Ilwoo Lyu
- Computer Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea
| | - Yuankai Huo
- Department of Electrical Engineering and Computer Engineering, Vanderbilt University, Nashville, TN, USA
| | - Leon Y Cai
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
| | - Silvia A Bunge
- Department of Psychology, University of California at Berkeley, Berkeley, USA
| | - Kevin S Weiner
- Department of Psychology, University of California at Berkeley, Berkeley, USA
- Helen Wills Neuroscience Institute, University of California at Berkeley, Berkeley, USA
| | - John C Gore
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA
| | - Adam W Anderson
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
| | - Bennett A Landman
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA
- Computer Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea
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8
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Derksen M, Zuidinga B, van der Veer M, Rhemrev V, Jolink L, Reneman L, Nederveen A, Forstmann B, Feenstra M, Willuhn I, Denys D. A comparison of how deep brain stimulation in two targets with anti-compulsive efficacy modulates brain activity using fMRI in awake rats. Psychiatry Res Neuroimaging 2023; 330:111611. [PMID: 36796237 DOI: 10.1016/j.pscychresns.2023.111611] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 12/21/2022] [Accepted: 02/06/2023] [Indexed: 02/11/2023]
Abstract
Deep brain stimulation (DBS) is an established neuromodulatory intervention against otherwise treatment-refractory obsessive-compulsive disorder (OCD). Several DBS targets, all of which are part of brain networks connecting basal ganglia and prefrontal cortex, alleviate OCD symptoms. Stimulation of these targets is thought to unfold its therapeutic effect by modulation of network activity through internal capsule (IC) connections. Research into DBS-induced network changes and the nature of IC-related effects of DBS in OCD is needed to further improve DBS. Here, we studied the effects of DBS at the ventral medial striatum (VMS) and IC on blood-oxygen level dependent (BOLD) responses in awake rats using functional magnetic resonance imaging (fMRI). BOLD-signal intensity was measured in five regions of interest (ROIs): medial and orbital prefrontal cortex, nucleus accumbens (NAc), IC area, and mediodorsal thalamus. In previous rodent studies, stimulation at both target locations resulted in a reduction of OCD-like behavior and activation of prefrontal cortical areas. Therefore, we hypothesized that stimulation at both targets would result in partially overlapping BOLD responses. Both differential and overlapping activity between VMS and IC stimulation was found. Stimulating the caudal part of the IC resulted in activation around the electrode, while stimulating the rostral part of the IC resulted in increased cross-correlations between the IC area, orbitofrontal cortex, and NAc. Stimulation of the dorsal part of the VMS resulted in increased activity in the IC area, suggesting this area is activated during both VMS and IC stimulation. This activation is also indicative of VMS-DBS impacting corticofugal fibers running through the medial caudate into the anterior IC, and both VMS and IC DBS might act on these fibers to induce OCD-reducing effects. These results show that rodent fMRI with simultaneous electrode stimulation is a promising approach to study the neural mechanisms of DBS. Comparing the effects of DBS in different target areas has the potential to improve our understanding of the neuromodulatory changes that take place across various networks and connections in the brain. Performing this research in animal disease models will lead to translational insights in the mechanisms underlying DBS, and can aid improvement and optimization of DBS in patient populations.
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Affiliation(s)
- Maik Derksen
- The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands; Department of Psychiatry, Amsterdam University Medical Centers (location AMC), University of Amsterdam, Amsterdam, The Netherlands
| | - Birte Zuidinga
- The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
| | - Marijke van der Veer
- The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
| | - Valerie Rhemrev
- The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
| | - Linda Jolink
- The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
| | - Liesbeth Reneman
- Department of Radiology and Nuclear Medicine, Amsterdam University Medical Centers (location AMC), University of Amsterdam, Amsterdam, The Netherlands
| | - Aart Nederveen
- Department of Radiology and Nuclear Medicine, Amsterdam University Medical Centers (location AMC), University of Amsterdam, Amsterdam, The Netherlands
| | - Birte Forstmann
- University of Amsterdam, Integrative Model-based Cognitive Neuroscience Research Unit, Amsterdam, The Netherlands
| | - Matthijs Feenstra
- The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands; Department of Psychiatry, Amsterdam University Medical Centers (location AMC), University of Amsterdam, Amsterdam, The Netherlands
| | - Ingo Willuhn
- The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands; Department of Psychiatry, Amsterdam University Medical Centers (location AMC), University of Amsterdam, Amsterdam, The Netherlands
| | - Damiaan Denys
- The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands; Department of Psychiatry, Amsterdam University Medical Centers (location AMC), University of Amsterdam, Amsterdam, The Netherlands
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9
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Pietrasik W, Cribben I, Olsen F, Malykhin N. Diffusion tensor imaging of superficial prefrontal white matter in healthy aging. Brain Res 2023; 1799:148152. [PMID: 36343726 DOI: 10.1016/j.brainres.2022.148152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 09/27/2022] [Accepted: 10/31/2022] [Indexed: 11/06/2022]
Abstract
The prefrontal cortex (PFC) is a heterogenous structure that is highly susceptible to the effects of aging. Few studies have investigated age effects on the superficial white matter (WM) contained within the PFC using in-vivo magnetic resonance imaging (MRI). This study used diffusion tensor imaging (DTI) tractography to examine the effects of age, sex, and intracranial volume (ICV) on superficial WM within specific PFC subregions, and to model the relationships with age using higher order polynomial regression modelling. PFC WM of 140 healthy individuals, aged 18-85, was segmented into medial and lateral orbitofrontal, medial prefrontal, and dorsolateral prefrontal subregions. Differences due to age in microstructural parameters such as fractional anisotropy (FA), axial and radial diffusivities, and macrostructural measures of tract volumes, fiber counts, average fiber lengths, and average number of fibers per voxel were examined. We found that most prefrontal subregions demonstrated age effects, with decreases in FA, tract volume, and fiber counts, and increases in all diffusivity measures. Age relationships were mostly non-linear, with higher order regressions chosen in most cases. Declines in PFC FA began at the onset of adulthood while the greatest changes in diffusivity and volume did not occur until middle age. The effects of age were most prominent in medial tracts while the lateral orbitofrontal tracts were less affected. Significant effects of sex and ICV were also observed in certain parameters. The patterns mostly followed myelination order, with late-myelinating prefrontal subregions experiencing earlier and more pronounced age effects, further supporting the frontal theory of aging.
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Affiliation(s)
- Wojciech Pietrasik
- Department of Biomedical Engineering, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada; Neuroscience and Mental Health Institute, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Ivor Cribben
- Neuroscience and Mental Health Institute, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada; Department of Accounting & Business Analytics, Alberta School of Business, University of Alberta, Edmonton, Alberta, Canada
| | - Fraser Olsen
- Department of Biomedical Engineering, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Nikolai Malykhin
- Neuroscience and Mental Health Institute, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada; Department of Psychiatry, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada.
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10
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Schilling KG, Archer D, Yeh FC, Rheault F, Cai LY, Shafer A, Resnick SM, Hohman T, Jefferson A, Anderson AW, Kang H, Landman BA. Short superficial white matter and aging: a longitudinal multi-site study of 1293 subjects and 2711 sessions. AGING BRAIN 2023; 3:100067. [PMID: 36817413 PMCID: PMC9937516 DOI: 10.1016/j.nbas.2023.100067] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
It is estimated that short association fibers running immediately beneath the cortex may make up as much as 60% of the total white matter volume. However, these have been understudied relative to the long-range association, projection, and commissural fibers of the brain. This is largely because of limitations of diffusion MRI fiber tractography, which is the primary methodology used to non-invasively study the white matter connections. Inspired by recent anatomical considerations and methodological improvements in superficial white matter (SWM) tractography, we aim to characterize changes in these fiber systems in cognitively normal aging, which provide insight into the biological foundation of age-related cognitive changes, and a better understanding of how age-related pathology differs from healthy aging. To do this, we used three large, longitudinal and cross-sectional datasets (N = 1293 subjects, 2711 sessions) to quantify microstructural features and length/volume features of several SWM systems. We find that axial, radial, and mean diffusivities show positive associations with age, while fractional anisotropy has negative associations with age in SWM throughout the entire brain. These associations were most pronounced in the frontal, temporal, and temporoparietal regions. Moreover, measures of SWM volume and length decrease with age in a heterogenous manner across the brain, with different rates of change in inter-gyri and intra-gyri SWM, and at slower rates than well-studied long-range white matter pathways. These features, and their variations with age, provide the background for characterizing normal aging, and, in combination with larger association pathways and gray matter microstructural features, may provide insight into fundamental mechanisms associated with aging and cognition.
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Affiliation(s)
- Kurt G Schilling
- Department of Radiology & Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN
| | - Derek Archer
- Vanderbilt Memory and Alzheimer’s Center, Vanderbilt University Medical Center, Nashville, TN, USA,Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA,Vanderbilt Genetics Institute, Vanderbilt University School of Medicine, Nashville, TN
| | - Fang-Cheng Yeh
- Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA, USA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
| | - Francois Rheault
- Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, TN, United States
| | - Leon Y Cai
- Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, TN, United States
| | - Andrea Shafer
- Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States of America
| | - Susan M. Resnick
- Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States of America
| | - Timothy Hohman
- Vanderbilt Memory and Alzheimer’s Center, Vanderbilt University Medical Center, Nashville, TN, USA,Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA,Vanderbilt Genetics Institute, Vanderbilt University School of Medicine, Nashville, TN
| | - Angela Jefferson
- Vanderbilt Memory and Alzheimer’s Center, Vanderbilt University Medical Center, Nashville, TN, USA,Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA,Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Adam W Anderson
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States
| | - Hakmook Kang
- Department of Biostatistics, Vanderbilt University, Nashville, TN, United States
| | - Bennett A Landman
- Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, TN, United States
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11
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Ali TS, Lv J, Calamante F. Gradual changes in microarchitectural properties of cortex and juxtacortical white matter: Observed by anatomical and diffusion MRI. Magn Reson Med 2022; 88:2485-2503. [PMID: 36045582 DOI: 10.1002/mrm.29413] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 07/18/2022] [Accepted: 07/22/2022] [Indexed: 01/07/2023]
Abstract
PURPOSE Characterization of cerebral cortex is challenged by the complexity and heterogeneity of its cyto- and myeloarchitecture. This study evaluates quantitative MRI metrics, measured across two cortical depths and in subcortical white matter (WM) adjacent to cortex (juxtacortical WM), indicative of myelin content, neurite density, and diffusion microenvironment, for a comprehensive characterization of cortical microarchitecture. METHODS High-quality structural and diffusion MRI data (N = 30) from the Human Connectome Project were processed to compute myelin index, neurite density index, fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity from superficial cortex, deep cortex, and juxtacortical WM. The distributional patterns of these metrics were analyzed individually, correlated to one another, and were compared to established parcellations. RESULTS Our results supported that myeloarchitectonic and the coexisting cytoarchitectonic structures influence the diffusion properties of water molecules residing in cortex. Full cortical thickness showed myelination patterns similar to those previously observed in humans. Higher myelin indices with similar distributional patterns were observed in deep cortex whereas lower myelin indices were observed in superficial cortex. Neurite density index and other diffusion MRI derived parameters provided complementary information to myelination. Reliable and reproducible correlations were identified among the cortical microarchitectural properties and fiber distributional patterns in proximal WM structures. CONCLUSION We demonstrated gradual changes across the cortical sheath by assessing depth-specific cortical micro-architecture using anatomical and diffusion MRI. Mutually independent but coexisting features of cortical layers and juxtacortical WM provided new insights towards structural organizational units and variabilities across cortical regions and through depth.
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Affiliation(s)
- Tonima S Ali
- School of Biomedical Engineering, The University of Sydney, Sydney, Australia.,Brain and Mind Centre, The University of Sydney, Sydney, Australia
| | - Jinglei Lv
- School of Biomedical Engineering, The University of Sydney, Sydney, Australia.,Brain and Mind Centre, The University of Sydney, Sydney, Australia.,Sydney Imaging, The University of Sydney, Sydney, Australia
| | - Fernando Calamante
- School of Biomedical Engineering, The University of Sydney, Sydney, Australia.,Brain and Mind Centre, The University of Sydney, Sydney, Australia.,Sydney Imaging, The University of Sydney, Sydney, Australia
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12
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Hassel B, Niehusmann P, Halvorsen B, Dahlberg D. Pro-inflammatory cytokines in cystic glioblastoma: A quantitative study with a comparison with bacterial brain abscesses. With an MRI investigation of displacement and destruction of the brain tissue surrounding a glioblastoma. Front Oncol 2022; 12:846674. [PMID: 35965529 PMCID: PMC9372434 DOI: 10.3389/fonc.2022.846674] [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: 01/07/2022] [Accepted: 06/27/2022] [Indexed: 11/13/2022] Open
Abstract
Cystic glioblastomas are aggressive primary brain tumors that may both destroy and displace the surrounding brain tissue as they grow. The mechanisms underlying these tumors’ destructive effect could include exposure of brain tissue to tumor-derived cytokines, but quantitative cytokine data are lacking. Here, we provide quantitative data on leukocyte markers and cytokines in the cyst fluid from 21 cystic glioblastomas, which we compare to values in 13 brain abscess pus samples. The concentration of macrophage/microglia markers sCD163 and MCP-1 was higher in glioblastoma cyst fluid than in brain abscess pus; lymphocyte marker sCD25 was similar in cyst fluid and pus, whereas neutrophil marker myeloperoxidase was higher in pus. Median cytokine levels in glioblastoma cyst fluid were high (pg/mL): TNF-α: 32, IL-6: 1064, IL-8: 23585, tissue factor: 28, the chemokine CXCL1: 639. These values were not significantly different from values in pus, pointing to a highly pro-inflammatory glioblastoma environment. In contrast, levels of IFN-γ, IL-1β, IL-2, IL-4, IL-10, IL-12, and IL-13 were higher in pus than in glioblastoma cyst fluid. Based on the quantitative data, we show for the first time that the concentrations of cytokines in glioblastoma cyst fluid correlate with blood leukocyte levels, suggesting an important interaction between glioblastomas and the circulation. Preoperative MRI of the cystic glioblastomas confirmed both destruction and displacement of brain tissue, but none of the cytokine levels correlated with degree of brain tissue displacement or peri-tumoral edema, as could be assessed by MRI. We conclude that cystic glioblastomas are highly pro-inflammatory environments that interact with the circulation and that they both displace and destroy brain tissue. These observations point to the need for neuroprotective strategies in glioblastoma therapy, which could include an anti-inflammatory approach.
