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Lu Y, Cui Y, Cao L, Dong Z, Cheng L, Wu W, Wang C, Liu X, Liu Y, Zhang B, Li D, Zhao B, Wang H, Li K, Ma L, Shi W, Li W, Ma Y, Du Z, Zhang J, Xiong H, Luo N, Liu Y, Hou X, Han J, Sun H, Cai T, Peng Q, Feng L, Wang J, Paxinos G, Yang Z, Fan L, Jiang T. Macaque Brainnetome Atlas: A multifaceted brain map with parcellation, connection, and histology. Sci Bull (Beijing) 2024; 69:2241-2259. [PMID: 38580551 DOI: 10.1016/j.scib.2024.03.031] [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: 10/12/2023] [Revised: 01/18/2024] [Accepted: 03/11/2024] [Indexed: 04/07/2024]
Abstract
The rhesus macaque (Macaca mulatta) is a crucial experimental animal that shares many genetic, brain organizational, and behavioral characteristics with humans. A macaque brain atlas is fundamental to biomedical and evolutionary research. However, even though connectivity is vital for understanding brain functions, a connectivity-based whole-brain atlas of the macaque has not previously been made. In this study, we created a new whole-brain map, the Macaque Brainnetome Atlas (MacBNA), based on the anatomical connectivity profiles provided by high angular and spatial resolution ex vivo diffusion MRI data. The new atlas consists of 248 cortical and 56 subcortical regions as well as their structural and functional connections. The parcellation and the diffusion-based tractography were evaluated with invasive neuronal-tracing and Nissl-stained images. As a demonstrative application, the structural connectivity divergence between macaque and human brains was mapped using the Brainnetome atlases of those two species to uncover the genetic underpinnings of the evolutionary changes in brain structure. The resulting resource includes: (1) the thoroughly delineated Macaque Brainnetome Atlas (MacBNA), (2) regional connectivity profiles, (3) the postmortem high-resolution macaque diffusion and T2-weighted MRI dataset (Brainnetome-8), and (4) multi-contrast MRI, neuronal-tracing, and histological images collected from a single macaque. MacBNA can serve as a common reference frame for mapping multifaceted features across modalities and spatial scales and for integrative investigation and characterization of brain organization and function. Therefore, it will enrich the collaborative resource platform for nonhuman primates and facilitate translational and comparative neuroscience research.
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Affiliation(s)
- Yuheng Lu
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China; School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yue Cui
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Long Cao
- Henan Key Laboratory of Imaging and Intelligent Processing, PLA Strategic Support Force Information Engineering University, Zhengzhou 450001, China; Key Laboratory for NeuroInformation of the Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Zhenwei Dong
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China; School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Luqi Cheng
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China; School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin 541004, China; Research Center for Augmented Intelligence, Zhejiang Lab, Hangzhou 311100, China
| | - Wen Wu
- Research Center for Augmented Intelligence, Zhejiang Lab, Hangzhou 311100, China
| | - Changshuo Wang
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China; Sino-Danish College, University of Chinese Academy of Science, Beijing 100049, China
| | - Xinyi Liu
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China; School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing 100049, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Youtong Liu
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China; School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Baogui Zhang
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Deying Li
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China; School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Bokai Zhao
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China; School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Haiyan Wang
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China
| | - Kaixin Li
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China; School of Mechanical and Power Engineering, Harbin University of Science and Technology, Harbin 150080, China
| | - Liang Ma
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China; School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Weiyang Shi
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China; School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wen Li
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yawei Ma
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China; Sino-Danish College, University of Chinese Academy of Science, Beijing 100049, China
| | - Zongchang Du
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China; School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jiaqi Zhang
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China; School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hui Xiong
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China
| | - Na Luo
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China
| | - Yanyan Liu
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China
| | - Xiaoxiao Hou
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China
| | - Jinglu Han
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China; Sino-Danish College, University of Chinese Academy of Science, Beijing 100049, China
| | - Hongji Sun
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China
| | - Tao Cai
- Research Center for Augmented Intelligence, Zhejiang Lab, Hangzhou 311100, China
| | - Qiang Peng
- Research Center for Augmented Intelligence, Zhejiang Lab, Hangzhou 311100, China
| | - Linqing Feng
- Research Center for Augmented Intelligence, Zhejiang Lab, Hangzhou 311100, China
| | - Jiaojian Wang
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming 650500, China
| | - George Paxinos
- Neuroscience Research Australia and The University of New South Wales, Sydney NSW 2031, Australia
| | - Zhengyi Yang
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China; Xiaoxiang Institute for Brain Health and Yongzhou Central Hospital, Yongzhou 425000, China.
| | - Lingzhong Fan
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China; School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Tianzi Jiang
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China; School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing 100049, China; Research Center for Augmented Intelligence, Zhejiang Lab, Hangzhou 311100, China; Xiaoxiang Institute for Brain Health and Yongzhou Central Hospital, Yongzhou 425000, China.
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2
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Haggie L, Besier T, McMorland A. Circuits in the motor cortex explain oscillatory responses to transcranial magnetic stimulation. Netw Neurosci 2024; 8:96-118. [PMID: 38562291 PMCID: PMC10861165 DOI: 10.1162/netn_a_00341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 10/11/2023] [Indexed: 04/04/2024] Open
Abstract
Transcranial magnetic stimulation (TMS) is a popular method used to investigate brain function. Stimulation over the motor cortex evokes muscle contractions known as motor evoked potentials (MEPs) and also high-frequency volleys of electrical activity measured in the cervical spinal cord. The physiological mechanisms of these experimentally derived responses remain unclear, but it is thought that the connections between circuits of excitatory and inhibitory neurons play a vital role. Using a spiking neural network model of the motor cortex, we explained the generation of waves of activity, so called 'I-waves', following cortical stimulation. The model reproduces a number of experimentally known responses including direction of TMS, increased inhibition, and changes in strength. Using populations of thousands of neurons in a model of cortical circuitry we showed that the cortex generated transient oscillatory responses without any tuning, and that neuron parameters such as refractory period and delays influenced the pattern and timing of those oscillations. By comparing our network with simpler, previously proposed circuits, we explored the contributions of specific connections and found that recurrent inhibitory connections are vital in producing later waves that significantly impact the production of motor evoked potentials in downstream muscles (Thickbroom, 2011). This model builds on previous work to increase our understanding of how complex circuitry of the cortex is involved in the generation of I-waves.
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Affiliation(s)
- Lysea Haggie
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Thor Besier
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Angus McMorland
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
- Department of Exercise Sciences, University of Auckland, Auckland, New Zealand
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Mendoza-Halliday D, Xu H, Azevedo FAC, Desimone R. Dissociable neuronal substrates of visual feature attention and working memory. Neuron 2024; 112:850-863.e6. [PMID: 38228138 PMCID: PMC10939754 DOI: 10.1016/j.neuron.2023.12.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 10/10/2023] [Accepted: 12/12/2023] [Indexed: 01/18/2024]
Abstract
Attention and working memory (WM) are distinct cognitive functions, yet given their close interactions, it is often assumed that they share the same neuronal mechanisms. We show that in macaques performing a WM-guided feature attention task, the activity of most neurons in areas middle temporal (MT), medial superior temporal (MST), lateral intraparietal (LIP), and posterior lateral prefrontal cortex (LPFC-p) displays attentional modulation or WM coding and not both. One area thought to play a role in both functions is LPFC-p. To test this, we optogenetically inactivated LPFC-p bilaterally during different task periods. Attention period inactivation reduced attentional modulation in LPFC-p, MST, and LIP neurons and impaired task performance. In contrast, WM period inactivation did not affect attentional modulation or performance and minimally affected WM coding. Our results suggest that feature attention and WM have dissociable neuronal substrates and that LPFC-p plays a critical role in feature attention, but not in WM.
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Affiliation(s)
- Diego Mendoza-Halliday
- Department of Brain and Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, USA.
| | - Haoran Xu
- Department of Brain and Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Frederico A C Azevedo
- Department of Brain and Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Robert Desimone
- Department of Brain and Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, USA
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He J, Zhang F, Pan Y, Feng Y, Rushmore J, Torio E, Rathi Y, Makris N, Kikinis R, Golby AJ, O'Donnell LJ. Reconstructing the somatotopic organization of the corticospinal tract remains a challenge for modern tractography methods. Hum Brain Mapp 2023; 44:6055-6073. [PMID: 37792280 PMCID: PMC10619402 DOI: 10.1002/hbm.26497] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 09/09/2023] [Accepted: 09/13/2023] [Indexed: 10/05/2023] Open
Abstract
The corticospinal tract (CST) is a critically important white matter fiber tract in the human brain that enables control of voluntary movements of the body. The CST exhibits a somatotopic organization, which means that the motor neurons that control specific body parts are arranged in order within the CST. Diffusion magnetic resonance imaging (MRI) tractography is increasingly used to study the anatomy of the CST. However, despite many advances in tractography algorithms over the past decade, modern, state-of-the-art methods still face challenges. In this study, we compare the performance of six widely used tractography methods for reconstructing the CST and its somatotopic organization. These methods include constrained spherical deconvolution (CSD) based probabilistic (iFOD1) and deterministic (SD-Stream) methods, unscented Kalman filter (UKF) tractography methods including multi-fiber (UKF2T) and single-fiber (UKF1T) models, the generalized q-sampling imaging (GQI) based deterministic tractography method, and the TractSeg method. We investigate CST somatotopy by dividing the CST into four subdivisions per hemisphere that originate in the leg, trunk, hand, and face areas of the primary motor cortex. A quantitative and visual comparison is performed using diffusion MRI data (N = 100 subjects) from the Human Connectome Project. Quantitative evaluations include the reconstruction rate of the eight anatomical subdivisions, the percentage of streamlines in each subdivision, and the coverage of the white matter-gray matter (WM-GM) interface. CST somatotopy is further evaluated by comparing the percentage of streamlines in each subdivision to the cortical volumes for the leg, trunk, hand, and face areas. Overall, UKF2T has the highest reconstruction rate and cortical coverage. It is the only method with a significant positive correlation between the percentage of streamlines in each subdivision and the volume of the corresponding motor cortex. However, our experimental results show that all compared tractography methods are biased toward generating many trunk streamlines (ranging from 35.10% to 71.66% of total streamlines across methods). Furthermore, the coverage of the WM-GM interface in the largest motor area (face) is generally low (under 40%) for all compared tractography methods. Different tractography methods give conflicting results regarding the percentage of streamlines in each subdivision and the volume of the corresponding motor cortex, indicating that there is generally no clear relationship, and that reconstruction of CST somatotopy is still a large challenge. Overall, we conclude that while current tractography methods have made progress toward the well-known challenge of improving the reconstruction of the lateral projections of the CST, the overall problem of performing a comprehensive CST reconstruction, including clinically important projections in the lateral (hand and face areas) and medial portions (leg area), remains an important challenge for diffusion MRI tractography.
