1
|
Morabito A, Zerlaut Y, Dhanasobhon D, Berthaux E, Tzilivaki A, Moneron G, Cathala L, Poirazi P, Bacci A, DiGregorio D, Lourenço J, Rebola N. A dendritic substrate for temporal diversity of cortical inhibition. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.09.602783. [PMID: 39026855 PMCID: PMC11257522 DOI: 10.1101/2024.07.09.602783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
In the mammalian neocortex, GABAergic interneurons (INs) inhibit cortical networks in profoundly different ways. The extent to which this depends on how different INs process excitatory signals along their dendrites is poorly understood. Here, we reveal that the functional specialization of two major populations of cortical INs is determined by the unique association of different dendritic integration modes with distinct synaptic organization motifs. We found that somatostatin (SST)-INs exhibit NMDAR-dependent dendritic integration and uniform synapse density along the dendritic tree. In contrast, dendrites of parvalbumin (PV)-INs exhibit passive synaptic integration coupled with proximally enriched synaptic distributions. Theoretical analysis shows that these two dendritic configurations result in different strategies to optimize synaptic efficacy in thin dendritic structures. Yet, the two configurations lead to distinct temporal engagement of each IN during network activity. We confirmed these predictions with in vivo recordings of IN activity in the visual cortex of awake mice, revealing a rapid and linear recruitment of PV-INs as opposed to a long-lasting integrative activation of SST-INs. Our work reveals the existence of distinct dendritic strategies that confer distinct temporal representations for the two major classes of neocortical INs and thus dynamics of inhibition.
Collapse
Affiliation(s)
- Annunziato Morabito
- ICM, Paris Brain Institute, Hôpital de la Pitié-Salpêtrière, Sorbonne Université, Inserm, CNRS, Paris, 75013, France
| | - Yann Zerlaut
- ICM, Paris Brain Institute, Hôpital de la Pitié-Salpêtrière, Sorbonne Université, Inserm, CNRS, Paris, 75013, France
| | - Dhanasak Dhanasobhon
- ICM, Paris Brain Institute, Hôpital de la Pitié-Salpêtrière, Sorbonne Université, Inserm, CNRS, Paris, 75013, France
| | - Emmanuelle Berthaux
- ICM, Paris Brain Institute, Hôpital de la Pitié-Salpêtrière, Sorbonne Université, Inserm, CNRS, Paris, 75013, France
| | - Alexandra Tzilivaki
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität zu Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Neuroscience Research Center, 10117 Berlin, Germany
- Einstein Center for Neurosciences, Chariteplatz 1, 10117 Berlin, Germany
- NeuroCure Cluster of Excellence, Chariteplatz 1, 10117 Berlin, Germany
| | - Gael Moneron
- Institut Pasteur, CNRS UMR3571, Synapse and Circuit Dynamics Unit, 75015 Paris, France
| | - Laurence Cathala
- ICM, Paris Brain Institute, Hôpital de la Pitié-Salpêtrière, Sorbonne Université, Inserm, CNRS, Paris, 75013, France
| | - Panayiota Poirazi
- Institute of Molecular Biology and Biotechnology (IMBB), Foundation for Research and Technology Hellas (FORTH), Heraklion, 70013, Greece
| | - Alberto Bacci
- ICM, Paris Brain Institute, Hôpital de la Pitié-Salpêtrière, Sorbonne Université, Inserm, CNRS, Paris, 75013, France
| | - David DiGregorio
- Institut Pasteur, CNRS UMR3571, Synapse and Circuit Dynamics Unit, 75015 Paris, France
| | - Joana Lourenço
- ICM, Paris Brain Institute, Hôpital de la Pitié-Salpêtrière, Sorbonne Université, Inserm, CNRS, Paris, 75013, France
| | - Nelson Rebola
- ICM, Paris Brain Institute, Hôpital de la Pitié-Salpêtrière, Sorbonne Université, Inserm, CNRS, Paris, 75013, France
| |
Collapse
|
2
|
Tzilivaki A, Tukker JJ, Maier N, Poirazi P, Sammons RP, Schmitz D. Hippocampal GABAergic interneurons and memory. Neuron 2023; 111:3154-3175. [PMID: 37467748 PMCID: PMC10593603 DOI: 10.1016/j.neuron.2023.06.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 01/04/2023] [Accepted: 06/21/2023] [Indexed: 07/21/2023]
Abstract
One of the most captivating questions in neuroscience revolves around the brain's ability to efficiently and durably capture and store information. It must process continuous input from sensory organs while also encoding memories that can persist throughout a lifetime. What are the cellular-, subcellular-, and network-level mechanisms that underlie this remarkable capacity for long-term information storage? Furthermore, what contributions do distinct types of GABAergic interneurons make to this process? As the hippocampus plays a pivotal role in memory, our review focuses on three aspects: (1) delineation of hippocampal interneuron types and their connectivity, (2) interneuron plasticity, and (3) activity patterns of interneurons during memory-related rhythms, including the role of long-range interneurons and disinhibition. We explore how these three elements, together showcasing the remarkable diversity of inhibitory circuits, shape the processing of memories in the hippocampus.
