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Sharma H, Azouz R. Global and local neuronal coding of tactile information in the barrel cortex. Front Neurosci 2024; 17:1291864. [PMID: 38249584 PMCID: PMC10796699 DOI: 10.3389/fnins.2023.1291864] [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: 09/10/2023] [Accepted: 11/24/2023] [Indexed: 01/23/2024] Open
Abstract
During tactile sensation in rodents, the whisker movements across surfaces give rise to intricate whisker motions that encompass discrete and transient stick-slip events, effectively conveying valuable information regarding surface properties. These surface characteristics are transformed into cortical neuronal responses. This study examined the coding strategies underlying these transformations in rat whiskers. We found that changes in surface coarseness modified the number and magnitude of stick-slip events, which in turn both modulated properties of neuronal responses. Global changes in the number of stick-slip events primarily affected neuronal discharge rates and the degree of neuronal synchronization. In contrast, local changes in the magnitude of stick-slip events affected the transformation of these kinematic and kinetic characteristics into neuronal discharges. Most cortical neurons exhibited surface coarseness selectivity through global and local stick-slip event properties. However, this selectivity varied across coding strategies in the same neurons, given that each coding strategy reflected different aspects of changes in whisker-surface interactions. The degree of spatial similarity in surface coarseness preference in adjacently recorded neurons differed among these coding strategies. Adjacently recorded neurons exhibited the same surface coarseness preference in their firing rates but not through other coding strategies. Through these results, we were able to show that local stick-slip event properties contribute to texture discrimination, complementing and surpassing global coding in this context. These findings suggest that the representation of surface coarseness in the cortex may rely on concurrent coding strategies that integrate tactile information across different spatiotemporal scales.
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Affiliation(s)
| | - Rony Azouz
- Department of Physiology and Cell Biology, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Be'er Sheva, Southern District, Israel
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2
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Oldenburg IA, Hendricks WD, Handy G, Shamardani K, Bounds HA, Doiron B, Adesnik H. The logic of recurrent circuits in the primary visual cortex. Nat Neurosci 2024; 27:137-147. [PMID: 38172437 PMCID: PMC10774145 DOI: 10.1038/s41593-023-01510-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 10/27/2023] [Indexed: 01/05/2024]
Abstract
Recurrent cortical activity sculpts visual perception by refining, amplifying or suppressing visual input. However, the rules that govern the influence of recurrent activity remain enigmatic. We used ensemble-specific two-photon optogenetics in the mouse visual cortex to isolate the impact of recurrent activity from external visual input. We found that the spatial arrangement and the visual feature preference of the stimulated ensemble and the neighboring neurons jointly determine the net effect of recurrent activity. Photoactivation of these ensembles drives suppression in all cells beyond 30 µm but uniformly drives activation in closer similarly tuned cells. In nonsimilarly tuned cells, compact, cotuned ensembles drive net suppression, while diffuse, cotuned ensembles drive activation. Computational modeling suggests that highly local recurrent excitatory connectivity and selective convergence onto inhibitory neurons explain these effects. Our findings reveal a straightforward logic in which space and feature preference of cortical ensembles determine their impact on local recurrent activity.
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Affiliation(s)
- Ian Antón Oldenburg
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA.
- The Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, USA.
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, and Center for Advanced Biotechnology and Medicine, Rutgers University, Piscataway, NJ, USA.
| | - William D Hendricks
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
- The Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, USA
| | - Gregory Handy
- Department of Neurobiology and Statistics, University of Chicago, Chicago, IL, USA.
- Grossman Center for Quantitative Biology and Human Behavior, University of Chicago, Chicago, IL, USA.
- Department of Mathematics, University of Minnesota, Minneapolis, MN, USA.
| | - Kiarash Shamardani
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, USA
| | - Hayley A Bounds
- The Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, USA
| | - Brent Doiron
- Department of Neurobiology and Statistics, University of Chicago, Chicago, IL, USA
- Grossman Center for Quantitative Biology and Human Behavior, University of Chicago, Chicago, IL, USA
| | - Hillel Adesnik
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA.
- The Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, USA.
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3
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van der Molen T, Spaeth A, Chini M, Bartram J, Dendukuri A, Zhang Z, Bhaskaran-Nair K, Blauvelt LJ, Petzold LR, Hansma PK, Teodorescu M, Hierlemann A, Hengen KB, Hanganu-Opatz IL, Kosik KS, Sharf T. Protosequences in human cortical organoids model intrinsic states in the developing cortex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.29.573646. [PMID: 38234832 PMCID: PMC10793448 DOI: 10.1101/2023.12.29.573646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
Neuronal firing sequences are thought to be the basic building blocks of neural coding and information broadcasting within the brain. However, when sequences emerge during neurodevelopment remains unknown. We demonstrate that structured firing sequences are present in spontaneous activity of human brain organoids and ex vivo neonatal brain slices from the murine somatosensory cortex. We observed a balance between temporally rigid and flexible firing patterns that are emergent phenomena in human brain organoids and early postnatal murine somatosensory cortex, but not in primary dissociated cortical cultures. Our findings suggest that temporal sequences do not arise in an experience-dependent manner, but are rather constrained by an innate preconfigured architecture established during neurogenesis. These findings highlight the potential for brain organoids to further explore how exogenous inputs can be used to refine neuronal circuits and enable new studies into the genetic mechanisms that govern assembly of functional circuitry during early human brain development.
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Affiliation(s)
- Tjitse van der Molen
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, CA 93106, USA
- Department of Molecular, Cellular and Developmental Biology, University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - Alex Spaeth
- UC Santa Cruz Genomics Institute, University of California Santa Cruz, Santa Cruz, CA 95060, USA
- Department of Electrical and Computer Engineering, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Mattia Chini
- Institute of Developmental Neurophysiology, Center for Molecular Neurobiology, Hamburg Center of Neuroscience, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Julian Bartram
- Department of Biosystems Science and Engineering, ETH Zürich, Klingelbergstrasse 48, 4056 Basel, Switzerland
| | - Aditya Dendukuri
- Department of Computer Science, University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - Zongren Zhang
- Department of Physics, University of California Santa Barbara, Santa Barbara, CA 93106
| | - Kiran Bhaskaran-Nair
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Lon J. Blauvelt
- UC Santa Cruz Genomics Institute, University of California Santa Cruz, Santa Cruz, CA 95060, USA
| | - Linda R. Petzold
- Department of Computer Science, University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - Paul K. Hansma
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, CA 93106, USA
- Department of Physics, University of California Santa Barbara, Santa Barbara, CA 93106
| | - Mircea Teodorescu
- UC Santa Cruz Genomics Institute, University of California Santa Cruz, Santa Cruz, CA 95060, USA
- Department of Electrical and Computer Engineering, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Andreas Hierlemann
- Department of Biosystems Science and Engineering, ETH Zürich, Klingelbergstrasse 48, 4056 Basel, Switzerland
| | - Keith B. Hengen
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Ileana L. Hanganu-Opatz
- Institute of Developmental Neurophysiology, Center for Molecular Neurobiology, Hamburg Center of Neuroscience, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Kenneth S. Kosik
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, CA 93106, USA
- Department of Molecular, Cellular and Developmental Biology, University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - Tal Sharf
- UC Santa Cruz Genomics Institute, University of California Santa Cruz, Santa Cruz, CA 95060, USA
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, CA 95064, USA
- Institute for the Biology of Stem Cells, University of California Santa Cruz, Santa Cruz, CA 95064, USA
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4
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Pan L, Ping A, Schriver KE, Roe AW, Zhu J, Xu K. Infrared neural stimulation in human cerebral cortex. Brain Stimul 2023; 16:418-430. [PMID: 36731770 DOI: 10.1016/j.brs.2023.01.1678] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 01/28/2023] [Accepted: 01/28/2023] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND Modulation of brain circuits by electrical stimulation has led to exciting and powerful therapies for diseases such as Parkinson's. Because human brain organization is based in mesoscale (millimeter-scale) functional nodes, having a method that can selectively target such nodes could enable more precise, functionally specific stimulation therapies. Infrared Neural Stimulation (INS) is an emerging stimulation technology that stimulates neural tissue via delivery of tiny heat pulses. In nonhuman primates, this optical method provides focal intensity-dependent stimulation of the brain without tissue damage. However, whether INS application to the human central nervous system (CNS) is similarly effective is unknown. OBJECTIVE To examine the effectiveness of INS on human cerebral cortex in intraoperative setting and to evaluate INS damage threshholds. METHODS Five epileptic subjects undergoing standard lobectomy for epilepsy consented to this study. Cortical response to INS was assessed by intrinsic signal optical imaging (OI, a method that detects changes in tissue reflectance due to neuronal activity). A custom integrated INS and OI system was developed specifically for short-duration INS and OI acquisition during surgical procedures. Single pulse trains of INS with intensities from 0.2 to 0.8 J/cm2 were delivered to the somatosensory cortex and responses were recorded via optical imaging. Following tissue resection, histological analysis was conducted to evaluate damage threshholds. RESULTS As assessed by OI, and similar to results in monkeys, INS induced responses in human cortex were highly focal (millimeter sized) and led to relative suppression of nearby cortical sites. Intensity dependence was observed at both stimulated and functionally connected sites. Histological analysis of INS-stimulated human cortical tissue provided damage threshold estimates. CONCLUSION This is the first study demonstrating application of INS to human CNS and shows feasibility for stimulating single cortical nodes and associated sites and provided INS damage threshold estimates for cortical tissue. Our results suggest that INS is a promising tool for stimulation of functionally selective mesoscale circuits in the human brain, and may lead to advances in the future of precision medicine.
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Affiliation(s)
- Li Pan
- Qiushi Academy for Advanced Studies (QAAS), Zhejiang University, Hangzhou, China; Key Laboratory of Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Zhejiang University, Hangzhou, China.
| | - An Ping
- Department of Neurosurgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China.
| | - Kenneth E Schriver
- Interdisciplinary Institute of Neuroscience and Technology (ZIINT), School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China.
| | - Anna Wang Roe
- Department of Neurosurgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China; Interdisciplinary Institute of Neuroscience and Technology (ZIINT), School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China; Key Laboratory of Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Zhejiang University, Hangzhou, China; MOE Frontier Science Center for Brain Science and Brain-machine Integration, Zhejiang University, Hangzhou, China.
| | - Junming Zhu
- Department of Neurosurgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China; MOE Frontier Science Center for Brain Science and Brain-machine Integration, Zhejiang University, Hangzhou, China.
| | - Kedi Xu
- Qiushi Academy for Advanced Studies (QAAS), Zhejiang University, Hangzhou, China; Key Laboratory of Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Zhejiang University, Hangzhou, China; MOE Frontier Science Center for Brain Science and Brain-machine Integration, Zhejiang University, Hangzhou, China.
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5
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Tuning instability of non-columnar neurons in the salt-and-pepper whisker map in somatosensory cortex. Nat Commun 2022; 13:6611. [PMID: 36329010 PMCID: PMC9633707 DOI: 10.1038/s41467-022-34261-1] [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: 12/02/2021] [Accepted: 10/19/2022] [Indexed: 11/06/2022] Open
Abstract
Rodent sensory cortex contains salt-and-pepper maps of sensory features, whose structure is not fully known. Here we investigated the structure of the salt-and-pepper whisker somatotopic map among L2/3 pyramidal neurons in somatosensory cortex, in awake mice performing one-vs-all whisker discrimination. Neurons tuned for columnar (CW) and non-columnar (non-CW) whiskers were spatially intermixed, with co-tuned neurons forming local (20 µm) clusters. Whisker tuning was markedly unstable in expert mice, with 35-46% of pyramidal cells significantly shifting tuning over 5-18 days. Tuning instability was highly concentrated in non-CW tuned neurons, and thus was structured in the map. Instability of non-CW neurons was unchanged during chronic whisker paralysis and when mice discriminated individual whiskers, suggesting it is an inherent feature. Thus, L2/3 combines two distinct components: a stable columnar framework of CW-tuned cells that may promote spatial perceptual stability, plus an intermixed, non-columnar surround with highly unstable tuning.
