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Guo Y, Lin Z, Fan Z, Tian X. Epileptic brain network mechanisms and neuroimaging techniques for the brain network. Neural Regen Res 2024; 19:2637-2648. [PMID: 38595282 PMCID: PMC11168515 DOI: 10.4103/1673-5374.391307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 09/08/2023] [Accepted: 11/22/2023] [Indexed: 04/11/2024] Open
Abstract
Epilepsy can be defined as a dysfunction of the brain network, and each type of epilepsy involves different brain-network changes that are implicated differently in the control and propagation of interictal or ictal discharges. Gaining more detailed information on brain network alterations can help us to further understand the mechanisms of epilepsy and pave the way for brain network-based precise therapeutic approaches in clinical practice. An increasing number of advanced neuroimaging techniques and electrophysiological techniques such as diffusion tensor imaging-based fiber tractography, diffusion kurtosis imaging-based fiber tractography, fiber ball imaging-based tractography, electroencephalography, functional magnetic resonance imaging, magnetoencephalography, positron emission tomography, molecular imaging, and functional ultrasound imaging have been extensively used to delineate epileptic networks. In this review, we summarize the relevant neuroimaging and neuroelectrophysiological techniques for assessing structural and functional brain networks in patients with epilepsy, and extensively analyze the imaging mechanisms, advantages, limitations, and clinical application ranges of each technique. A greater focus on emerging advanced technologies, new data analysis software, a combination of multiple techniques, and the construction of personalized virtual epilepsy models can provide a theoretical basis to better understand the brain network mechanisms of epilepsy and make surgical decisions.
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Affiliation(s)
- Yi Guo
- Department of Neurology, Sichuan Provincial People’s Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan Province, China
| | - Zhonghua Lin
- Sichuan Provincial Center for Mental Health, Sichuan Provincial People’s Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan Province, China
| | - Zhen Fan
- Department of Geriatrics, Sichuan Provincial People’s Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan Province, China
| | - Xin Tian
- Department of Neurology, Chongqing Key Laboratory of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
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2
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Lambert T, Niknejad HR, Kil D, Brunner C, Nuttin B, Montaldo G, Urban A. Functional ultrasound imaging and neuronal activity: how accurate is the spatiotemporal match? BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.10.602912. [PMID: 39026833 PMCID: PMC11257620 DOI: 10.1101/2024.07.10.602912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
Over the last decade, functional ultrasound (fUS) has risen as a critical tool in functional neuroimaging, leveraging hemodynamic changes to infer neural activity indirectly. Recent studies have established a strong correlation between neural spike rates (SR) and functional ultrasound signals. However, understanding their spatial distribution and variability across different brain areas is required to thoroughly interpret fUS signals. In this regard, we conducted simultaneous fUS imaging and Neuropixels recordings during stimulus-evoked activity in awake mice within three regions the visual pathway. Our findings indicate that the temporal dynamics of fUS and SR signals are linearly correlated, though the correlation coefficients vary among visual regions. Conversely, the spatial correlation between the two signals remains consistent across all regions with a spread of approximately 300 micrometers. Finally, we introduce a model that integrates the spatial and temporal components of the fUS signal, allowing for a more accurate interpretation of fUS images.
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Affiliation(s)
- Théo Lambert
- Neuro-Electronics Research Flanders, Leuven, Belgium
- VIB, Leuven, Belgium
- Imec, Leuven, Belgium
- Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Hamid Reza Niknejad
- Neuro-Electronics Research Flanders, Leuven, Belgium
- VIB, Leuven, Belgium
- Imec, Leuven, Belgium
- Department of Neurosciences, KU Leuven, Leuven, Belgium
- Department of Neurosurgery, UZ Leuven, Leuven, Belgium
- University Medical Center Utrecht, Utrecht, The Netherlands (current affiliation)
| | - Dries Kil
- Neuro-Electronics Research Flanders, Leuven, Belgium
- VIB, Leuven, Belgium
- Imec, Leuven, Belgium
- Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Clément Brunner
- Neuro-Electronics Research Flanders, Leuven, Belgium
- VIB, Leuven, Belgium
- Imec, Leuven, Belgium
- Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Bart Nuttin
- Department of Neurosciences, KU Leuven, Leuven, Belgium
- Department of Neurosurgery, UZ Leuven, Leuven, Belgium
| | - Gabriel Montaldo
- Neuro-Electronics Research Flanders, Leuven, Belgium
- VIB, Leuven, Belgium
- Imec, Leuven, Belgium
- Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Alan Urban
- Neuro-Electronics Research Flanders, Leuven, Belgium
- VIB, Leuven, Belgium
- Imec, Leuven, Belgium
- Department of Neurosciences, KU Leuven, Leuven, Belgium
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3
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Edelman BJ, Siegenthaler D, Wanken P, Jenkins B, Schmid B, Ressle A, Gogolla N, Frank T, Macé E. The COMBO window: A chronic cranial implant for multiscale circuit interrogation in mice. PLoS Biol 2024; 22:e3002664. [PMID: 38829885 PMCID: PMC11185485 DOI: 10.1371/journal.pbio.3002664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 06/18/2024] [Accepted: 05/03/2024] [Indexed: 06/05/2024] Open
Abstract
Neuroscientists studying the neural correlates of mouse behavior often lack access to the brain-wide activity patterns elicited during a specific task of interest. Fortunately, large-scale imaging is becoming increasingly accessible thanks to modalities such as Ca2+ imaging and functional ultrasound (fUS). However, these and other techniques often involve challenging cranial window procedures and are difficult to combine with other neuroscience tools. We address this need with an open-source 3D-printable cranial implant-the COMBO (ChrOnic Multimodal imaging and Behavioral Observation) window. The COMBO window enables chronic imaging of large portions of the brain in head-fixed mice while preserving orofacial movements. We validate the COMBO window stability using both brain-wide fUS and multisite two-photon imaging. Moreover, we demonstrate how the COMBO window facilitates the combination of optogenetics, fUS, and electrophysiology in the same animals to study the effects of circuit perturbations at both the brain-wide and single-neuron level. Overall, the COMBO window provides a versatile solution for performing multimodal brain recordings in head-fixed mice.
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Affiliation(s)
- Bradley J. Edelman
- Brain-Wide Circuits for Behavior Research Group, Max Planck Institute for Biological Intelligence, Planegg, Germany
- Emotion Research Department, Max Planck Institute of Psychiatry, Munich, Germany
- Dynamics of Excitable Cell Networks Research Group, Department of Ophthalmology, University Medical Center Göttingen, Göttingen, Germany
- Cluster of Excellence “Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells” (MBExC), University of Göttingen, Göttingen, Germany
| | - Dominique Siegenthaler
- Brain-Wide Circuits for Behavior Research Group, Max Planck Institute for Biological Intelligence, Planegg, Germany
- Dynamics of Excitable Cell Networks Research Group, Department of Ophthalmology, University Medical Center Göttingen, Göttingen, Germany
- Cluster of Excellence “Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells” (MBExC), University of Göttingen, Göttingen, Germany
| | - Paulina Wanken
- Brain-Wide Circuits for Behavior Research Group, Max Planck Institute for Biological Intelligence, Planegg, Germany
- Dynamics of Excitable Cell Networks Research Group, Department of Ophthalmology, University Medical Center Göttingen, Göttingen, Germany
- Cluster of Excellence “Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells” (MBExC), University of Göttingen, Göttingen, Germany
| | - Bethan Jenkins
- Cluster of Excellence “Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells” (MBExC), University of Göttingen, Göttingen, Germany
- Olfactory Memory Research Group, Max Planck Institute for Biological Intelligence, Planegg, Germany
- Olfactory Memory and Behavior Research Group, European Neuroscience Institute and Faculty for Biology and Psychology, University of Göttingen, Göttingen, Germany
| | - Bianca Schmid
- Emotion Research Department, Max Planck Institute of Psychiatry, Munich, Germany
| | - Andrea Ressle
- Emotion Research Department, Max Planck Institute of Psychiatry, Munich, Germany
| | - Nadine Gogolla
- Emotion Research Department, Max Planck Institute of Psychiatry, Munich, Germany
| | - Thomas Frank
- Cluster of Excellence “Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells” (MBExC), University of Göttingen, Göttingen, Germany
- Olfactory Memory Research Group, Max Planck Institute for Biological Intelligence, Planegg, Germany
- Olfactory Memory and Behavior Research Group, European Neuroscience Institute and Faculty for Biology and Psychology, University of Göttingen, Göttingen, Germany
| | - Emilie Macé
- Brain-Wide Circuits for Behavior Research Group, Max Planck Institute for Biological Intelligence, Planegg, Germany
- Dynamics of Excitable Cell Networks Research Group, Department of Ophthalmology, University Medical Center Göttingen, Göttingen, Germany
- Cluster of Excellence “Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells” (MBExC), University of Göttingen, Göttingen, Germany
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4
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Liu M, Wang Y, Jiang L, Zhang X, Wang C, Zhang T. Research progress of the inferior colliculus: from Neuron, neural circuit to auditory disease. Brain Res 2024; 1828:148775. [PMID: 38244755 DOI: 10.1016/j.brainres.2024.148775] [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: 10/06/2023] [Revised: 01/10/2024] [Accepted: 01/15/2024] [Indexed: 01/22/2024]
Abstract
The auditory midbrain, also known as the inferior colliculus (IC), serves as a crucial hub in the auditory pathway. Comprising diverse cell types, the IC plays a pivotal role in various auditory functions, including sound localization, auditory plasticity, sound detection, and sound-induced behaviors. Notably, the IC is implicated in several auditory central disorders, such as tinnitus, age-related hearing loss, autism and Fragile X syndrome. Accurate classification of IC neurons is vital for comprehending both normal and dysfunctional aspects of IC function. Various parameters, including dendritic morphology, neurotransmitter synthesis, potassium currents, biomarkers, and axonal targets, have been employed to identify distinct neuron types within the IC. However, the challenge persists in effectively classifying IC neurons into functional categories due to the limited clustering capabilities of most parameters. Recent studies utilizing advanced neuroscience technologies have begun to shed light on biomarker-based approaches in the IC, providing insights into specific cellular properties and offering a potential avenue for understanding IC functions. This review focuses on recent advancements in IC research, spanning from neurons and neural circuits to aspects related to auditory diseases.