Collapse
Affiliation(s)
- Alexandra Tzilivaki
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität Berlin, and Berlin Institute of Health, Neuroscience Research Center, 10117 Berlin, Germany; Einstein Center for Neurosciences, Chariteplatz 1, 10117 Berlin, Germany; NeuroCure Cluster of Excellence, Chariteplatz 1, 10117 Berlin, Germany
| | - John J Tukker
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität Berlin, and Berlin Institute of Health, Neuroscience Research Center, 10117 Berlin, Germany; German Center for Neurodegenerative Diseases (DZNE), 10117 Berlin, Germany
| | - Nikolaus Maier
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität Berlin, and Berlin Institute of Health, Neuroscience Research Center, 10117 Berlin, Germany
| | - Panayiota Poirazi
- Foundation for Research and Technology Hellas (FORTH), Institute of Molecular Biology and Biotechnology (IMBB), N. Plastira 100, Heraklion, Crete, Greece
| | - Rosanna P Sammons
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität Berlin, and Berlin Institute of Health, Neuroscience Research Center, 10117 Berlin, Germany
| | - Dietmar Schmitz
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität Berlin, and Berlin Institute of Health, Neuroscience Research Center, 10117 Berlin, Germany; Einstein Center for Neurosciences, Chariteplatz 1, 10117 Berlin, Germany; NeuroCure Cluster of Excellence, Chariteplatz 1, 10117 Berlin, Germany; German Center for Neurodegenerative Diseases (DZNE), 10117 Berlin, Germany; Bernstein Center for Computational Neuroscience, Humboldt-Universität zu Berlin, Philippstrasse. 13, 10115 Berlin, Germany; Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Straße 10, 13125 Berlin, Germany.
| |
Collapse
|
3
|
Liu M, Sun X. Spatial integration of dendrites in fast-spiking basket cells. Front Neurosci 2023; 17:1132980. [PMID: 37081933 PMCID: PMC10110864 DOI: 10.3389/fnins.2023.1132980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 03/20/2023] [Indexed: 04/07/2023] Open
Abstract
Dendrites of fast-spiking basket cells (FS BCs) impact neural circuit functions in brain with both supralinear and sublinear integration strategies. Diverse spatial synaptic inputs and active properties of dendrites lead to distinct neuronal firing patterns. How the FS BCs with this bi-modal dendritic integration respond to different spatial dispersion of synaptic inputs remains unclear. In this study, we construct a multi-compartmental model of FS BC and analyze neuronal firings following simulated synaptic protocols from fully clustered to fully dispersed. Under these stimulation protocols, we find that supralinear dendrites dominate somatic firing of FS BC, while the preference for dispersing is due to sublinear dendrites. Moreover, we find that dendritic diameter and Ca2+-permeable AMPA conductance play an important role in it, while A-type K+ channel and NMDA conductance have little effect. The obtained results may give some implications for understanding dendritic computation.