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Affiliation(s)
- Bjørnar Hassel
- Department of Neurohabilitation, Oslo University Hospital, Oslo, Norway
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway
- Norwegian Defence Research Establishment (FFI), Kjeller, Norway
- *Correspondence: Bjørnar Hassel,
| | - Pitt Niehusmann
- Department of Pathology, Oslo University Hospital, Oslo, Norway
- Division of Cancer Medicine, Oslo University Hospital, Oslo, Norway
| | - Bente Halvorsen
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway
- Research Institute of Internal Medicine, Oslo University Hospital, Oslo, Norway
| | - Daniel Dahlberg
- Department of Neurosurgery, Oslo University Hospital, Oslo, Norway
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13
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Rockland KS. Looking for the origins of axons. eLife 2022; 11:79839. [PMID: 35647816 PMCID: PMC9159749 DOI: 10.7554/elife.79839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Pyramidal neurons with axons that exit from dendrites rather than the cell body itself are relatively common in non-primates, but rare in monkeys and humans.
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Affiliation(s)
- Kathleen S Rockland
- Department of Anatomy and Neurobiology School of Medicine, Boston University, Boston, United States
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14
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Wahle P, Sobierajski E, Gasterstädt I, Lehmann N, Weber S, Lübke JHR, Engelhardt M, Distler C, Meyer G. Neocortical pyramidal neurons with axons emerging from dendrites are frequent in non-primates, but rare in monkey and human. eLife 2022; 11:76101. [PMID: 35441590 PMCID: PMC9159751 DOI: 10.7554/elife.76101] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 04/19/2022] [Indexed: 12/05/2022] Open
Abstract
The canonical view of neuronal function is that inputs are received by dendrites and somata, become integrated in the somatodendritic compartment and upon reaching a sufficient threshold, generate axonal output with axons emerging from the cell body. The latter is not necessarily the case. Instead, axons may originate from dendrites. The terms ‘axon carrying dendrite’ (AcD) and ‘AcD neurons’ have been coined to describe this feature. In rodent hippocampus, AcD cells are shown to be functionally ‘privileged’, since inputs here can circumvent somatic integration and lead to immediate action potential initiation in the axon. Here, we report on the diversity of axon origins in neocortical pyramidal cells of rodent, ungulate, carnivore, and primate. Detection methods were Thy-1-EGFP labeling in mouse, retrograde biocytin tracing in rat, cat, ferret, and macaque, SMI-32/βIV-spectrin immunofluorescence in pig, cat, and macaque, and Golgi staining in macaque and human. We found that in non-primate mammals, 10–21% of pyramidal cells of layers II–VI had an AcD. In marked contrast, in macaque and human, this proportion was lower and was particularly low for supragranular neurons. A comparison of six cortical areas (being sensory, association, and limbic in nature) in three macaques yielded percentages of AcD cells which varied by a factor of 2 between the areas and between the individuals. Unexpectedly, pyramidal cells in the white matter of postnatal cat and aged human cortex exhibit AcDs to much higher percentages. In addition, interneurons assessed in developing cat and adult human cortex had AcDs at type-specific proportions and for some types at much higher percentages than pyramidal cells. Our findings expand the current knowledge regarding the distribution and proportion of AcD cells in neocortex of non-primate taxa, which strikingly differ from primates where these cells are mainly found in deeper layers and white matter.
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Affiliation(s)
- Petra Wahle
- Developmental Neurobiology, Ruhr University Bochum, Bochum, Germany
| | - Eric Sobierajski
- Developmental Neurobiology, Ruhr University Bochum, Bochum, Germany
| | - Ina Gasterstädt
- Developmental Neurobiology, Ruhr University Bochum, Bochum, Germany
| | - Nadja Lehmann
- Mannheim Center for Translational Neuroscience, Heidelberg University, Mannheim, Germany
| | - Susanna Weber
- Mannheim Center for Translational Neuroscience, Heidelberg University, Mannheim, Germany
| | | | | | - Claudia Distler
- Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Gundela Meyer
- Department of Basic Medical Science, University of La Laguna, Santa Cruz de Tenerife, Spain
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15
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Sóki N, Richter Z, Karádi K, Lőrincz K, Horváth R, Gyimesi C, Szekeres-Paraczky C, Horváth Z, Janszky J, Dóczi T, Seress L, Ábrahám H. Investigation of synapses in the cortical white matter in human temporal lobe epilepsy. Brain Res 2022; 1779:147787. [PMID: 35041843 DOI: 10.1016/j.brainres.2022.147787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 12/27/2021] [Accepted: 01/10/2022] [Indexed: 11/02/2022]
Abstract
Temporal lobe epilepsy (TLE) is one of the most common focal pharmacotherapy-resistant epilepsy in adults. Previous studies have shown significantly higher numbers of neurons in the neocortical white matter in TLE patients than in controls. The aim of this work was to investigate whether white matter neurons are part of the neuronal circuitry. Therefore, we studied the distribution and density of synapses in surgically resected neocortical tissue of pharmacotherapy-resistant TLE patients. Neocortical white matter of temporal lobe from non-epileptic patients were used as controls. Synapses and neurons were visualized with immunohistochemistry using antibodies against synaptophysin and NeuN, respectively. The presence of synaptophysin in presynaptic terminals was verified by electron microscopy. Quantification of immunostaining was performed and the data of the patients' cognitive tests as well as clinical records were compared to the density of neurons and synapses. Synaptophysin density in the white matter of TLE patients was significantly higher than in controls. In TLE, a significant correlation was found between synaptophysin immunodensity and density of white matter neurons. Neuronal as well as synaptophysin density significantly correlated with scores of verbal memory of TLE patients. Neurosurgical outcome of TLE patients did not significantly correlate with histological data, although, higher neuronal and synaptophysin densities were observed in patients with favorable post-surgical outcome. Our results suggest that white matter neurons in TLE patients receive substantial synaptic input and indicate that white matter neurons may be integrated in epileptic neuronal networks responsible for the development or maintenance of seizures.
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Affiliation(s)
- Noémi Sóki
- Department of Medical Biology and Central Electron Microscopic Laboratory, University of Pécs Medical School Szigeti u. 12. Pécs, 7643, Hungary; Neuromorphology and Cellular Neurobiology Research Group, Center for Neuroscience, University of Pécs Ifjúság u. 20. Pécs, 7624, Hungary
| | - Zsófia Richter
- Department of Medical Biology and Central Electron Microscopic Laboratory, University of Pécs Medical School Szigeti u. 12. Pécs, 7643, Hungary
| | - Kázmér Karádi
- Department of Behavioral Sciences, University of Pécs Medical School Szigeti u. 12. Pécs, 7624, Hungary
| | - Katalin Lőrincz
- Department of Neurology, University of Pécs Medical School Rét u. 2. Pécs, 7623, Hungary
| | - Réka Horváth
- Department of Neurology, University of Pécs Medical School Rét u. 2. Pécs, 7623, Hungary
| | - Csilla Gyimesi
- Department of Neurology, University of Pécs Medical School Rét u. 2. Pécs, 7623, Hungary
| | - Cecília Szekeres-Paraczky
- Human Brain Research Laboratory, Institute of Experimental Medicine, ELKH Szigony u. 43. Budapest, 1083, Hungary
| | - Zsolt Horváth
- Department of Neurosurgery, University of Pécs Medical School Rét u. 2. Pécs, 7623, Hungary
| | - József Janszky
- Department of Neurology, University of Pécs Medical School Rét u. 2. Pécs, 7623, Hungary; MTA-PTE Clinical Neuroscience MR Research Group, Center for Neuroscience, University of Pécs Ifjúság u 20. Pécs, 7624, Hungary
| | - Tamás Dóczi
- Department of Neurosurgery, University of Pécs Medical School Rét u. 2. Pécs, 7623, Hungary; MTA-PTE Clinical Neuroscience MR Research Group, Center for Neuroscience, University of Pécs Ifjúság u 20. Pécs, 7624, Hungary
| | - László Seress
- Department of Medical Biology and Central Electron Microscopic Laboratory, University of Pécs Medical School Szigeti u. 12. Pécs, 7643, Hungary; Neuromorphology and Cellular Neurobiology Research Group, Center for Neuroscience, University of Pécs Ifjúság u. 20. Pécs, 7624, Hungary
| | - Hajnalka Ábrahám
- Department of Medical Biology and Central Electron Microscopic Laboratory, University of Pécs Medical School Szigeti u. 12. Pécs, 7643, Hungary; Neuromorphology and Cellular Neurobiology Research Group, Center for Neuroscience, University of Pécs Ifjúság u. 20. Pécs, 7624, Hungary.
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16
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Buyukturkoglu K, Vergara C, Fuentealba V, Tozlu C, Dahan JB, Carroll BE, Kuceyeski A, Riley CS, Sumowski JF, Guevara Oliva C, Sitaram R, Guevara P, Leavitt VM. Machine learning to investigate superficial white matter integrity in early multiple sclerosis. J Neuroimaging 2022; 32:36-47. [PMID: 34532924 PMCID: PMC8752496 DOI: 10.1111/jon.12934] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 09/01/2021] [Accepted: 09/03/2021] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND AND PURPOSE This study aims todetermine the sensitivity of superficial white matter (SWM) integrity as a metric to distinguish early multiple sclerosis (MS) patients from healthy controls (HC). METHODS Fractional anisotropy and mean diffusivity (MD) values from SWM bundles across the cortex and major deep white matter (DWM) tracts were extracted from 29 early MS patients and 31 age- and sex-matched HC. Thickness of 68 cortical regions and resting-state functional-connectivity (RSFC) among them were calculated. The distribution of structural and functional metrics between groups were compared using Wilcoxon rank-sum test. Utilizing a machine learning method (adaptive boosting), 6 models were built based on: 1-SWM, 2-DWM, 3-SWM and DWM, 4-cortical thickness, or 5-RSFC measures. In model 6, all features from previous models were incorporated. The models were trained with nested 5-folds cross-validation. Area under the receiver operating characteristic curve (AUCroc ) values were calculated to evaluate classification performance of each model. Permutation tests were used to compare the AUCroc values. RESULTS Patients had higher MD in SWM bundles including insula, inferior frontal, orbitofrontal, superior and medial temporal, and pre- and post-central cortices (p < .05). No group differences were found for any other MRI metric. The model incorporating SWM and DWM features provided the best classification (AUCroc = 0.75). The SWM model provided higher AUCroc (0.74), compared to DWM (0.63), cortical thickness (0.67), RSFC (0.63), and all-features (0.68) models (p < .001 for all). CONCLUSION Our results reveal a non-random pattern of SWM abnormalities at early stages of MS even before pronounced structural and functional alterations emerge.
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Affiliation(s)
- Korhan Buyukturkoglu
- Columbia University Irving Medical Center, Department of Neurology. New York, NY. USA
| | | | | | - Ceren Tozlu
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - Jacob B. Dahan
- Columbia University Irving Medical Center, Department of Neurology. New York, NY. USA
| | - Britta E. Carroll
- Columbia University Irving Medical Center, Department of Neurology. New York, NY. USA
| | - Amy Kuceyeski
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - Claire S. Riley
- Multiple Sclerosis Center, Department of Neurology, Columbia University Irving Medical Center, New York, NY, USA
| | - James F. Sumowski
- Corinne Goldsmith Dickinson Center for Multiple Sclerosis, Mount Sinai Hospital, New York, NY. USA
| | | | - Ranganatha Sitaram
- Diagnostic Imaging Department, St. Jude Children’s Research Hospital, Memphis TN. USA
| | | | - Victoria M. Leavitt
- Columbia University Irving Medical Center, Department of Neurology. New York, NY. USA
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17
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Veale T, Malone IB, Poole T, Parker TD, Slattery CF, Paterson RW, Foulkes AJM, Thomas DL, Schott JM, Zhang H, Fox NC, Cash DM. Loss and dispersion of superficial white matter in Alzheimer's disease: a diffusion MRI study. Brain Commun 2021; 3:fcab272. [PMID: 34859218 PMCID: PMC8633427 DOI: 10.1093/braincomms/fcab272] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 09/24/2021] [Accepted: 10/18/2021] [Indexed: 11/22/2022] Open
Abstract
Pathological cerebral white matter changes in Alzheimer's disease have been shown using diffusion tensor imaging. Superficial white matter changes are relatively understudied despite their importance in cortico-cortical connections. Measuring superficial white matter degeneration using diffusion tensor imaging is challenging due to its complex organizational structure and proximity to the cortex. To overcome this, we investigated diffusion MRI changes in young-onset Alzheimer's disease using standard diffusion tensor imaging and Neurite Orientation Dispersion and Density Imaging to distinguish between disease-related changes that are degenerative (e.g. loss of myelinated fibres) and organizational (e.g. increased fibre dispersion). Twenty-nine young-onset Alzheimer's disease patients and 22 healthy controls had both single-shell and multi-shell diffusion MRI. We calculated fractional anisotropy, mean diffusivity, neurite density index, orientation dispersion index and tissue fraction (1-free water fraction). Diffusion metrics were sampled in 15 a priori regions of interest at four points along the cortical profile: cortical grey matter, grey/white boundary, superficial white matter (1 mm below grey/white boundary) and superficial/deeper white matter (2 mm below grey/white boundary). To estimate cross-sectional group differences, we used average marginal effects from linear mixed effect models of participants' diffusion metrics along the cortical profile. The superficial white matter of young-onset Alzheimer's disease individuals had lower neurite density index compared to controls in five regions (superior and inferior parietal, precuneus, entorhinal and parahippocampus) (all P < 0.05), and higher orientation dispersion index in three regions (fusiform, entorhinal and parahippocampus) (all P < 0.05). Young-onset Alzheimer's disease individuals had lower fractional anisotropy in the entorhinal and parahippocampus regions (both P < 0.05) and higher fractional anisotropy within the postcentral region (P < 0.05). Mean diffusivity was higher in the young-onset Alzheimer's disease group in the parahippocampal region (P < 0.05) and lower in the postcentral, precentral and superior temporal regions (all P < 0.05). In the overlying grey matter, disease-related changes were largely consistent with superficial white matter findings when using neurite density index and fractional anisotropy, but appeared at odds with orientation dispersion and mean diffusivity. Tissue fraction was significantly lower across all grey matter regions in young-onset Alzheimer's disease individuals (all P < 0.001) but group differences reduced in magnitude and coverage when moving towards the superficial white matter. These results show that microstructural changes occur within superficial white matter and along the cortical profile in individuals with young-onset Alzheimer's disease. Lower neurite density and higher orientation dispersion suggests underlying fibres undergo neurodegeneration and organizational changes, two effects previously indiscernible using standard diffusion tensor metrics in superficial white matter.