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Affiliation(s)
- Jianzhong He
- Institution of Information Processing and AutomationZhejiang University of TechnologyHangzhouChina
| | - Fan Zhang
- Department of Radiology, Brigham and Women's HospitalHarvard Medical SchoolBostonMassachusettsUSA
- University of Electronic Science and Technology of ChinaChengduSichuanChina
| | - Yiang Pan
- Institution of Information Processing and AutomationZhejiang University of TechnologyHangzhouChina
| | - Yuanjing Feng
- Institution of Information Processing and AutomationZhejiang University of TechnologyHangzhouChina
| | - Jarrett Rushmore
- Departments of Psychiatry, Neurology and RadiologyMassachusetts General Hospital, Harvard Medical SchoolBostonMassachusettsUSA
- Department of Anatomy and NeurobiologyBoston University School of MedicineBostonMassachusettsUSA
| | - Erickson Torio
- Department of NeurosurgeryBrigham and Women's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Yogesh Rathi
- Department of Radiology, Brigham and Women's HospitalHarvard Medical SchoolBostonMassachusettsUSA
- Department of PsychiatryBrigham and Women's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Nikos Makris
- Departments of Psychiatry, Neurology and RadiologyMassachusetts General Hospital, Harvard Medical SchoolBostonMassachusettsUSA
- Department of PsychiatryBrigham and Women's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Ron Kikinis
- Department of Radiology, Brigham and Women's HospitalHarvard Medical SchoolBostonMassachusettsUSA
| | - Alexandra J. Golby
- Department of Radiology, Brigham and Women's HospitalHarvard Medical SchoolBostonMassachusettsUSA
- Department of NeurosurgeryBrigham and Women's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Lauren J. O'Donnell
- Department of Radiology, Brigham and Women's HospitalHarvard Medical SchoolBostonMassachusettsUSA
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Doubovikov ED, Serdyukova NA, Greenberg SB, Gascoigne DA, Minhaj MM, Aksenov DP. Electric Field Effects on Brain Activity: Implications for Epilepsy and Burst Suppression. Cells 2023; 12:2229. [PMID: 37759452 PMCID: PMC10527339 DOI: 10.3390/cells12182229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 08/07/2023] [Accepted: 09/04/2023] [Indexed: 09/29/2023] Open
Abstract
Electric fields are now considered a major mechanism of epileptiform activity. However, it is not clear if another electrophysiological phenomenon, burst suppression, utilizes the same mechanism for its bursting phase. Thus, the purpose of this study was to compare the role of ephaptic coupling-the recruitment of neighboring cells via electric fields-in generating bursts in epilepsy and burst suppression. We used local injections of the GABA-antagonist picrotoxin to elicit epileptic activity and a general anesthetic, sevoflurane, to elicit burst suppression in rabbits. Then, we applied an established computational model of pyramidal cells to simulate neuronal activity in a 3-dimensional grid, with an additional parameter to trigger a suppression phase based on extra-cellular calcium dynamics. We discovered that coupling via electric fields was sufficient to produce bursting in scenarios where inhibitory control of excitatory neurons was sufficiently low. Under anesthesia conditions, bursting occurs with lower neuronal recruitment in comparison to seizures. Our model predicts that due to the effect of electric fields, the magnitude of bursts during seizures should be roughly 2-3 times the magnitude of bursts that occur during burst suppression, which is consistent with our in vivo experimental results. The resulting difference in magnitude between bursts during anesthesia and epileptiform bursts reflects the strength of the electric field effect, which suggests that burst suppression and epilepsy share the same ephaptic coupling mechanism.
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Affiliation(s)
- Evan D. Doubovikov
- Department of Radiology, NorthShore University HealthSystem, Evanston, IL 60201, USA
| | - Natalya A. Serdyukova
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA
- Department of Pediatrics, NorthShore University HealthSystem, Evanston, IL 60201, USA
| | - Steven B. Greenberg
- Department of Anesthesiology, NorthShore University HealthSystem, Evanston, IL 60201, USA
| | - David A. Gascoigne
- Department of Radiology, NorthShore University HealthSystem, Evanston, IL 60201, USA
| | - Mohammed M. Minhaj
- Department of Anesthesiology, NorthShore University HealthSystem, Evanston, IL 60201, USA
| | - Daniil P. Aksenov
- Department of Radiology, NorthShore University HealthSystem, Evanston, IL 60201, USA
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA
- Department of Anesthesiology, NorthShore University HealthSystem, Evanston, IL 60201, USA
- Pritzker School of Medicine, University of Chicago, Chicago, IL 60637, USA
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Haggie L, Schmid L, Röhrle O, Besier T, McMorland A, Saini H. Linking cortex and contraction-Integrating models along the corticomuscular pathway. Front Physiol 2023; 14:1095260. [PMID: 37234419 PMCID: PMC10206006 DOI: 10.3389/fphys.2023.1095260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 04/21/2023] [Indexed: 05/28/2023] Open
Abstract
Computational models of the neuromusculoskeletal system provide a deterministic approach to investigate input-output relationships in the human motor system. Neuromusculoskeletal models are typically used to estimate muscle activations and forces that are consistent with observed motion under healthy and pathological conditions. However, many movement pathologies originate in the brain, including stroke, cerebral palsy, and Parkinson's disease, while most neuromusculoskeletal models deal exclusively with the peripheral nervous system and do not incorporate models of the motor cortex, cerebellum, or spinal cord. An integrated understanding of motor control is necessary to reveal underlying neural-input and motor-output relationships. To facilitate the development of integrated corticomuscular motor pathway models, we provide an overview of the neuromusculoskeletal modelling landscape with a focus on integrating computational models of the motor cortex, spinal cord circuitry, α-motoneurons and skeletal muscle in regard to their role in generating voluntary muscle contraction. Further, we highlight the challenges and opportunities associated with an integrated corticomuscular pathway model, such as challenges in defining neuron connectivities, modelling standardisation, and opportunities in applying models to study emergent behaviour. Integrated corticomuscular pathway models have applications in brain-machine-interaction, education, and our understanding of neurological disease.
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Affiliation(s)
- Lysea Haggie
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Laura Schmid
- Institute for Modelling and Simulation of Biomechanical Systems, University of Stuttgart, Stuttgart, Germany
| | - Oliver Röhrle
- Institute for Modelling and Simulation of Biomechanical Systems, University of Stuttgart, Stuttgart, Germany
- Stuttgart Center for Simulation Sciences (SC SimTech), University of Stuttgart, Stuttgart, Germany
| | - Thor Besier
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Angus McMorland
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
- Department of Exercise Sciences, University of Auckland, Auckland, New Zealand
| | - Harnoor Saini
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
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7
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Mendoza-Halliday D, Xu H, Azevedo FAC, Desimone R. Dissociable neuronal substrates of visual feature attention and working memory. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.01.530719. [PMID: 36909606 PMCID: PMC10002769 DOI: 10.1101/2023.03.01.530719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
Abstract
Attention and working memory (WM) are distinct cognitive functions, yet given their close interactions, it has been proposed that they share the same neuronal mechanisms. Here we show that in macaques performing a WM-guided feature attention task, the activity of most neurons in areas middle temporal (MT), medial superior temporal (MST), lateral intraparietal (LIP), and posterior lateral prefrontal cortex (LPFC-p) displays either WM coding or attentional modulation, but not both. One area thought to play a role in both functions is LPFC-p. To test this, we optogenetically inactivated LPFC-p bilaterally during the attention or WM periods of the task. Attention period inactivation reduced attentional modulation in LPFC-p, MST, and LIP neurons, and impaired task performance. WM period inactivation did not affect attentional modulation nor performance, and minimally reduced WM coding. Our results suggest that feature attention and WM have dissociable neuronal substrates, and that LPFC-p plays a critical role in attention but not WM.
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8
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Mercadal B, Lopez-Sola E, Galan-Gadea A, Al Harrach M, Sanchez-Todo R, Salvador R, Bartolomei F, Wendling F, Ruffini G. Towards a mesoscale physical modeling framework for stereotactic-EEG recordings. J Neural Eng 2023; 20. [PMID: 36548999 DOI: 10.1088/1741-2552/acae0c] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 12/22/2022] [Indexed: 12/24/2022]
Abstract
Objective.Stereotactic-electroencephalography (SEEG) and scalp EEG recordings can be modeled using mesoscale neural mass population models (NMMs). However, the relationship between those mathematical models and the physics of the measurements is unclear. In addition, it is challenging to represent SEEG data by combining NMMs and volume conductor models due to the intermediate spatial scale represented by these measurements.Approach.We provide a framework combining the multi-compartmental modeling formalism and a detailed geometrical model to simulate the transmembrane currents that appear in layer 3, 5 and 6 pyramidal cells due to a synaptic input. With this approach, it is possible to realistically simulate the current source density (CSD) depth profile inside a cortical patch due to inputs localized into a single cortical layer and the induced voltage measured by two SEEG contacts using a volume conductor model. Based on this approach, we built a framework to connect the activity of a NMM with a volume conductor model and we simulated an example of SEEG signal as a proof of concept.Main results.CSD depends strongly on the distribution of the synaptic inputs onto the different cortical layers and the equivalent current dipole strengths display substantial differences (of up to a factor of four in magnitude in our example). Thus, the inputs coming from different neural populations do not contribute equally to the electrophysiological recordings. A direct consequence of this is that the raw output of NMMs is not a good proxy for electrical recordings. We also show that the simplest CSD model that can accurately reproduce SEEG measurements can be constructed from discrete monopolar sources (one per cortical layer).Significance.Our results highlight the importance of including a physical model in NMMs to represent measurements. We provide a framework connecting microscale neuron models with the neural mass formalism and with physical models of the measurement process that can improve the accuracy of predicted electrophysiological recordings.
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Affiliation(s)
- Borja Mercadal
- Neuroelectrics, Av. Tibidabo 47b, 08035 Barcelona, Spain
| | | | | | - Mariam Al Harrach
- Université de Rennes, INSERM, LTSI (Laboratoire de Traitement du Signal et de l'Image) U1099, 35000 Rennes, France
| | | | | | - Fabrice Bartolomei
- Clinical Physiology Department, INSERM, UMR 1106 and Timone University Hospital, Aix-Marseille Université, Marseille, France
| | - Fabrice Wendling
- Université de Rennes, INSERM, LTSI (Laboratoire de Traitement du Signal et de l'Image) U1099, 35000 Rennes, France
| | - Giulio Ruffini
- Neuroelectrics, Av. Tibidabo 47b, 08035 Barcelona, Spain
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9
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Meseck EK, Guibinga G, Wang S, McElroy C, Hudry E, Mansfield K. Intrathecal sc-AAV9-CB-GFP: Systemic Distribution Predominates Following Single-Dose Administration in Cynomolgus Macaques. Toxicol Pathol 2022; 50:415-431. [PMID: 35658751 PMCID: PMC9284083 DOI: 10.1177/01926233221101309] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Biodistribution of self-complementary adeno-associated virus-9 (scAAV9)–chicken β-actin
promoter–green fluorescent protein (GFP) was assessed in juvenile cynomolgus macaques
infused intrathecally via lumbar puncture or the intracisterna magna (1.0×1013
or 3.0×1013 vg/animal), with necropsy 28 days later. Our results characterized
central nervous system biodistribution compared with systemic organs/tissues by droplet
digital polymerase chain reaction for DNA and in situ hybridization.