Collapse
|
4
|
Sharp-wave ripple doublets induce complex dendritic spikes in parvalbumin interneurons in vivo. Nat Commun 2022; 13:6715. [PMID: 36344570 PMCID: PMC9640570 DOI: 10.1038/s41467-022-34520-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 10/25/2022] [Indexed: 11/09/2022] Open
Abstract
Neuronal plasticity has been shown to be causally linked to coincidence detection through dendritic spikes (dSpikes). We demonstrate the existence of SPW-R-associated, branch-specific, local dSpikes and their computational role in basal dendrites of hippocampal PV+ interneurons in awake animals. To measure the entire dendritic arbor of long thin dendrites during SPW-Rs, we used fast 3D acousto-optical imaging through an eccentric deep-brain adapter and ipsilateral local field potential recording. The regenerative calcium spike started at variable, NMDA-AMPA-dependent, hot spots and propagated in both direction with a high amplitude beyond a critical distance threshold (~150 µm) involving voltage-gated calcium channels. A supralinear dendritic summation emerged during SPW-R doublets when two successive SPW-R events coincide within a short temporal window (~150 ms), e.g., during more complex association tasks, and generated large dSpikes with an about 2.5-3-fold amplitude increase which propagated down to the soma. Our results suggest that these doublet-associated dSpikes can work as a dendritic-level temporal and spatial coincidence detector during SPW-R-related network computation in awake mice.
Collapse
|
5
|
Larkum ME, Wu J, Duverdin SA, Gidon A. The guide to dendritic spikes of the mammalian cortex in vitro and in vivo. Neuroscience 2022; 489:15-33. [PMID: 35182699 DOI: 10.1016/j.neuroscience.2022.02.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 02/01/2022] [Accepted: 02/10/2022] [Indexed: 12/23/2022]
Abstract
Half a century since their discovery by Llinás and colleagues, dendritic spikes have been observed in various neurons in different brain regions, from the neocortex and cerebellum to the basal ganglia. Dendrites exhibit a terrifically diverse but stereotypical repertoire of spikes, sometimes specific to subregions of the dendrite. Despite their prevalence, we only have a glimpse into their role in the behaving animal. This article aims to survey the full range of dendritic spikes found in excitatory and inhibitory neurons, compare them in vivo versus in vitro, and discuss new studies describing dendritic spikes in the human cortex. We focus on dendritic spikes in neocortical and hippocampal neurons and present a roadmap to identify and understand the broader role of dendritic spikes in single-cell computation.
Collapse
Affiliation(s)
- Matthew E Larkum
- Institute for Biology, Humboldt-Universität zu Berlin, Berlin, Germany; NeuroCure Cluster, Charité - Universitätsmedizin Berlin, Germany
| | - Jiameng Wu
- Institute for Biology, Humboldt-Universität zu Berlin, Berlin, Germany; Einstein Center for Neurosciences Berlin, Berlin, Germany
| | - Sarah A Duverdin
- Institute for Biology, Humboldt-Universität zu Berlin, Berlin, Germany; Department of Integrative Neurophysiology, Amsterdam Neuroscience, Center for Neurogenomics and Cognitive Research (CNCR), Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Albert Gidon
- Institute for Biology, Humboldt-Universität zu Berlin, Berlin, Germany
| |
Collapse
|
6
|
Lafourcade M, van der Goes MSH, Vardalaki D, Brown NJ, Voigts J, Yun DH, Kim ME, Ku T, Harnett MT. Differential dendritic integration of long-range inputs in association cortex via subcellular changes in synaptic AMPA-to-NMDA receptor ratio. Neuron 2022; 110:1532-1546.e4. [PMID: 35180389 PMCID: PMC9081173 DOI: 10.1016/j.neuron.2022.01.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 11/04/2021] [Accepted: 01/21/2022] [Indexed: 12/21/2022]
Abstract
Synaptic NMDA receptors can produce powerful dendritic supralinearities that expand the computational repertoire of single neurons and their respective circuits. This form of supralinearity may represent a general principle for synaptic integration in thin dendrites. However, individual cortical neurons receive many diverse classes of input that may require distinct postsynaptic decoding schemes. Here, we show that sensory, motor, and thalamic inputs preferentially target basal, apical oblique, and distal tuft dendrites, respectively, in layer 5b pyramidal neurons of the mouse retrosplenial cortex, a visuospatial association area. These dendritic compartments exhibited differential expression of NMDA receptor-mediated supralinearity due to systematic changes in the AMPA-to-NMDA receptor ratio. Our results reveal a new schema for integration in cortical pyramidal neurons, in which dendrite-specific changes in synaptic receptors support input-localized decoding. This coexistence of multiple modes of dendritic integration in single neurons has important implications for synaptic plasticity and cortical computation.