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6
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Asahina T, Shimba K, Kotani K, Jimbo Y. Observing cell assemblies from spike train recordings based on the biological basis of synaptic connectivity. IEEE Trans Biomed Eng 2021; 69:1524-1532. [PMID: 34727019 DOI: 10.1109/tbme.2021.3123958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Cell assemblies are difficult to observe because they consist of many neurons. We aimed to observe cell assemblies based on biological statistics, such as synaptic connectivity. We developed an estimation method to estimate the activity and synaptic connectivity of cell assemblies from spike trains using mathematical models of individual neurons and cell assemblies. Synaptic transmissions were averaged to generate postsynaptic currents with the same timing and waveform but different amplitudes, as the number of presynaptic neurons was large. We estimated the average synaptic transmission and synaptic connectivity from active cell assemblies based on the stochastic prediction of membrane potentials and verified the estimation ability of the average synaptic transmission and synaptic connectivity using the proposed method on simulated neural activity. Different cell assembly activities evoked by electrical stimuli were correctly sorted into various clusters in experiments using rat cortical neurons cultured on microelectrode arrays. We observed multiple cell assemblies from the spontaneous activity of rat cortical networks on microelectrode arrays, based on the synaptic connectivity patterns estimated by the proposed method. The proposed method was superior to the conventional method for detecting the activity of multiple cell assemblies. Using the proposed method, it is possible to observe multiple cell assemblies based on the biological basis of synaptic connectivity. In summary, we report a novel method to observe cell assemblies from spike train recordings based on the biological basis of synaptic connectivity, rather than merely relying on a statistical method.
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7
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Cholinergic modulation of sensory processing in awake mouse cortex. Sci Rep 2021; 11:17525. [PMID: 34471145 PMCID: PMC8410938 DOI: 10.1038/s41598-021-96696-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 08/09/2021] [Indexed: 11/08/2022] Open
Abstract
Cholinergic modulation of brain activity is fundamental for awareness and conscious sensorimotor behaviours, but deciphering the timing and significance of acetylcholine actions for these behaviours is challenging. The widespread nature of cholinergic projections to the cortex means that new insights require access to specific neuronal populations, and on a time-scale that matches behaviourally relevant cholinergic actions. Here, we use fast, voltage imaging of L2/3 cortical pyramidal neurons exclusively expressing the genetically-encoded voltage indicator Butterfly 1.2, in awake, head-fixed mice, receiving sensory stimulation, whilst manipulating the cholinergic system. Altering muscarinic acetylcholine function re-shaped sensory-evoked fast depolarisation and subsequent slow hyperpolarisation of L2/3 pyramidal neurons. A consequence of this re-shaping was disrupted adaptation of the sensory-evoked responses, suggesting a critical role for acetylcholine during sensory discrimination behaviour. Our findings provide new insights into how the cortex processes sensory information and how loss of acetylcholine, for example in Alzheimer's Disease, disrupts sensory behaviours.
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8
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Yusuf PA, Hubka P, Tillein J, Vinck M, Kral A. Deafness Weakens Interareal Couplings in the Auditory Cortex. Front Neurosci 2021; 14:625721. [PMID: 33551733 PMCID: PMC7858676 DOI: 10.3389/fnins.2020.625721] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 12/30/2020] [Indexed: 12/22/2022] Open
Abstract
The function of the cerebral cortex essentially depends on the ability to form functional assemblies across different cortical areas serving different functions. Here we investigated how developmental hearing experience affects functional and effective interareal connectivity in the auditory cortex in an animal model with years-long and complete auditory deprivation (deafness) from birth, the congenitally deaf cat (CDC). Using intracortical multielectrode arrays, neuronal activity of adult hearing controls and CDCs was registered in the primary auditory cortex and the secondary posterior auditory field (PAF). Ongoing activity as well as responses to acoustic stimulation (in adult hearing controls) and electric stimulation applied via cochlear implants (in adult hearing controls and CDCs) were analyzed. As functional connectivity measures pairwise phase consistency and Granger causality were used. While the number of coupled sites was nearly identical between controls and CDCs, a reduced coupling strength between the primary and the higher order field was found in CDCs under auditory stimulation. Such stimulus-related decoupling was particularly pronounced in the alpha band and in top–down direction. Ongoing connectivity did not show such a decoupling. These findings suggest that developmental experience is essential for functional interareal interactions during sensory processing. The outcomes demonstrate that corticocortical couplings, particularly top-down connectivity, are compromised following congenital sensory deprivation.
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Affiliation(s)
- Prasandhya Astagiri Yusuf
- Department of Medical Physics/Medical Technology Core Cluster IMERI, Faculty of Medicine, University of Indonesia, Jakarta, Indonesia.,Institute of AudioNeuroTechnology, Hannover Medical School, Hanover, Germany.,Department of Experimental Otology of the ENT Clinics, Hannover Medical School, Hanover, Germany
| | - Peter Hubka
- Institute of AudioNeuroTechnology, Hannover Medical School, Hanover, Germany.,Department of Experimental Otology of the ENT Clinics, Hannover Medical School, Hanover, Germany
| | - Jochen Tillein
- Institute of AudioNeuroTechnology, Hannover Medical School, Hanover, Germany.,Department of Experimental Otology of the ENT Clinics, Hannover Medical School, Hanover, Germany.,Department of Otorhinolaryngology, Goethe University, Frankfurt am Main, Germany.,MedEL Company, Innsbruck, Austria
| | - Martin Vinck
- Ernst Strüngmann Institut for Neuroscience in Cooperation with Max Planck Society, Frankfurt, Germany.,Donders Centre for Neuroscience, Radboud University, Department of Neuroinformatics, Nijmegen, Netherlands
| | - Andrej Kral
- Institute of AudioNeuroTechnology, Hannover Medical School, Hanover, Germany.,Department of Experimental Otology of the ENT Clinics, Hannover Medical School, Hanover, Germany.,Department of Biomedical Sciences, School of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
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Kang J, Kadam SD, Elmore JS, Sullivan BJ, Valentine H, Malla AP, Harraz MM, Rahmim A, Kang JU, Loew LM, Baumann MH, Grace AA, Gjedde A, Boctor EM, Wong DF. Transcranial photoacoustic imaging of NMDA-evoked focal circuit dynamics in the rat hippocampus. J Neural Eng 2020; 17:025001. [PMID: 32084654 DOI: 10.1088/1741-2552/ab78ca] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVE We report the transcranial functional photoacoustic (fPA) neuroimaging of N-methyl-D-aspartate (NMDA) evoked neural activity in the rat hippocampus. Concurrent quantitative electroencephalography (qEEG) and microdialysis were used to record real-time circuit dynamics and excitatory neurotransmitter concentrations, respectively. APPROACH We hypothesized that location-specific fPA voltage-sensitive dye (VSD) contrast would identify neural activity changes in the hippocampus which correlate with NMDA-evoked excitatory neurotransmission. MAIN RESULTS Transcranial fPA VSD imaging at the contralateral side of the microdialysis probe provided NMDA-evoked VSD responses with positive correlation to extracellular glutamate concentration changes. qEEG validated a wide range of glutamatergic excitation, which culminated in focal seizure activity after a high NMDA dose. We conclude that transcranial fPA VSD imaging can distinguish focal glutamate loads in the rat hippocampus, based on the VSD redistribution mechanism which is sensitive to the electrophysiologic membrane potential. SIGNIFICANCE Our results suggest the future utility of this emerging technology in both laboratory and clinical sciences as an innovative functional neuroimaging modality.
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Affiliation(s)
- Jeeun Kang
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, United States of America. Laboratory of Computational Sensing and Robotics, Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, United States of America
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10
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Arzt M, Sakmann B, Meyer HS. Anatomical Correlates of Local, Translaminar, and Transcolumnar Inhibition by Layer 6 GABAergic Interneurons in Somatosensory Cortex. Cereb Cortex 2019; 28:2763-2774. [PMID: 28981591 DOI: 10.1093/cercor/bhx156] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2016] [Indexed: 01/01/2023] Open
Abstract
In the vibrissal area of rodent somatosensory cortex, information on whisker stimulation is processed by neuronal networks in a corresponding cortical column. To understand how sensory stimuli are represented in a column, it is essential to identify cell types constituting these networks. Layer 6 (L6) comprises 25% of all neurons in a column. In rats, 430 of these are inhibitory interneurons (INs). Little is known about the axon projection of L6 INs with reference to columnar and laminar organization. We quantified axonal projections of L6 INs (n = 68) with reference to columns and layers in somatosensory cortex of rats. We found distinct projection types differentially targeting layers of a cortical column. The majority of L6 INs did not show a column-specific innervation, densely projecting to neighboring columns as well as the home column. However, a small fraction targeted granular and supragranular layers, where axon projections were confined to the home column. We also quantified putative innervation of pyramidal cells as a functional correlate of axonal distribution. Electrophysiological properties were not correlated to axon projection. The quantitative data on axonal projections and electrophysiological properties of L6 INs can guide future studies investigating cortical processing of sensory information at the single cell level.
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Affiliation(s)
- Marlene Arzt
- Digital Neuroanatomy, Max Planck Florida Institute for Neuroscience, Jupiter, FL, USA
| | - Bert Sakmann
- Digital Neuroanatomy, Max Planck Florida Institute for Neuroscience, Jupiter, FL, USA
| | - Hanno S Meyer
- Digital Neuroanatomy, Max Planck Florida Institute for Neuroscience, Jupiter, FL, USA
- Cellular Neurosurgery Research Group, Department of Neurosurgery, Technical University of Munich, Munich, Germany
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11
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Bortel A, Yao ZS, Shmuel A. A rat model of somatosensory-evoked reflex seizures induced by peripheral stimulation. Epilepsy Res 2019; 157:106209. [PMID: 31629247 DOI: 10.1016/j.eplepsyres.2019.106209] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 08/31/2019] [Accepted: 09/19/2019] [Indexed: 01/14/2023]
Abstract
OBJECTIVE We introduce a novel animal model of somatosensory stimulation-induced reflex seizures which generates focal seizures without causing damage to the brain. METHODS Specifically, we electrically stimulated digits or forepaws of adult rats sedated with dexmedetomidine while imaging cerebral blood volume and recording neurophysiological activity in cortical area S1FL. For the recordings, we either inserted a linear probe into the D3 digit representation or we performed surface electrocorticography (ECoG) recordings. RESULTS Peripheral stimulation of a digit or the forepaw elicited seizures that were followed by a refractory period with decreased neuronal activity, or another seizure or normal response. LFP amplitudes in response to electrical pulses during the seizures (0.28 ± 0.03 mV) were higher than during normal evoked responses (0.25 ± 0.05 mV) and refractory periods (0.2 ± 0.08 mV). Seizures generated during the stimulation period showed prolonged after-discharges that were sustained for 20.9 ± 1.9 s following the cessation of the stimulus. High-frequency oscillations were observed prior to and during the seizures, with amplitudes higher than those associated with normal evoked responses. The seizures were initially focal. Optical imaging of the cerebral blood volume response showed that they propagated from the onset zone to adjacent cortical areas, beyond the S1FL representation of the stimulated digit or forepaw. The spatial extent during seizures was on average 1.74 times larger during the stimulation and 4.1 times following its cessation relative to normal evoked responses. Seizures were recorded not only by probes inserted into cortex but also with ECoG arrays (24.1 ± 5.8 seizures per rat) placed over the dura matter, indicating that the seizures were not induced by damage caused by inserting the probes to the cortex. Stimulation of the forepaw elicited more seizures (18.8 ± 8.5 seizures per rat) than stimulation of a digit (1.7 ± 0.7). Unlike rats sedated with dexmedetomidine, rats anesthetized with urethane showed no seizures, indicating that the seizures may depend on the use of the mild sedative dexmedetomidine. SIGNIFICANCE Our proposed animal model generates seizures induced by electrical sensory stimulation free of artifacts and brain damage. It can be used for studying the mechanisms underlying the generation and propagation of reflex seizures and for evaluating antiepileptic drugs.
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Affiliation(s)
- Aleksandra Bortel
- Montreal Neurological Institute, McConnell Brain Imaging Centre, McGill University, Montreal, QC, H3A 2B4, Canada; Department of Neurology and Neurosurgery, McGill University, Montreal, QC, H3A 2B4, Canada.
| | - Ze Shan Yao
- Montreal Neurological Institute, McConnell Brain Imaging Centre, McGill University, Montreal, QC, H3A 2B4, Canada; Department of Biomedical Engineering, McGill University, Montreal, QC, H3A 2B4, Canada
| | - Amir Shmuel
- Montreal Neurological Institute, McConnell Brain Imaging Centre, McGill University, Montreal, QC, H3A 2B4, Canada; Department of Neurology and Neurosurgery, McGill University, Montreal, QC, H3A 2B4, Canada; Department of Physiology, McGill University, Montreal, QC, H3A 2B4, Canada; Department of Biomedical Engineering, McGill University, Montreal, QC, H3A 2B4, Canada.