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Affiliation(s)
- Mengting Liu
- Department of Otolaryngology Head and Neck Surgery, First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, China
| | - Yuyao Wang
- Department of Otolaryngology Head and Neck Surgery, First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, China
| | - Li Jiang
- Department of Otolaryngology Head and Neck Surgery, First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, China
| | - Xiaopeng Zhang
- Department of Otolaryngology Head and Neck Surgery, First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, China
| | - Chunrui Wang
- Department of Otolaryngology Head and Neck Surgery, First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, China
| | - Tianhong Zhang
- Department of Otolaryngology Head and Neck Surgery, First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, China.
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5
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Lambert T, Brunner C, Kil D, Wuyts R, D'Hondt E, Montaldo G, Urban A. A deep learning classification task for brain navigation in rodents using micro-Doppler ultrasound imaging. Heliyon 2024; 10:e27432. [PMID: 38495198 PMCID: PMC10943389 DOI: 10.1016/j.heliyon.2024.e27432] [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: 06/15/2023] [Revised: 02/28/2024] [Accepted: 02/28/2024] [Indexed: 03/19/2024] Open
Abstract
Positioning and navigation are essential components of neuroimaging as they improve the quality and reliability of data acquisition, leading to advances in diagnosis, treatment outcomes, and fundamental understanding of the brain. Functional ultrasound imaging is an emerging technology providing high-resolution images of the brain vasculature, allowing for the monitoring of brain activity. However, as the technology is relatively new, there is no standardized tool for inferring the position in the brain from the vascular images. In this study, we present a deep learning-based framework designed to address this challenge. Our approach uses an image classification task coupled with a regression on the resulting probabilities to determine the position of a single image. To evaluate its performance, we conducted experiments using a dataset of 51 rat brain scans. The training positions were extracted at intervals of 375 μm, resulting in a positioning error of 176 μm. Further GradCAM analysis revealed that the predictions were primarily driven by subcortical vascular structures. Finally, we assessed the robustness of our method in a cortical stroke where the brain vasculature is severely impaired. Remarkably, no specific increase in the number of misclassifications was observed, confirming the method's reliability in challenging conditions. Overall, our framework provides accurate and flexible positioning, not relying on a pre-registered reference but rather on conserved vascular patterns.
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Affiliation(s)
- Théo Lambert
- Neuro-Electronics Research Flanders, Leuven, Belgium
- VIB, Leuven, Belgium
- Imec, Leuven, Belgium
- Department of Neuroscience, Faculty of Medicine, KU Leuven, Leuven, Belgium
| | - Clément Brunner
- Neuro-Electronics Research Flanders, Leuven, Belgium
- VIB, Leuven, Belgium
- Imec, Leuven, Belgium
- Department of Neuroscience, Faculty of Medicine, KU Leuven, Leuven, Belgium
| | - Dries Kil
- Neuro-Electronics Research Flanders, Leuven, Belgium
- VIB, Leuven, Belgium
- Imec, Leuven, Belgium
- Department of Neuroscience, Faculty of Medicine, KU Leuven, Leuven, Belgium
| | | | | | - Gabriel Montaldo
- Neuro-Electronics Research Flanders, Leuven, Belgium
- VIB, Leuven, Belgium
- Imec, Leuven, Belgium
- Department of Neuroscience, Faculty of Medicine, KU Leuven, Leuven, Belgium
| | - Alan Urban
- Neuro-Electronics Research Flanders, Leuven, Belgium
- VIB, Leuven, Belgium
- Imec, Leuven, Belgium
- Department of Neuroscience, Faculty of Medicine, KU Leuven, Leuven, Belgium
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6
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Liu M, Gao Y, Xin F, Hu Y, Wang T, Xie F, Shao C, Li T, Wang N, Yuan K. Parvalbumin and Somatostatin: Biomarkers for Two Parallel Tectothalamic Pathways in the Auditory Midbrain. J Neurosci 2024; 44:e1655232024. [PMID: 38326037 PMCID: PMC10919325 DOI: 10.1523/jneurosci.1655-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 01/15/2024] [Accepted: 01/20/2024] [Indexed: 02/09/2024] Open
Abstract
The inferior colliculus (IC) represents a crucial relay station in the auditory pathway, located in the midbrain's tectum and primarily projecting to the thalamus. Despite the identification of distinct cell classes based on various biomarkers in the IC, their specific contributions to the organization of auditory tectothalamic pathways have remained poorly understood. In this study, we demonstrate that IC neurons expressing parvalbumin (ICPV+) or somatostatin (ICSOM+) represent two minimally overlapping cell classes throughout the three IC subdivisions in mice of both sexes. Strikingly, regardless of their location within the IC, these neurons predominantly project to the primary and secondary auditory thalamic nuclei, respectively. Cell class-specific input tracing suggested that ICPV+ neurons primarily receive auditory inputs, whereas ICSOM+ neurons receive significantly more inputs from the periaqueductal gray and the superior colliculus (SC), which are sensorimotor regions critically involved in innate behaviors. Furthermore, ICPV+ neurons exhibit significant heterogeneity in both intrinsic electrophysiological properties and presynaptic terminal size compared with ICSOM+ neurons. Notably, approximately one-quarter of ICPV+ neurons are inhibitory neurons, whereas all ICSOM+ neurons are excitatory neurons. Collectively, our findings suggest that parvalbumin and somatostatin expression in the IC can serve as biomarkers for two functionally distinct, parallel tectothalamic pathways. This discovery suggests an alternative way to define tectothalamic pathways and highlights the potential usefulness of Cre mice in understanding the multifaceted roles of the IC at the circuit level.