Collapse
Affiliation(s)
- Mathieu Lafourcade
- Department of Brain & Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Marie-Sophie H van der Goes
- Department of Brain & Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Dimitra Vardalaki
- Department of Brain & Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Norma J Brown
- Department of Brain & Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Jakob Voigts
- Department of Brain & Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Dae Hee Yun
- Department of Brain & Cognitive Sciences, Picower Institute for Learning & Memory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Minyoung E Kim
- Department of Brain & Cognitive Sciences, Picower Institute for Learning & Memory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Taeyun Ku
- Department of Brain & Cognitive Sciences, Picower Institute for Learning & Memory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Mark T Harnett
- Department of Brain & Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
| |
Collapse
|
7
|
Tzilivaki A, Kastellakis G, Schmitz D, Poirazi P. GABAergic Interneurons with Nonlinear Dendrites: From Neuronal Computations to Memory Engrams. Neuroscience 2021; 489:34-43. [PMID: 34843894 DOI: 10.1016/j.neuroscience.2021.11.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Revised: 11/08/2021] [Accepted: 11/22/2021] [Indexed: 10/19/2022]
Abstract
GABAergic interneurons (INs) are a highly diverse class of neurons in the mammalian brain with a critical role in orchestrating multiple cognitive functions and maintaining the balance of excitation/inhibition across neuronal circuitries. In this perspective, we discuss recent findings regarding the ability of some IN subtypes to integrate incoming inputs in nonlinear ways within their dendritic branches. These recently discovered features may endow the specific INs with advanced computing capabilities, whose breadth and functional contributions remain an open question. Along these lines, we discuss theoretical and experimental evidence regarding the potential role of nonlinear IN dendrites in advancing single neuron computations and contributing to memory formation.
Collapse
Affiliation(s)
- Alexandra Tzilivaki
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117 Berlin, Germany; Einstein Center for Neurosciences Berlin, Charitéplatz 1, 10117 Berlin, Germany; Neurocure Cluster of Excellence, Charitéplatz 1, 10117 Berlin, Germany; Foundation for Research and Technology Hellas, Institute of Molecular Biology and Biotechnology, Greece
| | - George Kastellakis
- Foundation for Research and Technology Hellas, Institute of Molecular Biology and Biotechnology, Greece
| | - Dietmar Schmitz
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117 Berlin, Germany; Einstein Center for Neurosciences Berlin, Charitéplatz 1, 10117 Berlin, Germany; Neurocure Cluster of Excellence, Charitéplatz 1, 10117 Berlin, Germany
| | - Panayiota Poirazi
- Foundation for Research and Technology Hellas, Institute of Molecular Biology and Biotechnology, Greece.