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12
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Emmenegger V, Qi G, Wang H, Feldmeyer D. Morphological and Functional Characterization of Non-fast-Spiking GABAergic Interneurons in Layer 4 Microcircuitry of Rat Barrel Cortex. Cereb Cortex 2019; 28:1439-1457. [PMID: 29329401 PMCID: PMC6093438 DOI: 10.1093/cercor/bhx352] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Indexed: 12/23/2022] Open
Abstract
GABAergic interneurons are notorious for their heterogeneity, despite constituting a small fraction of the neuronal population in the neocortex. Classification of interneurons is crucial for understanding their widespread cortical functions as they provide a complex and dynamic network, balancing excitation and inhibition. Here, we investigated different types of non-fast-spiking (nFS) interneurons in Layer 4 (L4) of rat barrel cortex using whole-cell patch-clamp recordings with biocytin-filling. Based on a quantitative analysis on a combination of morphological and electrophysiological parameters, we identified 5 distinct types of L4 nFS interneurons: 1) trans-columnar projecting interneurons, 2) locally projecting non-Martinotti-like interneurons, 3) supra-granular projecting Martinotti-like interneurons, 4) intra-columnar projecting VIP-like interneurons, and 5) locally projecting neurogliaform-like interneurons. Trans-columnar projecting interneurons are one of the most striking interneuron types, which have not been described so far in Layer 4. They feature extensive axonal collateralization not only in their home barrel but also in adjacent barrels. Furthermore, we identified that most of the L4 nFS interneurons express somatostatin, while few are positive for the transcription factor Prox1. The morphological and electrophysiological characterization of different L4 nFS interneuron types presented here provides insights into their synaptic connectivity and functional role in cortical information processing.
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Affiliation(s)
- Vishalini Emmenegger
- Institute of Neuroscience and Medicine, INM-2 and INM-10, Research Centre Jülich, Jülich, Germany
- Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Aachen, Germany
- Department of Biosystems Sciences and Engineering, Bio Engineering Lab, ETH Zürich, Basel, Switzerland
| | - Guanxiao Qi
- Institute of Neuroscience and Medicine, INM-2 and INM-10, Research Centre Jülich, Jülich, Germany
| | - Haijun Wang
- Institute of Neuroscience and Medicine, INM-2 and INM-10, Research Centre Jülich, Jülich, Germany
- Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Aachen, Germany
- School of Electronic Engineering, Nanjing Xiaozhuang University, Nanjing, P.R. China
| | - Dirk Feldmeyer
- Institute of Neuroscience and Medicine, INM-2 and INM-10, Research Centre Jülich, Jülich, Germany
- Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Aachen, Germany
- Jülich Aachen Research Alliance, Translational Brain Medicine (JARA Brain), Aachen, Germany
- Address correspondence to Dirk Feldmeyer, Institute of Neuroscience and Medicine (INM-2), Research Centre Jülich, D-52425 Jülich, Germany.
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13
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Closed-Loop Systems and In Vitro Neuronal Cultures: Overview and Applications. ADVANCES IN NEUROBIOLOGY 2019; 22:351-387. [DOI: 10.1007/978-3-030-11135-9_15] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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14
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Song C, Piscopo DM, Niell CM, Knöpfel T. Cortical signatures of wakeful somatosensory processing. Sci Rep 2018; 8:11977. [PMID: 30097603 PMCID: PMC6086870 DOI: 10.1038/s41598-018-30422-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 07/24/2018] [Indexed: 12/13/2022] Open
Abstract
Sensory inputs carry critical information for the survival of an organism. In mice, tactile information conveyed by the whiskers is of high behavioural relevance, and is broadcasted across cortical areas beyond the primary somatosensory cortex. Mesoscopic voltage sensitive dye imaging (VSDI) of cortical population response to whisker stimulations has shown that seemingly 'simple' sensory stimuli can have extended impact on cortical circuit dynamics. Here we took advantage of genetically encoded voltage indicators (GEVIs) that allow for cell type-specific monitoring of population voltage dynamics in a chronic dual-hemisphere transcranial windowed mouse preparation to directly compare the cortex-wide broadcasting of sensory information in wakening (lightly anesthetized to sedated) and awake mice. Somatosensory-evoked cortex-wide dynamics is altered across brain states, with anatomically sequential hyperpolarising activity observed in the awake cortex. GEVI imaging revealed cortical activity maps with increased specificity, high spatial coverage, and at the timescale of cortical information processing.
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Affiliation(s)
- Chenchen Song
- Laboratory for Neuronal Circuit Dynamics, Imperial College London, W12 0NN, London, UK
| | - Denise M Piscopo
- Institute of Neuroscience, University of Oregon, Eugene, Oregon, 97403, USA
| | - Cristopher M Niell
- Institute of Neuroscience, University of Oregon, Eugene, Oregon, 97403, USA
| | - Thomas Knöpfel
- Laboratory for Neuronal Circuit Dynamics, Imperial College London, W12 0NN, London, UK. .,Centre for Neurotechnology, Institute of Biomedical Engineering, Imperial College London, SW7 2AZ, London, UK.
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15
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Deneux T, Grinvald A. Milliseconds of Sensory Input Abruptly Modulate the Dynamics of Cortical States for Seconds. Cereb Cortex 2018; 27:4549-4563. [PMID: 27707770 DOI: 10.1093/cercor/bhw259] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 07/16/2016] [Indexed: 12/20/2022] Open
Abstract
Spontaneous internal activity plays a major role in higher brain functions. The question of how it modulates sensory evoked activity and behavior has been explored in anesthetized rodents, cats, monkeys and in behaving human subjects. However, the complementary question of how a brief sensory input modulates the internally generated activity in vivo remains unresolved, and high-resolution mapping of these bidirectional interactions was never performed. Integrating complementary methodologies, at population and single cells levels, we explored this question. Voltage-sensitive dye imaging of population activity in anesthetized rats' somatosensory cortex revealed that spontaneous up-states were largely diminished for ~2 s, even after a single weak whisker deflection. This effect was maximal at the stimulated barrel but spread across several cortical areas. A higher velocity whisker deflection evoked activity at ~15Hz. Two-photon calcium imaging activity and cell-attached recordings confirmed the VSD results and revealed that for several seconds most single cells decreased their firing, but a small number increased firing. Comparing single deflection with long train stimulation, we found a dominant effect of the first population spike. We suggest that, at the onset of a sensory input, some internal messages are silenced to prevent overloading of the processing of relevant incoming sensory information.
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Affiliation(s)
- Thomas Deneux
- Department of Neurobiology, Weizmann Institute of Science, 76100 Rehovot, Israel.,Team InViBe, Institut de Neurosciences de la Timone, UMR 7289, CNRS and Aix-Marseille Université, 13385 Marseille Cedex 05, France.,Unité de Neuroscience, Information et Complexité (UNIC), UPR 3293, Centre National de la Recherche Scientifique, 1 Avenue de la Terrasse, 91198 Gif-sur-Yvette, France
| | - Amiram Grinvald
- Department of Neurobiology, Weizmann Institute of Science, 76100Rehovot, Israel
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16
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Eilam R, Segal M, Malach R, Sela M, Arnon R, Aharoni R. Astrocyte disruption of neurovascular communication is linked to cortical damage in an animal model of multiple sclerosis. Glia 2018; 66:1098-1117. [PMID: 29424049 DOI: 10.1002/glia.23304] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Revised: 01/04/2018] [Accepted: 01/29/2018] [Indexed: 12/19/2022]
Abstract
To elucidate mechanisms contributing to cortical pathology in multiple sclerosis (MS), we investigated neurovascular aberrations, in particular the association of astrocytes with cortical neurons and blood vessels, in mice induced with experimental autoimmune encephalomyelitis (EAE). Blood-brain barrier (BBB) dysfunction was evident by leakage of the tracer sodium fluorescein, along with reduced expression of claudin-5 by endothelial cells and desmin by pericytes. Immunohistological and ultrastructural analyses revealed detachment of the astroglial cell bodies from the blood vessels and loss of their connections with both the blood vessels and the neuronal synapses. Furthermore, examination of individual astrocytic processes at cortical layer IV, where well-defined neuronal columns (barrels) are linked to functional properties, revealed loss of astrocytic confinement to the functional neuronal boundaries. Thus, in contrast to the highly modulated patches of astrocyte processes in naïve mice overlapping the barrel cores, in EAE-mice process distribution was uniform ignoring the barrel boundaries. These aberrations are attributed to the surrounding inflammation, indicated by T-cells presence in the cortex as well as in the subcortical white matter and the meninges. Immunomodulatory treatment with glatiramer acetate partially abrogated the neurovascular damage. These combined findings indicate that under inflammatory conditions, activated perivascular astrocytes fail in neuro-hemodynamic coupling, resulting in obstructed cross-talk between the blood vessels and the neurons. We propose that loss of cortical astrocytic regulation and fine-tuning between the blood supply and the neuronal needs contributes to the neurological impairment and cognitive decline occurring in EAE/MS as well as to the disease progression.
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Affiliation(s)
- Raya Eilam
- Department of Veterinary Resources, The Weizmann Institute of Science, Rehovot, 761001, Israel
| | - Menahem Segal
- Department of Neurobiology, The Weizmann Institute of Science, Rehovot, 761001, Israel
| | - Rafael Malach
- Department of Neurobiology, The Weizmann Institute of Science, Rehovot, 761001, Israel
| | - Michael Sela
- Department of Immunology, The Weizmann Institute of Science, Rehovot, 761001, Israel
| | - Ruth Arnon
- Department of Immunology, The Weizmann Institute of Science, Rehovot, 761001, Israel
| | - Rina Aharoni
- Department of Immunology, The Weizmann Institute of Science, Rehovot, 761001, Israel
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17
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Chen G, Carter RE, Cleary JD, Reid TS, Ranum LP, Swanson MS, Ebner TJ. Altered levels of the splicing factor muscleblind modifies cerebral cortical function in mouse models of myotonic dystrophy. Neurobiol Dis 2018; 112:35-48. [PMID: 29331264 PMCID: PMC5859959 DOI: 10.1016/j.nbd.2018.01.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 12/20/2017] [Accepted: 01/08/2018] [Indexed: 01/18/2023] Open
Abstract
Myotonic dystrophy (DM) is a progressive, multisystem disorder affecting skeletal muscle, heart, and central nervous system. In both DM1 and DM2, microsatellite expansions of CUG and CCUG RNA repeats, respectively, accumulate and disrupt functions of alternative splicing factors, including muscleblind (MBNL) proteins. Grey matter loss and white matter changes, including the corpus callosum, likely underlie cognitive and executive function deficits in DM patients. However, little is known how cerebral cortical circuitry changes in DM. Here, flavoprotein optical imaging was used to assess local and contralateral responses to intracortical motor cortex stimulation in DM-related mouse models. In control mice, brief train stimulation generated ipsilateral and contralateral homotopic fluorescence increases, the latter mediated by the corpus callosum. Single pulse stimulation produced an excitatory response with an inhibitory-like surround response mediated by GABAA receptors. In a mouse model of DM2 (Mbnl2 KO), we observed prolonged and increased responsiveness to train stimulation and loss of the inhibition from single pulse stimulation. Conversely, mice overexpressing human MBNL1 (MBNL1-OE) exhibited decreased contralateral response to train stimulation and reduction of inhibitory-like surround to single pulse stimulation. Therefore, altering levels of two key DM-associated splicing factors modifies functions of local cortical circuits and contralateral responses mediated through the corpus callosum.
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Affiliation(s)
- Gang Chen
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, USA
| | - Russell E Carter
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, USA
| | - John D Cleary
- Center for NeuroGenetics, Department of Molecular Genetics & Microbiology and Neurology, College of Medicine, Genetics Institute, University of Florida, Gainesville, FL, USA
| | - Tammy S Reid
- Center for NeuroGenetics, Department of Molecular Genetics & Microbiology and Neurology, College of Medicine, Genetics Institute, University of Florida, Gainesville, FL, USA
| | - Laura P Ranum
- Center for NeuroGenetics, Department of Molecular Genetics & Microbiology and Neurology, College of Medicine, Genetics Institute, University of Florida, Gainesville, FL, USA
| | - Maurice S Swanson
- Center for NeuroGenetics, Department of Molecular Genetics & Microbiology and Neurology, College of Medicine, Genetics Institute, University of Florida, Gainesville, FL, USA
| | - Timothy J Ebner
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, USA.