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Affiliation(s)
- Mengting Liu
- Department of Otorhinolaryngology Head and Neck Surgery, First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, China
| | - Yixiao Gao
- Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China
| | - Fengyuan Xin
- School of Biomedical Engineering, Tsinghua University, Beijing 100084, China
| | - Ying Hu
- Zhili College, Tsinghua University, Beijing 100084, China
| | - Tao Wang
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China
- School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Fenghua Xie
- School of Biomedical Engineering, Tsinghua University, Beijing 100084, China
- Tsinghua Laboratory of Brain and Intelligence, Tsinghua University, Beijing 100084, China
| | - Chengjun Shao
- School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Tianyu Li
- School of Biomedical Engineering, Tsinghua University, Beijing 100084, China
| | - Ningyu Wang
- Department of Otorhinolaryngology Head and Neck Surgery, Beijing Chaoyang Hospital, Capital Medical University, Beijing 100020, China
| | - Kexin Yuan
- School of Biomedical Engineering, Tsinghua University, Beijing 100084, China
- Tsinghua Laboratory of Brain and Intelligence, Tsinghua University, Beijing 100084, China
- IDG/McGovern Institute for Brain Research at Tsinghua, Tsinghua University, Beijing 10084, China
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7
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El Hady A, Takahashi D, Sun R, Akinwale O, Boyd-Meredith T, Zhang Y, Charles AS, Brody CD. Chronic brain functional ultrasound imaging in freely moving rodents performing cognitive tasks. J Neurosci Methods 2024; 403:110033. [PMID: 38056633 PMCID: PMC10872377 DOI: 10.1016/j.jneumeth.2023.110033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 11/06/2023] [Accepted: 12/01/2023] [Indexed: 12/08/2023]
Abstract
BACKGROUND Functional ultrasound imaging (fUS) is an emerging imaging technique that indirectly measures neural activity via changes in blood volume. Chronic fUS imaging during cognitive tasks in freely moving animals faces multiple exceptional challenges: performing large durable craniotomies with chronic implants, designing behavioral experiments matching the hemodynamic timescale, stabilizing the ultrasound probe during freely moving behavior, accurately assessing motion artifacts, and validating that the animal can perform cognitive tasks while tethered. NEW METHOD We provide validated solutions for those technical challenges. In addition, we present standardized step-by-step reproducible protocols, procedures, and data processing pipelines. Finally, we present proof-of-concept analysis of brain dynamics during a decision making task. RESULTS We obtain stable recordings from which we can robustly decode task variables from fUS data over multiple months. Moreover, we find that brain wide imaging through hemodynamic response is nonlinearly related to cognitive variables, such as task difficulty, as compared to sensory responses previously explored. COMPARISON WITH EXISTING METHODS Computational pipelines in fUS are nascent and we present an initial development of a full processing pathway to correct and segment fUS data. CONCLUSIONS Our methods provide stable imaging and analysis of behavior with fUS that will enable new experimental paradigms in understanding brain-wide dynamics in naturalistic behaviors.
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Affiliation(s)
- Ahmed El Hady
- Princeton Neuroscience Institute, Princeton University, Princeton, United States; Center for advanced study of collective behavior, University of Konstanz, Germany; Max Planck Institute of Animal Behavior, Konstanz, Germany
| | - Daniel Takahashi
- Brain Institute, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Ruolan Sun
- Department of Biomedical Engineering, John Hopkins University, Baltimore, United States
| | - Oluwateniola Akinwale
- Department of Biomedical Engineering, John Hopkins University, Baltimore, United States
| | - Tyler Boyd-Meredith
- Princeton Neuroscience Institute, Princeton University, Princeton, United States
| | - Yisi Zhang
- Princeton Neuroscience Institute, Princeton University, Princeton, United States
| | - Adam S Charles
- Department of Biomedical Engineering, John Hopkins University, Baltimore, United States; Mathematical Institute for Data Science, Kavli Neuroscience Discovery Institute & Center for Imaging Science, John Hopkins University, Baltimore, United States.
| | - Carlos D Brody
- Princeton Neuroscience Institute, Princeton University, Princeton, United States; Howard Hughes Medical Institute, Princeton University, Princeton, United States; Department of Molecular Biology, Princeton University, Princeton, United States.
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8
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Brunner C, Denis NL, Gertz K, Grillet M, Montaldo G, Endres M, Urban A. Brain-wide continuous functional ultrasound imaging for real-time monitoring of hemodynamics during ischemic stroke. J Cereb Blood Flow Metab 2024; 44:6-18. [PMID: 37503862 PMCID: PMC10905631 DOI: 10.1177/0271678x231191600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 07/13/2023] [Accepted: 07/14/2023] [Indexed: 07/29/2023]
Abstract
Ischemic stroke occurs abruptly causing sudden neurologic deficits, and therefore, very little is known about hemodynamic perturbations in the brain immediately after stroke onset. Here, functional ultrasound imaging was used to monitor variations in relative cerebral blood volume (rCBV) compared to baseline. rCBV levels were analyzed brain-wide and continuously at high spatiotemporal resolution (100 μm, 2 Hz) until 70mins after stroke onset in rats. We compared two stroke models, with either a permanent occlusion of the middle cerebral artery (MCAo) or a tandem occlusion of both the common carotid and middle cerebral arteries (CCAo + MCAo). We observed a typical hemodynamic pattern, including a quick drop of the rCBV after MCAo, followed by spontaneous reperfusion of several brain regions located in the vicinity of the ischemic core. The severity and location of the ischemia were variable within groups. On average, the severity of the ischemia was in good agreement with the lesion volume (24 hrs after stroke) for MCAo group, while larger for the CCAo + MCAo model. For both groups, we observed that infarcts extended to initially non-ischemic regions located rostrally to the ischemic core. These regions strongly colocalize with the origin of transient hemodynamic events associated with spreading depolarizations.
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Affiliation(s)
- Clément Brunner
- Neuro-Electronics Research Flanders, Leuven, Belgium
- Vlaams Instituut voor Biotechnologie, Leuven, Belgium
- Interuniversity Microelectronics Centre, Leuven, Belgium
- Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Nielsen Lagumersindez Denis
- Department of Neurology and Center for Stroke Research Berlin, Charité-Universitätsmedizin, Berlin, Germany
- German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany
- German Centre for Cardiovascular Research (DZHK), Berlin, Germany
| | - Karen Gertz
- Department of Neurology and Center for Stroke Research Berlin, Charité-Universitätsmedizin, Berlin, Germany
- German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany
- German Centre for Cardiovascular Research (DZHK), Berlin, Germany
| | - Micheline Grillet
- Neuro-Electronics Research Flanders, Leuven, Belgium
- Vlaams Instituut voor Biotechnologie, Leuven, Belgium
- Interuniversity Microelectronics Centre, Leuven, Belgium
- Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Gabriel Montaldo
- Neuro-Electronics Research Flanders, Leuven, Belgium
- Vlaams Instituut voor Biotechnologie, Leuven, Belgium
- Interuniversity Microelectronics Centre, Leuven, Belgium
- Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Matthias Endres
- Department of Neurology and Center for Stroke Research Berlin, Charité-Universitätsmedizin, Berlin, Germany
- German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany
- German Centre for Cardiovascular Research (DZHK), Berlin, Germany
| | - Alan Urban
- Neuro-Electronics Research Flanders, Leuven, Belgium
- Vlaams Instituut voor Biotechnologie, Leuven, Belgium
- Interuniversity Microelectronics Centre, Leuven, Belgium
- Department of Neurosciences, KU Leuven, Leuven, Belgium
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Li B, Ma C, Huang YA, Ding X, Silverman D, Chen C, Darmohray D, Lu L, Liu S, Montaldo G, Urban A, Dan Y. Circuit mechanism for suppression of frontal cortical ignition during NREM sleep. Cell 2023; 186:5739-5750.e17. [PMID: 38070510 DOI: 10.1016/j.cell.2023.11.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 09/06/2023] [Accepted: 11/09/2023] [Indexed: 12/24/2023]
Abstract
Conscious perception is greatly diminished during sleep, but the underlying circuit mechanism is poorly understood. We show that cortical ignition-a brain process shown to be associated with conscious awareness in humans and non-human primates-is strongly suppressed during non-rapid-eye-movement (NREM) sleep in mice due to reduced cholinergic modulation and rapid inhibition of cortical responses. Brain-wide functional ultrasound imaging and cell-type-specific calcium imaging combined with optogenetics showed that activity propagation from visual to frontal cortex is markedly reduced during NREM sleep due to strong inhibition of frontal pyramidal neurons. Chemogenetic activation and inactivation of basal forebrain cholinergic neurons powerfully increased and decreased visual-to-frontal activity propagation, respectively. Furthermore, although multiple subtypes of dendrite-targeting GABAergic interneurons in the frontal cortex are more active during wakefulness, soma-targeting parvalbumin-expressing interneurons are more active during sleep. Chemogenetic manipulation of parvalbumin interneurons showed that sleep/wake-dependent cortical ignition is strongly modulated by perisomatic inhibition of pyramidal neurons.