| |
Collapse
|
8
|
Ramdas T, Mel BW. Optimizing a Neuron for Reliable Dendritic Subunit Pooling. Neuroscience 2021; 489:216-233. [PMID: 34715265 DOI: 10.1016/j.neuroscience.2021.10.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Revised: 10/10/2021] [Accepted: 10/15/2021] [Indexed: 12/16/2022]
Abstract
In certain biologically relevant computing scenarios, a neuron "pools" the outputs of multiple independent functional subunits, firing if any one of them crosses threshold. Recent studies suggest that active dendrites could provide the thresholding mechanism, so that both the thresholding and pooling operations could take place within a single neuron. A pooling neuron faces a difficult task, however. Dendrites can produce highly variable responses depending on the density and spatial patterning of their synaptic inputs, and bona fide dendritic firing may be very rare, making it difficult for a neuron to reliably detect when one of its many dendrites has "gone suprathreshold". Our goal has been to identify biological adaptations that optimize a neuron's performance at the binary subunit pooling (BSP) task. Katz et al. (2009) pointed to the importance of spine density gradients in shaping dendritic responses. In a similar vein, we used a compartmental model to study how a neuron's performance at the BSP task is affected by different spine density layouts and other biological variables. We found BSP performance was optimized when dendrites have (1) a decreasing spine density gradient (true for many types of pyramidal neurons); (2) low-to-medium resistance spine necks; (3) strong NMDA currents; (4) fast spiking Na+ channels; and (5) powerful hyperpolarizing inhibition. Our findings provide a normative account that links several neuronal properties within the context of a behaviorally relevant task, and thus provide new insights into nature's subtle strategies for optimizing the computing capabilities of neural tissue.
Collapse
Affiliation(s)
- Tejas Ramdas
- Computational Neuroscience Program, USC, United States.
| | - Bartlett W Mel
- Biomedical Engineering Department and Neuroscience Graduate Program, USC, United States.
| |
Collapse
|
9
|
Chiovini B, Pálfi D, Majoros M, Juhász G, Szalay G, Katona G, Szőri M, Frigyesi O, Lukácsné Haveland C, Szabó G, Erdélyi F, Máté Z, Szadai Z, Madarász M, Dékány M, Csizmadia IG, Kovács E, Rózsa B, Mucsi Z. Theoretical Design, Synthesis, and In Vitro Neurobiological Applications of a Highly Efficient Two-Photon Caged GABA Validated on an Epileptic Case. ACS OMEGA 2021; 6:15029-15045. [PMID: 34151084 PMCID: PMC8210458 DOI: 10.1021/acsomega.1c01164] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 05/20/2021] [Indexed: 06/13/2023]
Abstract
In this paper, we present an additional, new cage-GABA compound, called 4-amino-1-(4'-dimethylaminoisopropoxy-5',7'-dinitro-2',3'-dihydro-indol-1-yl)-1-oxobutane-γ-aminobutyric acid (iDMPO-DNI-GABA), and currently, this compound is the only photoreagent, which can be applied for GABA uncaging without experimental compromises. By a systematic theoretical design and successful synthesis of several compounds, the best reagent exhibits a high two-photon efficiency within the 700-760 nm range with excellent pharmacological behavior, which proved to be suitable for a complex epileptic study. Quantum chemical design showed that the optimal length of the cationic side chain enhances the two-photon absorption by 1 order of magnitude due to the cooperating internal hydrogen bonding to the extra nitro group on the core. This feature increased solubility while suppressing membrane permeability. The efficiency was demonstrated in a systematic, wide range of in vitro single-cell neurophysiological experiments by electrophysiological as well as calcium imaging techniques. Scalable inhibitory ion currents were elicited by iDMPO-DNI-GABA with appropriate spatial-temporal precision, blocking both spontaneous and evoked cell activity with excellent efficiency. Additionally, to demonstrate its applicability in a real neurobiological study, we could smoothly and selectively modulate neuronal activities during artificial epileptic rhythms first time in a neural network of GCaMP6f transgenic mouse brain slices.
