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Li R, Sun H, Hao H, Liu Y, Zhang Y, Zhang T, Wang G, Ming W. White matter integrity in patients with classic trigeminal neuralgia: a multi-node automated fiber tract quantification study. J Int Med Res 2021; 49:3000605211047071. [PMID: 34719991 PMCID: PMC8562620 DOI: 10.1177/03000605211047071] [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: 11/16/2022] Open
Abstract
OBJECTIVE To study the characteristics of point-by-point destruction of white matter tracts in patients using automated fiber tract quantification (AFQ). METHODS Thirty-four classic trigeminal neuralgia (CTN) patients and 34 healthy control (HC) subjects underwent 3.0 T diffusion tensor magnetic resonance imaging and T1-weighted imaging. The fractional anisotropy (FA) and mean diffusivity (MD) of 100 nodes of 20 fiber tracts were analyzed by AFQ, and the correlations of the FA and MD with the visual analogue scale (VAS) pain score were assessed. RESULTS The FA values of the left thalamic radiation (middle segment), left corticospinal tract, callosum forceps minor, and right uncinate fasciculus were significantly lower in CTN patients than in the HC group. The MD of the left thalamic tract (middle segment), left corticospinal tract, right superior longitudinal fasciculus, and left superior longitudinal fasciculus (anterior segment) were significantly higher in the CTN group. Additionally, the VAS pain score in CTN patients was positively correlated with FA and negatively correlated with MD. CONCLUSION Specific fiber tract nodes were damaged in CTN patients, which was related to the VAS pain score. Multi-node quantitative studies of fiber tract damage are valuable for understanding the white matter tract damage pattern in CTN patients.
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Affiliation(s)
- Rui Li
- Department of Radiology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, P.R. China.,Department of Radiology, Jining No. 1 People's Hospital, Jining, Shandong, P.R. China
| | - Hongfang Sun
- Department of Radiology, Pingyi County Hospital of Traditional Chinese Medicine, Linyi, Shandong, P.R. China
| | - Hongjuan Hao
- Department of Pediatrics, Jining Social Welfare Centre, Jining, Shandong, P.R. China
| | - Yali Liu
- Department of Radiology, Jining No. 1 People's Hospital, Jining, Shandong, P.R. China
| | - Yang Zhang
- Department of Neurosurgery, Jining No. 1 People's Hospital, Jining, Shandong, P.R. China
| | - Tianran Zhang
- Department of Clinical Medicine, Jining Medical College, Jining, Shandong, P.R. China
| | - Guangbin Wang
- Department of Radiology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, P.R. China.,Department of Radiology, Shandong Provincial Hospital Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, P.R. China *These authors contributed equally to this work
| | - Wang Ming
- Department of Radiology, Jining No. 1 People's Hospital, Jining, Shandong, P.R. China
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Superficial anatomy of the neonatal cerebrum - an ultrasonographic roadmap. Pediatr Radiol 2021; 51:353-370. [PMID: 33026469 PMCID: PMC7897227 DOI: 10.1007/s00247-020-04794-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 07/06/2020] [Accepted: 08/04/2020] [Indexed: 10/23/2022]
Abstract
Neurosonography is an essential imaging modality for assessing the neonatal brain, particularly as a screening tool to evaluate intracranial hemorrhage, hydrocephalus and periventricular leukomalacia. The primary advantages of neurosonography include portability, accessibility and lack of ionizing radiation. Its main limitations are intrinsic operator dependence and the need for an open fontanelle. Neurosonographic imaging acquisition is typically performed by placing a sector transducer over the anterior fontanelle and following sagittal and coronal sweeps. The sensitivity of neurosonography has markedly improved thanks to the adoption of modern imaging equipment, the use of dedicated head probes, and the employment of advanced diagnostic US techniques. These developments have facilitated more descriptive identification of specific cerebral anatomical details, improving understanding of the cerebral anatomy by conventional US. Such knowledge is fundamental for enhanced diagnostic sensitivity and is a key to understanding pathological states. Furthermore, familiarity with normal anatomy is crucial for understanding pathological states. Our primary goal in this review was to supplement these technological developments with a roadmap to the cerebral landscape. We accomplish this by presenting a systematic approach to using routine US for consistent identification of the most crucial cerebral landmarks, reviewing their relationship with adjacent structures, and briefly describing their primary function.