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Affiliation(s)
- Bing Li
- Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Chenyan Ma
- Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Yun-An Huang
- Neuro-Electronics Research Flanders, VIB, Department of Neurosciences, KU Leuven, imec, Leuven, Belgium
| | - Xinlu Ding
- Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Daniel Silverman
- Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Changwan Chen
- Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Dana Darmohray
- Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Lihui Lu
- Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Siqi Liu
- Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Gabriel Montaldo
- Neuro-Electronics Research Flanders, VIB, Department of Neurosciences, KU Leuven, imec, Leuven, Belgium
| | - Alan Urban
- Neuro-Electronics Research Flanders, VIB, Department of Neurosciences, KU Leuven, imec, Leuven, Belgium
| | - Yang Dan
- Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA.
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10
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Brunner C, Montaldo G, Urban A. Functional ultrasound imaging of stroke in awake rats. eLife 2023; 12:RP88919. [PMID: 37988288 PMCID: PMC10662948 DOI: 10.7554/elife.88919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2023] Open
Abstract
Anesthesia is a major confounding factor in preclinical stroke research as stroke rarely occurs in sedated patients. Moreover, anesthesia affects both brain functions and the stroke outcome acting as neurotoxic or protective agents. So far, no approaches were well suited to induce stroke while imaging hemodynamics along with simultaneous large-scale recording of brain functions in awake animals. For this reason, the first critical hours following the stroke insult and associated functional alteration remain poorly understood. Here, we present a strategy to investigate both stroke hemodynamics and stroke-induced functional alterations without the confounding effect of anesthesia, i.e., under awake condition. Functional ultrasound (fUS) imaging was used to continuously monitor variations in cerebral blood volume (CBV) in +65 brain regions/hemispheres for up to 3 hr after stroke onset. The focal cortical ischemia was induced using a chemo-thrombotic agent suited for permanent middle cerebral artery occlusion in awake rats and followed by ipsi- and contralesional whiskers stimulation to investigate on the dynamic of the thalamocortical functions. Early (0-3 hr) and delayed (day 5) fUS recording enabled to characterize the features of the ischemia (location, CBV loss), spreading depolarizations (occurrence, amplitude) and functional alteration of the somatosensory thalamocortical circuits. Post-stroke thalamocortical functions were affected at both early and later time points (0-3 hr and 5 days) after stroke. Overall, our procedure facilitates early, continuous, and chronic assessments of hemodynamics and cerebral functions. When integrated with stroke studies or other pathological analyses, this approach seeks to enhance our comprehension of physiopathologies towards the development of pertinent therapeutic interventions.
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Affiliation(s)
- Clément Brunner
- Neuro-Electronics Research FlandersLeuvenBelgium
- Vlaams Instituut voor BiotechnologieLeuvenBelgium
- Interuniversity Microelectronics CentreLeuvenBelgium
- Department of Neurosciences, KU LeuvenLeuvenBelgium
| | - Gabriel Montaldo
- Neuro-Electronics Research FlandersLeuvenBelgium
- Vlaams Instituut voor BiotechnologieLeuvenBelgium
- Interuniversity Microelectronics CentreLeuvenBelgium
- Department of Neurosciences, KU LeuvenLeuvenBelgium
| | - Alan Urban
- Neuro-Electronics Research FlandersLeuvenBelgium
- Vlaams Instituut voor BiotechnologieLeuvenBelgium
- Interuniversity Microelectronics CentreLeuvenBelgium
- Department of Neurosciences, KU LeuvenLeuvenBelgium
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11
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Wang Y, Lowerison MR, You Q, Lin BZ, Llano DA, Song P. Longitudinal Awake Imaging of Deep Mouse Brain Microvasculature with Super-resolution Ultrasound Localization Microscopy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.01.555789. [PMID: 37732191 PMCID: PMC10508721 DOI: 10.1101/2023.09.01.555789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
Super-resolution ultrasound localization microscopy (ULM) is an emerging imaging modality that resolves capillary-scale microvasculature in deep tissues. However, existing preclinical ULM applications are largely constrained to anesthetized animals, introducing confounding vascular effects such as vasodilation and altered hemodynamics. As such, ULM quantifications (e.g., vessel diameter, density, and flow velocity) may be confounded by the use of anesthesia, undermining the usefulness of ULM in practice. Here we introduce a method to address this limitation and achieve ULM imaging in awake mouse brain. Pupillary monitoring was used to confirm the awake state during ULM imaging. ULM revealed that veins showed a greater degree of vascularity reduction from anesthesia to awake states than did arteries. The reduction was most significant in the midbrain and least significant in the cortex. ULM also revealed a significant reduction in venous blood flow velocity across different brain regions under awake conditions. Serial in vivo imaging of the same animal brain at weekly intervals demonstrated the highly robust longitudinal imaging capability of the proposed technique. This is the first study demonstrating longitudinal ULM imaging in the awake mouse brain, which is essential for many ULM brain applications that require awake and behaving animals.
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12
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Li C, Kühn NK, Alkislar I, Sans-Dublanc A, Zemmouri F, Paesmans S, Calzoni A, Ooms F, Reinhard K, Farrow K. Pathway-specific inputs to the superior colliculus support flexible responses to visual threat. SCIENCE ADVANCES 2023; 9:eade3874. [PMID: 37647395 PMCID: PMC10468139 DOI: 10.1126/sciadv.ade3874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 07/31/2023] [Indexed: 09/01/2023]
Abstract
Behavioral flexibility requires directing feedforward sensory information to appropriate targets. In the superior colliculus, divergent outputs orchestrate different responses to visual threats, but the circuit organization enabling the flexible routing of sensory information remains unknown. To determine this structure, we focused on inhibitory projection (Gad2) neurons. Trans-synaptic tracing and neuronal recordings revealed that Gad2 neurons projecting to the lateral geniculate nucleus (LGN) and the parabigeminal nucleus (PBG) form two separate populations, each receiving a different set of non-retinal inputs. Inhibiting the LGN- or PBG-projecting Gad2 neurons resulted in opposing effects on behavior; increasing freezing or escape probability to visual looming, respectively. Optogenetic activation of selected inputs to the LGN- and PBG-projecting Gad2 cells predictably regulated responses to visual threat. These data suggest that projection-specific sampling of brain-wide inputs provides a circuit design principle that enables visual inputs to be selectively routed to produce context-specific behavior.
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Affiliation(s)
- Chen Li
- Neuro-Electronics Research Flanders, VIB, Leuven, Belgium
- Department of Biology, KU Leuven, Leuven, Belgium
| | - Norma K. Kühn
- Neuro-Electronics Research Flanders, VIB, Leuven, Belgium
- Department of Biology, KU Leuven, Leuven, Belgium
| | - Ilayda Alkislar
- Neuro-Electronics Research Flanders, VIB, Leuven, Belgium
- Northeastern University, Boston, MA, USA
| | - Arnau Sans-Dublanc
- Neuro-Electronics Research Flanders, VIB, Leuven, Belgium
- Department of Biology, KU Leuven, Leuven, Belgium
| | - Firdaouss Zemmouri
- Neuro-Electronics Research Flanders, VIB, Leuven, Belgium
- Faculty of Pharmaceutical, Biomedical, and Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | - Soraya Paesmans
- Neuro-Electronics Research Flanders, VIB, Leuven, Belgium
- Department of Biology, KU Leuven, Leuven, Belgium
| | - Alex Calzoni
- Neuro-Electronics Research Flanders, VIB, Leuven, Belgium
- Department of Biology, KU Leuven, Leuven, Belgium
| | - Frédérique Ooms
- Neuro-Electronics Research Flanders, VIB, Leuven, Belgium
- Imec, Leuven, Belgium
| | - Katja Reinhard
- Neuro-Electronics Research Flanders, VIB, Leuven, Belgium
- Department of Biology, KU Leuven, Leuven, Belgium
| | - Karl Farrow
- Neuro-Electronics Research Flanders, VIB, Leuven, Belgium
- Department of Biology, KU Leuven, Leuven, Belgium
- Imec, Leuven, Belgium
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13
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Wu Q, Zhang Y. Neural Circuit Mechanisms Involved in Animals' Detection of and Response to Visual Threats. Neurosci Bull 2023; 39:994-1008. [PMID: 36694085 PMCID: PMC10264346 DOI: 10.1007/s12264-023-01021-0] [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: 08/28/2022] [Accepted: 10/30/2022] [Indexed: 01/26/2023] Open
Abstract
Evading or escaping from predators is one of the most crucial issues for survival across the animal kingdom. The timely detection of predators and the initiation of appropriate fight-or-flight responses are innate capabilities of the nervous system. Here we review recent progress in our understanding of innate visually-triggered defensive behaviors and the underlying neural circuit mechanisms, and a comparison among vinegar flies, zebrafish, and mice is included. This overview covers the anatomical and functional aspects of the neural circuits involved in this process, including visual threat processing and identification, the selection of appropriate behavioral responses, and the initiation of these innate defensive behaviors. The emphasis of this review is on the early stages of this pathway, namely, threat identification from complex visual inputs and how behavioral choices are influenced by differences in visual threats. We also briefly cover how the innate defensive response is processed centrally. Based on these summaries, we discuss coding strategies for visual threats and propose a common prototypical pathway for rapid innate defensive responses.