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Affiliation(s)
- Thomas Veale
- The Dementia Research Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
- UK Dementia Research Institute at UCL, University College London, London, UK
| | - Ian B Malone
- The Dementia Research Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
| | - Teresa Poole
- Department of Medical Statistics, London School of Hygiene & Tropical Medicine, London, UK
| | - Thomas D Parker
- The Dementia Research Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
- Department of Brain Sciences, Imperial College London, London, UK
| | - Catherine F Slattery
- The Dementia Research Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
| | - Ross W Paterson
- The Dementia Research Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
- UK Dementia Research Institute at UCL, University College London, London, UK
| | - Alexander J M Foulkes
- The Dementia Research Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
| | - David L Thomas
- The Dementia Research Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, London, UK
- Department of Brain Repair and Rehabilitation, UCL Queen Square Institute of Neurology, London, UK
| | - Jonathan M Schott
- The Dementia Research Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
| | - Hui Zhang
- Department of Computer Science and Centre for Medical Image Computing, UCL, London, UK
| | - Nick C Fox
- The Dementia Research Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
- UK Dementia Research Institute at UCL, University College London, London, UK
| | - David M Cash
- The Dementia Research Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
- UK Dementia Research Institute at UCL, University College London, London, UK
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18
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Swiegers J, Bhagwandin A, Maseko BC, Sherwood CC, Hård T, Bertelsen MF, Spocter MA, Molnár Z, Manger PR. The distribution, number, and certain neurochemical identities of infracortical white matter neurons in the brains of a southern lesser galago, a black-capped squirrel monkey, and a crested macaque. J Comp Neurol 2021; 529:3676-3708. [PMID: 34259349 DOI: 10.1002/cne.25216] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 07/01/2021] [Accepted: 07/10/2021] [Indexed: 12/20/2022]
Abstract
In the current study, we examined the number, distribution, and aspects of the neurochemical identities of infracortical white matter neurons, also termed white matter interstitial cells (WMICs), in the brains of a southern lesser galago (Galago moholi), a black-capped squirrel monkey (Saimiri boliviensis boliviensis), and a crested macaque (Macaca nigra). Staining for neuronal nuclear marker (NeuN) revealed WMICs throughout the infracortical white matter, these cells being most dense close to inner cortical border, decreasing in density with depth in the white matter. Stereological analysis of NeuN-immunopositive cells revealed estimates of approximately 1.1, 10.8, and 37.7 million WMICs within the infracortical white matter of the galago, squirrel monkey, and crested macaque, respectively. The total numbers of WMICs form a distinct negative allometric relationship with brain mass and white matter volume when examined in a larger sample of primates where similar measures have been obtained. In all three primates studied, the highest densities of WMICs were in the white matter of the frontal lobe, with the occipital lobe having the lowest. Immunostaining revealed significant subpopulations of WMICs containing neuronal nitric oxide synthase (nNOS) and calretinin, with very few WMICs containing parvalbumin, and none containing calbindin. The nNOS and calretinin immunopositive WMICs represent approximately 21% of the total WMIC population; however, variances in the proportions of these neurochemical phenotypes were noted. Our results indicate that both the squirrel monkey and crested macaque might be informative animal models for the study of WMICs in neurodegenerative and psychiatric disorders in humans.
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Affiliation(s)
- Jordan Swiegers
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Adhil Bhagwandin
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Busisiwe C Maseko
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Chet C Sherwood
- Department of Anthropology, Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, District of Columbia, USA
| | | | - Mads F Bertelsen
- Centre for Zoo and Wild Animal Health, Copenhagen Zoo, Frederiksberg, Denmark
| | - Muhammad A Spocter
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,Department of Anatomy, Des Moines University, Des Moines, Iowa, USA
| | - Zoltán Molnár
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Paul R Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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19
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Swiegers J, Bhagwandin A, Williams VM, Maseko BC, Sherwood CC, Hård T, Bertelsen MF, Rockland KS, Molnár Z, Manger PR. The distribution, number, and certain neurochemical identities of infracortical white matter neurons in a chimpanzee (Pan troglodytes) brain. J Comp Neurol 2021; 529:3429-3452. [PMID: 34180538 DOI: 10.1002/cne.25202] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 06/21/2021] [Accepted: 06/24/2021] [Indexed: 01/06/2023]
Abstract
We examined the number, distribution, and immunoreactivity of the infracortical white matter neuronal population, also termed white matter interstitial cells (WMICs), throughout the telencephalic white matter of an adult female chimpanzee. Staining for neuronal nuclear marker (NeuN) revealed WMICs throughout the infracortical white matter, these cells being most numerous and dense close to the inner border of cortical layer VI, decreasing significantly in density with depth in the white matter. Stereological analysis of NeuN-immunopositive cells revealed an estimate of approximately 137.2 million WMICs within the infracortical white matter of the chimpanzee brain studied. Immunostaining revealed subpopulations of WMICs containing neuronal nitric oxide synthase (nNOS, approximately 14.4 million in number), calretinin (CR, approximately 16.7 million), very few WMICs containing parvalbumin (PV), and no calbindin-immunopositive neurons. The nNOS, CR, and PV immunopositive WMICs, possibly all inhibitory neurons, represent approximately 22.6% of the total WMIC population. As the white matter is affected in many cognitive conditions, such as schizophrenia, autism, epilepsy, and also in neurodegenerative diseases, understanding these neurons across species is important for the translation of findings of neural dysfunction in animal models to humans. Furthermore, studies of WMICs in species such as apes provide a crucial phylogenetic context for understanding the evolution of these cell types in the human brain.
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Affiliation(s)
- Jordan Swiegers
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa
| | - Adhil Bhagwandin
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa
| | - Victoria M Williams
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa
| | - Busisiwe C Maseko
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa
| | - Chet C Sherwood
- Department of Anthropology and Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, District of Columbia, USA
| | | | - Mads F Bertelsen
- Centre for Zoo and Wild Animal Health, Copenhagen Zoo, Frederiksberg, Denmark
| | - Kathleen S Rockland
- Department of Anatomy and Neurobiology, Boston University, School of Medicine, Boston, Massachusetts, USA
| | - Zoltán Molnár
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Paul R Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa
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20
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Influence of Cerebral Vasodilation on Blood Reelin Levels in Growth Restricted Fetuses. Diagnostics (Basel) 2021; 11:diagnostics11061036. [PMID: 34199942 PMCID: PMC8228107 DOI: 10.3390/diagnostics11061036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/26/2021] [Accepted: 06/02/2021] [Indexed: 11/23/2022] Open
Abstract
Fetal growth restriction (FGR) is one of the most important obstetric pathologies. It is frequently caused by placental insufficiency. Previous studies have shown a relationship between FGR and impaired new-born neurodevelopment, although the molecular mechanisms involved in this association have not yet been completely clarified. Reelin is an extracellular matrix glycoprotein involved in development of neocortex, hippocampus, cerebellum and spinal cord. Reelin has been demonstrated to play a key role in regulating perinatal neurodevelopment and to contribute to the emergence and development of various psychiatric pathologies, and its levels are highly influenced by pathological conditions of hypoxia. The purpose of this article is to study whether reelin levels in new-borns vary as a function of severity of fetal growth restriction by gestational age and sex. We sub-grouped fetuses in: normal weight group (Group 1, n = 17), FGR group with normal umbilical artery Doppler and cerebral redistribution at middle cerebral artery Doppler (Group 2, n = 9), and FGR with abnormal umbilical artery Doppler (Group 3, n = 8). Our results show a significant association of elevated Reelin levels in FGR fetuses with cerebral blood redistribution compared to the normal weight group and the FGR with abnormal umbilical artery group. Future research should focus on further expanding the knowledge of the relationship of reelin and its regulated products with neurodevelopment impairment in new-borns with FGR and should include larger and more homogeneous samples and the combined use of different in vivo techniques in neonates with impaired growth during their different adaptive phases.
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21
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Supernumerary neurons within the cerebral cortical subplate in autism spectrum disorders. Brain Res 2021; 1760:147350. [PMID: 33607045 DOI: 10.1016/j.brainres.2021.147350] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 02/01/2021] [Accepted: 02/02/2021] [Indexed: 12/11/2022]
Abstract
Autism spectrum disorders (ASDs) involve alterations to cortical connectivity that manifest as reduced coordinated activity between cortical regions. The neurons of the cortical subplate are a major contributor to establishing thalamocortical, corticothalamic and corticocortical long-range connections and only a subset of this cell population survives into adulthood. Previous reports of an indistinct gray-white matter boundary in subjects with ASD suggest that the adjacent subplate may also show organizational abnormalities. Frozen human postmortem tissue samples from the parietal lobe (BA7) were used to evaluate white-matter neuron densities adjacent to layer VI with an antibody to NeuN. In addition, fixed postmortem tissue samples from frontal (BA9), parietal (BA7) and temporal lobe (BA21) locations, were stained with a Golgi-Kopsch procedure, and used to examine the morphology of these neuronal profiles. Relative to control cases, ASD subjects showed a large average density increase of NeuN-positive profiles of 44.7 percent. The morphologies of these neurons were consistent with subplate cells of the fusiform, polymorphic and pyramidal cell types. Lower ratios of fusiform to other cell types are found early in development and although adult ASD subjects showed consistently lower ratios, these differences were not significant. The increased number of retained subplate profiles, along with cell type ratios redolent of earlier developmental stages, suggests either an abnormal initial population or a partial failure of the apoptosis seen in neurotypical development. These results indicate abnormalities within a neuron population that plays multiple roles in the developing and mature cerebral cortex, including the establishment of long-range cortical connections.
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22
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Del Campo N, Phillips O, Ory‐Magne F, Brefel‐Courbon C, Galitzky M, Thalamas C, Narr KL, Joshi S, Singh MK, Péran P, Pavy‐LeTraon A, Rascol O. Broad white matter impairment in multiple system atrophy. Hum Brain Mapp 2021; 42:357-366. [PMID: 33064319 PMCID: PMC7776008 DOI: 10.1002/hbm.25227] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 07/09/2020] [Accepted: 08/10/2020] [Indexed: 11/11/2022] Open
Abstract
Multiple system atrophy (MSA) is a rare neurodegenerative disorder characterized by the widespread aberrant accumulation of α-synuclein (α-syn). MSA differs from other synucleinopathies such as Parkinson's disease (PD) in that α-syn accumulates primarily in oligodendrocytes, the only source of white matter myelination in the brain. Previous MSA imaging studies have uncovered focal differences in white matter. Here, we sought to build on this work by taking a global perspective on whole brain white matter. In order to do this, in vivo structural imaging and diffusion magnetic resonance imaging were acquired on 26 MSA patients, 26 healthy controls, and 23 PD patients. A refined whole brain approach encompassing the major fiber tracts and the superficial white matter located at the boundary of the cortical mantle was applied. The primary observation was that MSA but not PD patients had whole brain deep and superficial white matter diffusivity abnormalities (p < .001). In addition, in MSA patients, these abnormalities were associated with motor (Unified MSA Rating Scale, Part II) and cognitive functions (Mini-Mental State Examination). The pervasive whole brain abnormalities we observe suggest that there is widespread white matter damage in MSA patients which mirrors the widespread aggregation of α-syn in oligodendrocytes. Importantly, whole brain white matter abnormalities were associated with clinical symptoms, suggesting that white matter impairment may be more central to MSA than previously thought.