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Zhou Z, Tong Q, Zhang L, Ding Q, Lu H, Jonkman LE, Yao J, He H, Zhu K, Zhong J. Evaluation of the diffusion MRI white matter tract integrity model using myelin histology and Monte-Carlo simulations. Neuroimage 2020; 223:117313. [PMID: 32882384 DOI: 10.1016/j.neuroimage.2020.117313] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Revised: 08/21/2020] [Accepted: 08/24/2020] [Indexed: 12/13/2022] Open
Abstract
Quantitative evaluation of brain myelination has drawn considerable attention. Conventional diffusion-based magnetic resonance imaging models, including diffusion tensor imaging and diffusion kurtosis imaging (DKI),1 have been used to infer the microstructure and its changes in neurological diseases. White matter tract integrity (WMTI) was proposed as a biophysical model to relate the DKI-derived metrics to the underlying microstructure. Although the model has been validated on ex vivo animal brains, it was not well evaluated with ex vivo human brains. In this study, histological samples (namely corpus callosum) from postmortem human brains have been investigated based on WMTI analyses on a clinical 3T scanner and comparisons with gold standard myelin staining in proteolipid protein and Luxol fast blue. In addition, Monte Carlo simulations were conducted to link changes from ex vivo to in vivo conditions based on the microscale parameters of water diffusivity and permeability. The results show that WMTI metrics, including axonal water fraction AWF, radial extra-axonal diffusivity De⊥, and intra-axonal diffusivity Dawere needed to characterize myelin content alterations. Thus, WMTI model metrics are shown to be promising candidates as sensitive biomarkers of demyelination.
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Affiliation(s)
- Zihan Zhou
- Center for Brain Imaging Science and Technology, Key Laboratory for Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and Instrumental Science, Zhejiang University, Zhouyiqing Building, Room 314, Yuquan Campus, Hangzhou 310027, China
| | - Qiqi Tong
- Center for Brain Imaging Science and Technology, Key Laboratory for Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and Instrumental Science, Zhejiang University, Zhouyiqing Building, Room 314, Yuquan Campus, Hangzhou 310027, China
| | - Lei Zhang
- China Brain Bank and Department of Neurology in Second Affiliated Hospital, Key Laboratory of Medical Neurobiology of Zhejiang Province, and Department of Neurobiology, Zhejiang University School of Medicine, Hangzhou 310058, China; Department of Pathology, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Qiuping Ding
- Center for Brain Imaging Science and Technology, Key Laboratory for Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and Instrumental Science, Zhejiang University, Zhouyiqing Building, Room 314, Yuquan Campus, Hangzhou 310027, China
| | - Hui Lu
- China Brain Bank and Department of Neurology in Second Affiliated Hospital, Key Laboratory of Medical Neurobiology of Zhejiang Province, and Department of Neurobiology, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Laura E Jonkman
- Department of Anatomy and Neurosciences, Amsterdam Neuroscience, Amsterdam UMC, location VUmc, the Netherlands
| | - Junye Yao
- Center for Brain Imaging Science and Technology, Key Laboratory for Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and Instrumental Science, Zhejiang University, Zhouyiqing Building, Room 314, Yuquan Campus, Hangzhou 310027, China
| | - Hongjian He
- Center for Brain Imaging Science and Technology, Key Laboratory for Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and Instrumental Science, Zhejiang University, Zhouyiqing Building, Room 314, Yuquan Campus, Hangzhou 310027, China.
| | - Keqing Zhu
- China Brain Bank and Department of Neurology in Second Affiliated Hospital, Key Laboratory of Medical Neurobiology of Zhejiang Province, and Department of Neurobiology, Zhejiang University School of Medicine, Hangzhou 310058, China; Department of Pathology, Zhejiang University School of Medicine, Hangzhou 310058, China.