Green fluorescent protein expression was characterized by Meso Scale Discovery
electrochemiluminescence immunosorbent assay and immunohistochemistry (IHC).
Biodistribution was widespread but variable, with vector DNA and GFP expression greatest
in the spinal cord, dorsal root ganglia (DRG), and certain systemic tissues (e.g., liver),
with low concentrations in many brain regions despite direct cerebrospinal fluid
administration. Transduction and expression were observed primarily in perivascular
astrocytes in the brain, with a paucity in neurons. Greater GFP expression was observed in
hepatocytes, striated myocytes, cardiomyocytes, spinal cord lower motor neurons, and DRG
sensory neurons by IHC. These results should be considered when evaluating scAAV9-based
intrathecal delivery with the current expression cassette as a modality for neurologic
diseases that require widespread brain neuronal expression. This capsid/expression
cassette combination may be better suited for diseases that express a secreted protein
and/or do not require widespread brain neuronal transduction.
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Affiliation(s)
- Emily K Meseck
- Novartis Pharmaceuticals Corporation, East Hanover, New Jersey, USA
| | - Ghiabe Guibinga
- Novartis Institutes for BioMedical Research Biologics Center, San Diego, California, USA
| | - Stephen Wang
- Novartis Institutes for BioMedical Research, Cambridge, Massachusetts, USA
| | - Cameron McElroy
- Novartis Pharmaceuticals Corporation, East Hanover, New Jersey, USA
| | - Eloise Hudry
- Novartis Institutes for BioMedical Research, Cambridge, Massachusetts, USA
| | - Keith Mansfield
- Novartis Institutes for BioMedical Research, Cambridge, Massachusetts, USA
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10
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Cheng X, Sie EJ, Naufel S, Boas DA, Marsili F. Measuring neuronal activity with diffuse correlation spectroscopy: a theoretical investigation. NEUROPHOTONICS 2021; 8:035004. [PMID: 34368390 PMCID: PMC8339443 DOI: 10.1117/1.nph.8.3.035004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 07/16/2021] [Indexed: 05/18/2023]
Abstract
Significance: Diffuse correlation spectroscopy (DCS) measures cerebral blood flow non-invasively. Variations in blood flow can be used to detect neuronal activities, but its peak has a latency of a few seconds, which is slow for real-time monitoring. Neuronal cells also deform during activation, which, in principle, can be utilized to detect neuronal activity on fast timescales (within 100 ms) using DCS. Aims: We aim to characterize DCS signal variation quantified as the change of the decay time of the speckle intensity autocorrelation function during neuronal activation on both fast (within 100 ms) and slow (100 ms to seconds) timescales. Approach: We extensively modeled the variations in the DCS signal that are expected to arise from neuronal activation using Monte Carlo simulations, including the impacts of neuronal cell motion, vessel wall dilation, and blood flow changes. Results: We found that neuronal cell motion induces a DCS signal variation of ∼ 10 - 5 . We also estimated the contrast and number of channels required to detect hemodynamic signals at different time delays. Conclusions: From this extensive analysis, we do not expect to detect neuronal cell motion using DCS in the near future based on current technology trends. However, multi-channel DCS will be able to detect hemodynamic response with sub-second latency, which is interesting for brain-computer interfaces.
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Affiliation(s)
- Xiaojun Cheng
- Boston University, Neurophotonics Center, Department of Biomedical Engineering, Massachusetts, United States
- Address all correspondence to Xiaojun Cheng,
| | - Edbert J. Sie
- Facebook Reality Labs Research, Menlo Park, California, United States
| | - Stephanie Naufel
- Facebook Reality Labs Research, Menlo Park, California, United States
| | - David A. Boas
- Boston University, Neurophotonics Center, Department of Biomedical Engineering, Massachusetts, United States
| | - Francesco Marsili
- Facebook Reality Labs Research, Menlo Park, California, United States
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11
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Villalba RM, Behnke JA, Pare JF, Smith Y. Comparative Ultrastructural Analysis of Thalamocortical Innervation of the Primary Motor Cortex and Supplementary Motor Area in Control and MPTP-Treated Parkinsonian Monkeys. Cereb Cortex 2021; 31:3408-3425. [PMID: 33676368 PMCID: PMC8599722 DOI: 10.1093/cercor/bhab020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 12/29/2020] [Accepted: 01/19/2021] [Indexed: 12/15/2022] Open
Abstract
The synaptic organization of thalamic inputs to motor cortices remains poorly understood in primates. Thus, we compared the regional and synaptic connections of vGluT2-positive thalamocortical glutamatergic terminals in the supplementary motor area (SMA) and the primary motor cortex (M1) between control and MPTP-treated parkinsonian monkeys. In controls, vGluT2-containing fibers and terminal-like profiles invaded layer II-III and Vb of M1 and SMA. A significant reduction of vGluT2 labeling was found in layer Vb, but not in layer II-III, of parkinsonian animals, suggesting a potential thalamic denervation of deep cortical layers in parkinsonism. There was a significant difference in the pattern of synaptic connectivity in layers II-III, but not in layer Vb, between M1 and SMA of control monkeys. However, this difference was abolished in parkinsonian animals. No major difference was found in the proportion of perforated versus macular post-synaptic densities at thalamocortical synapses between control and parkinsonian monkeys in both cortical regions, except for a slight increase in the prevalence of perforated axo-dendritic synapses in the SMA of parkinsonian monkeys. Our findings suggest that disruption of the thalamic innervation of M1 and SMA may underlie pathophysiological changes of the motor thalamocortical loop in the state of parkinsonism.
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Affiliation(s)
- Rosa M Villalba
- Division of Neuropharmacology and Neurological Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329, USA
- UDALL Center for Excellence for Parkinson’s Disease, Emory University, Atlanta, GA 30329, USA
| | - Joseph A Behnke
- Division of Neuropharmacology and Neurological Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329, USA
- UDALL Center for Excellence for Parkinson’s Disease, Emory University, Atlanta, GA 30329, USA
| | - Jean-Francois Pare
- Division of Neuropharmacology and Neurological Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329, USA
- UDALL Center for Excellence for Parkinson’s Disease, Emory University, Atlanta, GA 30329, USA
| | - Yoland Smith
- Division of Neuropharmacology and Neurological Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329, USA
- UDALL Center for Excellence for Parkinson’s Disease, Emory University, Atlanta, GA 30329, USA
- Department of Neurology, School of Medicine, Emory University, Atlanta, GA 30329, USA
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Monkey V1 epidural field potentials provide detailed information about stimulus location, size, shape, and color. Commun Biol 2021; 4:690. [PMID: 34099840 PMCID: PMC8184760 DOI: 10.1038/s42003-021-02207-w] [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] [Received: 02/02/2021] [Accepted: 05/11/2021] [Indexed: 02/05/2023] Open
Abstract
Brain signal recordings with epidural microarrays constitute a low-invasive approach for recording distributed neuronal signals. Epidural field potentials (EFPs) may serve as a safe and highly beneficial signal source for a variety of research questions arising from both basic and applied neuroscience. A wider use of these signals, however, is constrained by a lack of data on their specific information content. Here, we make use of the high spatial resolution and the columnar organization of macaque primary visual cortex (V1) to investigate whether and to what extent EFP signals preserve information about various visual stimulus features. Two monkeys were presented with different feature combinations of location, size, shape, and color, yielding a total of 375 stimulus conditions. Visual features were chosen to access different spatial levels of functional organization. We found that, besides being highly specific for locational information, EFPs were significantly modulated by small differences in size, shape, and color, allowing for high stimulus classification rates even at the single-trial level. The results support the notion that EFPs constitute a low-invasive, highly beneficial signal source for longer-term recordings for medical and basic research by showing that they convey detailed and reliable information about constituent features of activating stimuli.
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13
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Structure of Population Activity in Primary Motor Cortex for Single Finger Flexion and Extension. J Neurosci 2020; 40:9210-9223. [PMID: 33087474 DOI: 10.1523/jneurosci.0999-20.2020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 08/20/2020] [Accepted: 09/16/2020] [Indexed: 11/21/2022] Open
Abstract
How is the primary motor cortex (M1) organized to control fine finger movements? We investigated the population activity in M1 for single finger flexion and extension, using 7T functional magnetic resonance imaging (fMRI) in female and male human participants and compared these results to the neural spiking patterns recorded in two male monkeys performing the identical task. fMRI activity patterns were distinct for movements of different fingers, but were quite similar for flexion and extension of the same finger. In contrast, spiking patterns in monkeys were quite distinct for both fingers and directions, which is similar to what was found for muscular activity patterns. The discrepancy between fMRI and electrophysiological measurements can be explained by two (non-mutually exclusive) characteristics of the organization of finger flexion and extension movements. Given that fMRI reflects predominantly input and recurrent activity, the results can be explained by an architecture in which neural populations that control flexion or extension of the same finger produce distinct outputs, but interact tightly with each other and receive similar inputs. Additionally, neurons tuned to different movement directions for the same finger (or combination of fingers) may cluster closely together, while neurons that control different finger combinations may be more spatially separated. When measuring this organization with fMRI at a coarse spatial scale, the activity patterns for flexion and extension of the same finger would appear very similar. Overall, we suggest that the discrepancy between fMRI and electrophysiological measurements provides new insights into the general organization of fine finger movements in M1.SIGNIFICANCE STATEMENT The primary motor cortex (M1) is important for producing individuated finger movements. Recent evidence shows that movements that commonly co-occur are associated with more similar activity patterns in M1. Flexion and extension of the same finger, which never co-occur, should therefore be associated with distinct representations. However, using carefully controlled experiments and multivariate analyses, we demonstrate that human fMRI activity patterns for flexion or extension of the same finger are highly similar. In contrast, spiking patterns measured in monkey M1 are clearly distinct. This suggests that populations controlling opposite movements of the same finger, while producing distinct outputs, may cluster together and share inputs and local processing. These results provide testable hypotheses about the organization of hand control in M1.