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Affiliation(s)
- Natalia Del Campo
- CHU de Toulouse, Université de Toulouse‐Toulouse 3, INSERM, UMR1214 Toulouse NeuroImaging Centre “TONIC,” Center of Excellence in Neurodegeneration (CoEN), NeuroToul, Centre National de Reference AMS, Centre Expert Parkinson de Toulouse, Centre d'Investigation Clinique CIC1436, Services de Neurologie et de Pharmacologie Clinique, UMR 1048 Institute for Cardiovascular DiseasesToulouseFrance
| | - Owen Phillips
- CHU de Toulouse, Université de Toulouse‐Toulouse 3, INSERM, UMR1214 Toulouse NeuroImaging Centre “TONIC,” Center of Excellence in Neurodegeneration (CoEN), NeuroToul, Centre National de Reference AMS, Centre Expert Parkinson de Toulouse, Centre d'Investigation Clinique CIC1436, Services de Neurologie et de Pharmacologie Clinique, UMR 1048 Institute for Cardiovascular DiseasesToulouseFrance
- Division of Child and Adolescent Psychiatry, Department of PsychiatryStanford University School of MedicineStanfordCaliforniaUSA
- BrainKeySan FranciscoCaliforniaUSA
| | - Françoise Ory‐Magne
- CHU de Toulouse, Université de Toulouse‐Toulouse 3, INSERM, UMR1214 Toulouse NeuroImaging Centre “TONIC,” Center of Excellence in Neurodegeneration (CoEN), NeuroToul, Centre National de Reference AMS, Centre Expert Parkinson de Toulouse, Centre d'Investigation Clinique CIC1436, Services de Neurologie et de Pharmacologie Clinique, UMR 1048 Institute for Cardiovascular DiseasesToulouseFrance
| | - Christine Brefel‐Courbon
- CHU de Toulouse, Université de Toulouse‐Toulouse 3, INSERM, UMR1214 Toulouse NeuroImaging Centre “TONIC,” Center of Excellence in Neurodegeneration (CoEN), NeuroToul, Centre National de Reference AMS, Centre Expert Parkinson de Toulouse, Centre d'Investigation Clinique CIC1436, Services de Neurologie et de Pharmacologie Clinique, UMR 1048 Institute for Cardiovascular DiseasesToulouseFrance
| | - Monique Galitzky
- CHU de Toulouse, Université de Toulouse‐Toulouse 3, INSERM, UMR1214 Toulouse NeuroImaging Centre “TONIC,” Center of Excellence in Neurodegeneration (CoEN), NeuroToul, Centre National de Reference AMS, Centre Expert Parkinson de Toulouse, Centre d'Investigation Clinique CIC1436, Services de Neurologie et de Pharmacologie Clinique, UMR 1048 Institute for Cardiovascular DiseasesToulouseFrance
| | - Claire Thalamas
- CHU de Toulouse, Université de Toulouse‐Toulouse 3, INSERM, UMR1214 Toulouse NeuroImaging Centre “TONIC,” Center of Excellence in Neurodegeneration (CoEN), NeuroToul, Centre National de Reference AMS, Centre Expert Parkinson de Toulouse, Centre d'Investigation Clinique CIC1436, Services de Neurologie et de Pharmacologie Clinique, UMR 1048 Institute for Cardiovascular DiseasesToulouseFrance
| | - Katherine L. Narr
- Department of NeurologyAhmanson Lovelace Brain Mapping Center, David Geffen School of Medicine at UCLALos AngelesCaliforniaUSA
| | - Shantanu Joshi
- Department of NeurologyAhmanson Lovelace Brain Mapping Center, David Geffen School of Medicine at UCLALos AngelesCaliforniaUSA
| | - Manpreet K. Singh
- Division of Child and Adolescent Psychiatry, Department of PsychiatryStanford University School of MedicineStanfordCaliforniaUSA
| | - Patrice Péran
- CHU de Toulouse, Université de Toulouse‐Toulouse 3, INSERM, UMR1214 Toulouse NeuroImaging Centre “TONIC,” Center of Excellence in Neurodegeneration (CoEN), NeuroToul, Centre National de Reference AMS, Centre Expert Parkinson de Toulouse, Centre d'Investigation Clinique CIC1436, Services de Neurologie et de Pharmacologie Clinique, UMR 1048 Institute for Cardiovascular DiseasesToulouseFrance
| | - Anne Pavy‐LeTraon
- CHU de Toulouse, Université de Toulouse‐Toulouse 3, INSERM, UMR1214 Toulouse NeuroImaging Centre “TONIC,” Center of Excellence in Neurodegeneration (CoEN), NeuroToul, Centre National de Reference AMS, Centre Expert Parkinson de Toulouse, Centre d'Investigation Clinique CIC1436, Services de Neurologie et de Pharmacologie Clinique, UMR 1048 Institute for Cardiovascular DiseasesToulouseFrance
| | - Olivier Rascol
- CHU de Toulouse, Université de Toulouse‐Toulouse 3, INSERM, UMR1214 Toulouse NeuroImaging Centre “TONIC,” Center of Excellence in Neurodegeneration (CoEN), NeuroToul, Centre National de Reference AMS, Centre Expert Parkinson de Toulouse, Centre d'Investigation Clinique CIC1436, Services de Neurologie et de Pharmacologie Clinique, UMR 1048 Institute for Cardiovascular DiseasesToulouseFrance
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23
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White Matter Interstitial Neurons in the Adult Human Brain: 3% of Cortical Neurons in Quest for Recognition. Cells 2021; 10:cells10010190. [PMID: 33477896 PMCID: PMC7833373 DOI: 10.3390/cells10010190] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 01/11/2021] [Accepted: 01/13/2021] [Indexed: 02/03/2023] Open
Abstract
White matter interstitial neurons (WMIN) are a subset of cortical neurons located in the subcortical white matter. Although they were fist described over 150 years ago, they are still largely unexplored and often considered a small, functionally insignificant neuronal population. WMIN are adult remnants of neurons located in the transient fetal subplate zone (SP). Following development, some of the SP neurons undergo apoptosis, and the remaining neurons are incorporated in the adult white matter as WMIN. In the adult human brain, WMIN are quite a large population of neurons comprising at least 3% of all cortical neurons (between 600 and 1100 million neurons). They include many of the morphological neuronal types that can be found in the overlying cerebral cortex. Furthermore, the phenotypic and molecular diversity of WMIN is similar to that of the overlying cortical neurons, expressing many glutamatergic and GABAergic biomarkers. WMIN are often considered a functionally unimportant subset of neurons. However, upon closer inspection of the scientific literature, it has been shown that WMIN are integrated in the cortical circuitry and that they exhibit diverse electrophysiological properties, send and receive axons from the cortex, and have active synaptic contacts. Based on these data, we are able to enumerate some of the potential WMIN roles, such as the control of the cerebral blood flow, sleep regulation, and the control of information flow through the cerebral cortex. Also, there is a number of studies indicating the involvement of WMIN in the pathophysiology of many brain disorders such as epilepsy, schizophrenia, Alzheimer’s disease, etc. All of these data indicate that WMIN are a large population with an important function in the adult brain. Further investigation of WMIN could provide us with novel data crucial for an improved elucidation of the pathophysiology of many brain disorders. In this review, we provide an overview of the current WMIN literature, with an emphasis on studies conducted on the human brain.
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24
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Bhagwandin A, Debipersadh U, Kaswera-Kyamakya C, Gilissen E, Rockland KS, Molnár Z, Manger PR. Distribution, number, and certain neurochemical identities of infracortical white matter neurons in the brains of three megachiropteran bat species. J Comp Neurol 2020; 528:3023-3038. [PMID: 32103488 DOI: 10.1002/cne.24894] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 02/06/2020] [Accepted: 02/24/2020] [Indexed: 12/13/2022]
Abstract
A large population of infracortical white matter neurons, or white matter interstitial cells (WMICs), are found within the subcortical white matter of the mammalian telencephalon. We examined WMICs in three species of megachiropterans, Megaloglossus woermanni, Casinycteris argynnis, and Rousettus aegyptiacus, using immunohistochemical and stereological techniques. Immunostaining for neuronal nuclear marker (NeuN) revealed substantial numbers of WMICs in each species-M. woermanni 124,496 WMICs, C. argynnis 138,458 WMICs, and the larger brained R. aegyptiacus having an estimated WMIC population of 360,503. To examine the range of inhibitory neurochemical types we used antibodies against parvalbumin, calbindin, calretinin, and neural nitric oxide synthase (nNOS). The calbindin and nNOS immunostained neurons were the most commonly observed, while those immunoreactive for calretinin and parvalbumin were sparse. The proportion of WMICs exhibiting inhibitory neurochemical profiles was ~26%, similar to that observed in previously studied primates. While for the most part the WMIC population in the megachiropterans studied was similar to that observed in other mammals, the one feature that differed was the high proportion of WMICs immunoreactive to calbindin, whereas in primates (macaque monkey, lar gibbon and human) the highest proportion of inhibitory WMICs contain calretinin. Interestingly, there appears to be an allometric scaling of WMIC numbers with brain mass. Further quantitative comparative work across more mammalian species will reveal the developmental and evolutionary trends associated with this infrequently studied neuronal population.
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Affiliation(s)
- Adhil Bhagwandin
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Parktown, Johannesburg, South Africa
- Division of Clinical Anatomy and Biological Anthropology, Department of Human Biology, University of Cape Town, Cape Town, South Africa
| | - Ulsana Debipersadh
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Parktown, Johannesburg, South Africa
| | | | - Emmanuel Gilissen
- Department of African Zoology, Royal Museum for Central Africa, Tervuren, Belgium
- Laboratory of Histology and Neuropathology, Université Libre de Bruxelles, Brussels, Belgium
- Department of Anthropology, University of Arkansas, Fayetteville, Arkansas, USA
| | - Kathleen S Rockland
- Department of Anatomy and Neurobiology, Boston University, School of Medicine, Boston, Massachusetts, USA
| | - Zoltán Molnár
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Paul R Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Parktown, Johannesburg, South Africa
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25
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Bruguier H, Suarez R, Manger P, Hoerder-Suabedissen A, Shelton AM, Oliver DK, Packer AM, Ferran JL, García-Moreno F, Puelles L, Molnár Z. In search of common developmental and evolutionary origin of the claustrum and subplate. J Comp Neurol 2020; 528:2956-2977. [PMID: 32266722 DOI: 10.1002/cne.24922] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 04/01/2020] [Accepted: 04/02/2020] [Indexed: 02/06/2023]
Abstract
The human claustrum, a major hub of widespread neocortical connections, is a thin, bilateral sheet of gray matter located between the insular cortex and the striatum. The subplate is a largely transient cortical structure that contains some of the earliest generated neurons of the cerebral cortex and has important developmental functions to establish intra- and extracortical connections. In human and macaque some subplate cells undergo regulated cell death, but some remain as interstitial white matter cells. In mouse and rat brains a compact layer is formed, Layer 6b, and it remains underneath the cortex, adjacent to the white matter. Whether Layer 6b in rodents is homologous to primate subplate or interstitial white matter cells is still debated. Gene expression patterns, such as those of Nurr1/Nr4a2, have suggested that the rodent subplate and the persistent subplate cells in Layer 6b and the claustrum might have similar origins. Moreover, the birthdates of the claustrum and Layer 6b are similarly precocious in mice. These observations prompted our speculations on the common developmental and evolutionary origin of the claustrum and the subplate. Here we systematically compare the currently available data on cytoarchitecture, evolutionary origin, gene expression, cell types, birthdates, neurogenesis, lineage and migration, circuit connectivity, and cell death of the neurons that contribute to the claustrum and subplate. Based on their similarities and differences we propose a partially common early evolutionary origin of the cells that become claustrum and subplate, a likely scenario that is shared in these cell populations across all amniotes.
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Affiliation(s)
- Hannah Bruguier
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Rodrigo Suarez
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland, Australia
| | - Paul Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | | | - Andrew M Shelton
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - David K Oliver
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Adam M Packer
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - José L Ferran
- Department of Human Anatomy, Medical School, University of Murcia and Murcia Arrixaca Institute for Biomedical Research, Murcia, Spain
| | - Fernando García-Moreno
- Achucarro Basque Center for Neuroscience, Zamudio, Spain.,IKERBASQUE Foundation, Bilbao, Spain
| | - Luis Puelles
- Department of Human Anatomy, Medical School, University of Murcia and Murcia Arrixaca Institute for Biomedical Research, Murcia, Spain
| | - Zoltán Molnár
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
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26
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Kirilina E, Helbling S, Morawski M, Pine K, Reimann K, Jankuhn S, Dinse J, Deistung A, Reichenbach JR, Trampel R, Geyer S, Müller L, Jakubowski N, Arendt T, Bazin PL, Weiskopf N. Superficial white matter imaging: Contrast mechanisms and whole-brain in vivo mapping. SCIENCE ADVANCES 2020; 6:6/41/eaaz9281. [PMID: 33028535 PMCID: PMC7541072 DOI: 10.1126/sciadv.aaz9281] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 08/26/2020] [Indexed: 05/11/2023]
Abstract
Superficial white matter (SWM) contains the most cortico-cortical white matter connections in the human brain encompassing the short U-shaped association fibers. Despite its importance for brain connectivity, very little is known about SWM in humans, mainly due to the lack of noninvasive imaging methods. Here, we lay the groundwork for systematic in vivo SWM mapping using ultrahigh resolution 7 T magnetic resonance imaging. Using biophysical modeling informed by quantitative ion beam microscopy on postmortem brain tissue, we demonstrate that MR contrast in SWM is driven by iron and can be linked to the microscopic iron distribution. Higher SWM iron concentrations were observed in U-fiber-rich frontal, temporal, and parietal areas, potentially reflecting high fiber density or late myelination in these areas. Our SWM mapping approach provides the foundation for systematic studies of interindividual differences, plasticity, and pathologies of this crucial structure for cortico-cortical connectivity in humans.
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Affiliation(s)
- Evgeniya Kirilina
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103 Leipzig, Germany.