| | - Jianhui Zhong
- Center for Brain Imaging Science and Technology, Key Laboratory for Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and Instrumental Science, Zhejiang University, Zhouyiqing Building, Room 314, Yuquan Campus, Hangzhou 310027, China; Department of Imaging Sciences, University of Rochester, United States
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Brusini L, Menegaz G, Nilsson M. Monte Carlo Simulations of Water Exchange Through Myelin Wraps: Implications for Diffusion MRI. IEEE TRANSACTIONS ON MEDICAL IMAGING 2019; 38:1438-1445. [PMID: 30835213 DOI: 10.1109/tmi.2019.2894398] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Diffusion magnetic resonance imaging (dMRI) yields parameters sensitive to brain tissue microstructure. A structurally important aspect of this microstructure is the myelin wrapping around the axons. This paper investigated the forward problem concerning whether water exchange via the spiraling structure of the myelin can meaningfully contribute to the signal in dMRI. Monte Carlo simulations were performed in a system with intra-axonal, myelin, and extra-axonal compartments. Diffusion in the myelin was simulated as a spiral wrapping the axon, with a custom number of wraps. Exchange (or intra-axonal residence) times were analyzed for various number of wraps and axon diameters. Pulsed gradient sequences were employed to simulate the dMRI signal, which was analyzed using different methods. Diffusional kurtosis imaging analysis yielded the radial diffusivity (RD) and radial kurtosis (RK), while the two-compartment Kärger model yielded estimates the intra-axonal volume fraction ( ν ic ) and exchange time ( τ ). Results showed that τ was on the sub-second level for geometries with axon diameters below 1.0 μ m and less than eight wraps. Otherwise, exchange was negligible compared to typical experimental durations, with τ of seconds or longer. In situations where exchange influenced the signal, estimates of RK and ν ic increased with the number of wraps, while RD decreased. τ estimates from simulated signals were in agreement with predicted ones. In conclusion, exchange through spiraling myelin permits sub-second τ for small diameters and low number of wraps. Such conditions may arise in the developing brain or in neurodegenerative disease, and thus the results could aid the interpretation of dMRI studies.
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Lee BY, Zhu XH, Li X, Chen W. High-resolution imaging of distinct human corpus callosum microstructure and topography of structural connectivity to cortices at high field. Brain Struct Funct 2018; 224:949-960. [PMID: 30511335 DOI: 10.1007/s00429-018-1804-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 11/25/2018] [Indexed: 02/01/2023]
Abstract
Characterization of the microstructural properties and topography of the human corpus callosum (CC) is key to understanding interhemispheric neural communication and brain function. In this work, we tested the hypothesis that high-resolution T1 relaxometry at high field has adequate sensitivity and specificity for characterizing microstructural properties of the human CC, and elucidating the structural connectivity of the callosal fibers to the cortices of origin. The high-resolution parametric T1 images acquired from healthy subjects (N = 16) at 7 T clearly showed a consistent T1 distribution among individuals with substantial variation along the human CC axis, which is highly similar to the spatial patterns of myelin density and myelinated axon size based on the histology study. Compared to the anterior part of the CC, the posterior midbody and splenium had significantly higher T1 values. In conjunction with T1-based classification method, the splenial T1 values were decoded more reliably compared to a conventional partitioning method, showing a much higher T1 value in the inferior splenium than in the middle/superior splenium. Moreover, the T1 profile of the callosal subdivision represented the topology of the fiber connectivity to the projected cortical regions: the fibers in the posterior midbody and inferior splenium with a higher T1 (inferring a larger axon size) were mainly connected to motor-sensory and visual cortical areas, respectively; in contrast, the fibers in the anterior/posterior CC with a lower T1 (inferring a smaller axon size) were primarily connected to the frontal/parietal-temporal areas. These findings indicate that high-resolution T1 relaxometry imaging could provide a complementary and robust neuroimaging tool, useful for exploring the complex tissue properties and topographic organization of the human corpus callosum.
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Affiliation(s)
- Byeong-Yeul Lee
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, 2021 Sixth Street SE, Minneapolis, MN, 55455, USA.
| | - Xiao-Hong Zhu
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, 2021 Sixth Street SE, Minneapolis, MN, 55455, USA
| | - Xiufeng Li
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, 2021 Sixth Street SE, Minneapolis, MN, 55455, USA
| | - Wei Chen
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, 2021 Sixth Street SE, Minneapolis, MN, 55455, USA.
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Sheikhi S, Saboory E, Farjah GH. Correlation of nerve fibers in corpus callosum and number of neurons in cerebral cortex: an innovative mathematical model. Int J Neurosci 2018; 128:995-1002. [PMID: 29619891 DOI: 10.1080/00207454.2018.1458725] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Purpose/aim: It is estimated that 109 bits/s information are processed in the human brain. The transmission of this huge amount of information requires all connections in the brain to be highly accurate and have order. The current study attempted to present a new aspect of order and proportion in the ultra-structure of the human brain and to calculate the degree of neural interdependence between the two hemispheres. MATERIALS AND METHODS In this model, intensity of interdependence of the brain to hemispheres is estimated to be equal to the mathematical proportion of number of neurons in cerebral cortex divided by 2 (number of hemispheres), divided by number of nerve fibers in the human corpus callosum. RESULTS The calculated number is equal to 30-50 and it indicates that for every 30-50 neurons between the two hemispheres, there is a neural interconnecting bridge. CONCLUSIONS This connection indicates that the brain's function output follows a mathematical relation.