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18
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Uhlirova H, Kılıç K, Tian P, Sakadžić S, Gagnon L, Thunemann M, Desjardins M, Saisan PA, Nizar K, Yaseen MA, Hagler DJ, Vandenberghe M, Djurovic S, Andreassen OA, Silva GA, Masliah E, Kleinfeld D, Vinogradov S, Buxton RB, Einevoll GT, Boas DA, Dale AM, Devor A. The roadmap for estimation of cell-type-specific neuronal activity from non-invasive measurements. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0356. [PMID: 27574309 DOI: 10.1098/rstb.2015.0356] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/14/2016] [Indexed: 12/22/2022] Open
Abstract
The computational properties of the human brain arise from an intricate interplay between billions of neurons connected in complex networks. However, our ability to study these networks in healthy human brain is limited by the necessity to use non-invasive technologies. This is in contrast to animal models where a rich, detailed view of cellular-level brain function with cell-type-specific molecular identity has become available due to recent advances in microscopic optical imaging and genetics. Thus, a central challenge facing neuroscience today is leveraging these mechanistic insights from animal studies to accurately draw physiological inferences from non-invasive signals in humans. On the essential path towards this goal is the development of a detailed 'bottom-up' forward model bridging neuronal activity at the level of cell-type-specific populations to non-invasive imaging signals. The general idea is that specific neuronal cell types have identifiable signatures in the way they drive changes in cerebral blood flow, cerebral metabolic rate of O2 (measurable with quantitative functional Magnetic Resonance Imaging), and electrical currents/potentials (measurable with magneto/electroencephalography). This forward model would then provide the 'ground truth' for the development of new tools for tackling the inverse problem-estimation of neuronal activity from multimodal non-invasive imaging data.This article is part of the themed issue 'Interpreting BOLD: a dialogue between cognitive and cellular neuroscience'.
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Affiliation(s)
- Hana Uhlirova
- Department of Radiology, UCSD, La Jolla, CA 92093, USA CEITEC-Central European Institute of Technology and Institute of Physical Engineering, Faculty of Mechanical Engineering, Brno University of Technology, Brno, Czech Republic
| | - Kıvılcım Kılıç
- Department of Neurosciences, UCSD, La Jolla, CA 92093, USA
| | - Peifang Tian
- Department of Neurosciences, UCSD, La Jolla, CA 92093, USA Department of Physics, John Carroll University, University Heights, OH 44118, USA
| | - Sava Sakadžić
- Martinos Center for Biomedical Imaging, MGH, Harvard Medical School, Charlestown, MA 02129, USA
| | - Louis Gagnon
- Martinos Center for Biomedical Imaging, MGH, Harvard Medical School, Charlestown, MA 02129, USA
| | | | | | - Payam A Saisan
- Department of Neurosciences, UCSD, La Jolla, CA 92093, USA
| | - Krystal Nizar
- Neurosciences Graduate Program, UCSD, La Jolla, CA 92093, USA
| | - Mohammad A Yaseen
- Martinos Center for Biomedical Imaging, MGH, Harvard Medical School, Charlestown, MA 02129, USA
| | | | - Matthieu Vandenberghe
- Department of Radiology, UCSD, La Jolla, CA 92093, USA NORMENT, KG Jebsen Centre for Psychosis Research, Division of Mental Health and Addiction, Oslo University Hospital and University of Oslo, 0407 Oslo, Norway
| | - Srdjan Djurovic
- Department of Medical Genetics, Oslo University Hospital, 0407 Oslo, Norway NORMENT, KG Jebsen Centre for Psychosis Research, Department of Clinical Science, University of Bergen, 5020 Bergen, Norway
| | - Ole A Andreassen
- NORMENT, KG Jebsen Centre for Psychosis Research, Division of Mental Health and Addiction, Oslo University Hospital and University of Oslo, 0407 Oslo, Norway
| | - Gabriel A Silva
- Department of Bioengineering, UCSD, La Jolla, CA 92093, USA Department of Opthalmology, UCSD, La Jolla, CA 92093, USA
| | | | - David Kleinfeld
- Department of Physics, UCSD, La Jolla, CA 92093, USA Department of Electrical and Computer Engineering, UCSD, La Jolla, CA 92093, USA Section of Neurobiology, UCSD, La Jolla, CA 92093, USA
| | - Sergei Vinogradov
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | - Gaute T Einevoll
- Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences, 1432 Ås, Norway Department of Physics, University of Oslo, 0316 Oslo, Norway
| | - David A Boas
- Martinos Center for Biomedical Imaging, MGH, Harvard Medical School, Charlestown, MA 02129, USA
| | - Anders M Dale
- Department of Radiology, UCSD, La Jolla, CA 92093, USA Department of Neurosciences, UCSD, La Jolla, CA 92093, USA
| | - Anna Devor
- Department of Radiology, UCSD, La Jolla, CA 92093, USA Department of Neurosciences, UCSD, La Jolla, CA 92093, USA Martinos Center for Biomedical Imaging, MGH, Harvard Medical School, Charlestown, MA 02129, USA
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19
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Ferezou I, Deneux T. Review: How do spontaneous and sensory-evoked activities interact? NEUROPHOTONICS 2017; 4:031221. [PMID: 28630882 PMCID: PMC5469390 DOI: 10.1117/1.nph.4.3.031221] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 05/16/2017] [Indexed: 11/14/2023]
Abstract
Twenty years ago, the seminal work of Grinvald et al. revolutionized the view cast on spontaneous cortical activity by showing how, instead of being a mere measure of noise, it profoundly impacts cortical responses to a sensory input and therefore could play a role in sensory processing. This paved the way for a number of studies on the interactions between spontaneous and sensory-evoked activities. Spontaneous activity has subsequently been found to be highly structured and to participate in high cognitive functions, such as influencing conscious perception in humans. However, its functional role remains poorly understood, and only a few speculations exist, from the maintenance of the cortical network to the internal representation of an a priori knowledge of the environment. Furthermore, elucidation of this functional role could stem from studying the opposite relationship between spontaneous and sensory-evoked activities, namely, how a sensory input influences subsequent internal activities. Indeed, this question has remained largely unexplored, but a recent study by the Grinvald laboratory shows that a brief sensory input largely dampens spontaneous rhythms, suggesting a more sophisticated view where some spontaneous rhythms might relate to sensory processing and some others not.
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Affiliation(s)
- Isabelle Ferezou
- Unité de Neurosciences, Information et Complexité, Centre National de la Recherche Scientifique, Gif-sur-Yvette, France
| | - Thomas Deneux
- Unité de Neurosciences, Information et Complexité, Centre National de la Recherche Scientifique, Gif-sur-Yvette, France
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20
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Kyriakatos A, Sadashivaiah V, Zhang Y, Motta A, Auffret M, Petersen CCH. Voltage-sensitive dye imaging of mouse neocortex during a whisker detection task. NEUROPHOTONICS 2017; 4:031204. [PMID: 27921068 PMCID: PMC5120151 DOI: 10.1117/1.nph.4.3.031204] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Accepted: 10/19/2016] [Indexed: 06/06/2023]
Abstract
Sensorimotor processing occurs in a highly distributed manner in the mammalian neocortex. The spatiotemporal dynamics of electrical activity in the dorsal mouse neocortex can be imaged using voltage-sensitive dyes (VSDs) with near-millisecond temporal resolution and [Formula: see text] spatial resolution. Here, we trained mice to lick a water reward spout after a 1-ms deflection of the C2 whisker, and we imaged cortical dynamics during task execution with VSD RH1691. Responses to whisker deflection were highly dynamic and spatially highly distributed, exhibiting high variability from trial to trial in amplitude and spatiotemporal dynamics. We differentiated trials based on licking and whisking behavior. Hit trials, in which the mouse licked after the whisker stimulus, were accompanied by overall greater depolarization compared to miss trials, with the strongest hit versus miss differences being found in frontal cortex. Prestimulus whisking decreased behavioral performance by increasing the fraction of miss trials, and these miss trials had attenuated cortical sensorimotor responses. Our data suggest that the spatiotemporal dynamics of depolarization in mouse sensorimotor cortex evoked by a single brief whisker deflection are subject to important behavioral modulation during the execution of a simple, learned, goal-directed sensorimotor transformation.
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Song C, Barnes S, Knöpfel T. Mammalian cortical voltage imaging using genetically encoded voltage indicators: a review honoring professor Amiram Grinvald. NEUROPHOTONICS 2017; 4:031214. [PMID: 28491906 PMCID: PMC5416838 DOI: 10.1117/1.nph.4.3.031214] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 04/05/2017] [Indexed: 06/07/2023]
Abstract
The pioneering work of Amiram Grinvald established voltage-sensitive dye imaging (VSDI) in the mammalian cortex in the 1980s and inspired decades of cortical voltage imaging and the associated technological developments. The recent conception and development of genetically encoded voltage indicators (GEVIs) overcome many of the limitations of classical VSDI, and open experimental approaches that provide accruing support for orchestrated neuronal circuit dynamics of spatially distributed neuronal circuit underlying behaviors. We will review recent achievements using GEVIs to optically monitor the cortical activity in mammalian brains in vivo and provide a perspective for potential future directions.
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Affiliation(s)
- Chenchen Song
- Imperial College London, Laboratory for Neuronal Circuit Dynamics, London, United Kingdom
| | - Samuel Barnes
- Imperial College London, Laboratory for Neuronal Circuit Dynamics, London, United Kingdom
- Imperial College London, Division of Brain Sciences, London, United Kingdom
| | - Thomas Knöpfel
- Imperial College London, Laboratory for Neuronal Circuit Dynamics, London, United Kingdom
- Imperial College London, Division of Brain Sciences, London, United Kingdom
- Institute of Biomedical Engineering, Imperial College London, Centre for Neurotechnology, South Kensington, London, United Kingdom
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22
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Sreenivasan V, Kyriakatos A, Mateo C, Jaeger D, Petersen CC. Parallel pathways from whisker and visual sensory cortices to distinct frontal regions of mouse neocortex. NEUROPHOTONICS 2017; 4:031203. [PMID: 27921067 PMCID: PMC5120210 DOI: 10.1117/1.nph.4.3.031203] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Accepted: 09/16/2016] [Indexed: 06/06/2023]
Abstract
The spatial organization of mouse frontal cortex is poorly understood. Here, we used voltage-sensitive dye to image electrical activity in the dorsal cortex of awake head-restrained mice. Whisker-deflection evoked the earliest sensory response in a localized region of primary somatosensory cortex and visual stimulation evoked the earliest responses in a localized region of primary visual cortex. Over the next milliseconds, the initial sensory response spread within the respective primary sensory cortex and into the surrounding higher order sensory cortices. In addition, secondary hotspots in the frontal cortex were evoked by whisker and visual stimulation, with the frontal hotspot for whisker deflection being more anterior and lateral compared to the frontal hotspot evoked by visual stimulation. Investigating axonal projections, we found that the somatosensory whisker cortex and the visual cortex directly innervated frontal cortex, with visual cortex axons innervating a region medial and posterior to the innervation from somatosensory cortex, consistent with the location of sensory responses in frontal cortex. In turn, the axonal outputs of these two frontal cortical areas innervate distinct regions of striatum, superior colliculus, and brainstem. Sensory input, therefore, appears to map onto modality-specific regions of frontal cortex, perhaps participating in distinct sensorimotor transformations, and directing distinct motor outputs.