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14
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Carson RG. Inter‐hemispheric inhibition sculpts the output of neural circuits by co‐opting the two cerebral hemispheres. J Physiol 2020; 598:4781-4802. [DOI: 10.1113/jp279793] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 06/04/2020] [Indexed: 01/11/2023] Open
Affiliation(s)
- Richard G. Carson
- Trinity College Institute of Neuroscience and School of Psychology Trinity College Dublin Dublin 2 Ireland
- School of Psychology Queen's University Belfast Belfast BT7 1NN UK
- School of Human Movement and Nutrition Sciences University of Queensland St Lucia QLD 4072 Australia
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15
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Chen Y, Zhang ZK, He Y, Zhou C. A Large-Scale High-Density Weighted Structural Connectome of the Macaque Brain Acquired by Predicting Missing Links. Cereb Cortex 2020; 30:4771-4789. [PMID: 32313935 PMCID: PMC7391281 DOI: 10.1093/cercor/bhaa060] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 02/20/2020] [Accepted: 02/24/2020] [Indexed: 01/21/2023] Open
Abstract
As a substrate for function, large-scale brain structural networks are crucial for fundamental and systems-level understanding of primate brains. However, it is challenging to acquire a complete primate whole-brain structural connectome using track tracing techniques. Here, we acquired a weighted brain structural network across 91 cortical regions of a whole macaque brain hemisphere with a connectivity density of 59% by predicting missing links from the CoCoMac-based binary network with a low density of 26.3%. The prediction model combines three factors, including spatial proximity, topological similarity, and cytoarchitectural similarity-to predict missing links and assign connection weights. The model was tested on a recently obtained high connectivity density yet partial-coverage experimental weighted network connecting 91 sources to 29 target regions; the model showed a prediction sensitivity of 74.1% in the predicted network. This predicted macaque hemisphere-wide weighted network has module segregation closely matching functional domains. Interestingly, the areas that act as integrators linking the segregated modules are mainly distributed in the frontoparietal network and correspond to the regions with large wiring costs in the predicted weighted network. This predicted weighted network provides a high-density structural dataset for further exploration of relationships between structure, function, and metabolism in the primate brain.
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Affiliation(s)
- Yuhan Chen
- National Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing 100875, China
- IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China
- Beijing Key Laboratory of Brain Imaging and Connectomics, Beijing Normal University, Beijing 100875, China
- Department of Physics, Centre for Nonlinear Studies, and Beijing-Hong Kong-Singapore Joint Centre for Nonlinear and Complex Systems (Hong Kong), Institute of Computational and Theoretical Studies, Hong Kong Baptist University, Hong Kong
| | - Zi-Ke Zhang
- College of Media and International Culture, Zhejiang University, Hangzhou 310058, China
- Alibaba Research Center for Complex Sciences, Hangzhou Normal University, Hangzhou 311121, China
| | - Yong He
- National Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing 100875, China
- IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China
- Beijing Key Laboratory of Brain Imaging and Connectomics, Beijing Normal University, Beijing 100875, China
| | - Changsong Zhou
- Department of Physics, Centre for Nonlinear Studies, and Beijing-Hong Kong-Singapore Joint Centre for Nonlinear and Complex Systems (Hong Kong), Institute of Computational and Theoretical Studies, Hong Kong Baptist University, Hong Kong
- Department of Physics, Zhejiang University, Hangzhou 310027, China
- Research Centre, HKBU Institute of Research and Continuing Education, Shenzhen 518000, China
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16
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Cohen S, Sazan H, Kenigsberg A, Schori H, Piperno S, Shpaisman H, Shefi O. Large-scale acoustic-driven neuronal patterning and directed outgrowth. Sci Rep 2020; 10:4932. [PMID: 32188875 PMCID: PMC7080736 DOI: 10.1038/s41598-020-60748-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 01/31/2020] [Indexed: 11/09/2022] Open
Abstract
Acoustic manipulation is an emerging non-invasive method enabling precise spatial control of cells in their native environment. Applying this method for organizing neurons is invaluable for neural tissue engineering applications. Here, we used surface and bulk standing acoustic waves for large-scale patterning of Dorsal Root Ganglia neurons and PC12 cells forming neuronal cluster networks, organized biomimetically. We showed that by changing parameters such as voltage intensity or cell concentration we were able to affect cluster properties. We examined the effects of acoustic arrangement on cells atop 3D hydrogels for up to 6 days and showed that assembled cells spontaneously grew branches in a directed manner towards adjacent clusters, infiltrating the matrix. These findings have great relevance for tissue engineering applications as well as for mimicking architectures and properties of native tissues.
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Affiliation(s)
- Sharon Cohen
- Faculty of Engineering, Bar-Ilan University, Ramat Gan, Israel
- Bar-Ilan Institute of Nanotechnologies and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel
- Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan, Israel
| | - Haim Sazan
- Bar-Ilan Institute of Nanotechnologies and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel
- Department of Chemistry, Bar-Ilan University, Ramat Gan, 5290002, Israel
| | - Avraham Kenigsberg
- Bar-Ilan Institute of Nanotechnologies and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel
- Department of Chemistry, Bar-Ilan University, Ramat Gan, 5290002, Israel
| | - Hadas Schori
- Faculty of Engineering, Bar-Ilan University, Ramat Gan, Israel
- Bar-Ilan Institute of Nanotechnologies and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel
| | - Silvia Piperno
- Bar-Ilan Institute of Nanotechnologies and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel
- Department of Chemistry, Bar-Ilan University, Ramat Gan, 5290002, Israel
| | - Hagay Shpaisman
- Bar-Ilan Institute of Nanotechnologies and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel.
- Department of Chemistry, Bar-Ilan University, Ramat Gan, 5290002, Israel.
| | - Orit Shefi
- Faculty of Engineering, Bar-Ilan University, Ramat Gan, Israel.
- Bar-Ilan Institute of Nanotechnologies and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel.
- Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan, Israel.
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17
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Mirbagheri A, Schneider H, Zdunczyk A, Vajkoczy P, Picht T. NTMS mapping of non-primary motor areas in brain tumour patients and healthy volunteers. Acta Neurochir (Wien) 2020; 162:407-416. [PMID: 31768755 DOI: 10.1007/s00701-019-04086-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 09/20/2019] [Indexed: 11/24/2022]
Abstract
OBJECTIVE Navigated transcranial magnetic stimulation (nTMS) has been increasingly used for presurgical cortical mapping of the primary motor cortex (M1) but remains controversial for the evaluation of non-primary motor areas (NPMA). This study investigates clinical and neurophysiological parameters in brain tumour patients and healthy volunteers to decide whether single-pulse biphasic nTMS allows to reliably elicite MEP outside from M1 or not. MATERIALS AND METHODS Twelve brain tumour patients and six healthy volunteers underwent M1 nTMS mapping. NPMA nTMS mapping followed using 120% and 150% M1 resting motor threshold (RMT) stimulation intensity. Spearman's correlation analysis tested the association of clinical and neurophysiological parameters between M1 and NPMA mapping. RESULTS A total of 88.81% of nTMS stimulations in NPMA in patients/83.87% in healthy volunteers in patients/83.87% in healthy volunteers did not result in MEPs ≥ 50 μV. Positive nTMS mapping in NPMA correlated with higher stimulation intensity and larger M1 areas in patients (120% M1 RMT SI p = 0.005/150% M1 RMT SI p = 0.198). CONCLUSION Our findings indicate that in case of positive nTMS mapping in NPMA, MEPs originate mostly from M1. For future studies, MEP parameters and TMS coil rotation should be studied closely to assess the risk for postoperative motor deterioration.
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Affiliation(s)
- Andia Mirbagheri
- Department of Neurosurgery, Charité University Medicine, Charitéplatz 1, Berlin, Germany.
| | - Heike Schneider
- Department of Neurosurgery, Charité University Medicine, Charitéplatz 1, Berlin, Germany
| | - Anna Zdunczyk
- Department of Neurosurgery, Charité University Medicine, Charitéplatz 1, Berlin, Germany
| | - Peter Vajkoczy
- Department of Neurosurgery, Charité University Medicine, Charitéplatz 1, Berlin, Germany
| | - Thomas Picht
- Department of Neurosurgery, Charité University Medicine, Charitéplatz 1, Berlin, Germany
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18
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Abstract
The gold standard in brain-computer interface (BCI) modalities is multi single-unit recordings in the primary motor cortex. It yields the fastest and most elegant control (i.e., most degrees of freedom and bitrate). Unfortunately, single-unit electrodes are prone to encapsulation, which limit their single-unit recording life. However, encapsulation does not significantly affect intracortical local field potentials (LFPs). LFPs and single-unit activity were recorded from the motor cortices of three monkeys (Macaca fascicularis) while they performed a standard 3D center-out reaching task and a 3D circle-drawing task. The high frequency (HF) (60-200 Hz) spectral amplitudes of a subset of the LFPs were found to be directionally tuned much like single units. In fact, stable isolation of single units on the same electrode increased the likelihood that the HF-LFP would be significantly cosine tuned to hand direction. The presence of significantly tuned single units further increased the likelihood of a tuned HF-LFP, suggesting that this band of HF-LFP activity is at least partially generated by local neuronal action potential currents (i.e., single-unit activity). Given that encapsulation makes recording single units over a long period of time difficult, these results suggest that HF-LFPs may be a more stable and efficient method of monitoring neural activity for BCI applications.
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Affiliation(s)
| | - Daniel W Moran
- Biomedical Engineering, Washington University, St. Louis, MO, United States.
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19
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Bhatia KD, Krishnan P, Kortman H, Klostranec J, Krings T. Acute Cortical Lesions in MELAS Syndrome: Anatomic Distribution, Symmetry, and Evolution. AJNR Am J Neuroradiol 2019; 41:167-173. [PMID: 31806591 DOI: 10.3174/ajnr.a6325] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 10/02/2019] [Indexed: 12/27/2022]
Abstract
BACKGROUND AND PURPOSE Mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) syndrome is a rare mitochondrial disorder affecting children and young adults. Stroke-like episodes are often associated with acute cortical lesions in the posterior cerebral cortex and are classically described as asymmetric and transient. In this study we assessed the anatomic distribution of acute cortical lesions, the incidence of symmetry, and the temporal evolution of lesions. MATERIALS AND METHODS This was a retrospective cohort study of patients who had a confirmed genetic diagnosis of a pathogenic variant associated with MELAS and MR imaging performed at our center (2006-2018). Each MR imaging study was assessed for new lesions using T1, T2, FLAIR, DWI, ADC, and SWI. The anatomic location, symmetry, and temporal evolution of lesions were analyzed. RESULTS Eight patients with the same pathogenic variant of MELAS (MT-TL1 m.3243A>G) with 31 MR imaging studies were included. Forty-one new lesions were identified in 17 of the studies (5 deep, 36 cortical). Cortical lesions most commonly affected the primary visual cortex, the middle-third of the primary somatosensory cortex, and the primary auditory cortex. Thirty of 36 cortical lesions had acute cortical diffusion restriction, of which 21 developed cortical laminar necrosis on subacute imaging. Six of 11 studies with multiple lesions showed symmetric cortical involvement. CONCLUSIONS Acute cortical lesions in MELAS most commonly affect the primary visual, somatosensory, and auditory cortices, all regions of high neuronal density and metabolic demand. The most common pattern of temporal evolution is acute cortical diffusion restriction with subacute cortical laminar necrosis and chronic volume loss. Symmetric involvement is more common than previously described.