Collapse
Affiliation(s)
- Balázs Chiovini
- The
Faculty of Information Technology, Pázmány
Péter Catholic University, 50 Práter str., H-1083 Budapest, Hungary
- Laboratory
of 3D Functional Network and Dendritic Imaging, Institute of Experimental Medicine, 43 Szigony str., H-1083 Budapest, Hungary
| | - Dénes Pálfi
- The
Faculty of Information Technology, Pázmány
Péter Catholic University, 50 Práter str., H-1083 Budapest, Hungary
| | - Myrtill Majoros
- The
Faculty of Information Technology, Pázmány
Péter Catholic University, 50 Práter str., H-1083 Budapest, Hungary
| | - Gábor Juhász
- The
Faculty of Information Technology, Pázmány
Péter Catholic University, 50 Práter str., H-1083 Budapest, Hungary
- Laboratory
of 3D Functional Network and Dendritic Imaging, Institute of Experimental Medicine, 43 Szigony str., H-1083 Budapest, Hungary
| | - Gergely Szalay
- Laboratory
of 3D Functional Network and Dendritic Imaging, Institute of Experimental Medicine, 43 Szigony str., H-1083 Budapest, Hungary
| | - Gergely Katona
- Laboratory
of 3D Functional Network and Dendritic Imaging, Institute of Experimental Medicine, 43 Szigony str., H-1083 Budapest, Hungary
| | - Milán Szőri
- Institute
of Chemistry, Faculty of Materials Science and Engineering, University of Miskolc, H-3515 Miskolc, Hungary
| | - Orsolya Frigyesi
- Chemistry
Department, Femtonics Limited, Tűzoltó str. 59, H-1094 Budapest, Hungary
| | | | - Gábor Szabó
- Transgenic
Facility, Institute of Experimental Medicine, 43 Szigony str., H-1083 Budapest, Hungary
| | - Ferenc Erdélyi
- Transgenic
Facility, Institute of Experimental Medicine, 43 Szigony str., H-1083 Budapest, Hungary
| | - Zoltán Máté
- Transgenic
Facility, Institute of Experimental Medicine, 43 Szigony str., H-1083 Budapest, Hungary
| | - Zoltán Szadai
- The
Faculty of Information Technology, Pázmány
Péter Catholic University, 50 Práter str., H-1083 Budapest, Hungary
| | - Miklós Madarász
- Laboratory
of 3D Functional Network and Dendritic Imaging, Institute of Experimental Medicine, 43 Szigony str., H-1083 Budapest, Hungary
| | - Miklós Dékány
- Gedeon Richter
Plc, Gyömrői
str. 19-21, H-1103 Budapest, Hungary
| | - Imre G. Csizmadia
- Department
of Chemistry, University of Toronto, 80 St. George Street, M5S 3H6 Toronto, Ontario, Canada
| | - Ervin Kovács
- Chemistry
Department, Femtonics Limited, Tűzoltó str. 59, H-1094 Budapest, Hungary
- Institute
of Materials and Environmental Chemistry, Research Centre for Natural Sciences, 2 Magyar tudósok körútja, H-1117 Budapest, Hungary
| | - Balázs Rózsa
- The
Faculty of Information Technology, Pázmány
Péter Catholic University, 50 Práter str., H-1083 Budapest, Hungary
- Laboratory
of 3D Functional Network and Dendritic Imaging, Institute of Experimental Medicine, 43 Szigony str., H-1083 Budapest, Hungary
| | - Zoltán Mucsi
- Institute
of Chemistry, Faculty of Materials Science and Engineering, University of Miskolc, H-3515 Miskolc, Hungary
- Chemistry
Department, Femtonics Limited, Tűzoltó str. 59, H-1094 Budapest, Hungary
| |
Collapse
|
10
|
Chavlis S, Poirazi P. Drawing inspiration from biological dendrites to empower artificial neural networks. Curr Opin Neurobiol 2021; 70:1-10. [PMID: 34087540 DOI: 10.1016/j.conb.2021.04.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 04/21/2021] [Accepted: 04/28/2021] [Indexed: 12/24/2022]
Abstract
This article highlights specific features of biological neurons and their dendritic trees, whose adoption may help advance artificial neural networks used in various machine learning applications. Advancements could take the form of increased computational capabilities and/or reduced power consumption. Proposed features include dendritic anatomy, dendritic nonlinearities, and compartmentalized plasticity rules, all of which shape learning and information processing in biological networks. We discuss the computational benefits provided by these features in biological neurons and suggest ways to adopt them in artificial neurons in order to exploit the respective benefits in machine learning.