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Affiliation(s)
- Qiwen Wu
- Institute of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yifeng Zhang
- Institute of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China.
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14
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Claron J, Provansal M, Salardaine Q, Tissier P, Dizeux A, Deffieux T, Picaud S, Tanter M, Arcizet F, Pouget P. Co-variations of cerebral blood volume and single neurons discharge during resting state and visual cognitive tasks in non-human primates. Cell Rep 2023; 42:112369. [PMID: 37043356 DOI: 10.1016/j.celrep.2023.112369] [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: 07/18/2022] [Revised: 01/11/2023] [Accepted: 03/22/2023] [Indexed: 04/13/2023] Open
Abstract
To better understand how the brain allows primates to perform various sets of tasks, the ability to simultaneously record neural activity at multiple spatiotemporal scales is challenging but necessary. However, the contribution of single-unit activities (SUAs) to neurovascular activity remains to be fully understood. Here, we combine functional ultrasound imaging of cerebral blood volume (CBV) and SUA recordings in visual and fronto-medial cortices of behaving macaques. We show that SUA provides a significant estimate of the neurovascular response below the typical fMRI spatial resolution of 2mm3. Furthermore, our results also show that SUAs and CBV activities are statistically uncorrelated during the resting state but correlate during tasks. These results have important implications for interpreting functional imaging findings while one constructs inferences of SUA during resting state or tasks.
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Affiliation(s)
- Julien Claron
- Stem Cell and Brain Research Institute, INSERM U1208, Bron, France; Paris Brain Institute, Institut du Cerveau, INSERM 1127, CNRS 7225 Sorbonne Université, Paris, France
| | | | - Quentin Salardaine
- Paris Brain Institute, Institut du Cerveau, INSERM 1127, CNRS 7225 Sorbonne Université, Paris, France
| | - Pierre Tissier
- Paris Brain Institute, Institut du Cerveau, INSERM 1127, CNRS 7225 Sorbonne Université, Paris, France
| | - Alexandre Dizeux
- Physics for Medicine, ESPCI, INSERM, CNRS, PSL Research University, Paris, France
| | - Thomas Deffieux
- Physics for Medicine, ESPCI, INSERM, CNRS, PSL Research University, Paris, France
| | - Serge Picaud
- Institut de la Vision, CNRS, INSERM, Sorbonne Université, Paris, France
| | - Mickael Tanter
- Physics for Medicine, ESPCI, INSERM, CNRS, PSL Research University, Paris, France.
| | - Fabrice Arcizet
- Institut de la Vision, CNRS, INSERM, Sorbonne Université, Paris, France.
| | - Pierre Pouget
- Paris Brain Institute, Institut du Cerveau, INSERM 1127, CNRS 7225 Sorbonne Université, Paris, France.
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15
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Solomon SG, Janbon H, Bimson A, Wheatcroft T. Visual spatial location influences selection of instinctive behaviours in mouse. ROYAL SOCIETY OPEN SCIENCE 2023; 10:230034. [PMID: 37122945 PMCID: PMC10130721 DOI: 10.1098/rsos.230034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 04/04/2023] [Indexed: 05/03/2023]
Abstract
Visual stimuli can elicit instinctive approach and avoidance behaviours. In mouse, vision is known to be important for both avoidance of an overhead threat and approach toward a potential terrestrial prey. The stimuli used to characterize these behaviours, however, vary in both spatial location (overhead or near the ground plane) and visual feature (rapidly expanding disc or slowly moving disc). We therefore asked how mice responded to the same visual features presented in each location. We found that a looming black disc induced escape behaviour when presented overhead or to the side of the animal, but the escapes produced by side-looms were less vigorous and often preceded by freezing behaviour. Similarly, small moving discs induced freezing behaviour when presented overhead or to the side of the animal, but side sweeps also elicited approach behaviours, such that mice explored the area of the arena near where the stimulus had been presented. Our observations therefore show that mice combine cues to the location and features of visual stimuli when selecting among potential behaviours.
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Affiliation(s)
- Samuel G. Solomon
- Institute of Behavioural Neuroscience and Department of Experimental Psychology, University College London, London WC1H 0AP, UK
| | - Hadrien Janbon
- Institute of Behavioural Neuroscience and Department of Experimental Psychology, University College London, London WC1H 0AP, UK
| | - Adam Bimson
- Institute of Behavioural Neuroscience and Department of Experimental Psychology, University College London, London WC1H 0AP, UK
| | - Thomas Wheatcroft
- Institute of Behavioural Neuroscience and Department of Experimental Psychology, University College London, London WC1H 0AP, UK
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16
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Aurup C, Pouliopoulos AN, Kwon N, Murillo MF, Konofagou EE. Evaluation of Non-invasive Optogenetic Stimulation with Transcranial Functional Ultrasound Imaging. ULTRASOUND IN MEDICINE & BIOLOGY 2023; 49:908-917. [PMID: 36460567 PMCID: PMC10319350 DOI: 10.1016/j.ultrasmedbio.2022.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 10/27/2022] [Accepted: 11/03/2022] [Indexed: 06/17/2023]
Abstract
Optogenetics employs engineered viruses to genetically modify cells to express specific light-sensitive ion channels. The standard method for gene delivery in the brain involves invasive craniotomies that expose the brain and direct injections of viruses that invariably damage neural tissue along the syringe tract. A recently proposed alternative in which non-invasive optogenetics is performed with focused ultrasound (FUS)-mediated blood-brain barrier (BBB) openings has been found to non-invasively facilitate gene delivery for optogenetics in mice. Although gene delivery can be performed non-invasively, validating successful viral transduction and expression of encoded ion channels in target tissue typically involves similar invasive techniques, such as craniotomies in longitudinal studies and/or postmortem histology. Functional ultrasound imaging (fUSi) is an emerging neuroimaging technique that can be used to transcranially detect changes in cerebral blood volume following introduction of a stimulus. In this study, we implemented a fully non-invasive combined FUS-fUSi technique for performing optogenetics in mice. FUS successfully delivered viruses encoding the red-shifted channelrhodopsin variant ChrimsonR in all treated subjects. fUSi successfully identified stimulus-evoked cerebral blood volume changes preferentially in brain regions expressing the light-sensitive ion channels. Improvements in cell-specific targeting of viral vectors and transcranial ultrasound imaging will make the combined technique a useful tool for neuroscience research in small animals.
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Affiliation(s)
- Christian Aurup
- Department of Biomedical Engineering, Columbia University, New York, New York, USA
| | | | - Nancy Kwon
- Department of Biomedical Engineering, Columbia University, New York, New York, USA
| | - Maria F Murillo
- Department of Biomedical Engineering, Columbia University, New York, New York, USA
| | - Elisa E Konofagou
- Department of Biomedical Engineering, Columbia University, New York, New York, USA; Department of Radiology, Columbia University, New York, New York, USA.
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17
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Abstract
Functional ultrasound (fUS) is a neuroimaging method that uses ultrasound to track changes in cerebral blood volume as an indirect readout of neuronal activity at high spatiotemporal resolution. fUS is capable of imaging head-fixed or freely behaving rodents and of producing volumetric images of the entire mouse brain. It has been applied to many species, including primates and humans. Now that fUS is reaching maturity, it is being adopted by the neuroscience community. However, the nature of the fUS signal and the different implementations of fUS are not necessarily accessible to nonspecialists. This review aims to introduce these ultrasound concepts to all neuroscientists. We explain the physical basis of the fUS signal and the principles of the method, present the state of the art of its hardware implementation, and give concrete examples of current applications in neuroscience. Finally, we suggest areas for improvement during the next few years.