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Affiliation(s)
- K D Bhatia
- From the Division of Neuroradiology (K.D.B., H.K., J.K., T.K.), Joint Department of Medical Imaging, Toronto Western Hospital, Toronto, Ontario, Canada
| | - P Krishnan
- Department of Diagnostic Imaging (P.K.), Hospital for Sick Children, Toronto, Ontario, Canada
| | - H Kortman
- From the Division of Neuroradiology (K.D.B., H.K., J.K., T.K.), Joint Department of Medical Imaging, Toronto Western Hospital, Toronto, Ontario, Canada
| | - J Klostranec
- From the Division of Neuroradiology (K.D.B., H.K., J.K., T.K.), Joint Department of Medical Imaging, Toronto Western Hospital, Toronto, Ontario, Canada
| | - T Krings
- From the Division of Neuroradiology (K.D.B., H.K., J.K., T.K.), Joint Department of Medical Imaging, Toronto Western Hospital, Toronto, Ontario, Canada
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20
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Veersema TJ, Neef A, Scheppingen J, Ferrier CH, Eijsden P, Gosselaar PH, Rijen PC, Spliet WG, Braun KP, Mühlebner A, Aronica E. Changes in vascular density in resected tissue of 97 patients with mild malformation of cortical development, focal cortical dysplasia or TSC‐related cortical tubers. Int J Dev Neurosci 2019; 79:96-104. [DOI: 10.1016/j.ijdevneu.2019.11.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 10/13/2019] [Accepted: 11/22/2019] [Indexed: 11/30/2022] Open
Affiliation(s)
- Tim J. Veersema
- Department of Neurology and NeurosurgeryUMC Utrecht Brain CenterUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Andrew Neef
- Department of (Neuro) PathologyAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Jackelien Scheppingen
- Department of (Neuro) PathologyAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Cyrille H. Ferrier
- Department of Neurology and NeurosurgeryUMC Utrecht Brain CenterUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Pieter Eijsden
- Department of Neurology and NeurosurgeryUMC Utrecht Brain CenterUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Peter H. Gosselaar
- Department of Neurology and NeurosurgeryUMC Utrecht Brain CenterUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Peter C. Rijen
- Department of Neurology and NeurosurgeryUMC Utrecht Brain CenterUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Wim G.M. Spliet
- Department of PathologyUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Kees P.J. Braun
- Department of Neurology and NeurosurgeryUMC Utrecht Brain CenterUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Angelika Mühlebner
- Department of (Neuro) PathologyAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Eleonora Aronica
- Department of (Neuro) PathologyAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
- Stichting Epilepsie Instellingen Nederland (SEIN)The Netherlands
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21
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Arm movements induced by noninvasive optogenetic stimulation of the motor cortex in the common marmoset. Proc Natl Acad Sci U S A 2019; 116:22844-22850. [PMID: 31636197 PMCID: PMC6842633 DOI: 10.1073/pnas.1903445116] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Which brain area drives hand/arm movements after learning or brain injury? When does motor cortical activity generate appropriate hand/arm movements? To address these issues, it is necessary to manipulate motor cortical activity in a controlled manner. Optogenetic tools allow neuronal activity to be manipulated in a variety of animals, but forelimb movements in nonhuman primates have not previously been optogenetically induced or modulated. Here, we improved a method of optogenetic cortical stimulation and induced overt forelimb movements in the common marmoset, a New World monkey. Photostimulation also modulated voluntary forelimb movements, with the modulated movement trajectories depending on the stimulation site and timing. Our results open doors for noninvasive interrogation of motor circuits in behaving nonhuman primates. Optogenetics is now a fundamental tool for investigating the relationship between neuronal activity and behavior. However, its application to the investigation of motor control systems in nonhuman primates is rather limited, because optogenetic stimulation of cortical neurons in nonhuman primates has failed to induce or modulate any hand/arm movements. Here, we used a tetracycline-inducible gene expression system carrying CaMKII promoter and the gene encoding a Channelrhodopsin-2 variant with fast kinetics in the common marmoset, a small New World monkey. In an awake state, forelimb movements could be induced when Channelrhodopsin-2−expressing neurons in the motor cortex were illuminated by blue laser light with a spot diameter of 1 mm or 2 mm through a cranial window without cortical invasion. Forelimb muscles responded 10 ms to 50 ms after photostimulation onset. Long-duration (500 ms) photostimulation induced discrete forelimb movements that could be markerlessly tracked with charge-coupled device cameras and a deep learning algorithm. Long-duration photostimulation mapping revealed that the primary motor cortex is divided into multiple domains that can induce hand and elbow movements in different directions. During performance of a forelimb movement task, movement trajectories were modulated by weak photostimulation, which did not induce visible forelimb movements at rest, around the onset of task-relevant movement. The modulation was biased toward the movement direction induced by the strong photostimulation. Combined with calcium imaging, all-optical interrogation of motor circuits should be possible in behaving marmosets.
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22
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Development and Arealization of the Cerebral Cortex. Neuron 2019; 103:980-1004. [DOI: 10.1016/j.neuron.2019.07.009] [Citation(s) in RCA: 145] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 05/15/2019] [Accepted: 07/03/2019] [Indexed: 12/16/2022]
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23
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Ragagnin AMG, Shadfar S, Vidal M, Jamali MS, Atkin JD. Motor Neuron Susceptibility in ALS/FTD. Front Neurosci 2019; 13:532. [PMID: 31316328 PMCID: PMC6610326 DOI: 10.3389/fnins.2019.00532] [Citation(s) in RCA: 120] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 05/08/2019] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the death of both upper and lower motor neurons (MNs) in the brain, brainstem and spinal cord. The neurodegenerative mechanisms leading to MN loss in ALS are not fully understood. Importantly, the reasons why MNs are specifically targeted in this disorder are unclear, when the proteins associated genetically or pathologically with ALS are expressed ubiquitously. Furthermore, MNs themselves are not affected equally; specific MNs subpopulations are more susceptible than others in both animal models and human patients. Corticospinal MNs and lower somatic MNs, which innervate voluntary muscles, degenerate more readily than specific subgroups of lower MNs, which remain resistant to degeneration, reflecting the clinical manifestations of ALS. In this review, we discuss the possible factors intrinsic to MNs that render them uniquely susceptible to neurodegeneration in ALS. We also speculate why some MN subpopulations are more vulnerable than others, focusing on both their molecular and physiological properties. Finally, we review the anatomical network and neuronal microenvironment as determinants of MN subtype vulnerability and hence the progression of ALS.
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Affiliation(s)
- Audrey M G Ragagnin
- Centre for Motor Neuron Disease Research, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Sina Shadfar
- Centre for Motor Neuron Disease Research, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Marta Vidal
- Centre for Motor Neuron Disease Research, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Md Shafi Jamali
- Centre for Motor Neuron Disease Research, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Julie D Atkin
- Centre for Motor Neuron Disease Research, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia.,Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, Australia
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24
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Kaas JH. The origin and evolution of neocortex: From early mammals to modern humans. PROGRESS IN BRAIN RESEARCH 2019; 250:61-81. [DOI: 10.1016/bs.pbr.2019.03.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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25
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Atapour N, Majka P, Wolkowicz IH, Malamanova D, Worthy KH, Rosa MGP. Neuronal Distribution Across the Cerebral Cortex of the Marmoset Monkey (Callithrix jacchus). Cereb Cortex 2018; 29:3836-3863. [DOI: 10.1093/cercor/bhy263] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Revised: 09/13/2018] [Accepted: 09/19/2018] [Indexed: 01/18/2023] Open
Abstract
Abstract
Using stereological analysis of NeuN-stained sections, we investigated neuronal density and number of neurons per column throughout the marmoset cortex. Estimates of mean neuronal density encompassed a greater than 3-fold range, from >150 000 neurons/mm3 in the primary visual cortex to ~50 000 neurons/mm3 in the piriform complex. There was a trend for density to decrease from posterior to anterior cortex, but also local gradients, which resulted in a complex pattern; for example, in frontal, auditory, and somatosensory cortex neuronal density tended to increase towards anterior areas. Anterior cingulate, motor, premotor, insular, and ventral temporal areas were characterized by relatively low neuronal densities. Analysis across the depth of the cortex revealed greater laminar variation of neuronal density in occipital, parietal, and inferior temporal areas, in comparison with other regions. Moreover, differences between areas were more pronounced in the supragranular layers than in infragranular layers. Calculations of the number of neurons per unit column revealed a pattern that was distinct from that of neuronal density, including local peaks in the posterior parietal, superior temporal, precuneate, frontopolar, and temporopolar regions. These results suggest that neuronal distribution in adult cortex result from a complex interaction of developmental/ evolutionary determinants and functional requirements.
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Affiliation(s)
- Nafiseh Atapour
- Neuroscience Program, Monash Biomedicine Discovery Institute, 19 Innovation Walk, Clayton, Melbourne, VIC, Australia
- Department of Physiology, Monash University, 26 Innovation Walk, Clayton, Melbourne, VIC, Australia
- Australian Research Council, Centre of Excellence for Integrative Brain Function, Monash University Node, 770 Blackburn Road, Clayton, Melbourne, VIC, Australia
| | - Piotr Majka
- Neuroscience Program, Monash Biomedicine Discovery Institute, 19 Innovation Walk, Clayton, Melbourne, VIC, Australia
- Department of Physiology, Monash University, 26 Innovation Walk, Clayton, Melbourne, VIC, Australia
- Australian Research Council, Centre of Excellence for Integrative Brain Function, Monash University Node, 770 Blackburn Road, Clayton, Melbourne, VIC, Australia
- Laboratory of Neuroinformatics, Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur Street, Warsaw, Poland
| | - Ianina H Wolkowicz
- Neuroscience Program, Monash Biomedicine Discovery Institute, 19 Innovation Walk, Clayton, Melbourne, VIC, Australia
- Department of Physiology, Monash University, 26 Innovation Walk, Clayton, Melbourne, VIC, Australia
| | - Daria Malamanova
- Neuroscience Program, Monash Biomedicine Discovery Institute, 19 Innovation Walk, Clayton, Melbourne, VIC, Australia
- Department of Physiology, Monash University, 26 Innovation Walk, Clayton, Melbourne, VIC, Australia
| | - Katrina H Worthy
- Neuroscience Program, Monash Biomedicine Discovery Institute, 19 Innovation Walk, Clayton, Melbourne, VIC, Australia
- Department of Physiology, Monash University, 26 Innovation Walk, Clayton, Melbourne, VIC, Australia
| | - Marcello G P Rosa
- Neuroscience Program, Monash Biomedicine Discovery Institute, 19 Innovation Walk, Clayton, Melbourne, VIC, Australia
- Department of Physiology, Monash University, 26 Innovation Walk, Clayton, Melbourne, VIC, Australia
- Australian Research Council, Centre of Excellence for Integrative Brain Function, Monash University Node, 770 Blackburn Road, Clayton, Melbourne, VIC, Australia
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26
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O'Shea DJ, Kalanithi P, Ferenczi EA, Hsueh B, Chandrasekaran C, Goo W, Diester I, Ramakrishnan C, Kaufman MT, Ryu SI, Yeom KW, Deisseroth K, Shenoy KV. Development of an optogenetic toolkit for neural circuit dissection in squirrel monkeys. Sci Rep 2018; 8:6775. [PMID: 29712920 PMCID: PMC5928036 DOI: 10.1038/s41598-018-24362-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 04/03/2018] [Indexed: 01/01/2023] Open
Abstract
Optogenetic tools have opened a rich experimental landscape for understanding neural function and disease. Here, we present the first validation of eight optogenetic constructs driven by recombinant adeno-associated virus (AAV) vectors and a WGA-Cre based dual injection strategy for projection targeting in a widely-used New World primate model, the common squirrel monkey Saimiri sciureus. We observed opsin expression around the local injection site and in axonal projections to downstream regions, as well as transduction to thalamic neurons, resembling expression patterns observed in macaques. Optical stimulation drove strong, reliable excitatory responses in local neural populations for two depolarizing opsins in anesthetized monkeys. Finally, we observed continued, healthy opsin expression for at least one year. These data suggest that optogenetic tools can be readily applied in squirrel monkeys, an important first step in enabling precise, targeted manipulation of neural circuits in these highly trainable, cognitively sophisticated animals. In conjunction with similar approaches in macaques and marmosets, optogenetic manipulation of neural circuits in squirrel monkeys will provide functional, comparative insights into neural circuits which subserve dextrous motor control as well as other adaptive behaviors across the primate lineage. Additionally, development of these tools in squirrel monkeys, a well-established model system for several human neurological diseases, can aid in identifying novel treatment strategies.