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Affiliation(s)
- Varun Sreenivasan
- École Polytechnique Fédérale de Lausanne (EPFL), Faculty of Life Sciences, Brain Mind Institute, Laboratory of Sensory Processing, CH-1015 Lausanne, Switzerland
| | - Alexandros Kyriakatos
- École Polytechnique Fédérale de Lausanne (EPFL), Faculty of Life Sciences, Brain Mind Institute, Laboratory of Sensory Processing, CH-1015 Lausanne, Switzerland
| | - Celine Mateo
- École Polytechnique Fédérale de Lausanne (EPFL), Faculty of Life Sciences, Brain Mind Institute, Laboratory of Sensory Processing, CH-1015 Lausanne, Switzerland
| | - Dieter Jaeger
- Emory University, Department of Biology, Atlanta, Georgia 30322, United States
| | - Carl C.H. Petersen
- École Polytechnique Fédérale de Lausanne (EPFL), Faculty of Life Sciences, Brain Mind Institute, Laboratory of Sensory Processing, CH-1015 Lausanne, Switzerland
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Frostig RD, Chen-Bee CH, Johnson BA, Jacobs NS. Imaging Cajal's neuronal avalanche: how wide-field optical imaging of the point-spread advanced the understanding of neocortical structure-function relationship. NEUROPHOTONICS 2017; 4:031217. [PMID: 28630879 PMCID: PMC5467767 DOI: 10.1117/1.nph.4.3.031217] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Accepted: 05/12/2017] [Indexed: 06/17/2023]
Abstract
This review brings together a collection of studies that specifically use wide-field high-resolution mesoscopic level imaging techniques (intrinsic signal optical imaging; voltage-sensitive dye optical imaging) to image the cortical point spread (PS): the total spread of cortical activation comprising a large neuronal ensemble evoked by spatially restricted (point) stimulation of the sensory periphery (e.g., whisker, pure tone, point visual stimulation). The collective imaging findings, combined with supporting anatomical and electrophysiological findings, revealed some key aspects about the PS including its very large (radius of several mm) and relatively symmetrical spatial extent capable of crossing cytoarchitectural borders and trespassing into other cortical areas; its relationship with underlying evoked subthreshold activity and underlying anatomical system of long-range horizontal projections within gray matter, both also crossing borders; its contextual modulation and plasticity; the ability of its relative spatiotemporal profile to remain invariant to major changes in stimulation parameters; its potential role as a building block for integrative cortical activity; and its ubiquitous presence across various cortical areas and across mammalian species. Together, these findings advance our understanding about the neocortex at the mesoscopic level by underscoring that the cortical PS constitutes a fundamental motif of neocortical structure-function relationship.
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Affiliation(s)
- Ron D. Frostig
- University of California Irvine, Department of Neurobiology and Behavior, Irvine, California, United States
- University of California Irvine, Department of Biomedical Engineering, Irvine, California, United States
- University of California Irvine, Center for the Neurobiology of Learning and Memory, Irvine, California, United States
| | - Cynthia H. Chen-Bee
- University of California Irvine, Department of Neurobiology and Behavior, Irvine, California, United States
| | - Brett A. Johnson
- University of California Irvine, Department of Neurobiology and Behavior, Irvine, California, United States
| | - Nathan S. Jacobs
- University of California Irvine, Department of Neurobiology and Behavior, Irvine, California, United States
- University of California Irvine, Center for the Neurobiology of Learning and Memory, Irvine, California, United States
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Vincis R, Fontanini A. Associative learning changes cross-modal representations in the gustatory cortex. eLife 2016; 5. [PMID: 27572258 PMCID: PMC5026467 DOI: 10.7554/elife.16420] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2016] [Accepted: 08/16/2016] [Indexed: 01/03/2023] Open
Abstract
A growing body of literature has demonstrated that primary sensory cortices are not exclusively unimodal, but can respond to stimuli of different sensory modalities. However, several questions concerning the neural representation of cross-modal stimuli remain open. Indeed, it is poorly understood if cross-modal stimuli evoke unique or overlapping representations in a primary sensory cortex and whether learning can modulate these representations. Here we recorded single unit responses to auditory, visual, somatosensory, and olfactory stimuli in the gustatory cortex (GC) of alert rats before and after associative learning. We found that, in untrained rats, the majority of GC neurons were modulated by a single modality. Upon learning, both prevalence of cross-modal responsive neurons and their breadth of tuning increased, leading to a greater overlap of representations. Altogether, our results show that the gustatory cortex represents cross-modal stimuli according to their sensory identity, and that learning changes the overlap of cross-modal representations. DOI:http://dx.doi.org/10.7554/eLife.16420.001 Imagine that you are waiting for a cappuccino at your favorite café. You hear the sound of the steamer, and shortly afterwards the barista calls your name and announces that your cappuccino is ready. As they hand it to you, you see the foam sprinkled with cocoa and the aroma of the cappuccino reaches your nose. You can almost taste it. When you finally take your first sip, the taste is hardly a surprise; it is just as your eyes and nose predicted. How does the brain deal with such a rich and multisensory experience? How does it learn to associate the sight and smell of a cappuccino with its taste? Specialized regions of the brain called associative areas were traditionally thought to perform this task. These areas receive inputs from every sensory system and can link information from these different sources together. According to this view, the job of each individual sensory system is to pass along information relevant to one particular sense. More recent results, however, challenge this strict division of labor and suggest that individual sensory systems may be able to combine information from multiple senses. Thus the sights, sounds and odors associated with our cappuccino may also activate the area of the brain in charge of processing taste: the gustatory cortex. To investigate this possibility, Vincis and Fontanini set out to determine whether neurons in the gustatory cortex of rats can process stimuli belonging to senses other than taste. As predicted, neurons in the gustatory cortex did change their firing rates in response to odors, touch, sounds and light. However, more of the gustatory neurons responded to odors and touch than to sounds and light. In addition, of the four stimuli, the rats most easily learned to associate odors and touch with a sugary solution. This is consistent with the fact that rodents rely more upon their whiskers and their sense of smell to find food they do their eyes and ears. Finally, learning to associate a stimulus other than taste with a sugary solution increased the number of neurons in the gustatory cortex that subsequently responded to other senses and changed their response properties. Further studies are now required to answer three questions. Why can some senses more effectively influence the activity of the gustatory cortex than others? Can gustatory neurons distinguish between different stimuli of the same type – different odors, for example? What are the neural pathways that convey multisensory information to the gustatory cortex? Answering these questions will help us to better understand how sensory systems link information from multiple senses. DOI:http://dx.doi.org/10.7554/eLife.16420.002
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Affiliation(s)
- Roberto Vincis
- Department of Neurobiology and Behavior, State University of New York at Stony Brook, Stony Brook, United States
| | - Alfredo Fontanini
- Department of Neurobiology and Behavior, State University of New York at Stony Brook, Stony Brook, United States
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Eilam R, Aharoni R, Arnon R, Malach R. Astrocyte morphology is confined by cortical functional boundaries in mammals ranging from mice to human. eLife 2016; 5. [PMID: 27282388 PMCID: PMC4945151 DOI: 10.7554/elife.15915] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 06/09/2016] [Indexed: 12/19/2022] Open
Abstract
Cortical blood flow can be modulated by local activity across a range of species; from barrel-specific blood flow in the rodent somatosensory cortex to the human cortex, where BOLD-fMRI reveals numerous functional borders. However, it appears that the distribution of blood capillaries largely ignores these functional boundaries. Here we report that, by contrast, astrocytes, a major player in blood-flow control, show a striking morphological sensitivity to functional borders. Specifically, we show that astrocyte processes are structurally confined by barrel boundaries in the mouse, by the border of primary auditory cortex in the rat and by layers IIIa/b and Cytochrome Oxidase (CO)-blobs boundaries in the human primary visual cortex. Thus, astrocytes which are critical elements in neuro-hemodynamic coupling show a significant anatomical segregation along functional boundaries across different mammalian species. These results may open a new anatomical marker for delineating functional borders across species, including post-mortem human brains. DOI:http://dx.doi.org/10.7554/eLife.15915.001 The brain is subdivided into many specialized regions that each has distinct roles. A key aim of brain research is to define the boundaries of these areas. Researchers have attempted to map the transitions between brain regions by identifying changes in the properties and activity of neurons (the cells that transmit information around the brain). However, these approaches cannot be used in some circumstances, such as when studying the living human brain, where only non-invasive experimental techniques can be used. Cells other than neurons are also present in the brain. Astrocytes (a sub-type of glia cells) are support cells that have an extensive array of branches that project from each astrocyte’s cell body, often giving it a characteristic star shape. Now, using high-magnification light microscopy, Eliam et al. show that the branches of individual astrocytes tend to avoid crossing the borders of brain regions with different roles. These changes in crossing densities define measurable boundaries between such subdivisions. These density-change boundaries formed by the astrocytes are present in multiple species – mouse, rat and human – and in multiple systems: touch, auditory and visual. This discovery could provide a new window into the functional organization of the brain. It may also offer insights into how the brain optimizes its blood-flow control across different subregions. The results of this study raise an additional question: is the confinement of astrocytes to single regions of the brain shaped by experience or is it present from birth? Exposing animals to different sensory experiences at different developmental stages will hopefully shed further light on this phenomenon. DOI:http://dx.doi.org/10.7554/eLife.15915.002
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Affiliation(s)
- Raya Eilam
- Department of Veterinary Resources, The Weizmann Institute of Science, Rehovot, Israel
| | - Rina Aharoni
- Department of Immunology, The Weizmann Institute of Science, Rehovot, Israel
| | - Ruth Arnon
- Department of Immunology, The Weizmann Institute of Science, Rehovot, Israel
| | - Rafael Malach
- Department of Neurobiology, The Weizmann Institute of Science, Rehovot, Israel
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26
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Maatuf Y, Stern EA, Slovin H. Abnormal Population Responses in the Somatosensory Cortex of Alzheimer's Disease Model Mice. Sci Rep 2016; 6:24560. [PMID: 27079783 PMCID: PMC4832196 DOI: 10.1038/srep24560] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 03/31/2016] [Indexed: 01/04/2023] Open
Abstract
Alzheimer's disease (AD) is the most common form of dementia. One of the neuropathological hallmarks of AD is the accumulation of amyloid-β plaques. Overexpression of human amyloid precursor protein in transgenic mice induces hippocampal and neocortical amyloid-β accumulation and plaque deposition that increases with age. The impact of these effects on neuronal population responses and network activity in sensory cortex is not well understood. We used Voltage Sensitive Dye Imaging, to investigate at high spatial and temporal resolution, the sensory evoked population responses in the barrel cortex of aged transgenic (Tg) mice and of age-matched non-transgenic littermate controls (Ctrl) mice. We found that a whisker deflection evoked abnormal sensory responses in the barrel cortex of Tg mice. The response amplitude and the spatial spread of the cortical responses were significantly larger in Tg than in Ctrl mice. At the network level, spontaneous activity was less synchronized over cortical space than in Ctrl mice, however synchronization during evoked responses induced by whisker deflection did not differ between the two groups. Thus, the presence of elevated Aβ and plaques may alter population responses and disrupts neural synchronization in large-scale networks, leading to abnormalities in sensory processing.
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Affiliation(s)
- Yossi Maatuf
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002 Israel
| | - Edward A Stern
- The Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan, 5290002 Israel.,MassGeneral Institute of Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Charlestown, Massachusetts 02129, USA
| | - Hamutal Slovin
- The Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan, 5290002 Israel
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27
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Antic SD, Empson RM, Knöpfel T. Voltage imaging to understand connections and functions of neuronal circuits. J Neurophysiol 2016; 116:135-52. [PMID: 27075539 DOI: 10.1152/jn.00226.2016] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 04/11/2016] [Indexed: 12/30/2022] Open
Abstract
Understanding of the cellular mechanisms underlying brain functions such as cognition and emotions requires monitoring of membrane voltage at the cellular, circuit, and system levels. Seminal voltage-sensitive dye and calcium-sensitive dye imaging studies have demonstrated parallel detection of electrical activity across populations of interconnected neurons in a variety of preparations. A game-changing advance made in recent years has been the conceptualization and development of optogenetic tools, including genetically encoded indicators of voltage (GEVIs) or calcium (GECIs) and genetically encoded light-gated ion channels (actuators, e.g., channelrhodopsin2). Compared with low-molecular-weight calcium and voltage indicators (dyes), the optogenetic imaging approaches are 1) cell type specific, 2) less invasive, 3) able to relate activity and anatomy, and 4) facilitate long-term recordings of individual cells' activities over weeks, thereby allowing direct monitoring of the emergence of learned behaviors and underlying circuit mechanisms. We highlight the potential of novel approaches based on GEVIs and compare those to calcium imaging approaches. We also discuss how novel approaches based on GEVIs (and GECIs) coupled with genetically encoded actuators will promote progress in our knowledge of brain circuits and systems.