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Affiliation(s)
- Gabriel Montaldo
- Neuro-Electronics Research Flanders, Vlaams Instituut voor Biotechnologie, and Interuniversity Microelectronics Centre, Leuven, Belgium;
| | - Alan Urban
- Neuro-Electronics Research Flanders, Vlaams Instituut voor Biotechnologie, and Interuniversity Microelectronics Centre, Leuven, Belgium; .,Department of Neuroscience, Faculty of Medicine, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Emilie Macé
- Brain-Wide Circuits for Behavior Research Group, Max Planck Institute of Neurobiology, Martinsried, Germany.,Current address: Max Planck Institute for Biological Intelligence, In Foundation, Martinsried, Germany;
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18
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Jure R. The “Primitive Brain Dysfunction” Theory of Autism: The Superior Colliculus Role. Front Integr Neurosci 2022; 16:797391. [PMID: 35712344 PMCID: PMC9194533 DOI: 10.3389/fnint.2022.797391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 04/19/2022] [Indexed: 11/20/2022] Open
Abstract
A better understanding of the pathogenesis of autism will help clarify our conception of the complexity of normal brain development. The crucial deficit may lie in the postnatal changes that vision produces in the brainstem nuclei during early life. The superior colliculus is the primary brainstem visual center. Although difficult to examine in humans with present techniques, it is known to support behaviors essential for every vertebrate to survive, such as the ability to pay attention to relevant stimuli and to produce automatic motor responses based on sensory input. From birth to death, it acts as a brain sentinel that influences basic aspects of our behavior. It is the main brainstem hub that lies between the environment and the rest of the higher neural system, making continuous, implicit decisions about where to direct our attention. The conserved cortex-like organization of the superior colliculus in all vertebrates allows the early appearance of primitive emotionally-related behaviors essential for survival. It contains first-line specialized neurons enabling the detection and tracking of faces and movements from birth. During development, it also sends the appropriate impulses to help shape brain areas necessary for social-communicative abilities. These abilities require the analysis of numerous variables, such as the simultaneous evaluation of incoming information sustained by separate brain networks (visual, auditory and sensory-motor, social, emotional, etc.), and predictive capabilities which compare present events to previous experiences and possible responses. These critical aspects of decision-making allow us to evaluate the impact that our response or behavior may provoke in others. The purpose of this review is to show that several enigmas about the complexity of autism might be explained by disruptions of collicular and brainstem functions. The results of two separate lines of investigation: 1. the cognitive, etiologic, and pathogenic aspects of autism on one hand, and two. the functional anatomy of the colliculus on the other, are considered in order to bridge the gap between basic brain science and clinical studies and to promote future research in this unexplored area.
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19
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Nunez-Elizalde AO, Krumin M, Reddy CB, Montaldo G, Urban A, Harris KD, Carandini M. Neural correlates of blood flow measured by ultrasound. Neuron 2022; 110:1631-1640.e4. [PMID: 35278361 PMCID: PMC9235295 DOI: 10.1016/j.neuron.2022.02.012] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 01/06/2022] [Accepted: 02/15/2022] [Indexed: 12/17/2022]
Abstract
Functional ultrasound imaging (fUSI) is an appealing method for measuring blood flow and thus infer brain activity, but it relies on the physiology of neurovascular coupling and requires extensive signal processing. To establish to what degree fUSI trial-by-trial signals reflect neural activity, we performed simultaneous fUSI and neural recordings with Neuropixels probes in awake mice. fUSI signals strongly correlated with the slow (<0.3 Hz) fluctuations in the local firing rate and were closely predicted by the smoothed firing rate of local neurons, particularly putative inhibitory neurons. The optimal smoothing filter had a width of ∼3 s, matched the hemodynamic response function of awake mice, was invariant across mice and stimulus conditions, and was similar in the cortex and hippocampus. fUSI signals also matched neural firing spatially: firing rates were as highly correlated across hemispheres as fUSI signals. Thus, blood flow measured by ultrasound bears a simple and accurate relationship to neuronal firing.
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Affiliation(s)
| | - Michael Krumin
- UCL Institute of Ophthalmology, University College London, London WC1E 6AE, UK
| | - Charu Bai Reddy
- UCL Institute of Ophthalmology, University College London, London WC1E 6AE, UK
| | - Gabriel Montaldo
- Neuro-Electronics Research Flanders, 3001 Leuven, Belgium; Vlaams Instituut voor Biotechnologie (VIB), 3000 Leuven, Belgium; imec, 3001 Leuven, Belgium; Department of Neuroscience, KU Leuven, 3000 Leuven, Belgium
| | - Alan Urban
- Neuro-Electronics Research Flanders, 3001 Leuven, Belgium; Vlaams Instituut voor Biotechnologie (VIB), 3000 Leuven, Belgium; imec, 3001 Leuven, Belgium; Department of Neuroscience, KU Leuven, 3000 Leuven, Belgium
| | - Kenneth D Harris
- UCL Queen Square Institute of Neurology, University College London, London WC1E 6AE, UK
| | - Matteo Carandini
- UCL Institute of Ophthalmology, University College London, London WC1E 6AE, UK.
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20
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Tangential high-density electrode insertions allow to simultaneously measure neuronal activity across an extended region of the visual field in mouse superior colliculus. J Neurosci Methods 2022; 376:109622. [PMID: 35525463 DOI: 10.1016/j.jneumeth.2022.109622] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 04/13/2022] [Accepted: 05/02/2022] [Indexed: 11/21/2022]
Abstract
BACKGROUND The superior colliculus (SC) is a midbrain structure that plays a central role in visual processing. Although we have learned a considerable amount about the function of single SC neurons, the way in which sensory information is represented and processed on the population level in awake behaving animals and across a large region of the retinotopic map is still largely unknown. Partially because the SC is anatomically located below the cortical sheet and the transverse sinus, which render the measure of neuronal activity from a large population of neurons in the SC technically difficult to perform. NEW METHOD To address this, we propose a tangential recording configuration using high-density electrode probes (Neuropixels) in mouse SC in vivo. This method permits a large number of recording sites (~200) inside the SC circuitry allowing to record from a large population of SC neurons along a vast area of retinotopic space. RESULTS This approach provides a unique opportunity to measure the activity of SC neuronal populations over up to ~2mm of SC tissue reporting for the first time the continuous receptive fields coverage of almost the entire SC retinotopy. Here we describe how to perform targeted tangential recordings along the anterior-posterior and the medio-lateral axis of the mouse SC in vivo in the upper visual layers. Furthermore, we describe how to combine this approach with optogenetic tools for cell-type identification on the population level. COMPARISON WITH EXISTING METHODS Vertical insertion has been a standard way to record visual responses in the SC. Inserting multi-shank probes vertically allows to cover a larger region of the SC but misses both the complete extent of the available retinotopy and the continuous measure allowed by the high density of recording sites on Neuropixels probes. CONCLUSION Altogether tangential insertions in the upper visual layers of the mouse SC using Neuropixels permit for the first time to access a majority of the retinotopically organized visual representation of the world at an unprecedented precision.
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21
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Wheatcroft T, Saleem AB, Solomon SG. Functional Organisation of the Mouse Superior Colliculus. Front Neural Circuits 2022; 16:792959. [PMID: 35601532 PMCID: PMC9118347 DOI: 10.3389/fncir.2022.792959] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 03/07/2022] [Indexed: 11/30/2022] Open
Abstract
The superior colliculus (SC) is a highly conserved area of the mammalian midbrain that is widely implicated in the organisation and control of behaviour. SC receives input from a large number of brain areas, and provides outputs to a large number of areas. The convergence and divergence of anatomical connections with different areas and systems provides challenges for understanding how SC contributes to behaviour. Recent work in mouse has provided large anatomical datasets, and a wealth of new data from experiments that identify and manipulate different cells within SC, and their inputs and outputs, during simple behaviours. These data offer an opportunity to better understand the roles that SC plays in these behaviours. However, some of the observations appear, at first sight, to be contradictory. Here we review this recent work and hypothesise a simple framework which can capture the observations, that requires only a small change to previous models. Specifically, the functional organisation of SC can be explained by supposing that three largely distinct circuits support three largely distinct classes of simple behaviours-arrest, turning towards, and the triggering of escape or capture. These behaviours are hypothesised to be supported by the optic, intermediate and deep layers, respectively.