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Affiliation(s)
- Daniel J O'Shea
- Neurosciences Program, Stanford University, Stanford, CA, USA.
- Department of Electrical Engineering, Stanford University, Stanford, CA, USA.
| | - Paul Kalanithi
- Department of Electrical Engineering, Stanford University, Stanford, CA, USA
- Department of Neurosurgery, Stanford University, Stanford, CA, USA
| | | | - Brian Hsueh
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | | | - Werapong Goo
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Ilka Diester
- Department of Electrical Engineering, Stanford University, Stanford, CA, USA
- Department of Bioengineering, Stanford University, Stanford, CA, USA
- Department of Otophysiologie, Albert Ludwig University of Freiburg, Freiburg im Breisgau, Germany
- BrainLinks-BrainTools, Albert Ludwig University of Freiburg, Freiburg im Breisgau, Germany
| | | | - Matthew T Kaufman
- Neurosciences Program, Stanford University, Stanford, CA, USA
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Stephen I Ryu
- Department of Electrical Engineering, Stanford University, Stanford, CA, USA
- Palo Alto Medical Foundation, Palo Alto, CA, USA
| | - Kristen W Yeom
- Department of Radiology, Stanford University, Stanford, CA, USA
| | - Karl Deisseroth
- Department of Bioengineering, Stanford University, Stanford, CA, USA
- Department of Psychiatry and Behavioral Science, Stanford University, Stanford, CA, USA
- Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA
| | - Krishna V Shenoy
- Neurosciences Program, Stanford University, Stanford, CA, USA
- Department of Electrical Engineering, Stanford University, Stanford, CA, USA
- Department of Bioengineering, Stanford University, Stanford, CA, USA
- Department of Neurobiology, Stanford University, Stanford, CA, USA
- Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA
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27
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Rougier NP. A Density-Driven Method for the Placement of Biological Cells Over Two-Dimensional Manifolds. Front Neuroinform 2018; 12:12. [PMID: 29615887 PMCID: PMC5869184 DOI: 10.3389/fninf.2018.00012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Accepted: 02/27/2018] [Indexed: 11/13/2022] Open
Abstract
We introduce a graphical method originating from the computer graphics domain that is used for the arbitrary placement of cells over a two-dimensional manifold. Using a bitmap image whose luminance provides cell density, this method guarantees a discrete distribution of the positions of the cells respecting the local density. This method scales to any number of cells, allows one to specify arbitrary enclosing shapes and provides a scalable and versatile alternative to the more classical assumption of a uniform spatial distribution. The method is illustrated on a discrete homogeneous neural field, on the distribution of cones and rods in the retina and on the neural density of a flattened piece of cortex.
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Affiliation(s)
- Nicolas P Rougier
- UMR5293 Institut des Maladies Neurodégénératives (IMN), Bordeaux, France.,UMR5800 Laboratoire Bordelais de Recherche en Informatique (LaBRI), Talence, France.,Inria Bordeaux - Sud-Ouest Research Centre, Talence, France
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28
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Feng W, Rosca M, Fan Y, Hu Y, Feng P, Lee HG, Monnier VM, Fan X. Gclc deficiency in mouse CNS causes mitochondrial damage and neurodegeneration. Hum Mol Genet 2017; 26:1376-1390. [PMID: 28158580 DOI: 10.1093/hmg/ddx040] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 01/26/2017] [Indexed: 01/14/2023] Open
Abstract
Gamma glutamyl cysteine ligase (GCL) is the rate-limiting enzyme for intracellular glutathione (GSH) synthesis. The GSH concentration and GCL activity are declining with age in the central nervous system (CNS), and is accompanied by elevated reactive oxygen species (ROS). To study the biological effects of low GSH levels, we disrupted its synthesis both at birth by breeding a Gclc loxP mouse with a thy1-cre mouse (NEGSKO mouse) and at a later age by breeding with a CaMKII-ERT2-Cre (FIGSKO mouse). NEGSKO mice with deficiency of the Gclc in their entire CNS neuronal cells develop at 4 weeks: progressive motor neuron loss, gait problems, muscle denervation and atrophy, paralysis, and have diminished life expectancy. The observed neurodegeneration in Gclc deficiency is of more chronic rather than acute nature as demonstrated by Gclc targeted single-neuron labeling from the inducible Cre-mediated knockout (SLICK) mice. FIGSKO mice with inducible Gclc deficiency in the forebrain at 23 weeks after tamoxifen induction demonstrate profound brain atrophy, elevated astrogliosis and neurodegeneration, particularly in the hippocampus region. FIGSKO mice also develop cognitive abnormalities, i.e. learning impairment and nesting behaviors based on passive avoidance, T-Maze, and nesting behavior tests. Mechanistic studies show that impaired mitochondrial glutathione homeostasis and subsequent mitochondrial dysfunction are responsible for neuronal cell loss. This was confirmed by mitochondrial electron transporter chain activity analysis and transmission electron microscopy that demonstrate remarkable impairment of state 3 respiratory activity, impaired complex IV function, and mitochondrial swollen morphology in the hippocampus and cerebral cortex. These mouse genetic tools of oxidative stress open new insights into potential pharmacological control of apoptotic signaling pathways triggered by mitochondrial dysfunction.
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Affiliation(s)
- Weiyi Feng
- First Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, Shaanxi, P.R. China
| | - Mariana Rosca
- College of Medicine, Central Michigan University, Mount Pleasant, MI 48859, USA
| | | | - Yufen Hu
- Division of Pulmonary and Critical Care, Department of Medicine
| | - Pingfu Feng
- Division of Pulmonary and Critical Care, Department of Medicine
| | - Hyoung-Gon Lee
- Department of Biology, The University of Texas at San Antonio
| | - Vincent M Monnier
- Department of Pathology.,Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
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29
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Charvet CJ, Stimpson CD, Kim YD, Raghanti MA, Lewandowski AH, Hof PR, Gómez-Robles A, Krienen FM, Sherwood CC. Gradients in cytoarchitectural landscapes of the isocortex: Diprotodont marsupials in comparison to eutherian mammals. J Comp Neurol 2017; 525:1811-1826. [PMID: 28001295 DOI: 10.1002/cne.24160] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Revised: 11/26/2016] [Accepted: 12/02/2016] [Indexed: 02/03/2023]
Abstract
Although it has been claimed that marsupials possess a lower density of isocortical neurons compared with other mammals, little is known about cross-cortical variation in neuron distributions in this diverse taxonomic group. We quantified upper-layer (layers II-IV) and lower-layer (layers V-VI) neuron numbers per unit of cortical surface area in three diprotodont marsupial species (two macropodiformes, the red kangaroo and the parma wallaby, and a vombatiform, the koala) and compared these results to eutherian mammals (e.g., xenarthrans, rodents, primates). In contrast to the notion that the marsupial isocortex contains a low density of neurons, we found that neuron numbers per unit of cortical surface area in several marsupial species overlap with those found in eutherian mammals. Furthermore, neuron numbers vary systematically across the isocortex of the marsupial mammals examined. Neuron numbers under a unit of cortical surface area are low toward the frontal cortex and high toward the caudo-medial (occipital) pole. Upper-layer neurons (i.e., layers II-IV) account for most of the variation in neuron numbers across the isocortex. The variation in neuron numbers across the rostral to the caudal pole resembles primates. These findings suggest that diprotodont marsupials and eutherian mammals share a similar cortical architecture despite their distant evolutionary divergence.
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Affiliation(s)
- Christine J Charvet
- Department of Anthropology and Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, DC
| | - Cheryl D Stimpson
- Department of Anthropology and Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, DC
| | - Young Do Kim
- Department of Anthropology and Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, DC
| | - Mary Ann Raghanti
- Department of Anthropology and School of Biomedical Sciences, Kent State University, Kent, Ohio
| | | | - Patrick R Hof
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, Mount Sinai, New York, New York
| | - Aida Gómez-Robles
- Department of Anthropology and Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, DC
| | - Fenna M Krienen
- Department of Anthropology and Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, DC
| | - Chet C Sherwood
- Department of Anthropology and Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, DC
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30
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Turner EC, Young NA, Reed JL, Collins CE, Flaherty DK, Gabi M, Kaas JH. Distributions of Cells and Neurons across the Cortical Sheet in Old World Macaques. BRAIN, BEHAVIOR AND EVOLUTION 2016; 88:1-13. [DOI: 10.1159/000446762] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 05/04/2016] [Indexed: 11/19/2022]
Abstract
According to previous research, cell and neuron densities vary across neocortex in a similar manner across primate taxa. Here, we provide a more extensive examination of this effect in macaque monkeys. We separated neocortex from the underlying white matter in 4 macaque monkey hemispheres (1 Macaca nemestrina, 2 Macaca radiata, and 1 Macaca mulatta), manually flattened the neocortex, and divided it into smaller tissue pieces for analysis. The number of cells and neurons were determined for each piece across the cortical sheet using flow cytometry. Primary visual cortex had the most densely packed neurons and primary motor cortex had the least densely packed neurons. With respect to differences in brain size between cases, there was little variability in the total cell and neuron numbers within specific areas, and overall trends were similar to what has been previously described in Old World baboons and other primates. The average hemispheric total cell number per hemisphere ranged from 2.9 to 3.7 billion, while the average total neuron number ranged from 1.3 to 1.7 billion neurons. The visual cortex neuron densities were predictably higher, ranging from 18.2 to 34.7 million neurons/cm2 in macaques, in comparison to a range of 9.3-17.7 million neurons/cm2 across cortex as a whole. The results support other evidence that neuron surface densities vary across the cortical sheet in a predictable pattern within and across primate taxa.