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Affiliation(s)
- Siamak Sheikhi
- a Neurophysiology Research Center , Urmia University of Medical Sciences , Urmia , Iran
| | - Ehsan Saboory
- a Neurophysiology Research Center , Urmia University of Medical Sciences , Urmia , Iran
| | - Gholam Hosein Farjah
- b Department of Anatomy, Faculty of medicine , Urmia University of Medical Sciences , Urmia Iran
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Hopkins WD, Hopkins AM, Misiura M, Latash EM, Mareno MC, Schapiro SJ, Phillips KA. Sex differences in the relationship between planum temporale asymmetry and corpus callosum morphology in chimpanzees (Pan troglodytes): A combined MRI and DTI analysis. Neuropsychologia 2016; 93:325-334. [PMID: 27055947 PMCID: PMC5050170 DOI: 10.1016/j.neuropsychologia.2016.04.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 02/23/2016] [Accepted: 04/03/2016] [Indexed: 12/31/2022]
Abstract
Increases brain size has been hypothesized to be inversely associated with the expression of behavioral and brain asymmetries within and between species. We tested this hypothesis by analyzing the relation between asymmetries in the planum temporale (PT) and different measures of the corpus callosum (CC) including surface area, streamline count as measured from diffusion tensor imaging, fractional anisotropy values and the ratio in the number of fibers to surface area in a sample of chimpanzees. We found that chimpanzees with larger PT asymmetries in absolute terms had smaller CC surface areas, fewer streamlines and a smaller ratio of fibers to surface area. These results were largely specific to male but not female chimpanzees. Our results partially support the hypothesis that brain asymmetries are linked to variation in corpus callosum morphology, although these associations may be sex-dependent.
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Affiliation(s)
- William D Hopkins
- Neuroscience Institute and Language Research Center, Georgia State University, Atlanta, GA 30302, USA; Division of Developmental and Cognitive Neuroscience, Yerkes National Primate Research Center, Atlanta, GA 30329, USA.
| | - Anna M Hopkins
- Division of Developmental and Cognitive Neuroscience, Yerkes National Primate Research Center, Atlanta, GA 30329, USA
| | - Maria Misiura
- Department of Psychology, Georgia State University, Atlanta, GA 30302, USA
| | - Elitaveta M Latash
- Neuroscience Institute and Language Research Center, Georgia State University, Atlanta, GA 30302, USA
| | - Mary Catherine Mareno
- Department of Veterinary Science, The University of Texas MD Anderson Cancer Center, Bastrop, TX 78602, USA
| | - Steven J Schapiro
- Department of Veterinary Science, The University of Texas MD Anderson Cancer Center, Bastrop, TX 78602, USA
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Hopkins WD, Misiura M, Pope SM, Latash EM. Behavioral and brain asymmetries in primates: a preliminary evaluation of two evolutionary hypotheses. Ann N Y Acad Sci 2015; 1359:65-83. [PMID: 26426409 PMCID: PMC4715693 DOI: 10.1111/nyas.12936] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Contrary to many historical views, recent evidence suggests that species-level behavioral and brain asymmetries are evident in nonhuman species. Here, we briefly present evidence of behavioral, perceptual, cognitive, functional, and neuroanatomical asymmetries in nonhuman primates. In addition, we describe two historical accounts of the evolutionary origins of hemispheric specialization and present data from nonhuman primates that address these specific theories. Specifically, we first discuss the evidence that genes play specific roles in determining left-right differences in anatomical and functional asymmetries in primates. We next consider and present data on the hypothesis that hemispheric specialization evolved as a by-product of increasing brain size relative to the surface area of the corpus callosum in different primate species. Last, we discuss some of the challenges in the study of hemispheric specialization in primates and offer some suggestions on how to advance the field.