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Affiliation(s)
| | | | - Samuel G. Solomon
- Institute of Behavioural Neuroscience, University College London, London, United Kingdom
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22
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Liu X, Huang H, Snutch TP, Cao P, Wang L, Wang F. The Superior Colliculus: Cell Types, Connectivity, and Behavior. Neurosci Bull 2022; 38:1519-1540. [PMID: 35484472 DOI: 10.1007/s12264-022-00858-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 02/16/2022] [Indexed: 10/18/2022] Open
Abstract
The superior colliculus (SC), one of the most well-characterized midbrain sensorimotor structures where visual, auditory, and somatosensory information are integrated to initiate motor commands, is highly conserved across vertebrate evolution. Moreover, cell-type-specific SC neurons integrate afferent signals within local networks to generate defined output related to innate and cognitive behaviors. This review focuses on the recent progress in understanding of phenotypic diversity amongst SC neurons and their intrinsic circuits and long-projection targets. We further describe relevant neural circuits and specific cell types in relation to behavioral outputs and cognitive functions. The systematic delineation of SC organization, cell types, and neural connections is further put into context across species as these depend upon laminar architecture. Moreover, we focus on SC neural circuitry involving saccadic eye movement, and cognitive and innate behaviors. Overall, the review provides insight into SC functioning and represents a basis for further understanding of the pathology associated with SC dysfunction.
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Affiliation(s)
- Xue Liu
- Shenzhen Key Lab of Neuropsychiatric Modulation, Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Key Laboratory of Brain Connectome and Manipulation, the Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, 518055, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hongren Huang
- Shenzhen Key Lab of Neuropsychiatric Modulation, Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Key Laboratory of Brain Connectome and Manipulation, the Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, 518055, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Terrance P Snutch
- Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, V6T 1Z4, Canada
| | - Peng Cao
- National Institute of Biological Sciences, Beijing, 100049, China
| | - Liping Wang
- Shenzhen Key Lab of Neuropsychiatric Modulation, Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Key Laboratory of Brain Connectome and Manipulation, the Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, 518055, China.
| | - Feng Wang
- Shenzhen Key Lab of Neuropsychiatric Modulation, Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Key Laboratory of Brain Connectome and Manipulation, the Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, 518055, China.
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23
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Villalobos CA, Basso MA. Optogenetic activation of the inhibitory nigro-collicular circuit evokes contralateral orienting movements in mice. Cell Rep 2022; 39:110699. [PMID: 35443172 PMCID: PMC10144672 DOI: 10.1016/j.celrep.2022.110699] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 09/20/2021] [Accepted: 03/29/2022] [Indexed: 11/03/2022] Open
Abstract
We report that increasing inhibition from the basal ganglia (BG) to the superior colliculus (SC) through the substantia nigra pars reticulata (nigra) using in vivo optogenetic activation of GABAergic terminals in mice produces contralateral orienting movements. These movements are unexpected because decreases, and not increases, in nigral activity are generally associated with the initiation of orienting movements. We found that, in slice recordings, the same optogenetic stimulation of nigral terminals producing movements in vivo evokes post-inhibitory rebound depolarization followed by Na+ spikes in SC output neurons. Moreover, blocking T-type Ca2+ channels in slices prevent post-inhibitory rebound and subsequent Na+ spiking in SC output neurons and also reduce the likelihood of contralateral orienting in vivo. On the basis of these results, we propose that, in addition to the permissive role, the BG may play an active role in the generation of orienting movements in mice by driving post-inhibitory rebound depolarization in SC output neurons.
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Affiliation(s)
- Claudio A Villalobos
- Fuster Laboratory of Cognitive Neuroscience, Department of Psychiatry and Biobehavioral Sciences, The Jane and Terry Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA.
| | - Michele A Basso
- Fuster Laboratory of Cognitive Neuroscience, Department of Psychiatry and Biobehavioral Sciences, The Jane and Terry Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA.
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24
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Brunner C, Macé E, Montaldo G, Urban A. Quantitative Hemodynamic Measurements in Cortical Vessels Using Functional Ultrasound Imaging. Front Neurosci 2022; 16:831650. [PMID: 35495056 PMCID: PMC9039668 DOI: 10.3389/fnins.2022.831650] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 02/23/2022] [Indexed: 01/17/2023] Open
Abstract
Red blood cell velocity (RBCv), cerebral blood flow (CBF), and volume (CBV) are three key parameters when describing brain hemodynamics. Functional ultrasound imaging is a Doppler-based method allowing for real-time measurement of relative CBV at high spatiotemporal resolution (100 × 110 × 300 μm3, up to 10 Hz) and large scale. Nevertheless, the measure of RBCv and CBF in small cortical vessels with functional ultrasound imaging remains challenging because of their orientation and size, which impairs the ability to perform precise measurements. We designed a directional flow filter to overpass these limitations allowing us to measure RBCv in single vessels using a standard functional ultrasound imaging system without contrast agents (e.g., microbubbles). This method allows to quickly extract the number of vessels in the cortex that was estimated to be approximately 650/cm3 in adult rats, with a 55-45% ratio for penetrating arterioles versus ascending venules. Then, we analyzed the changes in RBCv in these vessels during forepaw stimulation. We observed that ∼40 vessels located in the primary somatosensory forelimb cortex display a significant increase of the RBCv (median ΔRBCv ∼15%, maximal ΔRBCv ∼60%). As expected, we show that RBCv was higher for penetrating arterioles located in the center than in the periphery of the activated area. The proposed approach extends the capabilities of functional ultrasound imaging, which may contribute to a better understanding of the neurovascular coupling at the brain-wide scale.
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Affiliation(s)
- Clément Brunner
- Neuro-Electronics Research Flanders, Leuven, Belgium
- VIB, Leuven, Belgium
- Imec, Leuven, Belgium
- Department of Neuroscience, Faculty of Medicine, KU Leuven, Leuven, Belgium
| | - Emilie Macé
- Brain-Wide Circuits for Behavior Research Group, Max Planck Institute of Neurobiology, Martinsried, Germany
| | - Gabriel Montaldo
- Neuro-Electronics Research Flanders, Leuven, Belgium
- VIB, Leuven, Belgium
- Imec, Leuven, Belgium
- Department of Neuroscience, Faculty of Medicine, KU Leuven, Leuven, Belgium
| | - Alan Urban
- Neuro-Electronics Research Flanders, Leuven, Belgium
- VIB, Leuven, Belgium
- Imec, Leuven, Belgium
- Department of Neuroscience, Faculty of Medicine, KU Leuven, Leuven, Belgium
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25
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Cheung V, Chung P, Bjorni M, Shvareva VA, Lopez YC, Feinberg EH. Virally encoded connectivity transgenic overlay RNA sequencing (VECTORseq) defines projection neurons involved in sensorimotor integration. Cell Rep 2021; 37:110131. [PMID: 34936877 PMCID: PMC8719358 DOI: 10.1016/j.celrep.2021.110131] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 10/26/2021] [Accepted: 11/22/2021] [Indexed: 02/05/2023] Open
Abstract
Behavior arises from concerted activity throughout the brain. Consequently, a major focus of modern neuroscience is defining the physiology and behavioral roles of projection neurons linking different brain areas. Single-cell RNA sequencing has facilitated these efforts by revealing molecular determinants of cellular physiology and markers that enable genetically targeted perturbations such as optogenetics, but existing methods for sequencing defined projection populations are low throughput, painstaking, and costly. We developed a straightforward, multiplexed approach, virally encoded connectivity transgenic overlay RNA sequencing (VECTORseq). VECTORseq repurposes commercial retrogradely infecting viruses typically used to express functional transgenes (e.g., recombinases and fluorescent proteins) by treating viral transgene mRNA as barcodes within single-cell datasets. VECTORseq is compatible with different viral families, resolves multiple populations with different projection targets in one sequencing run, and identifies cortical and subcortical excitatory and inhibitory projection populations. Our study provides a roadmap for high-throughput identification of neuronal subtypes based on connectivity.
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Affiliation(s)
- Victoria Cheung
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94158, USA; Tetrad Graduate Program, University of California, San Francisco, San Francisco, CA 94158, USA.
| | - Philip Chung
- Department of Anesthesiology & Pain Medicine, University of Washington, Seattle, WA 98195, USA
| | - Max Bjorni
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Varvara A Shvareva
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Yesenia C Lopez
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Evan H Feinberg
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94158, USA; Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94158, USA.