Collapse
Affiliation(s)
- Spyridon Chavlis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, 70013, Greece
| | - Panayiota Poirazi
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, 70013, Greece.
| |
Collapse
|
11
|
May MA, Bawart M, Langeslag M, Bernet S, Kress M, Ritsch-Marte M, Jesacher A. High-NA two-photon single cell imaging with remote focusing using a diffractive tunable lens. BIOMEDICAL OPTICS EXPRESS 2020; 11:7183-7191. [PMID: 33408989 PMCID: PMC7747902 DOI: 10.1364/boe.405863] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 10/22/2020] [Accepted: 10/25/2020] [Indexed: 06/12/2023]
Abstract
Fast, volumetric structural and functional imaging of cellular and sub-cellular dynamics inside the living brain is one of the most desired capabilities in the neurosciences, but still faces serious challenges. Specifically, while few solutions for rapid 3D scanning exist, it is generally much easier to facilitate fast in-plane scanning than it is to scan axially at high speeds. Remote focusing in which the imaging plane is shifted along the optical axis by a tunable lens while maintaining the position of the sample and objective is a promising approach to increase the axial scan speed, but existing techniques often introduce severe optical aberrations in high-NA imaging systems, eliminating the possibility of diffraction-limited single-cell imaging. Here, we demonstrate near diffraction-limited, volumetric two-photon fluorescence microscopy in which we resolve the deep sub-micron structures of single microglia cells with axial scanning performed using a novel high-NA remote focusing method. Image contrast is maintained to within 7% compared to mechanical sample stepping and the focal volume remains nearly diffraction-limited over an axial range greater than 86 µm.
Collapse
Affiliation(s)
- Molly A. May
- Institute of Biomedical Physics, Medical University of Innsbruck, Müllerstraße 44, 6020 Innsbruck, Austria
| | - Martin Bawart
- Institute of Biomedical Physics, Medical University of Innsbruck, Müllerstraße 44, 6020 Innsbruck, Austria
| | - Michiel Langeslag
- Institute of Physiology, Medical University of Innsbruck, Schöpfstraße 41, 6020 Innsbruck, Austria
| | - Stefan Bernet
- Institute of Biomedical Physics, Medical University of Innsbruck, Müllerstraße 44, 6020 Innsbruck, Austria
| | - Michaela Kress
- Institute of Physiology, Medical University of Innsbruck, Schöpfstraße 41, 6020 Innsbruck, Austria
| | - Monika Ritsch-Marte
- Institute of Biomedical Physics, Medical University of Innsbruck, Müllerstraße 44, 6020 Innsbruck, Austria
| | - Alexander Jesacher
- Institute of Biomedical Physics, Medical University of Innsbruck, Müllerstraße 44, 6020 Innsbruck, Austria
| |
Collapse
|
12
|
Functional interrogation of neural circuits with virally transmitted optogenetic tools. J Neurosci Methods 2020; 345:108905. [PMID: 32795553 DOI: 10.1016/j.jneumeth.2020.108905] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 08/03/2020] [Accepted: 08/06/2020] [Indexed: 12/12/2022]
Abstract
The vertebrate brain comprises a plethora of cell types connected by intertwined pathways. Optogenetics enriches the neuroscientific tool set for disentangling these neuronal circuits in a manner which exceeds the spatio-temporal precision of previously existing techniques. Technically, optogenetics can be divided in three types of optical and genetic combinations: (1) it is primarily understood as the manipulation of the activity of genetically modified cells (typically neurons) with light, i.e. optical actuators. (2) A second combination refers to visualizing the activity of genetically modified cells (again typically neurons), i.e. optical sensors. (3) A completely different interpretation of optogenetics refers to the light activated expression of a genetically induced construct. Here, we focus on the first two types of optogenetics, i.e. the optical actuators and sensors in an attempt to give an overview into the topic. We first cover methods to express opsins into neurons and introduce strategies of targeting specific neuronal populations in different animal species. We then summarize combinations of optogenetics with behavioral read out and neuronal imaging. Finally, we give an overview of the current state-of-the-art and an outlook on future perspectives.