- Center for Cognitive Neuroscience Berlin, Free University Berlin, Habelschwerdter Allee 45, 14195 Berlin, Germany
| | - Saskia Helbling
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103 Leipzig, Germany
| | - Markus Morawski
- Paul Flechsig Institute of Brain Research, Leipzig University, Liebigstr. 19, 04103 Leipzig, Germany
| | - Kerrin Pine
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103 Leipzig, Germany
| | - Katja Reimann
- Paul Flechsig Institute of Brain Research, Leipzig University, Liebigstr. 19, 04103 Leipzig, Germany
| | - Steffen Jankuhn
- Felix Bloch Institute for Solid State Physics, Faculty of Physics and Earth Sciences, Leipzig University, Linnéstraße 5, 04103 Leipzig, Germany
| | - Juliane Dinse
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103 Leipzig, Germany
| | - Andreas Deistung
- Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital-Friedrich Schiller University Jena, Philosophenweg 3, 07743 Jena, Germany
- Department of Radiology University Hospital Halle (Saale), Ernst-Grube-Str. 40, 06120 Halle, Germany
| | - Jürgen R Reichenbach
- Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital-Friedrich Schiller University Jena, Philosophenweg 3, 07743 Jena, Germany
| | - Robert Trampel
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103 Leipzig, Germany
| | - Stefan Geyer
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103 Leipzig, Germany
| | - Larissa Müller
- Federal Institute for Materials Research and Testing, Richard-Willstätter-Straße 11, 12489 Berlin, Germany
| | - Norbert Jakubowski
- Federal Institute for Materials Research and Testing, Richard-Willstätter-Straße 11, 12489 Berlin, Germany
- Spetec GmbH, Berghamer Str. 2, 85435 Erding, Germany
| | - Thomas Arendt
- Paul Flechsig Institute of Brain Research, Leipzig University, Liebigstr. 19, 04103 Leipzig, Germany
| | - Pierre-Louis Bazin
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103 Leipzig, Germany
- Integrative Model-Based Cognitive Neuroscience Research Unit, University of Amsterdam, 1001 NK Amsterdam, The Netherlands
| | - Nikolaus Weiskopf
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103 Leipzig, Germany
- Felix Bloch Institute for Solid State Physics, Faculty of Physics and Earth Sciences, Leipzig University, Linnéstraße 5, 04103 Leipzig, Germany
- Wellcome Centre for Human Neuroimaging, Wellcome Centre for Human Neuroimaging, Institute of Neurology, University College London, 12 Queen Square, London WC1N 3AR, UK
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Kostović I. The enigmatic fetal subplate compartment forms an early tangential cortical nexus and provides the framework for construction of cortical connectivity. Prog Neurobiol 2020; 194:101883. [PMID: 32659318 DOI: 10.1016/j.pneurobio.2020.101883] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 06/05/2020] [Accepted: 07/06/2020] [Indexed: 12/19/2022]
Abstract
The most prominent transient compartment of the primate fetal cortex is the deep, cell-sparse, synapse-containing subplate compartment (SPC). The developmental role of the SPC and its extraordinary size in humans remain enigmatic. This paper evaluates evidence on the development and connectivity of the SPC and discusses its role in the pathogenesis of neurodevelopmental disorders. A synthesis of data shows that the subplate becomes a prominent compartment by its expansion from the deep cortical plate (CP), appearing well-delineated on MR scans and forming a tangential nexus across the hemisphere, consisting of an extracellular matrix, randomly distributed postmigratory neurons, multiple branches of thalamic and long corticocortical axons. The SPC generates early spontaneous non-synaptic and synaptic activity and mediates cortical response upon thalamic stimulation. The subplate nexus provides large-scale interareal connectivity possibly underlying fMR resting-state activity, before corticocortical pathways are established. In late fetal phase, when synapses appear within the CP, transient the SPC coexists with permanent circuitry. The histogenetic role of the SPC is to provide interactive milieu and capacity for guidance, sorting, "waiting" and target selection of thalamocortical and corticocortical pathways. The new evolutionary role of the SPC and its remnant white matter neurons is linked to the increasing number of associative pathways in the human neocortex. These roles attributed to the SPC are regulated using a spatiotemporal gene expression during critical periods, when pathogenic factors may disturb vulnerable circuitry of the SPC, causing neurodevelopmental cognitive circuitry disorders.
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Affiliation(s)
- Ivica Kostović
- Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Scientific Centre of Excellence for Basic, Clinical and Translational Neuroscience, Salata 12, 10000 Zagreb, Croatia.
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28
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Kubo KI. Increased densities of white matter neurons as a cross-disease feature of neuropsychiatric disorders. Psychiatry Clin Neurosci 2020; 74:166-175. [PMID: 31788900 DOI: 10.1111/pcn.12962] [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: 09/30/2019] [Revised: 11/22/2019] [Accepted: 11/26/2019] [Indexed: 12/12/2022]
Abstract
While neurons of the human cerebral cortex are mainly distributed in the gray matter, the white matter (WM) also contains some excitatory and inhibitory neurons, so-called WM neurons. Studies on the cytoarchitectural alterations in the brains of patients with neuropsychiatric disorders have repeatedly reported increased densities of the WM neurons in a proportion of patients with schizophrenia and autism spectrum disorder. Although some studies have demonstrated increased densities of superficial WM neurons, others have demonstrated increased densities of deep WM neurons and increased WM neuron densities can be considered as one of the cross-disease features of neuropsychiatric disorders. Nevertheless, what actually causes the increase in the densities of the WM neurons still remains under debate, and several hypothetical mechanisms have been proposed. The WM neurons in normal brains are considered as remnants of the subplate neurons, which represent a transient cytoarchitectural zone present during development of the mammalian neocortex; it has been suggested that increased densities of the WM neurons could result from inappropriate apoptosis of the subplate neurons in the brains of patients with neuropsychiatric disorders. On the other hand, recent experimental studies have demonstrated that genetic and environmental factors that enhance the risk of development of neuropsychiatric disorders could cause altered distribution of neurons in the WM. To understand the pathophysiology underlying the increased densities of the WM neurons, it is important to investigate the cellular characteristics of the WM neurons in the brains of both normal subjects and patients with neuropsychiatric disorders.
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Affiliation(s)
- Ken-Ichiro Kubo
- Department of Anatomy, Keio University School of Medicine, Tokyo, Japan.,Department of Anatomy, The Jikei University School of Medicine, Tokyo, Japan
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29
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Beer AL, Plank T, Greenlee MW. Aging and central vision loss: Relationship between the cortical macro-structure and micro-structure. Neuroimage 2020; 212:116670. [PMID: 32088318 DOI: 10.1016/j.neuroimage.2020.116670] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 02/13/2020] [Accepted: 02/17/2020] [Indexed: 12/17/2022] Open
Abstract
Aging and central vision loss are associated with cortical atrophies, but little is known about the relationship between cortical thinning and the underlying cellular structure. We compared the macro- and micro-structure of the cortical gray and superficial white matter of 38 patients with juvenile (JMD) or age-related (AMD) macular degeneration and 38 healthy humans (19-84 years) by multimodal MRI including diffusion-tensor imaging (DTI). A factor analysis showed that cortical thickness, tissue-dependent measures, and DTI-based measures were sensitive to distinct components of brain structure. Age-related cortical thinning and increased diffusion were observed across most of the cortex, but increased T1-weighted intensities (frontal), reduced T2-weighted intensities (occipital), and reduced anisotropy (medial) were limited to confined cortical regions. Vision loss was associated with cortical thinning and enhanced diffusion in the gray matter (less in the white matter) of the occipital central visual field representation. Moreover, AMD (but not JMD) patients showed enhanced diffusion in lateral occipito-temporal cortex and cortical thinning in the posterior cingulum. These findings demonstrate that changes in brain structure are best quantified by multimodal imaging. They further suggest that age-related brain atrophies (cortical thinning) reflect diverse micro-structural etiologies. Moreover, juvenile and age-related macular degeneration are associated with distinct patterns of micro-structural alterations.
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Affiliation(s)
- Anton L Beer
- Institut für Psychologie, Universität Regensburg, Regensburg, Germany.
| | - Tina Plank
- Institut für Psychologie, Universität Regensburg, Regensburg, Germany
| | - Mark W Greenlee
- Institut für Psychologie, Universität Regensburg, Regensburg, Germany
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30
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Borra E, Luppino G, Gerbella M, Rozzi S, Rockland KS. Projections to the putamen from neurons located in the white matter and the claustrum in the macaque. J Comp Neurol 2019; 528:453-467. [PMID: 31483857 DOI: 10.1002/cne.24768] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 08/24/2019] [Accepted: 08/26/2019] [Indexed: 12/21/2022]
Abstract
Continuing investigations of corticostriatal connections in rodents emphasize an intricate architecture where striatal projections originate from different combinations of cortical layers, include an inhibitory component, and form terminal arborizations which are cell-type dependent, extensive, or compact. Here, we report that in macaque monkeys, deep and superficial cortical white matter neurons (WMNs), peri-claustral WMNs, and the claustrum proper project to the putamen. WMNs retrogradely labeled by injections in the putamen (four injections in three macaques) were widely distributed, up to 10 mm antero-posterior from the injection site, mainly dorsal to the putamen in the external capsule, and below the premotor cortex. Striatally projecting labeled WMNs (WMNsST) were heterogeneous in size and shape, including a small GABAergic component. We compared the number of WMNsST with labeled claustral and cortical neurons and also estimated their proportion in relation to total WMNs. Since some WMNsST were located adjoining the claustrum, we wanted to compare results for density and distribution of striatally projecting claustral neurons (ClaST). ClaST neurons were morphologically heterogeneous and mainly located in the dorsal and anterior claustrum, in regions known to project to frontal, motor, and cingulate cortical areas. The ratio of ClaST to WMNsST was about 4:1 averaged across the four injections. These results provide new specifics on the connectional networks of WMNs in nonhuman primates, and delineate additional loops in the corticostriatal architecture, consisting of interconnections across cortex, claustralstriatal and striatally projecting WMNs.
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Affiliation(s)
- Elena Borra
- Department of Medicine and Surgery, Neuroscience Unit, University of Parma, Parma, Italy
| | - Giuseppe Luppino
- Department of Medicine and Surgery, Neuroscience Unit, University of Parma, Parma, Italy
| | - Marzio Gerbella
- Department of Medicine and Surgery, Neuroscience Unit, University of Parma, Parma, Italy
| | - Stefano Rozzi
- Department of Medicine and Surgery, Neuroscience Unit, University of Parma, Parma, Italy
| | - Kathleen S Rockland
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA
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31
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On the existence of mechanoreceptors within the neurovascular unit of the mammalian brain. Brain Struct Funct 2019; 224:2247-2267. [PMID: 31190162 DOI: 10.1007/s00429-019-01863-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 03/16/2019] [Indexed: 10/26/2022]
Abstract
We describe a set of perivascular interneurons (PINs) with series of fibro-vesicular complexes (FVCs) throughout the gray matter of the adult rabbit and rat brains. PIN-FVCs are ubiquitous throughout the brain vasculature as detected in Golgi-impregnated specimens. Most PINs are small, aspiny cells with short or long (> 1 mm) axons that split and travel along arterial blood vessels. Upon ramification, axons form FVCs around the arising vascular branches; then, paired axons run parallel to the vessel wall until another ramification ensues, and a new FVC is formed. Cytologically, FVCs consist of clusters of perivascular bulbs (PVBs) encircling the precapillary and capillary wall surrounded by end-feet and the extracellular matrix of endothelial cells and pericytes. A PVB contains mitochondria, multivesicular bodies, and granules with a membranous core, similar to Meissner corpuscles and other mechanoreceptors. Some PVBs form asymmetrical, axo-spinous synapses with presumptive adjacent neurons. PINs appear to correspond to the type 1 nNOS-positive neurons whose FVCs co-label with markers of sensory fiber-terminals surrounded by astrocytic end-feet. The PIN is conserved in adult cats and rhesus monkey specimens. The location, ubiquity throughout the vasculature of the mammalian brain, and cytological organization of the PIN-FVCs suggests that it is a sensory receptor intrinsic to the mammalian neurovascular unit that corresponds to an afferent limb of the sensorimotor feed-back mechanism controlling local blood flow.
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32
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Sedmak G, Judaš M. The total number of white matter interstitial neurons in the human brain. J Anat 2019; 235:626-636. [PMID: 31173356 DOI: 10.1111/joa.13018] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/24/2019] [Indexed: 02/06/2023] Open
Abstract
In the adult human brain, the interstitial neurons (WMIN) of the subcortical white matter are the surviving remnants of the fetal subplate zone. It has been suggested that they perform certain important functions and may be involved in the pathogenesis of several neurological and psychiatric disorders. However, many important features of this class of human cortical neurons remain insufficiently explored. In this study, we analyzed the total number, and regional and topological distribution of WMIN in the adult human subcortical white matter, using a combined immunocytochemical (NeuN) and stereological approaches. We found that the average number of WMIN in 1 mm3 of the subcortical white matter is 1.230 ± 549, which translates to the average total number of 593 811 183.6 ± 264 849 443.35 of WMIN in the entire subcortical telencephalic white matter. While there were no significant differences in their regional distribution, the lowest number of WMIN has been consistently observed in the limbic cortex, and the highest number in the frontal cortex. With respect to their topological distribution, the WMIN were consistently more numerous within gyral crowns, less numerous along gyral walls and least numerous at the bottom of cortical sulci (where they occupy a narrow and compact zone below the cortical-white matter border). The topological location of WMIN is also significantly correlated with their morphology: pyramidal and multipolar forms are the most numerous within gyral crowns, whereas bipolar forms predominate at the bottom of cortical sulci. Our results indicate that WMIN represent substantial neuronal population in the adult human cerebral cortex (e.g. more numerous than thalamic or basal ganglia neurons) and thus deserve more detailed morphological and functional investigations in the future.