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Affiliation(s)
- Srdjan D Antic
- Stem Cell Institute, Institute for Systems Genomics, UConn Health, Farmington, Connecticut
| | - Ruth M Empson
- Department of Physiology, Brain Research New Zealand, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand; and
| | - Thomas Knöpfel
- Division of Brain Sciences, Department of Medicine and Centre for Neurotechnology, Institute of Biomedical Engineering, Imperial College London, London, United Kingdom
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28
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Dordek Y, Soudry D, Meir R, Derdikman D. Extracting grid cell characteristics from place cell inputs using non-negative principal component analysis. eLife 2016; 5:e10094. [PMID: 26952211 PMCID: PMC4841785 DOI: 10.7554/elife.10094] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 03/08/2016] [Indexed: 11/13/2022] Open
Abstract
Many recent models study the downstream projection from grid cells to place cells, while recent data have pointed out the importance of the feedback projection. We thus asked how grid cells are affected by the nature of the input from the place cells. We propose a single-layer neural network with feedforward weights connecting place-like input cells to grid cell outputs. Place-to-grid weights are learned via a generalized Hebbian rule. The architecture of this network highly resembles neural networks used to perform Principal Component Analysis (PCA). Both numerical results and analytic considerations indicate that if the components of the feedforward neural network are non-negative, the output converges to a hexagonal lattice. Without the non-negativity constraint, the output converges to a square lattice. Consistent with experiments, grid spacing ratio between the first two consecutive modules is -1.4. Our results express a possible linkage between place cell to grid cell interactions and PCA.
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Affiliation(s)
- Yedidyah Dordek
- Faculty of Electrical Engineering, Technion - Israel Institute of Technology, Haifa, Israel.,Rappaport Faculty of Medicine and Research Institute, Technion - Israel Institute of Technology, Haifa, Israel
| | - Daniel Soudry
- Department of Statistics, Columbia University, New York, United States.,Center for Theoretical Neuroscience, Columbia University, New York, United States
| | - Ron Meir
- Faculty of Electrical Engineering, Technion - Israel Institute of Technology, Haifa, Israel
| | - Dori Derdikman
- Rappaport Faculty of Medicine and Research Institute, Technion - Israel Institute of Technology, Haifa, Israel
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29
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Grinvald A, Omer DB, Sharon D, Vanzetta I, Hildesheim R. Voltage-Sensitive Dye Imaging of Neocortical Activity. Cold Spring Harb Protoc 2016; 2016:pdb.top089367. [PMID: 26729915 DOI: 10.1101/pdb.top089367] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Neural computations underlying sensory perception, cognition, and motor control are performed by populations of neurons at different anatomical and temporal scales. Few techniques are currently available for exploring the dynamics of local and large range populations. Voltage-sensitive dye imaging (VSDI), based on organic voltage probes, reveals neural population activity in areas ranging from a few tens of micrometers to a couple of centimeters, or two areas up to ~10 cm apart. VSDI provides a submillisecond temporal resolution and a spatial resolution of ~50 µm. The dye signal emphasizes subthreshold synaptic potentials. VSDI has been applied in the mouse, rat, gerbil, ferret, tree shrew, cat, and monkey cortices to explore the lateral spread of retinotopic or somatotopic activation; the dynamic spatiotemporal pattern resulting from sensory activation, including the somatosensory, olfactory, auditory, and visual modalities; and motor preparation and the properties of spontaneously occurring population activity. In this introduction, we focus on VSDI in vivo and review results obtained mostly in the visual system in our laboratory.
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30
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Hiu T, Farzampour Z, Paz JT, Wang EHJ, Badgely C, Olson A, Micheva KD, Wang G, Lemmens R, Tran KV, Nishiyama Y, Liang X, Hamilton SA, O'Rourke N, Smith SJ, Huguenard JR, Bliss TM, Steinberg GK. Enhanced phasic GABA inhibition during the repair phase of stroke: a novel therapeutic target. Brain 2015; 139:468-80. [PMID: 26685158 PMCID: PMC4805083 DOI: 10.1093/brain/awv360] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 10/20/2015] [Indexed: 11/13/2022] Open
Abstract
Ischaemic stroke is the leading cause of severe long-term disability yet lacks drug therapies that promote the repair phase of recovery. This repair phase of stroke occurs days to months after stroke onset and involves brain remapping and plasticity within the peri-infarct zone. Elucidating mechanisms that promote this plasticity is critical for the development of new therapeutics with a broad treatment window. Inhibiting tonic (extrasynaptic) GABA signalling during the repair phase was reported to enhance functional recovery in mice suggesting that GABA plays an important function in modulating brain repair. While tonic GABA appears to suppress brain repair after stroke, less is known about the role of phasic (synaptic) GABA during the repair phase. We observed an increase in postsynaptic phasic GABA signalling in mice within the peri-infarct cortex specific to layer 5; we found increased numbers of α1 receptor subunit-containing GABAergic synapses detected using array tomography, and an associated increased efficacy of spontaneous and miniature inhibitory postsynaptic currents in pyramidal neurons. Furthermore, we demonstrate that enhancing phasic GABA signalling using zolpidem, a Food and Drug Administration (FDA)-approved GABA-positive allosteric modulator, during the repair phase improved behavioural recovery. These data identify potentiation of phasic GABA signalling as a novel therapeutic strategy, indicate zolpidem’s potential to improve recovery, and underscore the necessity to distinguish the role of tonic and phasic GABA signalling in stroke recovery.
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Affiliation(s)
- Takeshi Hiu
- 1 Department of Neurosurgery, Stanford University, Stanford, CA, USA 2 Stanford Stroke Centre, Palo Alto, CA 94304, USA
| | - Zoya Farzampour
- 3 Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, USA
| | - Jeanne T Paz
- 3 Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, USA 4 Gladstone Institute of Neurological Disease and University of California, San Francisco San Francisco, CA USA
| | - Eric Hou Jen Wang
- 1 Department of Neurosurgery, Stanford University, Stanford, CA, USA 2 Stanford Stroke Centre, Palo Alto, CA 94304, USA
| | - Corrine Badgely
- 3 Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, USA
| | - Andrew Olson
- 1 Department of Neurosurgery, Stanford University, Stanford, CA, USA
| | - Kristina D Micheva
- 5 Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA
| | - Gordon Wang
- 5 Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA
| | - Robin Lemmens
- 1 Department of Neurosurgery, Stanford University, Stanford, CA, USA 2 Stanford Stroke Centre, Palo Alto, CA 94304, USA 6 KU Leuven - University of Leuven, Department of Neurosciences, Experimental Neurology; VIB - Vesalius Research Center University Hospitals Leuven, Department of Neurology, B-3000 Leuven, Belgium
| | - Kevin V Tran
- 1 Department of Neurosurgery, Stanford University, Stanford, CA, USA 2 Stanford Stroke Centre, Palo Alto, CA 94304, USA
| | - Yasuhiro Nishiyama
- 1 Department of Neurosurgery, Stanford University, Stanford, CA, USA 2 Stanford Stroke Centre, Palo Alto, CA 94304, USA
| | - Xibin Liang
- 1 Department of Neurosurgery, Stanford University, Stanford, CA, USA 2 Stanford Stroke Centre, Palo Alto, CA 94304, USA
| | - Scott A Hamilton
- 1 Department of Neurosurgery, Stanford University, Stanford, CA, USA 2 Stanford Stroke Centre, Palo Alto, CA 94304, USA
| | - Nancy O'Rourke
- 5 Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA
| | - Stephen J Smith
- 5 Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA
| | - John R Huguenard
- 3 Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, USA
| | - Tonya M Bliss
- 1 Department of Neurosurgery, Stanford University, Stanford, CA, USA 2 Stanford Stroke Centre, Palo Alto, CA 94304, USA
| | - Gary K Steinberg
- 1 Department of Neurosurgery, Stanford University, Stanford, CA, USA 2 Stanford Stroke Centre, Palo Alto, CA 94304, USA 3 Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, USA
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31
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Tang Q, Tsytsarev V, Liang CP, Akkentli F, Erzurumlu RS, Chen Y. In Vivo Voltage-Sensitive Dye Imaging of Subcortical Brain Function. Sci Rep 2015; 5:17325. [PMID: 26612326 PMCID: PMC4661443 DOI: 10.1038/srep17325] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 10/28/2015] [Indexed: 12/29/2022] Open
Abstract
The whisker system of rodents is an excellent model to study peripherally evoked neural activity in the brain. Discrete neural modules represent each whisker in the somatosensory cortex (“barrels”), thalamus (“barreloids”), and brain stem (“barrelettes”). Stimulation of a single whisker evokes neural activity sequentially in its corresponding barrelette, barreloid, and barrel. Conventional optical imaging of functional activation in the brain is limited to surface structures such as the cerebral cortex. To access subcortical structures and image sensory-evoked neural activity, we designed a needle-based optical system using gradient-index (GRIN) rod lens. We performed voltage-sensitive dye imaging (VSDi) with GRIN rod lens to visualize neural activity evoked in the thalamic barreloids by deflection of whiskers in vivo. We stimulated several whiskers together to determine the sensitivity of our approach in differentiating between different barreloid responses. We also carried out stimulation of different whiskers at different times. Finally, we used muscimol in the barrel cortex to silence the corticothalamic inputs while imaging in the thalamus. Our results show that it is possible to obtain functional maps of the sensory periphery in deep brain structures such as the thalamic barreloids. Our approach can be broadly applicable to functional imaging of other core brain structures.
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Affiliation(s)
- Qinggong Tang
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742 USA
| | - Vassiliy Tsytsarev
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742 USA.,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Chia-Pin Liang
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742 USA
| | - Fatih Akkentli
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Reha S Erzurumlu
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Yu Chen
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742 USA
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32
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Luczak A, McNaughton BL, Harris KD. Packet-based communication in the cortex. Nat Rev Neurosci 2015; 16:745-55. [PMID: 26507295 DOI: 10.1038/nrn4026] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Peron SP, Freeman J, Iyer V, Guo C, Svoboda K. A Cellular Resolution Map of Barrel Cortex Activity during Tactile Behavior. Neuron 2015; 86:783-99. [PMID: 25913859 DOI: 10.1016/j.neuron.2015.03.027] [Citation(s) in RCA: 203] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Revised: 01/29/2015] [Accepted: 03/11/2015] [Indexed: 11/17/2022]
Abstract
Comprehensive measurement of neural activity remains challenging due to the large numbers of neurons in each brain area. We used volumetric two-photon imaging in mice expressing GCaMP6s and nuclear red fluorescent proteins to sample activity in 75% of superficial barrel cortex neurons across the relevant cortical columns, approximately 12,000 neurons per animal, during performance of a single whisker object localization task. Task-related activity peaked during object palpation. An encoding model related activity to behavioral variables. In the column corresponding to the spared whisker, 300 layer (L) 2/3 pyramidal neurons (17%) each encoded touch and whisker movements. Touch representation declined by half in surrounding columns; whisker movement representation was unchanged. Following the emergence of stereotyped task-related movement, sensory representations showed no measurable plasticity. Touch direction was topographically organized, with distinct organization for passive and active touch. Our work reveals sparse and spatially intermingled representations of multiple tactile features. VIDEO ABSTRACT.
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Affiliation(s)
- Simon P Peron
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Jeremy Freeman
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Vijay Iyer
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Caiying Guo
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Karel Svoboda
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA.
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34
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Haroush N, Marom S. Slow dynamics in features of synchronized neural network responses. Front Comput Neurosci 2015; 9:40. [PMID: 25926787 PMCID: PMC4396531 DOI: 10.3389/fncom.2015.00040] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 03/16/2015] [Indexed: 11/13/2022] Open
Abstract
In this report trial-to-trial variations in the synchronized responses of neural networks are explored over time scales of minutes, in ex-vivo large scale cortical networks. We show that sub-second measures of the individual synchronous response, namely-its latency and decay duration, are related to minutes-scale network response dynamics. Network responsiveness is reflected as residency in, or shifting amongst, areas of the latency-decay plane. The different sensitivities of latency and decay durations to synaptic blockers imply that these two measures reflect aspects of inhibitory and excitatory activities. Taken together, the data suggest that trial-to-trial variations in the synchronized responses of neural networks might be related to effective excitation-inhibition ratio being a dynamic variable over time scales of minutes.