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31
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No relative expansion of the number of prefrontal neurons in primate and human evolution. Proc Natl Acad Sci U S A 2016; 113:9617-22. [PMID: 27503881 DOI: 10.1073/pnas.1610178113] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Human evolution is widely thought to have involved a particular expansion of prefrontal cortex. This popular notion has recently been challenged, although controversies remain. Here we show that the prefrontal region of both human and nonhuman primates holds about 8% of cortical neurons, with no clear difference across humans and other primates in the distribution of cortical neurons or white matter cells along the anteroposterior axis. Further, we find that the volumes of human prefrontal gray and white matter match the expected volumes for the number of neurons in the gray matter and for the number of other cells in the white matter compared with other primate species. These results indicate that prefrontal cortical expansion in human evolution happened along the same allometric trajectory as for other primate species, without modification of the distribution of neurons across its surface or of the volume of the underlying white matter. We thus propose that the most distinctive feature of the human prefrontal cortex is its absolute number of neurons, not its relative volume.
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32
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Abstract
The density of cells and neurons in the neocortex of many mammals varies across cortical areas and regions. This variability is, perhaps, most pronounced in primates. Nonuniformity in the composition of cortex suggests regions of the cortex have different specializations. Specifically, regions with densely packed neurons contain smaller neurons that are activated by relatively few inputs, thereby preserving information, whereas regions that are less densely packed have larger neurons that have more integrative functions. Here we present the numbers of cells and neurons for 742 discrete locations across the neocortex in a chimpanzee. Using isotropic fractionation and flow fractionation methods for cell and neuron counts, we estimate that neocortex of one hemisphere contains 9.5 billion cells and 3.7 billion neurons. Primary visual cortex occupies 35 cm(2) of surface, 10% of the total, and contains 737 million densely packed neurons, 20% of the total neurons contained within the hemisphere. Other areas of high neuron packing include secondary visual areas, somatosensory cortex, and prefrontal granular cortex. Areas of low levels of neuron packing density include motor and premotor cortex. These values reflect those obtained from more limited samples of cortex in humans and other primates.
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33
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Herculano-Houzel S, Kaas JH, de Oliveira-Souza R. Corticalization of motor control in humans is a consequence of brain scaling in primate evolution. J Comp Neurol 2015; 524:448-55. [PMID: 25891512 DOI: 10.1002/cne.23792] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 04/15/2015] [Accepted: 04/16/2015] [Indexed: 12/31/2022]
Abstract
Control over spinal and brainstem somatomotor neurons is exerted by two sets of descending fibers, corticospinal/pyramidal and extrapyramidal. Although in nonhuman primates the effect of bilateral pyramidal lesions is mostly limited to an impairment of the independent use of digits in skilled manual actions, similar injuries in humans result in the locked-in syndrome, a state of mutism and quadriplegia in which communication can be established only by residual vertical eye movements. This behavioral contrast makes humans appear to be outliers compared with other primates because of our almost total dependence on the corticospinal/pyramidal system for the effectuation of movement. Here we propose, instead, that an increasing preponderance of the corticospinal/pyramidal system over motor control is an expected consequence of increasing brain size in primates because of the faster scaling of the number of neurons in the primary motor cortex over the brainstem and spinal cord motor neuron pools, explaining the apparent uniqueness of the corticalization of motor control in humans.
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Affiliation(s)
- Suzana Herculano-Houzel
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro CEP 21941-902, Brazil.,Instituto Nacional de Neurociência Translacional, Ministério de Ciência e Tecnologia, São Paulo 03023-900, Brazil
| | - Jon H Kaas
- Department of Psychology, Vanderbilt University, Nashville, Tennessee, 37240-7817
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Herculano-Houzel S, von Bartheld CS, Miller DJ, Kaas JH. How to count cells: the advantages and disadvantages of the isotropic fractionator compared with stereology. Cell Tissue Res 2015; 360:29-42. [PMID: 25740200 DOI: 10.1007/s00441-015-2127-6] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 01/15/2015] [Indexed: 01/12/2023]
Abstract
The number of cells comprising biological structures represents fundamental information in basic anatomy, development, aging, drug tests, pathology and genetic manipulations. Obtaining unbiased estimates of cell numbers, however, was until recently possible only through stereological techniques, which require specific training, equipment, histological processing and appropriate sampling strategies applied to structures with a homogeneous distribution of cell bodies. An alternative, the isotropic fractionator (IF), became available in 2005 as a fast and inexpensive method that requires little training, no specific software and only a few materials before it can be used to quantify total numbers of neuronal and non-neuronal cells in a whole organ such as the brain or any dissectible regions thereof. This method entails transforming a highly anisotropic tissue into a homogeneous suspension of free-floating nuclei that can then be counted under the microscope or by flow cytometry and identified morphologically and immunocytochemically as neuronal or non-neuronal. We compare the advantages and disadvantages of each method and provide researchers with guidelines for choosing the best method for their particular needs. IF is as accurate as unbiased stereology and faster than stereological techniques, as it requires no elaborate histological processing or sampling paradigms, providing reliable estimates in a few days rather than many weeks. Tissue shrinkage is also not an issue, since the estimates provided are independent of tissue volume. The main disadvantage of IF, however, is that it necessarily destroys the tissue analyzed and thus provides no spatial information on the cellular composition of biological regions of interest.
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Affiliation(s)
- Suzana Herculano-Houzel
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil,
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35
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Tsvetanov KA, Henson RNA, Tyler LK, Davis SW, Shafto MA, Taylor JR, Williams N, Cam-Can, Rowe JB. The effect of ageing on fMRI: Correction for the confounding effects of vascular reactivity evaluated by joint fMRI and MEG in 335 adults. Hum Brain Mapp 2015; 36:2248-69. [PMID: 25727740 PMCID: PMC4730557 DOI: 10.1002/hbm.22768] [Citation(s) in RCA: 133] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Revised: 02/04/2015] [Accepted: 02/05/2015] [Indexed: 11/08/2022] Open
Abstract
In functional magnetic resonance imaging (fMRI) research one is typically interested in neural activity. However, the blood‐oxygenation level‐dependent (BOLD) signal is a composite of both neural and vascular activity. As factors such as age or medication may alter vascular function, it is essential to account for changes in neurovascular coupling when investigating neurocognitive functioning with fMRI. The resting‐state fluctuation amplitude (RSFA) in the fMRI signal (rsfMRI) has been proposed as an index of vascular reactivity. The RSFA compares favourably with other techniques such as breath‐hold and hypercapnia, but the latter are more difficult to perform in some populations, such as older adults. The RSFA is therefore a candidate for use in adjusting for age‐related changes in vascular reactivity in fMRI studies. The use of RSFA is predicated on its sensitivity to vascular rather than neural factors; however, the extent to which each of these factors contributes to RSFA remains to be characterized. The present work addressed these issues by comparing RSFA (i.e., rsfMRI variability) to proxy measures of (i) cardiovascular function in terms of heart rate (HR) and heart rate variability (HRV) and (ii) neural activity in terms of resting state magnetoencephalography (rsMEG). We derived summary scores of RSFA, a sensorimotor task BOLD activation, cardiovascular function and rsMEG variability for 335 healthy older adults in the population‐based Cambridge Centre for Ageing and Neuroscience cohort (Cam‐CAN; http://www.cam-can.com). Mediation analysis revealed that the effects of ageing on RSFA were significantly mediated by vascular factors, but importantly not by the variability in neuronal activity. Furthermore, the converse effects of ageing on the rsMEG variability were not mediated by vascular factors. We then examined the effect of RSFA scaling of task‐based BOLD in the sensorimotor task. The scaling analysis revealed that much of the effects of age on task‐based activation studies with fMRI do not survive correction for changes in vascular reactivity, and are likely to have been overestimated in previous fMRI studies of ageing. The results from the mediation analysis demonstrate that RSFA is modulated by measures of vascular function and is not driven solely by changes in the variance of neural activity. Based on these findings we propose that the RSFA scaling method is articularly useful in large scale and longitudinal neuroimaging studies of ageing, or with frail participants, where alternative measures of vascular reactivity are impractical. Hum Brain Mapp 36:2248–2269, 2015. © 2015 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.
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Affiliation(s)
- Kamen A Tsvetanov
- Centre for Speech, Language and the Brain, Department of Psychology, University of Cambridge, Cambridge, United Kingdom
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36
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Lewitus E, Kelava I, Kalinka AT, Tomancak P, Huttner WB. An adaptive threshold in mammalian neocortical evolution. PLoS Biol 2014; 12:e1002000. [PMID: 25405475 PMCID: PMC4236020 DOI: 10.1371/journal.pbio.1002000] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 10/09/2014] [Indexed: 01/19/2023] Open
Abstract
A study of the evolutionary history of cortical folding in mammals, its relationship to physiological and life-history traits and the underlying cortical progenitor behavior during embryogenesis, explains the diversity of folding we see across modern mammals. The diversity of neocortical folding among mammals can be explained by two distinct neurogenic programs, which give rise to mammals with a highly folded neocortex and mammals with slightly folded or unfolded neocortex, each occupying a distinct ecological niche. Expansion of the neocortex is a hallmark of human evolution. However, determining which adaptive mechanisms facilitated its expansion remains an open question. Here we show, using the gyrencephaly index (GI) and other physiological and life-history data for 102 mammalian species, that gyrencephaly is an ancestral mammalian trait. We find that variation in GI does not evolve linearly across species, but that mammals constitute two principal groups above and below a GI threshold value of 1.5, approximately equal to 109 neurons, which may be characterized by distinct constellations of physiological and life-history traits. By integrating data on neurogenic period, neuroepithelial founder pool size, cell-cycle length, progenitor-type abundances, and cortical neuron number into discrete mathematical models, we identify symmetric proliferative divisions of basal progenitors in the subventricular zone of the developing neocortex as evolutionarily necessary for generating a 14-fold increase in daily prenatal neuron production, traversal of the GI threshold, and thus establishment of two principal groups. We conclude that, despite considerable neuroanatomical differences, changes in the length of the neurogenic period alone, rather than any novel neurogenic progenitor lineage, are sufficient to explain differences in neuron number and neocortical size between species within the same principal group. What are the key differences in the development and evolution of the cerebral cortex that underlie the differences in its size and degree of folding across mammals? Here, we present phylogenetic evidence that the Jurassic era mammalian ancestor may have been a relatively large-brained species with a folded neocortex. We then show that variation in the degree of cortical folding (gyrencephaly index [GI]) does not evolve linearly across species, as previously assumed, but that mammals fall into two principal groups associated with distinct ecological niches: low-GI mammals (such as mice and tarsiers) and high-GI mammals (such as dolphins and humans), which are found to generate on average 14-fold more brain weight per day of gestation. This greater daily brain weight production in mammals with a highly folded neocortex requires a specific class of progenitor cell-type to adopt a special mode of cell division, which is absent in mammals with slightly folded or unfolded neocortices. Differences among mammals within the same GI group (high or low) are not due to different programming, but rather the result of differences in the length of the neurogenic period. So, the impressively large and folded human neocortex, which is three times the size of the chimpanzee neocortex, can be explained by a modest evolutionary extension of the neurogenic period with respect to its closest primate ancestors.