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Affiliation(s)
- Goran Sedmak
- Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia.,Center for Excellence in Basic, Clinical and Translational Neuroscience, Zagreb, Croatia
| | - Miloš Judaš
- Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia.,Center for Excellence in Basic, Clinical and Translational Neuroscience, Zagreb, Croatia
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Kanold PO, Deng R, Meng X. The Integrative Function of Silent Synapses on Subplate Neurons in Cortical Development and Dysfunction. Front Neuroanat 2019; 13:41. [PMID: 31040772 PMCID: PMC6476909 DOI: 10.3389/fnana.2019.00041] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 03/26/2019] [Indexed: 12/20/2022] Open
Abstract
The thalamocortical circuit is of central importance in relaying information to the cortex. In development, subplate neurons (SPNs) form an integral part of the thalamocortical pathway. These early born cortical neurons are the first neurons to receive thalamic inputs and excite neurons in the cortical plate. This feed-forward circuit topology of SPNs supports the role of SPNs in shaping the formation and plasticity of thalamocortical connections. Recently it has been shown that SPNs also receive inputs from the developing cortical plate and project to the thalamus. The cortical inputs to SPNs in early ages are mediated by N-methyl-D-aspartate (NMDA)-receptor only containing synapses while at later ages α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-receptors are present. Thus, SPNs perform a changing integrative function over development. NMDA-receptor only synapses are crucially influenced by the resting potential and thus insults to the developing brain that causes depolarizations, e.g., hypoxia, can influence the integrative function of SPNs. Since such insults in humans cause symptoms of neurodevelopmental disorders, NMDA-receptor only synapses on SPNs might provide a crucial link between early injuries and later circuit dysfunction. We thus here review subplate associated circuits, their changing functions, and discuss possible roles in development and disease.
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Affiliation(s)
- Patrick O. Kanold
- Department of Biology, University of Maryland, College Park, MD, United States
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Serati M, Delvecchio G, Orsenigo G, Mandolini GM, Lazzaretti M, Scola E, Triulzi F, Brambilla P. The Role of the Subplate in Schizophrenia and Autism: A Systematic Review. Neuroscience 2019; 408:58-67. [PMID: 30930130 DOI: 10.1016/j.neuroscience.2019.03.049] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 03/19/2019] [Accepted: 03/20/2019] [Indexed: 02/07/2023]
Abstract
The subplate (SP) represents a transitory cytoarchitectural fetal compartment containing most subcortical and cortico-cortical afferents, and has a fundamental role in the structural development of the healthy adult brain. There is evidence that schizophrenia and autism may be determined by developmental defects in the cortex or cortical circuitry during the earliest stages of pregnancy. This article provides an overview on fetal SP development, considering its role in schizophrenia and autism, as supported by a systematic review of the main databases. The SP has been described as a cortical amplifier with a role in the coordination of cortical activity, and sensitive growth and migration windows have crucial consequences with respect to cognitive functioning. Although there are not enough studies to draw final conclusions, improved knowledge of the SP's role in schizophrenia and autism spectrum disorders may help to elucidate and possibly prevent the onset of these two severe disorders.
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Affiliation(s)
- Marta Serati
- Department of Mental Health, ASST Rhodense, Rho, Milan, Italy.
| | - Giuseppe Delvecchio
- Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
| | - Giulia Orsenigo
- Department of Neurosciences and Mental Health, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, University of Milan, Italy
| | - Gian Mario Mandolini
- Department of Neurosciences and Mental Health, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, University of Milan, Italy
| | - Matteo Lazzaretti
- Department of Neurosciences and Mental Health, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, University of Milan, Italy
| | - Elisa Scola
- Department of Neuroradiology, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Fabio Triulzi
- Department of Neuroradiology, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Paolo Brambilla
- Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy; Department of Psychiatry and Behavioural Neurosciences, University of Texas at Houston, TX, USA
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35
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Cebada-Sánchez S, Marcos Rabal P, Insausti AM, Insausti R. Postnatal Development of NPY and Somatostatin-28 Peptidergic Populations in the Human Angular Bundle. Front Neuroanat 2019; 12:116. [PMID: 30687024 PMCID: PMC6338036 DOI: 10.3389/fnana.2018.00116] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 12/05/2018] [Indexed: 01/05/2023] Open
Abstract
The angular bundle is a white matter fiber fascicle, which runs longitudinally along the parahippocampal gyrus. It is best known for carrying fibers from the entorhinal cortex (EC) to the hippocampus through the perforant and alvear pathways, as well as for carrying hippocampal output to the neocortex, and distributing fibers to polysensory cortex. The angular bundle is already present prenatally at the beginning of the fetal period. Connections between the EC and the hippocampus are established by the 20th gestational week (gw). In the postnatal period, it shows increasing myelination. The angular bundle, as well as other white matter portions of gyral surfaces in the brain, presents interstitial neurons, a remnant of subplate neurons. Those interstitial neurons show neurochemical phenotypes both prenatally and postnatally, among which, neuropeptide Y (NPY) and Somatostatin-28 (SOM-28) peptidergic populations are noticeable, and accompany the fiber connections in the maturation of the hippocampal formation. We sought to investigate the topography of the postnatal distribution and relative density of neurons immunoreactive for NPY or SOM in the angular bundle along the rostrocaudal axis of the hippocampus. The study was carried out in 15 cases, ranging from 35 gws, up to 14 year old. All cases showed positive neurons showing a polygonal or spindle shaped morphology for both peptides, scattered throughout the angular bundle. The highest number of positive neurons appeared around birth and the ensuing weeks. Up to one and a half years, the density of both peptidergic populations decreased slightly. However, cases older than 2 years of age showed a substantial decrease in density of immunolabeled neurons, density that did not showed a minor decrease in density of positive neurons in cases older than 2 years. In addition, a topography from caudal to rostral levels of the angular bundle was detected at all ages. The functional significance of interstitial cells is unknown, but the existence of SOM and NPY peptidergic neurons, presumably inhibitory, in the white matter of the angular bundle, could contribute to the basic wiring of the hippocampal formation, through which autobiographical and spatial memories can begin to be stored in the infant brain.
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Affiliation(s)
| | - Pilar Marcos Rabal
- Human Neuroanatomy Laboratory, University of Castilla-La Mancha, Albacete, Spain
| | - Ana María Insausti
- Human Neuroanatomy Laboratory, University of Castilla-La Mancha, Albacete, Spain
| | - Ricardo Insausti
- Human Neuroanatomy Laboratory, University of Castilla-La Mancha, Albacete, Spain
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36
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Abstract
The prenatal period is increasingly considered as a crucial target for the primary prevention of neurodevelopmental and psychiatric disorders. Understanding their pathophysiological mechanisms remains a great challenge. Our review reveals new insights from prenatal brain development research, involving (epi)genetic research, neuroscience, recent imaging techniques, physical modeling, and computational simulation studies. Studies examining the effect of prenatal exposure to maternal distress on offspring brain development, using brain imaging techniques, reveal effects at birth and up into adulthood. Structural and functional changes are observed in several brain regions including the prefrontal, parietal, and temporal lobes, as well as the cerebellum, hippocampus, and amygdala. Furthermore, alterations are seen in functional connectivity of amygdalar-thalamus networks and in intrinsic brain networks, including default mode and attentional networks. The observed changes underlie offspring behavioral, cognitive, emotional development, and susceptibility to neurodevelopmental and psychiatric disorders. It is concluded that used brain measures have not yet been validated with regard to sensitivity, specificity, accuracy, or robustness in predicting neurodevelopmental and psychiatric disorders. Therefore, more prospective long-term longitudinal follow-up studies starting early in pregnancy should be carried out, in order to examine brain developmental measures as mediators in mediating the link between prenatal stress and offspring behavioral, cognitive, and emotional problems and susceptibility for disorders.
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37
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Swiegers J, Bhagwandin A, Sherwood CC, Bertelsen MF, Maseko BC, Hemingway J, Rockland KS, Molnár Z, Manger PR. The distribution, number, and certain neurochemical identities of infracortical white matter neurons in a lar gibbon (Hylobates lar) brain. J Comp Neurol 2018; 527:1633-1653. [PMID: 30378128 DOI: 10.1002/cne.24545] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 09/04/2018] [Accepted: 09/21/2018] [Indexed: 01/08/2023]
Abstract
We examined the number, distribution, and immunoreactivity of the infracortical white matter neuronal population, also termed white matter interstitial cells (WMICs), in the brain of a lesser ape, the lar gibbon. Staining for neuronal nuclear marker (NeuN) revealed WMICs throughout the infracortical white matter, these cells being most numerous and dense close to cortical layer VI, decreasing significantly in density with depth in the white matter. Stereological analysis of NeuN-immunopositive cells revealed a global estimate of ~67.5 million WMICs within the infracortical white matter of the gibbon brain, indicating that the WMICs are a numerically significant population, ~2.5% of the total cortical gray matter neurons that would be estimated for a primate brain the mass of that of the lar gibbon. Immunostaining revealed subpopulations of WMICs containing neuronal nitric oxide synthase (nNOS, ~7 million in number, with both small and large soma volumes), calretinin (~8.6 million in number, all of similar soma volume), very few WMICs containing parvalbumin, and no calbindin-immunopositive neurons. These nNOS, calretinin, and parvalbumin immunopositive WMICs, presumably all inhibitory neurons, represent ~23.1% of the total WMIC population. As the white matter is affected in many cognitive conditions, such as schizophrenia, autism and also in neurodegenerative diseases, understanding these neurons across species is important for the translation of findings of neural dysfunction in animal models to humans. Furthermore, studies of WMICs in species such as apes provide a crucial phylogenetic context for understanding the evolution of these cell types in the human brain.
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Affiliation(s)
- Jordan Swiegers
- Faculty of Health Sciences, School of Anatomical Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa
| | - Adhil Bhagwandin
- Faculty of Health Sciences, School of Anatomical Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa
| | - Chet C Sherwood
- Department of Anthropology and Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, District of Columbia
| | - Mads F Bertelsen
- Centre for Zoo and Wild Animal Health, Copenhagen Zoo, Frederiksberg, Denmark
| | - Busisiwe C Maseko
- Faculty of Health Sciences, School of Anatomical Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa
| | - Jason Hemingway
- Faculty of Health Sciences, School of Anatomical Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa
| | - Kathleen S Rockland
- Department of Anatomy and Neurobiology, School of Medicine, Boston University, Boston, Massachusetts
| | - Zoltán Molnár
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, England
| | - Paul R Manger
- Faculty of Health Sciences, School of Anatomical Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa
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38
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Ernst L, Darschnik S, Roos J, González-Gómez M, Beemelmans C, Beemelmans C, Engelhardt M, Meyer G, Wahle P. Fast prenatal development of the NPY neuron system in the neocortex of the European wild boar, Sus scrofa. Brain Struct Funct 2018; 223:3855-3873. [PMID: 30094604 DOI: 10.1007/s00429-018-1725-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 07/26/2018] [Indexed: 11/25/2022]
Abstract
Knowledge on cortical development is based mainly on small rodents besides primates and carnivores, all being altricial nestlings. Ungulates are precocial and born with nearly mature sensory and motor systems. Almost no information is available on ungulate brain development. Here, we analyzed European wild boar cortex development, focusing on the neuropeptide Y immunoreactive (NPY-ir) neuron system in dorsoparietal cortex from E35 to P30. Transient NPY-ir neuron types including archaic cells of the cortical plate and axonal loop cells of the subplate which appear by E60 concurrent with the establishment of the ungulate brain basic sulcal pattern. From E70, NPY-ir axons have an axon initial segment which elongates and shifts closer towards the axon's point of origin until P30. From E85 onwards (birth at E114), NPY-ir neurons in cortical layers form basket cell-like local and Martinotti cell-like ascending axonal projections. The mature NPY-ir pattern is recognizable at E110. Together, morphologies are conserved across species, but timing is not: in pig, the adult pattern largely forms prenatally.
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Affiliation(s)
- Laura Ernst
- Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, 44870, Bochum, Germany
| | - Simon Darschnik
- Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, 44870, Bochum, Germany
| | - Johannes Roos
- Institute of Neuroanatomy, Medical Faculty Mannheim, CBTM, Heidelberg University, Heidelberg, Germany
| | - Miriam González-Gómez
- Unit of Histology, Anatomy and Histology, Department of Basic Medical Science, Faculty of Medicine, University of La Laguna, 38200, Santa Cruz de Tenerife, Tenerife, Spain
| | - Christa Beemelmans
- Regionalverband Ruhr Grün, Forsthof Üfter Mark, Forsthausweg 306, 46514, Schermbeck, Germany
| | - Christoph Beemelmans
- Regionalverband Ruhr Grün, Forsthof Üfter Mark, Forsthausweg 306, 46514, Schermbeck, Germany
| | - Maren Engelhardt
- Institute of Neuroanatomy, Medical Faculty Mannheim, CBTM, Heidelberg University, Heidelberg, Germany
| | - Gundela Meyer
- Unit of Histology, Department of Basic Medical Science, Faculty of Medicine, University of La Laguna, 38200, Santa Cruz de Tenerife, Tenerife, Spain
| | - Petra Wahle
- Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, 44870, Bochum, Germany.
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Stassart RM, Möbius W, Nave KA, Edgar JM. The Axon-Myelin Unit in Development and Degenerative Disease. Front Neurosci 2018; 12:467. [PMID: 30050403 PMCID: PMC6050401 DOI: 10.3389/fnins.2018.00467] [Citation(s) in RCA: 131] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 06/19/2018] [Indexed: 12/15/2022] Open
Abstract
Axons are electrically excitable, cable-like neuronal processes that relay information between neurons within the nervous system and between neurons and peripheral target tissues. In the central and peripheral nervous systems, most axons over a critical diameter are enwrapped by myelin, which reduces internodal membrane capacitance and facilitates rapid conduction of electrical impulses. The spirally wrapped myelin sheath, which is an evolutionary specialisation of vertebrates, is produced by oligodendrocytes and Schwann cells; in most mammals myelination occurs during postnatal development and after axons have established connection with their targets. Myelin covers the vast majority of the axonal surface, influencing the axon's physical shape, the localisation of molecules on its membrane and the composition of the extracellular fluid (in the periaxonal space) that immerses it. Moreover, myelinating cells play a fundamental role in axonal support, at least in part by providing metabolic substrates to the underlying axon to fuel its energy requirements. The unique architecture of the myelinated axon, which is crucial to its function as a conduit over long distances, renders it particularly susceptible to injury and confers specific survival and maintenance requirements. In this review we will describe the normal morphology, ultrastructure and function of myelinated axons, and discuss how these change following disease, injury or experimental perturbation, with a particular focus on the role the myelinating cell plays in shaping and supporting the axon.