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Affiliation(s)
- William D Hopkins
- Neuroscience Institute and Language Research Center, Georgia State University, Atlanta, Georgia
- Division of Developmental and Cognitive Neuroscience, Yerkes National Primate Research Center, Atlanta, Georgia
| | - Maria Misiura
- Department of Psychology, Georgia State University, Atlanta, Georgia
| | - Sarah M Pope
- Neuroscience Institute and Language Research Center, Georgia State University, Atlanta, Georgia
| | - Elitaveta M Latash
- Neuroscience Institute and Language Research Center, Georgia State University, Atlanta, Georgia
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Labadie C, Lee JH, Rooney WD, Jarchow S, Aubert-Frécon M, Springer CS, Möller HE. Myelin water mapping by spatially regularized longitudinal relaxographic imaging at high magnetic fields. Magn Reson Med 2013; 71:375-87. [PMID: 23468414 DOI: 10.1002/mrm.24670] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2012] [Revised: 01/09/2013] [Accepted: 01/10/2013] [Indexed: 11/07/2022]
Affiliation(s)
- Christian Labadie
- Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; Laboratoire de Spectrométrie Ionique et Moléculaire, Université Claude-Bernard, Lyon, France; Faculty of Physics and Earth Sciences, University of Leipzig, Leipzig, Germany
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Planum temporale asymmetries correlate with corpus callosum axon fiber density in chimpanzees (Pan troglodytes). Behav Brain Res 2012; 234:248-54. [PMID: 22766214 DOI: 10.1016/j.bbr.2012.06.030] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Accepted: 06/25/2012] [Indexed: 02/01/2023]
Abstract
The corpus callosum (CC) is the major white matter tract that connects the two cerebral hemispheres. Some have theorized that individual differences in behavioral and brain asymmetries are linked to variation in the density of axon fibers that traverse different sections of the CC. In this study, we examined whether variation in axon fiber density in the CC was associated with variation in asymmetries in the planum temporale (PT) in a sample of 20 post-mortem chimpanzee brains. We further tested for sex differences in small and large CC fiber proportions and density in the chimpanzees. We found that the distribution of small and large fibers within the CC of chimpanzees follows a similar pattern to those reported in humans. We also found that chimpanzees with larger asymmetries in the PT had fewer large fibers in the posterior portion of the CC, particularly among females. As has been reported in human brains, the findings reported here indicate that individual differences in brain asymmetries are associated with variation in interhemispheric connectivity as manifest in axon fiber density and size.
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Abstract
The corpus callosum (CC) is the largest commissural white matter tract in mammalian brains, connecting homotopic and heterotopic regions of the cerebral cortex. Knowledge of the distribution of callosal fibers projecting into specific cortical regions has important implications for understanding the evolution of lateralized structures and functions of the cerebral cortex. No comparisons of CC topography in humans and great apes have yet been conducted. We investigated the topography of the CC in 21 chimpanzees using high-resolution magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI). Tractography was conducted based on fiber assignment by continuous tracking (FACT) algorithm. We expected chimpanzees to display topographical organization similar to humans, especially concerning projections into the frontal cortical regions. Similar to recent studies in humans, tractography identified five clusters of CC fibers projecting into defined cortical regions: prefrontal; premotor and supplementary motor; motor; sensory; parietal, temporal and occipital. Significant differences in fractional anisotropy (FA) were found in callosal regions, with highest FA values in regions projecting to higher-association areas of posterior cortical (including parietal, temporal and occipital cortices) and prefrontal cortical regions (p<0.001). The lowest FA values were seen in regions projecting into motor and sensory cortical areas. Our results indicate chimpanzees display similar topography of the CC as humans, in terms of distribution of callosal projections and microstructure of fibers as determined by anisotropy measures.
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Abstract
The production of genotypic and phenotypic diversity (differentiation) is the final outcome of both development and evolution, of nervous systems and of their components. Cortical axons, in particular, differentiate into a variety of phenotypes which are responsible for computational transformations of messages exchanged among neurons. One aspect of this differentiation concerns axon diameters whose diversity in development, but also within and across species, is enhanced by the addition of a relatively small proportion of thicker axons to some axonal pathways. This, combined with differences in the length of pathways and in brain volumes, has rescaled and expanded the temporal range of interneuronal communication. In both development and evolution, this and other aspects of axonal phenotypes, namely the structure and distribution of axonal arbors, differentiate by the combined action of cell intrinsic (genetic) variation, overproduction, and selection by the environment.
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