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Affiliation(s)
- Eric Lewitus
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
- * E-mail: (EL); (WBH)
| | - Iva Kelava
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Alex T. Kalinka
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Pavel Tomancak
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Wieland B. Huttner
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
- * E-mail: (EL); (WBH)
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37
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Miller DJ, Balaram P, Young NA, Kaas JH. Three counting methods agree on cell and neuron number in chimpanzee primary visual cortex. Front Neuroanat 2014; 8:36. [PMID: 24904305 PMCID: PMC4032965 DOI: 10.3389/fnana.2014.00036] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 04/29/2014] [Indexed: 11/18/2022] Open
Abstract
Determining the cellular composition of specific brain regions is crucial to our understanding of the function of neurobiological systems. It is therefore useful to identify the extent to which different methods agree when estimating the same properties of brain circuitry. In this study, we estimated the number of neuronal and non-neuronal cells in the primary visual cortex (area 17 or V1) of both hemispheres from a single chimpanzee. Specifically, we processed samples distributed across V1 of the right hemisphere after cortex was flattened into a sheet using two variations of the isotropic fractionator cell and neuron counting method. We processed the left hemisphere as serial brain slices for stereological investigation. The goal of this study was to evaluate the agreement between these methods in the most direct manner possible by comparing estimates of cell density across one brain region of interest in a single individual. In our hands, these methods produced similar estimates of the total cellular population (approximately 1 billion) as well as the number of neurons (approximately 675 million) in chimpanzee V1, providing evidence that both techniques estimate the same parameters of interest. In addition, our results indicate the strengths of each distinct tissue preparation procedure, highlighting the importance of attention to anatomical detail. In summary, we found that the isotropic fractionator and the stereological optical fractionator produced concordant estimates of the cellular composition of V1, and that this result supports the conclusion that chimpanzees conform to the primate pattern of exceptionally high packing density in V1. Ultimately, our data suggest that investigators can optimize their experimental approach by using any of these counting methods to obtain reliable cell and neuron counts.
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Affiliation(s)
- Daniel J. Miller
- Department of Psychology, Vanderbilt UniversityNashville, TN, USA
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Herculano-Houzel S. The glia/neuron ratio: how it varies uniformly across brain structures and species and what that means for brain physiology and evolution. Glia 2014; 62:1377-91. [PMID: 24807023 DOI: 10.1002/glia.22683] [Citation(s) in RCA: 370] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 10/03/2013] [Accepted: 04/18/2014] [Indexed: 12/11/2022]
Abstract
It is a widespread notion that the proportion of glial to neuronal cells in the brain increases with brain size, to the point that glial cells represent "about 90% of all cells in the human brain." This notion, however, is wrong on both counts: neither does the glia/neuron ratio increase uniformly with brain size, nor do glial cells represent the majority of cells in the human brain. This review examines the origin of interest in the glia/neuron ratio; the original evidence that led to the notion that it increases with brain size; the extent to which this concept can be applied to white matter and whole brains and the recent supporting evidence that the glia/neuron ratio does not increase with brain size, but rather, and in surprisingly uniform fashion, with decreasing neuronal density due to increasing average neuronal cell size, across brain structures and species. Variations in the glia/neuron ratio are proposed to be related not to the supposed larger metabolic cost of larger neurons (given that this cost is not found to vary with neuronal density), but simply to the large variation in neuronal sizes across brain structures and species in the face of less overall variation in glial cell sizes, with interesting implications for brain physiology. The emerging evidence that the glia/neuron ratio varies uniformly across the different brain structures of mammalian species that diverged as early as 90 million years ago in evolution highlights how fundamental for brain function must be the interaction between glial cells and neurons.
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Affiliation(s)
- Suzana Herculano-Houzel
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil; Instituto Nacional de Neurociência Translacional, São Paulo, SP, Brazil
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39
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Karbowski J. Constancy and trade-offs in the neuroanatomical and metabolic design of the cerebral cortex. Front Neural Circuits 2014; 8:9. [PMID: 24574975 PMCID: PMC3920482 DOI: 10.3389/fncir.2014.00009] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Accepted: 01/23/2014] [Indexed: 12/13/2022] Open
Abstract
Mammalian brains span about four orders of magnitude in cortical volume and have to operate in different environments that require diverse behavioral skills. Despite these geometric and behavioral diversities, the examination of cerebral cortex across species reveals that it contains a substantial number of conserved characteristics that are associated with neuroanatomy and metabolism, i.e., with neuronal connectivity and function. Some of these cortical constants or invariants have been known for a long time but not sufficiently appreciated, and others were only recently discovered. The focus of this review is to present the cortical invariants and discuss their role in the efficient information processing. Global conservation in neuroanatomy and metabolism, as well as their correlated regional and developmental variability suggest that these two parallel systems are mutually coupled. It is argued that energetic constraint on cortical organization can be strong if cerebral blood supplied is either below or above a certain level, and it is rather soft otherwise. Moreover, because maximization or minimization of parameters associated with cortical connectivity, function and cost often leads to conflicts in design, it is argued that the architecture of the cerebral cortex is a result of structural and functional compromises.
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Affiliation(s)
- Jan Karbowski
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences Warsaw, Poland ; Department of Mathematics, Informatics and Mechanics, Institute of Applied Mathematics and Mechanics, University of Warsaw Warsaw, Poland ; Division of Biology Caltech, Pasadena, CA, USA
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40
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Elston GN, Manger P. Pyramidal cells in V1 of African rodents are bigger, more branched and more spiny than those in primates. Front Neuroanat 2014; 8:4. [PMID: 24574977 PMCID: PMC3918685 DOI: 10.3389/fnana.2014.00004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 01/20/2014] [Indexed: 01/21/2023] Open
Abstract
Pyramidal cells are characterized by markedly different sized dendritic trees, branching patterns, and spine density across the cortical mantle. Moreover, pyramidal cells have been shown to differ in structure among homologous cortical areas in different species; however, most of these studies have been conducted in primates. Whilst pyramidal cells have been quantified in a few cortical areas in some other species there are, as yet, no uniform comparative data on pyramidal cell structure in a homologous cortical area among species in different Orders. Here we studied layer III pyramidal cells in V1 of three species of rodents, the greater cane rat, highveld gerbil, and four-striped mouse, by the same methodology used to sample data from layer III pyramidal cells in primates. The data reveal markedly different trends between rodents and primates: there is an appreciable increase in the size, branching complexity, and number of spines in the dendritic trees of pyramidal cells with increasing size of V1 in the brain in rodents, whereas there is relatively little difference in primates. Moreover, pyramidal cells in rodents are larger, more branched and more spinous than those in primates. For example, the dendritic trees of pyramidal cells in V1 of the adult cane rat are nearly three times larger, and have more than 10 times the number of spines in their basal dendritic trees, than those in V1 of the adult macaque (7900 and 600, respectively), which has a V1 40 times the size that of the cane rat. It remains to be determined to what extent these differences may result from development or reflect evolutionary and/or processing specializations.
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Affiliation(s)
- Guy N Elston
- Centre for Cognitive Neuroscience Sunshine Coast, QLD, Australia
| | - Paul Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand Johannesburg, South Africa
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41
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Brecht M, Hatsopoulos NG, Kaneko T, Shepherd GMG. Motor cortex microcircuits. Front Neural Circuits 2013; 7:196. [PMID: 24376400 PMCID: PMC3859911 DOI: 10.3389/fncir.2013.00196] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2013] [Accepted: 11/26/2013] [Indexed: 12/04/2022] Open
Affiliation(s)
- Michael Brecht
- Bernstein Center for Computational Neuroscience, Humboldt University, and Cluster of Excellence NeuroCure, Charité-Universitätsmedizin Berlin, Germany
| | - Nicholas G Hatsopoulos
- Department of Organismal Biology and Anatomy, Committees on Computational Neuroscience and Neurobiology, University of Chicago Chicago, IL, USA
| | - Takeshi Kaneko
- Department of Morphological Brain Science, Graduate School of Medicine, Kyoto University Kyoto, Japan
| | - Gordon M G Shepherd
- Department of Physiology, Feinberg School of Medicine, Northwestern University Chicago, IL, USA
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Epileptic baboons have lower numbers of neurons in specific areas of cortex. Proc Natl Acad Sci U S A 2013; 110:19107-12. [PMID: 24191031 DOI: 10.1073/pnas.1318894110] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Epilepsy is characterized by recurrent seizure activity that can induce pathological reorganization and alter normal function in neocortical networks. In the present study, we determined the numbers of cells and neurons across the complete extent of the cortex for two epileptic baboons with naturally occurring seizures and two baboons without epilepsy. Overall, the two epileptic baboons had a 37% average reduction in the number of cortical neurons compared with the two nonepileptic baboons. The loss of neurons was variable across cortical areas, with the most pronounced loss in the primary motor cortex, especially in lateral primary motor cortex, representing the hand and face. Less-pronounced reductions of neurons were found in other parts of the frontal cortex and in somatosensory cortex, but no reduction was apparent in the primary visual cortex and little in other visual areas. The results provide clear evidence that epilepsy in the baboon is associated with considerable reduction in the numbers of cortical neurons, especially in frontal areas of the cortex related to motor functions. Whether or not the reduction of neurons is a cause or an effect of seizures needs further investigation.
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Charvet CJ, Cahalane DJ, Finlay BL. Systematic, cross-cortex variation in neuron numbers in rodents and primates. Cereb Cortex 2013; 25:147-60. [PMID: 23960207 DOI: 10.1093/cercor/bht214] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Uniformity, local variability, and systematic variation in neuron numbers per unit of cortical surface area across species and cortical areas have been claimed to characterize the isocortex. Resolving these claims has been difficult, because species, techniques, and cortical areas vary across studies. We present a stereological assessment of neuron numbers in layers II-IV and V-VI per unit of cortical surface area across the isocortex in rodents (hamster, Mesocricetus auratus; agouti, Dasyprocta azarae; paca, Cuniculus paca) and primates (owl monkey, Aotus trivigratus; tamarin, Saguinus midas; capuchin, Cebus apella); these chosen to vary systematically in cortical size. The contributions of species, cortical areas, and techniques (stereology, "isotropic fractionator") to neuron estimates were assessed. Neurons per unit of cortical surface area increase across the rostro-caudal (RC) axis in primates (varying by a factor of 1.64-2.13 across the rostral and caudal poles) but less in rodents (varying by a factor of 1.15-1.54). Layer II-IV neurons account for most of this variation. When integrated into the context of species variation, and this RC gradient in neuron numbers, conflicts between studies can be accounted for. The RC variation in isocortical neurons in adulthood mirrors the gradients in neurogenesis duration in development.
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Affiliation(s)
- Christine J Charvet
- Behavioral and Evolutionary Neuroscience Group, Department of Psychology and
| | | | - Barbara L Finlay
- Behavioral and Evolutionary Neuroscience Group, Department of Psychology and
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