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Affiliation(s)
- Netta Haroush
- Department of Physiology, Faculty of Medicine, Technion-Israel Institute of Technology Haifa, Israel ; Network Biology Research Laboratories, Faculty of Electrical Engineering, Technion-Israel Institute of Technology Haifa, Israel
| | - Shimon Marom
- Department of Physiology, Faculty of Medicine, Technion-Israel Institute of Technology Haifa, Israel ; Network Biology Research Laboratories, Faculty of Electrical Engineering, Technion-Israel Institute of Technology Haifa, Israel
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35
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Thimm A, Funke K. Multiple blocks of intermittent and continuous theta-burst stimulation applied via transcranial magnetic stimulation differently affect sensory responses in rat barrel cortex. J Physiol 2015; 593:967-85. [PMID: 25504571 PMCID: PMC4398532 DOI: 10.1113/jphysiol.2014.282467] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 11/26/2014] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Theta-burst stimulation (TBS) applied via transcranial magnetic stimulation is able to modulate human cortical excitability. Here we investigated in a rat model how two different forms of TBS, intermittent (iTBS) and continuous (cTBS), affect sensory responses in rat barrel cortex. We found that iTBS but less cTBS promoted late (>18 ms) sensory response components while not affecting the earliest response (8-18 ms). The effect increased with each of the five iTBS blocks applied. cTBS somewhat reduced the early response component after the first block but had a similar effect as iTBS after four to five blocks. We conclude that iTBS primarly modulates the activity of (inhibitory) cortical interneurons while cTBS may first reduce general neuronal excitability with a single block but reverse to iTBS-like effects with application of several blocks. ABSTRACT Cortical sensory processing varies with cortical state and the balance of inhibition to excitation. Repetitive transcranial magnetic stimulation (rTMS) has been shown to modulate human cortical excitability. In a rat model, we recently showed that intermittent theta-burst stimulation (iTBS) applied to the corpus callosum, to activate primarily supragranular cortical pyramidal cells but fewer subcortical neurons, strongly reduced the cortical expression of parvalbumin (PV), indicating reduced activity of fast-spiking interneurons. Here, we used the well-studied rodent barrel cortex system to test how iTBS and continuous TBS (cTBS) modulate sensory responses evoked by either single or double stimuli applied to the principal (PW) and/or adjacent whisker (AW) in urethane-anaesthetized rats. Compared to sham stimulation, iTBS but not cTBS particularly enhanced late (>18 ms) response components of multi-unit spiking and local field potential responses in layer 4 but not the very early response (<18 ms). Similarly, only iTBS diminished the suppression of the second response evoked by paired PW or AW-PW stimulation at 20 ms intervals. The effects increased with each of the five iTBS blocks applied. With cTBS a mild effect similar to that of iTBS was first evident after 4-5 stimulation blocks. Enhanced cortical c-Fos and zif268 expression but reduced PV and GAD67 expression was found only after iTBS, indicating increased cortical activity due to lowered inhibition. We conclude that iTBS but less cTBS may primarily weaken a late recurrent-type cortical inhibition mediated via a subset of PV+ interneurons, enabling stronger late response components believed to contribute to the perception of sensory events.
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Affiliation(s)
- Andreas Thimm
- Department of Neurophysiology, Medical Faculty, Ruhr-University Bochum, 44780, Bochum, Germany
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36
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Loew LM. Design and Use of Organic Voltage Sensitive Dyes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 859:27-53. [PMID: 26238048 DOI: 10.1007/978-3-319-17641-3_2] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The chemistry and the physics of voltage sensitive dyes (VSDs) should be understood and appreciated as a prerequisite for their optimal application to problems in neuroscience cardiology. This chapter provides a basic understanding of the properties of the large variety of available organic VSDs. The mechanisms by which the dyes respond to voltage guides the best set up of the optics for recording or imaging electrophysiological activity. The physical and chemical properties of the dyes can be tuned to optimize delivery to and staining of the cells in different experimental preparations. The aim of this chapter is to arm the experimentalists who use the dyes with enough information and data to be able to intelligently choose the best dye for their specific requirements.
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Affiliation(s)
- Leslie M Loew
- Department of Cell Biology, R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, CT, 06030-6406, USA,
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Hama N, Ito SI, Hirota A. Optical imaging of the propagation patterns of neural responses in the rat sensory cortex: comparison under two different anesthetic conditions. Neuroscience 2014; 284:125-133. [PMID: 25301752 DOI: 10.1016/j.neuroscience.2014.08.059] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 08/26/2014] [Accepted: 08/26/2014] [Indexed: 11/26/2022]
Abstract
Although many studies have reported the influence of anesthetics on the shape of somatic evoked potential, none has evaluated the influence on the spatio-temporal pattern of neural activity in detail. It is practically impossible to analyze neural activities spatially, using conventional electrophysiological methods. Applying our multiple-site optical recording technique for measuring membrane potential from multiple-sites with a high time resolution, we compared the spatio-temporal pattern of the evoked activity under two different anesthetic conditions induced by urethane or α-chloralose. The somatic cortical response was evoked by electrical stimulation of the hindlimb, and the optical signals were recorded from the rat sensorimotor cortex stained with a voltage-sensitive dye (RH414). The evoked activity emerged in a restricted area and propagated in a concentric manner. The spatio-temporal pattern of the evoked activity was analyzed using isochrone maps. There were significant differences in the latency and propagation velocity of the evoked activity, as well as the full width at half maximum of optical signal between the two anesthetic conditions. Differences in the amplitude and the slope of the rising phase were not significant.
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Affiliation(s)
- N Hama
- Department of Neural and Muscular Physiology, Shimane University School of Medicine, Izumo, Shimane 693-8501, Japan
| | - S-I Ito
- Department of Neural and Muscular Physiology, Shimane University School of Medicine, Izumo, Shimane 693-8501, Japan.
| | - A Hirota
- Department of Neural and Muscular Physiology, Shimane University School of Medicine, Izumo, Shimane 693-8501, Japan
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Bains AS, Schweighofer N. Time-sensitive reorganization of the somatosensory cortex poststroke depends on interaction between Hebbian and homeoplasticity: a simulation study. J Neurophysiol 2014; 112:3240-50. [PMID: 25274347 DOI: 10.1152/jn.00433.2013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Together with Hebbian plasticity, homeoplasticity presumably plays a significant, yet unclear, role in recovery postlesion. Here, we undertake a simulation study addressing the role of homeoplasticity and rehabilitation timing poststroke. We first hypothesize that homeoplasticity is essential for recovery and second that rehabilitation training delivered too early, before homeoplasticity has compensated for activity disturbances postlesion, is less effective for recovery than training delivered after a delay. We developed a neural network model of the sensory cortex driven by muscle spindle inputs arising from a six-muscle arm. All synapses underwent Hebbian plasticity, while homeoplasticity adjusted cell excitability to maintain a desired firing distribution. After initial training, the network was lesioned, leading to areas of hyper- and hypoactivity due to the loss of lateral synaptic connections. The network was then retrained through rehabilitative arm movements. We found that network recovery was unsuccessful in the absence of homeoplasticity, as measured by reestablishment of lesion-affected inputs. We also found that a delay preceding rehabilitation led to faster network recovery during the rehabilitation training than no delay. Our simulation results thus suggest that homeoplastic restoration of prelesion activity patterns is essential to functional network recovery via Hebbian plasticity.
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Affiliation(s)
- Amarpreet Singh Bains
- Neuroscience Graduate Program, University of Southern California, Los Angeles, California;
| | - Nicolas Schweighofer
- Neuroscience Graduate Program, University of Southern California, Los Angeles, California; Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, California; and M2H Laboratory, Euromov, University of Montpellier I, Montpellier, France
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39
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Roland PE, Hilgetag CC, Deco G. Cortico-cortical communication dynamics. Front Syst Neurosci 2014; 8:19. [PMID: 24847217 PMCID: PMC4017159 DOI: 10.3389/fnsys.2014.00019] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Accepted: 01/25/2014] [Indexed: 11/13/2022] Open
Abstract
In principle, cortico-cortical communication dynamics is simple: neurons in one cortical area communicate by sending action potentials that release glutamate and excite their target neurons in other cortical areas. In practice, knowledge about cortico-cortical communication dynamics is minute. One reason is that no current technique can capture the fast spatio-temporal cortico-cortical evolution of action potential transmission and membrane conductances with sufficient spatial resolution. A combination of optogenetics and monosynaptic tracing with virus can reveal the spatio-temporal cortico-cortical dynamics of specific neurons and their targets, but does not reveal how the dynamics evolves under natural conditions. Spontaneous ongoing action potentials also spread across cortical areas and are difficult to separate from structured evoked and intrinsic brain activity such as thinking. At a certain state of evolution, the dynamics may engage larger populations of neurons to drive the brain to decisions, percepts and behaviors. For example, successfully evolving dynamics to sensory transients can appear at the mesoscopic scale revealing how the transient is perceived. As a consequence of these methodological and conceptual difficulties, studies in this field comprise a wide range of computational models, large-scale measurements (e.g., by MEG, EEG), and a combination of invasive measurements in animal experiments. Further obstacles and challenges of studying cortico-cortical communication dynamics are outlined in this critical review.
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Affiliation(s)
- Per E Roland
- Department of Neuroscience and Pharmacology, Faculty of Health Sciences, University of Copenhagen Copenhagen, Denmark
| | - Claus C Hilgetag
- Department of Computational Neuroscience, University Medical Center Hamburg-Eppendorf Hamburg, Germany ; Department of Health Sciences, Boston University Boston, MA, USA
| | - Gustavo Deco
- Department of Technology, University of Pompeu Fabra Barcelona, Spain
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40
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Lizier JT. Measuring the Dynamics of Information Processing on a Local Scale in Time and Space. UNDERSTANDING COMPLEX SYSTEMS 2014. [DOI: 10.1007/978-3-642-54474-3_7] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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41
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Willadt S, Nenniger M, Vogt KE. Hippocampal feedforward inhibition focuses excitatory synaptic signals into distinct dendritic compartments. PLoS One 2013; 8:e80984. [PMID: 24244727 PMCID: PMC3823620 DOI: 10.1371/journal.pone.0080984] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 10/17/2013] [Indexed: 12/03/2022] Open
Abstract
Feedforward inhibition controls the time window for synaptic integration and ensures temporal precision in cortical circuits. There is little information whether feedforward inhibition affects neurons uniformly, or whether it contributes to computational refinement within the dendritic tree. Here we demonstrate that feedforward inhibition crucially shapes the integration of synaptic signals in pyramidal cell dendrites. Using voltage-sensitive dye imaging we studied the transmembrane voltage patterns in CA1 pyramidal neurons after Schaffer collateral stimulation in acute brain slices from mice. We observed a high degree of variability in the excitation-inhibition ratio between different branches of the dendritic tree. Many dendritic segments showed no depolarizing signal at all, especially the basal dendrites that received predominantly inhibitory signals. Application of the GABAA receptor antagonist bicuculline resulted in the spread of depolarizing signals throughout the dendritic tree. Tetanic stimulation of Schaffer collateral inputs induced significant alterations in the patterns of excitation/inhibition, indicating that they are modified by synaptic plasticity. In summary, we show that feedforward inhibition restricts the occurrence of depolarizing signals within the dendritic tree of CA1 pyramidal neurons and thus refines signal integration spatially.
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Affiliation(s)
- Silvia Willadt
- Neurobiology/Pharmacology, Biozentrum, University of Basel, Basel, Switzerland
| | - Markus Nenniger
- Neurobiology/Pharmacology, Biozentrum, University of Basel, Basel, Switzerland
| | - Kaspar E. Vogt
- Neurobiology/Pharmacology, Biozentrum, University of Basel, Basel, Switzerland
- * E-mail:
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42
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Cayce JM, Friedman RM, Chen G, Jansen ED, Mahadevan-Jansen A, Roe AW. Infrared neural stimulation of primary visual cortex in non-human primates. Neuroimage 2013; 84:181-90. [PMID: 23994125 DOI: 10.1016/j.neuroimage.2013.08.040] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2013] [Revised: 08/05/2013] [Accepted: 08/15/2013] [Indexed: 11/16/2022] Open
Abstract
Infrared neural stimulation (INS) is an alternative neurostimulation modality that uses pulsed infrared light to evoke spatially precise neural activity that does not require direct contact with neural tissue. With these advantages INS has the potential to increase our understanding of specific neural pathways and impact current diagnostic and therapeutic clinical applications. In order to develop this technique, we investigate the feasibility of INS (λ=1.875μm, fiber diameter=100-400μm) to activate and modulate neural activity in primary visual cortex (V1) of Macaque monkeys. Infrared neural stimulation was found to evoke localized neural responses as evidenced by both electrophysiology and intrinsic signal optical imaging (OIS). Single unit recordings acquired during INS indicated statistically significant increases in neuron firing rates that demonstrate INS evoked excitatory neural activity. Consistent with this, INS stimulation led to focal intensity-dependent reflectance changes recorded with OIS. We also asked whether INS is capable of stimulating functionally specific domains in visual cortex and of modulating visually evoked activity in visual cortex. We found that application of INS via 100μm or 200μm fiber optics produced enhancement of visually evoked OIS response confined to the eye column where INS was applied and relative suppression of the other eye column. Stimulating the cortex with a 400μm fiber, exceeding the ocular dominance width, led to relative suppression, consistent with involvement of inhibitory surrounds. This study is the first to demonstrate that INS can be used to either enhance or diminish visual cortical response and that this can be done in a functional domain specific manner. INS thus holds great potential for use as a safe, non-contact, focally specific brain stimulation technology in primate brains.