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26
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Functional ultrasound imaging: A useful tool for functional connectomics? Neuroimage 2021; 245:118722. [PMID: 34800662 DOI: 10.1016/j.neuroimage.2021.118722] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 09/15/2021] [Accepted: 11/10/2021] [Indexed: 12/28/2022] Open
Abstract
Functional ultrasound (fUS) is a hemodynamic-based functional neuroimaging technique, primarily used in animal models, that combines a high spatiotemporal resolution, a large field of view, and compatibility with behavior. These assets make fUS especially suited to interrogating brain activity at the systems level. In this review, we describe the technical capabilities offered by fUS and discuss how this technique can contribute to the field of functional connectomics. First, fUS can be used to study intrinsic functional connectivity, namely patterns of correlated activity between brain regions. In this area, fUS has made the most impact by following connectivity changes in disease models, across behavioral states, or dynamically. Second, fUS can also be used to map brain-wide pathways associated with an external event. For example, fUS has helped obtain finer descriptions of several sensory systems, and uncover new pathways implicated in specific behaviors. Additionally, combining fUS with direct circuit manipulations such as optogenetics is an attractive way to map the brain-wide connections of defined neuronal populations. Finally, technological improvements and the application of new analytical tools promise to boost fUS capabilities. As brain coverage and the range of behavioral contexts that can be addressed with fUS keep on increasing, we believe that fUS-guided connectomics will only expand in the future. In this regard, we consider the incorporation of fUS into multimodal studies combining diverse techniques and behavioral tasks to be the most promising research avenue.
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27
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Edelman BJ, Ielacqua GD, Chan RW, Asaad M, Choy M, Lee JH. High-sensitivity detection of optogenetically-induced neural activity with functional ultrasound imaging. Neuroimage 2021; 242:118434. [PMID: 34333106 PMCID: PMC9584544 DOI: 10.1016/j.neuroimage.2021.118434] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 07/20/2021] [Accepted: 07/26/2021] [Indexed: 12/11/2022] Open
Abstract
Whole-brain imaging approaches and optogenetic manipulations are powerful tools to map brain-wide neural circuits in vivo. To date, functional magnetic resonance imaging (fMRI) provides the most comprehensive evaluation of such large-scale circuitry. However, functional ultrasound imaging (fUSI) has recently emerged as a complementary imaging modality that can extend such measurements towards the context of diverse behavioral states and tasks. Nevertheless, in order to properly interpret the fUSI signal during these complicated scenarios, it must first be carefully validated against well-established technologies, such as fMRI, in highly controlled experimental settings. Here, to address this need, we compared subsequent fMRI and fUSI recordings in response to direct neuronal activation via optogenetics in the same animals under an identical anesthetic protocol. Specifically, we applied various intensities of light stimulation to the primary motor cortex (M1) of mice and compared the spatiotemporal dynamics of the elicited fMRI and fUSI signals. Overall, our general linear model analysis (t-scores) and time series analysis (z-scores) revealed that fUSI was more sensitive than fMRI for detecting optogenetically-induced neuronal activation. Local field potential recordings in the bilateral M1 and striatum also better co-localized with fUSI activation patterns than those of fMRI. Finally, the fUSI response contained distinct arterial and venous components that provide vascular readouts of neuronal activity with vessel-type specificity.
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Affiliation(s)
- Bradley Jay Edelman
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305, USA
| | - Giovanna D Ielacqua
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305, USA
| | - Russell W Chan
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305, USA
| | - Mazen Asaad
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305, USA; Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, 94305, USA
| | - Mankin Choy
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305, USA
| | - Jin Hyung Lee
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305, USA; Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA; Department of Electrical Engineering, Stanford University, CA, 94305, USA; Department of Neurosurgery, Stanford University, Stanford, CA, 94305, USA.
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28
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Brunner C, Grillet M, Urban A, Roska B, Montaldo G, Macé E. Whole-brain functional ultrasound imaging in awake head-fixed mice. Nat Protoc 2021; 16:3547-3571. [PMID: 34089019 DOI: 10.1038/s41596-021-00548-8] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 03/30/2021] [Indexed: 12/13/2022]
Abstract
Most brain functions engage a network of distributed regions. Full investigation of these functions thus requires assessment of whole brains; however, whole-brain functional imaging of behaving animals remains challenging. This protocol describes how to follow brain-wide activity in awake head-fixed mice using functional ultrasound imaging, a method that tracks cerebral blood volume dynamics. We describe how to set up a functional ultrasound imaging system with a provided acquisition software (miniScan), establish a chronic cranial window (timing surgery: ~3-4 h) and image brain-wide activity associated with a stimulus at high resolution (100 × 110 × 300 µm and 10 Hz per brain slice, which takes ~45 min per imaging session). We include codes that enable data to be registered to a reference atlas, production of 3D activity maps, extraction of the activity traces of ~250 brain regions and, finally, combination of data from multiple sessions (timing analysis averages ~2 h). This protocol enables neuroscientists to observe global brain processes in mice.
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Affiliation(s)
- Clément Brunner
- Neuro-Electronics Research Flanders, Leuven, Belgium
- VIB, Leuven, Belgium
- Imec, Leuven, Belgium
- Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Micheline Grillet
- Neuro-Electronics Research Flanders, Leuven, Belgium
- VIB, Leuven, Belgium
- Imec, Leuven, Belgium
- Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Alan Urban
- Neuro-Electronics Research Flanders, Leuven, Belgium
- VIB, Leuven, Belgium
- Imec, Leuven, Belgium
- Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Botond Roska
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
- University of Basel, Basel, Switzerland
- NCCR Molecular Systems Engineering, Basel, Switzerland
| | - Gabriel Montaldo
- Neuro-Electronics Research Flanders, Leuven, Belgium.
- VIB, Leuven, Belgium.
- Imec, Leuven, Belgium.
- Department of Neurosciences, KU Leuven, Leuven, Belgium.
| | - Emilie Macé
- Brain-Wide Circuits for Behavior Lab, Max Planck Institute of Neurobiology, Martinsried, Germany.
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29
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Bernier LP, Brunner C, Cottarelli A, Balbi M. Location Matters: Navigating Regional Heterogeneity of the Neurovascular Unit. Front Cell Neurosci 2021; 15:696540. [PMID: 34276312 PMCID: PMC8277940 DOI: 10.3389/fncel.2021.696540] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 05/31/2021] [Indexed: 12/27/2022] Open
Abstract
The neurovascular unit (NVU) of the brain is composed of multiple cell types that act synergistically to modify blood flow to locally match the energy demand of neural activity, as well as to maintain the integrity of the blood-brain barrier (BBB). It is becoming increasingly recognized that the functional specialization, as well as the cellular composition of the NVU varies spatially. This heterogeneity is encountered as variations in vascular and perivascular cells along the arteriole-capillary-venule axis, as well as through differences in NVU composition throughout anatomical regions of the brain. Given the wide variations in metabolic demands between brain regions, especially those of gray vs. white matter, the spatial heterogeneity of the NVU is critical to brain function. Here we review recent evidence demonstrating regional specialization of the NVU between brain regions, by focusing on the heterogeneity of its individual cellular components and briefly discussing novel approaches to investigate NVU diversity.
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Affiliation(s)
- Louis-Philippe Bernier
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Clément Brunner
- Neuro-Electronics Research Flanders, Leuven, Belgium.,Vlaams Instituut voor Biotechnologie, Leuven, Belgium.,Interuniversity Microeletronics Centre, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
| | | | - Matilde Balbi
- Queensland Brain Institute, University of Queensland, Brisbane, QLD, Australia
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30
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Functional ultrasound imaging of the spreading activity following optogenetic stimulation of the rat visual cortex. Sci Rep 2021; 11:12603. [PMID: 34131223 PMCID: PMC8206208 DOI: 10.1038/s41598-021-91972-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 05/31/2021] [Indexed: 02/05/2023] Open
Abstract
Optogenetics has revolutionized neurosciences by allowing fine control of neuronal activity. An important aspect for this control is assessing the activation and/or adjusting the stimulation, which requires imaging the entire volume of optogenetically-induced neuronal activity. An ideal technique for this aim is fUS imaging, which allows one to generate brain-wide activation maps with submesoscopic spatial resolution. However, optical stimulation of the brain with blue light might lead to non-specific activations at high irradiances. fUS imaging of optogenetic activations can be obtained at these wavelengths using lower light power (< 2mW) but it limits the depth of directly activatable neurons from the cortical surface. Our main goal was to report that we can detect specific optogenetic activations in V1 even in deep layers following stimulation at the cortical surface. Here, we show the possibility to detect deep optogenetic activations in anesthetized rats expressing the red-shifted opsin ChrimsonR in V1 using fUS imaging. We demonstrate the optogenetic specificity of these activations and their neuronal origin with electrophysiological recordings. Finally, we show that the optogenetic response initiated in V1 spreads to downstream (LGN) and upstream (V2) visual areas.
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