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Affiliation(s)
- Ruth M. Stassart
- Department of Neurogenetics, Max-Planck-Institute of Experimental Medicine, Göttingen, Germany
- Department of Neuropathology, University Medical Center Leipzig, Leipzig, Germany
| | - Wiebke Möbius
- Department of Neurogenetics, Max-Planck-Institute of Experimental Medicine, Göttingen, Germany
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max-Planck-Institute of Experimental Medicine, Göttingen, Germany
| | - Julia M. Edgar
- Department of Neurogenetics, Max-Planck-Institute of Experimental Medicine, Göttingen, Germany
- Institute of Infection, Immunity and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
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40
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Phillips OR, Joshi SH, Narr KL, Shattuck DW, Singh M, Di Paola M, Ploner CJ, Prüss H, Paul F, Finke C. Superficial white matter damage in anti-NMDA receptor encephalitis. J Neurol Neurosurg Psychiatry 2018; 89:518-525. [PMID: 29101253 PMCID: PMC5899027 DOI: 10.1136/jnnp-2017-316822] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 10/09/2017] [Accepted: 10/19/2017] [Indexed: 12/18/2022]
Abstract
BACKGROUND Clinical brain MRI is normal in the majority of patients with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis. However, extensive deep white matter damage wasrecently identifiedin these patients using diffusion weighted imaging. Here, our aim was to study a particularly vulnerable brain compartment, the late myelinating superficial white matter. METHODS Forty-six patients with anti-NMDAR encephalitis were included. Ten out of these were considered neurologically recovered (modified Rankin scale of zero), while 36 patients were non-recovered. In addition, 30 healthy controls were studied. MRI data were collected from all subjects and superficial white matter mean diffusivity derived from diffusion tensor imaging was compared between groups in whole brain, lobar and vertex-based analyses. Patients underwent comprehensive cognitive testing, and correlation analyses were performed between cognitive performance and superficial white matter integrity. RESULTS Non-recovered patients showed widespread superficial white matter damage in comparison to recovered patients and healthy controls. Vertex-based analyses revealed that damage predominated in frontal and temporal lobes. In contrast, the superficial white matter was intact in recovered patients. Importantly, persistent cognitive impairments in working memory, verbal memory, visuospatial memory and attention significantly correlated with damage of the superficial white matter in patients. CONCLUSIONS Anti-NMDAR encephalitis is associated with extensive superficial white matter damage in patients with incomplete recovery. The strong association with impairment in several cognitive domains highlights the clinical relevance of white matter damage in this disorder and warrants investigations of the underlying pathophysiological mechanisms.
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Affiliation(s)
- Owen Robert Phillips
- Department of Psychiatry, Division of Child and Adolescent Psychiatry, Stanford University School of Medicine, Stanford, California, USA
| | - Shantanu H Joshi
- Department of Neurology, Ahmanson Lovelace Brain Mapping Center, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Katherine L Narr
- Department of Neurology, Ahmanson Lovelace Brain Mapping Center, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - David W Shattuck
- Department of Neurology, Ahmanson Lovelace Brain Mapping Center, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Manpreet Singh
- Department of Psychiatry, Division of Child and Adolescent Psychiatry, Stanford University School of Medicine, Stanford, California, USA
| | - Margherita Di Paola
- Department of Mental Health, King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia.,Department of Clinical and Behavioral Neurology, IRCCS Santa Lucia Foundation, Rome, Italy
| | - Christoph J Ploner
- Department of Neurology, Charité University Medicine Berlin, Berlin, Germany
| | - Harald Prüss
- Department of Neurology, Charité University Medicine Berlin, Berlin, Germany.,German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany
| | - Friedemann Paul
- Department of Neurology, Charité University Medicine Berlin, Berlin, Germany.,NeuroCure Clinical Research Center, Berlin, Germany.,Experimental and Clinical Research Center, Charité Universitätsmedizin, Berlin, Germany.,Experimental and Clinical Research Center, Max Delbrueck Center for Molecular Medicine, Berlin, Germany
| | - Carsten Finke
- Department of Neurology, Charité University Medicine Berlin, Berlin, Germany.,Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, Berlin, Germany
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41
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Deleo F, Thom M, Concha L, Bernasconi A, Bernhardt BC, Bernasconi N. Histological and MRI markers of white matter damage in focal epilepsy. Epilepsy Res 2017; 140:29-38. [PMID: 29227798 DOI: 10.1016/j.eplepsyres.2017.11.010] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 11/10/2017] [Accepted: 11/20/2017] [Indexed: 12/21/2022]
Abstract
Growing evidence highlights the importance of white matter in the pathogenesis of focal epilepsy. Ex vivo and post-mortem studies show pathological changes in epileptic patients in white matter myelination, axonal integrity, and cellular composition. Diffusion-weighted MRI and its analytical extensions, particularly diffusion tensor imaging (DTI), have been the most widely used technique to image the white matter in vivo for the last two decades, and have shown microstructural alterations in multiple tracts both in the vicinity and at distance from the epileptogenic focus. These techniques have also shown promising ability to predict cognitive status and response to pharmacological or surgical treatments. More recently, the hypothesis that focal epilepsy may be more adequately described as a system-level disorder has motivated a shift towards the study of macroscale brain connectivity. This review will cover emerging findings contributing to our understanding of white matter alterations in focal epilepsy, studied by means of histological and ultrastructural analyses, diffusion MRI, and large-scale network analysis. Focus is put on temporal lobe epilepsy and focal cortical dysplasia. This topic was addressed in a special interest group on neuroimaging at the 70th annual meeting of the American Epilepsy Society, held in Houston December 2-6, 2016.
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Affiliation(s)
- Francesco Deleo
- NeuroImaging of Epilepsy Laboratory, Montreal Neurological Institute, McGill University, Canada
| | - Maria Thom
- Division of Neuropathology and Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Luis Concha
- Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, Mexico
| | - Andrea Bernasconi
- NeuroImaging of Epilepsy Laboratory, Montreal Neurological Institute, McGill University, Canada
| | - Boris C Bernhardt
- NeuroImaging of Epilepsy Laboratory, Montreal Neurological Institute, McGill University, Canada; Multimodal Imaging and Connectome Analysis Laboratory, Montreal Neurological Institute, McGill University, Canada
| | - Neda Bernasconi
- NeuroImaging of Epilepsy Laboratory, Montreal Neurological Institute, McGill University, Canada.
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42
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Mortazavi F, Romano SE, Rosene DL, Rockland KS. A Survey of White Matter Neurons at the Gyral Crowns and Sulcal Depths in the Rhesus Monkey. Front Neuroanat 2017; 11:69. [PMID: 28860975 PMCID: PMC5559435 DOI: 10.3389/fnana.2017.00069] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 07/31/2017] [Indexed: 12/14/2022] Open
Abstract
Gyrencephalic brains exhibit deformations of the six neocortical laminae at gyral crowns and sulcal depths, where the deeper layers are, respectively, expanded and compressed. The present study addresses: (1) the degree to which the underlying white matter neurons (WMNs) observe the same changes at gyral crowns and sulcal depths; and (2) whether these changes are consistent or variable across different cortical regions. WMNs were visualized by immunohistochemistry using the pan-neuronal label NeuN, and their density was quantified in eight rhesus monkey brains for four regions; namely, frontal (FR), superior frontal gyrus (SFG), parietal (Par) and temporal (TE). In all four regions, there were about 50% fewer WMNs in the sulcal depth, but there was also distinct variability from region to region. For the gyral crown, we observed an average density per 0.21 mm2 of 82 WMNs for the FR, 51 WMNs for SFG, 80 WMNs for Par and 93 WMNs for TE regions. By contrast, for the sulcal depth, the average number of WMNs per 0.21 mm2 was 41 for FR, 31 for cingulate sulcus (underlying the SFG), 54 for Par and 63 for TE cortical regions. Since at least some WMNs participate in cortical circuitry, these results raise the possibility of their differential influence on cortical circuitry in the overlying gyral and sulcal locations. The results also point to a possible role of WMNs in the differential vulnerability of gyral vs. sulcal regions in disease processes, and reinforce the increasing awareness of the WMNs as part of a complex, heterogeneous and structured microenvironment.
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Affiliation(s)
- Farzad Mortazavi
- Department of Anatomy and Neurobiology, Boston University School of MedicineBoston, MA, United States
| | - Samantha E. Romano
- Department of Anatomy and Neurobiology, Boston University School of MedicineBoston, MA, United States
| | - Douglas L. Rosene
- Department of Anatomy and Neurobiology, Boston University School of MedicineBoston, MA, United States
| | - Kathleen S. Rockland
- Department of Anatomy and Neurobiology, Boston University School of MedicineBoston, MA, United States
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43
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Millar LJ, Shi L, Hoerder-Suabedissen A, Molnár Z. Neonatal Hypoxia Ischaemia: Mechanisms, Models, and Therapeutic Challenges. Front Cell Neurosci 2017; 11:78. [PMID: 28533743 PMCID: PMC5420571 DOI: 10.3389/fncel.2017.00078] [Citation(s) in RCA: 213] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 03/07/2017] [Indexed: 12/11/2022] Open
Abstract
Neonatal hypoxia-ischaemia (HI) is the most common cause of death and disability in human neonates, and is often associated with persistent motor, sensory, and cognitive impairment. Improved intensive care technology has increased survival without preventing neurological disorder, increasing morbidity throughout the adult population. Early preventative or neuroprotective interventions have the potential to rescue brain development in neonates, yet only one therapeutic intervention is currently licensed for use in developed countries. Recent investigations of the transient cortical layer known as subplate, especially regarding subplate's secretory role, opens up a novel set of potential molecular modulators of neonatal HI injury. This review examines the biological mechanisms of human neonatal HI, discusses evidence for the relevance of subplate-secreted molecules to this condition, and evaluates available animal models. Neuroserpin, a neuronally released neuroprotective factor, is discussed as a case study for developing new potential pharmacological interventions for use post-ischaemic injury.
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Affiliation(s)
- Lancelot J. Millar
- Molnár Group, Department of Physiology, Anatomy and Genetics, University of OxfordOxford, UK
| | - Lei Shi
- Molnár Group, Department of Physiology, Anatomy and Genetics, University of OxfordOxford, UK
- JNU-HKUST Joint Laboratory for Neuroscience and Innovative Drug Research, College of Pharmacy, Jinan UniversityGuangzhou, China
| | | | - Zoltán Molnár
- Molnár Group, Department of Physiology, Anatomy and Genetics, University of OxfordOxford, UK
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44
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Meyer G, González-Gómez M. The Subpial Granular Layer and Transient Versus Persisting Cajal-Retzius Neurons of the Fetal Human Cortex. Cereb Cortex 2017; 28:2043-2058. [DOI: 10.1093/cercor/bhx110] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 04/18/2017] [Indexed: 12/20/2022] Open
Affiliation(s)
- Gundela Meyer
- Units of Anatomy (MGG) and Histology (GM), Department of Basic Medical Science, Faculty of Medicine, University of La Laguna, Tenerife, Spain
| | - Miriam González-Gómez
- Units of Anatomy (MGG) and Histology (GM), Department of Basic Medical Science, Faculty of Medicine, University of La Laguna, Tenerife, Spain
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45
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Frazer S, Prados J, Niquille M, Cadilhac C, Markopoulos F, Gomez L, Tomasello U, Telley L, Holtmaat A, Jabaudon D, Dayer A. Transcriptomic and anatomic parcellation of 5-HT 3AR expressing cortical interneuron subtypes revealed by single-cell RNA sequencing. Nat Commun 2017; 8:14219. [PMID: 28134272 PMCID: PMC5290279 DOI: 10.1038/ncomms14219] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 12/08/2016] [Indexed: 11/09/2022] Open
Abstract
Cortical GABAergic interneurons constitute a highly diverse population of inhibitory neurons that are key regulators of cortical microcircuit function. An important and heterogeneous group of cortical interneurons specifically expresses the serotonin receptor 3A (5-HT3AR) but how this diversity emerges during development is poorly understood. Here we use single-cell transcriptomics to identify gene expression patterns operating in Htr3a-GFP+ interneurons during early steps of cortical circuit assembly. We identify three main molecular types of Htr3a-GFP+ interneurons, each displaying distinct developmental dynamics of gene expression. The transcription factor Meis2 is specifically enriched in a type of Htr3a-GFP+ interneurons largely confined to the cortical white matter. These MEIS2-expressing interneurons appear to originate from a restricted region located at the embryonic pallial–subpallial boundary. Overall, this study identifies MEIS2 as a subclass-specific marker for 5-HT3AR-containing interstitial interneurons and demonstrates that the transcriptional and anatomical parcellation of cortical interneurons is developmentally coupled. Cortical GABAergic interneurons are highly diverse in their gene expression, electrophysiological properties, and connectivity. Here the authors reveal three distinct subtypes of Htr3a-GFP+ interneurons using the single-cell RNA-seq approach, and identify MEIS2 as a marker for one such subtype.