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Affiliation(s)
- Jonathan M Cayce
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
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43
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Blinder P, Tsai PS, Kaufhold JP, Knutsen PM, Suhl H, Kleinfeld D. The cortical angiome: an interconnected vascular network with noncolumnar patterns of blood flow. Nat Neurosci 2013; 16:889-97. [PMID: 23749145 DOI: 10.1038/nn.3426] [Citation(s) in RCA: 365] [Impact Index Per Article: 33.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Accepted: 05/04/2013] [Indexed: 12/11/2022]
Abstract
What is the nature of the vascular architecture in the cortex that allows the brain to meet the energy demands of neuronal computations? We used high-throughput histology to reconstruct the complete angioarchitecture and the positions of all neuronal somata of multiple cubic millimeter regions of vibrissa primary sensory cortex in mouse. Vascular networks were derived from the reconstruction. In contrast with the standard model of cortical columns that are tightly linked with the vascular network, graph-theoretical analyses revealed that the subsurface microvasculature formed interconnected loops with a topology that was invariant to the position and boundary of columns. Furthermore, the calculated patterns of blood flow in the networks were unrelated to location of columns. Rather, blood sourced by penetrating arterioles was effectively drained by the penetrating venules to limit lateral perfusion. This analysis provides the underpinning to understand functional imaging and the effect of penetrating vessels strokes on brain viability.
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Affiliation(s)
- Pablo Blinder
- Department of Physics, University of California at San Diego, La Jolla, California, USA
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44
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Omer DB, Hildesheim R, Grinvald A. Temporally-structured acquisition of multidimensional optical imaging data facilitates visualization of elusive cortical representations in the behaving monkey. Neuroimage 2013; 82:237-51. [PMID: 23689017 DOI: 10.1016/j.neuroimage.2013.05.045] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2012] [Revised: 04/13/2013] [Accepted: 05/05/2013] [Indexed: 11/24/2022] Open
Abstract
Fundamental understanding of higher cognitive functions can greatly benefit from imaging of cortical activity with high spatiotemporal resolution in the behaving non-human primate. To achieve rapid imaging of high-resolution dynamics of cortical representations of spontaneous and evoked activity, we designed a novel data acquisition protocol for sensory stimulation by rapidly interleaving multiple stimuli in continuous sessions of optical imaging with voltage-sensitive dyes. We also tested a new algorithm for the "temporally structured component analysis" (TSCA) of a multidimensional time series that was developed for our new data acquisition protocol, but was tested only on simulated data (Blumenfeld, 2010). In addition to the raw data, the algorithm incorporates prior knowledge about the temporal structure of the data as well as input from other information. Here we showed that TSCA can successfully separate functional signal components from other signals referred to as noise. Imaging of responses to multiple visual stimuli, utilizing voltage-sensitive dyes, was performed on the visual cortex of awake monkeys. Multiple cortical representations, including orientation and ocular dominance maps as well as the hitherto elusive retinotopic representation of orientation stimuli, were extracted in only 10s of imaging, approximately two orders of magnitude faster than accomplished by conventional methods. Since the approach is rather general, other imaging techniques may also benefit from the same stimulation protocol. This methodology can thus facilitate rapid optical imaging explorations in monkeys, rodents and other species with a versatility and speed that were not feasible before.
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Affiliation(s)
- David B Omer
- Department of Neurobiology, The Weizmann Institute of Science, 76100 Rehovot, Israel.
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45
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Lustig BR, Friedman RM, Winberry JE, Ebner FF, Roe AW. Voltage-sensitive dye imaging reveals shifting spatiotemporal spread of whisker-induced activity in rat barrel cortex. J Neurophysiol 2013; 109:2382-92. [PMID: 23390314 DOI: 10.1152/jn.00430.2012] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In rats, navigating through an environment requires continuous information about objects near the head. Sensory information such as object location and surface texture are encoded by spike firing patterns of single neurons within rat barrel cortex. Although there are many studies using single-unit electrophysiology, much less is known regarding the spatiotemporal pattern of activity of populations of neurons in barrel cortex in response to whisker stimulation. To examine cortical response at the population level, we used voltage-sensitive dye (VSD) imaging to examine ensemble spatiotemporal dynamics of barrel cortex in response to stimulation of single or two adjacent whiskers in urethane-anesthetized rats. Single whisker stimulation produced a poststimulus fluorescence response peak within 12-16 ms in the barrel corresponding to the stimulated whisker (principal whisker). This fluorescence subsequently propagated throughout the barrel field, spreading anisotropically preferentially along a barrel row. After paired whisker stimulation, the VSD signal showed sublinear summation (less than the sum of 2 single whisker stimulations), consistent with previous electrophysiological and imaging studies. Surprisingly, we observed a spatial shift in the center of activation occurring over a 10- to 20-ms period with shift magnitudes of 1-2 barrels. This shift occurred predominantly in the posteromedial direction within the barrel field. Our data thus reveal previously unreported spatiotemporal patterns of barrel cortex activation. We suggest that this nontopographical shift is consistent with known functional and anatomic asymmetries in barrel cortex and that it may provide an important insight for understanding barrel field activation during whisking behavior.
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Affiliation(s)
- Brian R Lustig
- Department of Psychology, Vanderbilt University, Nashville, TN 37203, USA
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46
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Abstract
Electrode recordings and imaging studies have revealed that localized visual stimuli elicit waves of activity that travel across primary visual cortex. Traveling waves are present also during spontaneous activity, but they can be greatly reduced by widespread and intensive visual stimulation. In this Review, we summarize the evidence in favor of these traveling waves. We suggest that their substrate may lie in long-range horizontal connections and that their functional role may involve the integration of information over large regions of space.
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47
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Luo W, Li P, Chen S, Luo Q. Surrounding inhibition in rat somatosensory cortex during noxious electrical stimulation of the sciatic nerve. CONFERENCE PROCEEDINGS : ... ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL CONFERENCE 2012; 2005:1777-9. [PMID: 17282560 DOI: 10.1109/iembs.2005.1616791] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Surrounding inhibition is a physiologic mechanism to focus neuronal activity. Here we applied optical imaging of intrinsic signal to observing the temporal-spatial characteristic of rat primary somatosensory cortex during graded electrical stimulation of the sciatic nerve (5 Hz, duration of 2 s, 0.5 ms pulse, 1 and 10 muscle twitching threshold). We found that the magnitude and change duration (time course) of the optical signal were larger and longer with the intensity raising. The spatial extent was also wider under noxious electrical stimulus. Meanwhile, we found the inverted optical signal changes in the regions surround the activated primary somatosensory cortex. This phenomenon was similar to the inhibition surrounding focal itcal events observed by optical imaging of intrinsic signal. It suggests the surrounding inhibition under noxious electrical stimulus was probably induced by the excess discharge of excited neurons or it may provide finer discrimination during the noxious stimulus and support the view that the role of somatosensory cortex in pain localization is to finely discriminate the stimulus site.
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Affiliation(s)
- Weihua Luo
- Key Laboratory of Biomedical Photonics of Ministry of Education, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
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48
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Muller L, Destexhe A. Propagating waves in thalamus, cortex and the thalamocortical system: Experiments and models. ACTA ACUST UNITED AC 2012; 106:222-38. [PMID: 22863604 DOI: 10.1016/j.jphysparis.2012.06.005] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Accepted: 06/07/2012] [Indexed: 11/26/2022]
Abstract
Propagating waves of activity have been recorded in many species, in various brain states, brain areas, and under various stimulation conditions. Here, we review the experimental literature on propagating activity in thalamus and neocortex across various levels of anesthesia and stimulation conditions. We also review computational models of propagating waves in networks of thalamic cells, cortical cells and of the thalamocortical system. Some discrepancies between experiments can be explained by the "network state", which differs vastly between anesthetized and awake conditions. We introduce a network model displaying different states and investigate their effect on the spatial structure of self-sustained and externally driven activity. This approach is a step towards understanding how the intrinsically-generated ongoing activity of the network affects its ability to process and propagate extrinsic input.
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Affiliation(s)
- Lyle Muller
- Unité de Neurosciences, Information, et Complexité, CNRS, Gif-sur-Yvette, France.
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49
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Imaging the spatio-temporal dynamics of supragranular activity in the rat somatosensory cortex in response to stimulation of the paws. PLoS One 2012; 7:e40174. [PMID: 22829873 PMCID: PMC3400596 DOI: 10.1371/journal.pone.0040174] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Accepted: 06/03/2012] [Indexed: 11/25/2022] Open
Abstract
We employed voltage-sensitive dye (VSD) imaging to investigate the spatio-temporal dynamics of the responses of the supragranular somatosensory cortex to stimulation of the four paws in urethane-anesthetized rats. We obtained the following main results. (1) Stimulation of the contralateral forepaw evoked VSD responses with greater amplitude and smaller latency than stimulation of the contralateral hindpaw, and ipsilateral VSD responses had a lower amplitude and greater latency than contralateral responses. (2) While the contralateral stimulation initially activated only one focus, the ipsilateral stimulation initially activated two foci: one focus was typically medial to the focus activated by contralateral stimulation and was stereotaxically localized in the motor cortex; the other focus was typically posterior to the focus activated by contralateral stimulation and was stereotaxically localized in the somatosensory cortex. (3) Forepaw and hindpaw somatosensory stimuli activated large areas of the sensorimotor cortex, well beyond the forepaw and hindpaw somatosensory areas of classical somatotopic maps, and forepaw stimuli activated larger cortical areas with greater activation velocity than hindpaw stimuli. (4) Stimulation of the forepaw and hindpaw evoked different cortical activation dynamics: forepaw responses displayed a clear medial directionality, whereas hindpaw responses were much more uniform in all directions. In conclusion, this work offers a complete spatio-temporal map of the supragranular VSD cortical activation in response to stimulation of the paws, showing important somatotopic differences between contralateral and ipsilateral maps as well as differences in the spatio-temporal activation dynamics in response to forepaw and hindpaw stimuli.
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50
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Shih AY, Driscoll JD, Drew PJ, Nishimura N, Schaffer CB, Kleinfeld D. Two-photon microscopy as a tool to study blood flow and neurovascular coupling in the rodent brain. J Cereb Blood Flow Metab 2012; 32:1277-309. [PMID: 22293983 PMCID: PMC3390800 DOI: 10.1038/jcbfm.2011.196] [Citation(s) in RCA: 300] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Revised: 10/18/2011] [Accepted: 11/13/2011] [Indexed: 01/09/2023]
Abstract
The cerebral vascular system services the constant demand for energy during neuronal activity in the brain. Attempts to delineate the logic of neurovascular coupling have been greatly aided by the advent of two-photon laser scanning microscopy to image both blood flow and the activity of individual cells below the surface of the brain. Here we provide a technical guide to imaging cerebral blood flow in rodents. We describe in detail the surgical procedures required to generate cranial windows for optical access to the cortex of both rats and mice and the use of two-photon microscopy to accurately measure blood flow in individual cortical vessels concurrent with local cellular activity. We further provide examples on how these techniques can be applied to the study of local blood flow regulation and vascular pathologies such as small-scale stroke.
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Affiliation(s)
- Andy Y Shih
- Department of Physics, University of California at San Diego, La Jolla, California, USA
| | - Jonathan D Driscoll
- Department of Physics, University of California at San Diego, La Jolla, California, USA
| | - Patrick J Drew
- Department of Engineering Science and Mechanics, Pennsylvania State University, University Park, Pennsylvania, USA
- Department of Neurosurgery, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Nozomi Nishimura
- Department of Biomedical Engineering, Cornell University, Ithaca, New York, USA
| | - Chris B Schaffer
- Department of Biomedical Engineering, Cornell University, Ithaca, New York, USA
| | - David Kleinfeld
- Department of Physics, University of California at San Diego, La Jolla, California, USA
- Section of Neurobiology, University of California at San Diego, La Jolla, California, USA
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