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Affiliation(s)
- Sarah Frazer
- Department of Psychiatry, University of Geneva Medical School, Geneva 4 CH-1211, Switzerland.,Department of Basic Neurosciences, University of Geneva Medical School, Geneva 4 CH-1211, Switzerland
| | - Julien Prados
- Department of Psychiatry, University of Geneva Medical School, Geneva 4 CH-1211, Switzerland.,Department of Basic Neurosciences, University of Geneva Medical School, Geneva 4 CH-1211, Switzerland
| | - Mathieu Niquille
- Department of Psychiatry, University of Geneva Medical School, Geneva 4 CH-1211, Switzerland.,Department of Basic Neurosciences, University of Geneva Medical School, Geneva 4 CH-1211, Switzerland
| | - Christelle Cadilhac
- Department of Psychiatry, University of Geneva Medical School, Geneva 4 CH-1211, Switzerland.,Department of Basic Neurosciences, University of Geneva Medical School, Geneva 4 CH-1211, Switzerland
| | - Foivos Markopoulos
- Department of Basic Neurosciences, University of Geneva Medical School, Geneva 4 CH-1211, Switzerland
| | - Lucia Gomez
- Department of Psychiatry, University of Geneva Medical School, Geneva 4 CH-1211, Switzerland.,Department of Basic Neurosciences, University of Geneva Medical School, Geneva 4 CH-1211, Switzerland
| | - Ugo Tomasello
- Department of Psychiatry, University of Geneva Medical School, Geneva 4 CH-1211, Switzerland.,Department of Basic Neurosciences, University of Geneva Medical School, Geneva 4 CH-1211, Switzerland
| | - Ludovic Telley
- Department of Basic Neurosciences, University of Geneva Medical School, Geneva 4 CH-1211, Switzerland
| | - Anthony Holtmaat
- Department of Basic Neurosciences, University of Geneva Medical School, Geneva 4 CH-1211, Switzerland
| | - Denis Jabaudon
- Department of Basic Neurosciences, University of Geneva Medical School, Geneva 4 CH-1211, Switzerland
| | - Alexandre Dayer
- Department of Psychiatry, University of Geneva Medical School, Geneva 4 CH-1211, Switzerland.,Department of Basic Neurosciences, University of Geneva Medical School, Geneva 4 CH-1211, Switzerland
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46
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Richter Z, Janszky J, Sétáló G, Horváth R, Horváth Z, Dóczi T, Seress L, Ábrahám H. Characterization of neurons in the cortical white matter in human temporal lobe epilepsy. Neuroscience 2016; 333:140-50. [DOI: 10.1016/j.neuroscience.2016.07.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 06/18/2016] [Accepted: 07/07/2016] [Indexed: 12/20/2022]
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47
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Taylor SR, Smith CM, Keeley KL, McGuone D, Dodge CP, Duhaime AC, Costine BA. Neuroblast Distribution after Cortical Impact Is Influenced by White Matter Injury in the Immature Gyrencephalic Brain. Front Neurosci 2016; 10:387. [PMID: 27601978 PMCID: PMC4994423 DOI: 10.3389/fnins.2016.00387] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 08/08/2016] [Indexed: 11/13/2022] Open
Abstract
Cortical contusions are a common type of traumatic brain injury (TBI) in children. Current knowledge of neuroblast response to cortical injury arises primarily from studies utilizing aspiration or cryoinjury in rodents. In infants and children, cortical impact affects both gray and white matter and any neurogenic response may be complicated by the large expanse of white matter between the subventricular zone (SVZ) and the cortex, and the large number of neuroblasts in transit along the major white matter tracts to populate brain regions. Previously, we described an age-dependent increase of neuroblasts in the SVZ in response to cortical impact in the immature gyrencephalic brain. Here, we investigate if neuroblasts target the injury, if white matter injury influences repair efforts, and if postnatal population of brain regions are disrupted. Piglets received a cortical impact to the rostral gyrus cortex or sham surgery at postnatal day (PND) 7, BrdU 2 days prior to (PND 5 and 6) or after injury (PND 7 and 8), and brains were collected at PND 14. Injury did not alter the number of neuroblasts in the white matter between the SVZ and the rostral gyrus. In the gray matter of the injury site, neuroblast density was increased in cavitated lesions, and the number of BrdU(+) neuroblasts was increased, but comprised less than 1% of all neuroblasts. In the white matter of the injury site, neuroblasts with differentiating morphology were densely arranged along the cavity edge. In a ventral migratory stream, neuroblast density was greater in subjects with a cavitated lesion, indicating that TBI may alter postnatal development of regions supplied by that stream. Cortical impact in the immature gyrencephalic brain produced complicated and variable lesions, increased neuroblast density in cavitated gray matter, resulted in potentially differentiating neuroblasts in the white matter, and may alter the postnatal population of brain regions utilizing a population of neuroblasts that were born prior to PND 5. This platform may be useful to continue to study potential complications of white matter injury and alterations of postnatal population of brain regions, which may contribute to the chronic effects of TBI in children.
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Affiliation(s)
- Sabrina R Taylor
- Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital Charlestown, MA, USA
| | - Colin M Smith
- Brain Trauma Lab, Department of Neurosurgery, Massachusetts General Hospital Boston, MA, USA
| | - Kristen L Keeley
- Brain Trauma Lab, Department of Neurosurgery, Massachusetts General Hospital Boston, MA, USA
| | | | - Carter P Dodge
- Department of Anesthesiology, Dartmouth Medical School, Children's Hospital at Dartmouth Lebanon, PA, USA
| | - Ann-Christine Duhaime
- Brain Trauma Lab, Department of Neurosurgery, Massachusetts General HospitalBoston, MA, USA; Department of Neurosurgery, Harvard Medical SchoolBoston, MA, USA
| | - Beth A Costine
- Brain Trauma Lab, Department of Neurosurgery, Massachusetts General HospitalBoston, MA, USA; Department of Neurosurgery, Harvard Medical SchoolBoston, MA, USA
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48
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Phillips OR, Joshi SH, Piras F, Orfei MD, Iorio M, Narr KL, Shattuck DW, Caltagirone C, Spalletta G, Di Paola M. The superficial white matter in Alzheimer's disease. Hum Brain Mapp 2016; 37:1321-34. [PMID: 26801955 PMCID: PMC5125444 DOI: 10.1002/hbm.23105] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 12/03/2015] [Accepted: 12/17/2015] [Indexed: 12/24/2022] Open
Abstract
White matter abnormalities have been shown in the large deep fibers of Alzheimer's disease patients. However, the late myelinating superficial white matter comprised of intracortical myelin and short-range association fibers has not received much attention. To investigate this area, we extracted a surface corresponding to the superficial white matter beneath the cortex and then applied a cortical pattern-matching approach which allowed us to register and subsequently sample diffusivity along thousands of points at the interface between the gray matter and white matter in 44 patients with Alzheimer's disease (Age: 71.02 ± 5.84, 16M/28F) and 47 healthy controls (Age 69.23 ± 4.45, 19M/28F). In patients we found an overall increase in the axial and radial diffusivity across most of the superficial white matter (P < 0.001) with increases in diffusivity of more than 20% in the bilateral parahippocampal regions and the temporal and frontal lobes. Furthermore, diffusivity correlated with the cognitive deficits measured by the Mini-Mental State Examination scores (P < 0.001). The superficial white matter has a unique microstructure and is critical for the integration of multimodal information during brain maturation and aging. Here we show that there are major abnormalities in patients and the deterioration of these fibers relates to clinical symptoms in Alzheimer's disease.
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Affiliation(s)
- Owen R Phillips
- Morphology and Morphometry for NeuroImaging Lab, Clinical and Behavioural Neurology Dept. IRCCS Santa Lucia FoundationRomeItaly
- Neuroscience Dept. University of Rome“Tor Vergata”Italy
| | - Shantanu H. Joshi
- Ahmanson Lovelace Brain Mapping CenterNeurology Dept. UCLACaliforniaUSA
| | - Fabrizio Piras
- Museo Storico della Fisica e Centro di Studi e Ricerche “Enrico Fermi”RomeItaly
- Neuropsychiatry Laboratory, Clinical and Behavioural Neurology Dept. IRCCS Santa Lucia FoundationRomeItaly
| | - Maria Donata Orfei
- Neuropsychiatry Laboratory, Clinical and Behavioural Neurology Dept. IRCCS Santa Lucia FoundationRomeItaly
| | - Mariangela Iorio
- Neuropsychiatry Laboratory, Clinical and Behavioural Neurology Dept. IRCCS Santa Lucia FoundationRomeItaly
| | - Katherine L. Narr
- Ahmanson Lovelace Brain Mapping CenterNeurology Dept. UCLACaliforniaUSA
| | - David W. Shattuck
- Ahmanson Lovelace Brain Mapping CenterNeurology Dept. UCLACaliforniaUSA
| | - Carlo Caltagirone
- Neuroscience Dept. University of Rome“Tor Vergata”Italy
- Clinical and Behavioural Neurology Dept. IRCCS Santa Lucia FoundationRomeItaly
| | - Gianfranco Spalletta
- Neuropsychiatry Laboratory, Clinical and Behavioural Neurology Dept. IRCCS Santa Lucia FoundationRomeItaly
| | - Margherita Di Paola
- Morphology and Morphometry for NeuroImaging Lab, Clinical and Behavioural Neurology Dept. IRCCS Santa Lucia FoundationRomeItaly
- Human Studies Dept. LUMSA UniversityRomeItaly
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49
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Mortazavi F, Wang X, Rosene DL, Rockland KS. White Matter Neurons in Young Adult and Aged Rhesus Monkey. Front Neuroanat 2016; 10:15. [PMID: 26941613 PMCID: PMC4761867 DOI: 10.3389/fnana.2016.00015] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 02/05/2016] [Indexed: 01/21/2023] Open
Abstract
In humans and non-human primates (NHP), white matter neurons (WMNs) persist beyond early development. Their functional importance is largely unknown, but they have both corticothalamic and corticocortical connectivity and at least one subpopulation has been implicated in vascular regulation and sleep. Several other studies have reported that the density of WMNs in humans is altered in neuropathological or psychiatric conditions. The present investigation evaluates and compares the density of superficial and deep WMNs in frontal (FR), temporal (TE), and parietal (Par) association regions of four young adult and four aged male rhesus monkeys. A major aim was to determine whether there was age-related neuronal loss, as might be expected given the substantial age-related changes known to occur in the surrounding white matter environment. Neurons were visualized by immunocytochemistry for Neu-N in coronal tissue sections (30 μm thickness), and neuronal density was assessed by systematic random sampling. Per 0.16 mm2 sampling box, this yielded about 40 neurons in the superficial WM and 10 in the deep WM. Consistent with multiple studies of cell density in the cortical gray matter of normal brains, neither the superficial nor deep WM populations showed statistically significant age-related neuronal loss, although we observed a moderate decrease with age for the deep WMNs in the frontal region. Morphometric analyses, in contrast, showed significant age effects in soma size and circularity. In specific, superficial WMNs were larger in FR and Par WM regions of the young monkeys; but in the TE, these were larger in the older monkeys. An age effect was also observed for soma circularity: superficial WMNs were more circular in FR and Par of the older monkeys. This second, morphometric result raises the question of whether other age-related morphological, connectivity, or molecular changes occur in the WMNs. These could have multiple impacts, given the wide range of putative WMN functions and their involvement in both corticothalamic and corticocortical circuitry.
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Affiliation(s)
- Farzad Mortazavi
- Department of Anatomy and Neurobiology, Boston University School of Medicine Boston, MA, USA
| | - Xiyue Wang
- Department of Anatomy and Neurobiology, Boston University School of Medicine Boston, MA, USA
| | - Douglas L Rosene
- Department of Anatomy and Neurobiology, Boston University School of Medicine Boston, MA, USA
| | - Kathleen S Rockland
- Department of Anatomy and Neurobiology, Boston University School of Medicine Boston, MA, USA
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50
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Postnatal development of GABAergic interneurons in the neocortical subplate of mice. Neuroscience 2016; 322:78-93. [PMID: 26892297 DOI: 10.1016/j.neuroscience.2016.02.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 01/28/2016] [Accepted: 02/10/2016] [Indexed: 11/22/2022]
Abstract
The subplate (SP) plays important roles in developmental and functional events in the neocortex, such as thalamocortical and corticofugal projection, cortical oscillation generation and corticocortical connectivity. Although accumulated evidence indicates that SP interneurons are crucial for SP function, the molecular composition of SP interneurons as well as their developmental profile and distribution remain largely unclear. In this study, we systematically investigated dynamic development of SP thickness and chemical marker expression in SP interneurons in distinct cortical regions during the first postnatal month. We found that, although the relative area of the SP in the cerebral cortex significantly declined with postnatal development, the absolute thickness did not change markedly. We also found that somatostatin (SOM), the ionotropic serotonin receptor 3A (5HT3AR), and parvalbumin (PV) reliably identify three distinct non-overlapping subpopulations of SP interneurons. The SOM group, which represents ~30% of total SP interneurons, expresses neuronal nitric oxide synthase (nNOS) and calbindin (CB) and colocalizes entirely with neuropeptide Y (NPY). The 5HT3AR group, which accounts for ~60% of the total interneuronal population, expresses calretinin (CR) and GABA-A receptor subunit delta (GABAARδ). The PV group accounts for ~10% of total SP interneurons and coexpressed GABAARδ. Moreover, distinct interneuron subtypes show characteristic temporal and spatial distribution in the SP. nNOS(+) interneurons in the SP increase from the anterior motor cortex to posterior visual cortex, while CR(+) and CB(+) interneurons the opposite. Interestedly, the majority of GABAARδ(+) neurons in SP are non-GABAergic neurons in contrast to other cortical layers. These findings clarify and extend our understanding of SP interneurons in the developing cerebral cortex and will underpin further study of SP function.
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