Collapse
|
13
|
Sakaki KDR, Podgorski K, Dellazizzo Toth TA, Coleman P, Haas K. Comprehensive Imaging of Sensory-Evoked Activity of Entire Neurons Within the Awake Developing Brain Using Ultrafast AOD-Based Random-Access Two-Photon Microscopy. Front Neural Circuits 2020; 14:33. [PMID: 32612514 PMCID: PMC7308460 DOI: 10.3389/fncir.2020.00033] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Accepted: 05/07/2020] [Indexed: 11/18/2022] Open
Abstract
Determining how neurons transform synaptic input and encode information in action potential (AP) firing output is required for understanding dendritic integration, neural transforms and encoding. Limitations in the speed of imaging 3D volumes of brain encompassing complex dendritic arbors in vivo using conventional galvanometer mirror-based laser-scanning microscopy has hampered fully capturing fluorescent sensors of activity throughout an individual neuron's entire complement of synaptic inputs and somatic APs. To address this problem, we have developed a two-photon microscope that achieves high-speed scanning by employing inertia-free acousto-optic deflectors (AODs) for laser beam positioning, enabling random-access sampling of hundreds to thousands of points-of-interest restricted to a predetermined neuronal structure, avoiding wasted scanning of surrounding extracellular tissue. This system is capable of comprehensive imaging of the activity of single neurons within the intact and awake vertebrate brain. Here, we demonstrate imaging of tectal neurons within the brains of albino Xenopus laevis tadpoles labeled using single-cell electroporation for expression of a red space-filling fluorophore to determine dendritic arbor morphology, and either the calcium sensor jGCaMP7s or the glutamate sensor iGluSnFR as indicators of neural activity. Using discrete, point-of-interest scanning we achieve sampling rates of 3 Hz for saturation sampling of entire arbors at 2 μm resolution, 6 Hz for sequentially sampling 3 volumes encompassing the dendritic arbor and soma, and 200–250 Hz for scanning individual planes through the dendritic arbor. This system allows investigations of sensory-evoked information input-output relationships of neurons within the intact and awake brain.
Collapse
Affiliation(s)
- Kelly D R Sakaki
- Department of Cellular and Physiological Sciences, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | | | - Tristan A Dellazizzo Toth
- Department of Cellular and Physiological Sciences, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Patrick Coleman
- Department of Cellular and Physiological Sciences, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Kurt Haas
- Department of Cellular and Physiological Sciences, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| |
Collapse
|
14
|
Dendritic Spikes Expand the Range of Well Tolerated Population Noise Structures. J Neurosci 2019; 39:9173-9184. [PMID: 31558617 DOI: 10.1523/jneurosci.0638-19.2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 08/08/2019] [Accepted: 09/14/2019] [Indexed: 12/11/2022] Open
Abstract
The brain operates surprisingly well despite the noisy nature of individual neurons. The central mechanism for noise mitigation in the nervous system is thought to involve averaging over multiple noise-corrupted inputs. Subsequently, there has been considerable interest in identifying noise structures that can be integrated linearly in a way that preserves reliable signal encoding. By analyzing realistic synaptic integration in biophysically accurate neuronal models, I report a complementary denoising approach that is mediated by focal dendritic spikes. Dendritic spikes might seem to be unlikely candidates for noise reduction due to their miniscule integration compartments and poor averaging abilities. Nonetheless, the extra thresholding step introduced by dendritic spike generation increases neuronal tolerance for a broad category of noise structures, some of which cannot be resolved well with averaging. This property of active dendrites compensates for compartment size constraints and expands the repertoire of conditions that can be processed by neuronal populations.SIGNIFICANCE STATEMENT Noise, or random variability, is a prominent feature of the neuronal code and poses a fundamental challenge for information processing. To reconcile the surprisingly accurate output of the brain with the inherent noisiness of biological systems, previous work examined signal integration in idealized neurons. The notion that emerged from this body of work is that accurate signal representation relies largely on input averaging in neuronal dendrites. In contrast to the prevailing view, I show that denoising in simulated neurons with realistic morphology and biophysical properties follows a different strategy: dendritic spikes act as classifiers that assist in extracting information from a variety of noise structures that have been considered before to be particularly disruptive for reliable brain function.
Collapse
|
15
|
Tzilivaki A, Kastellakis G, Poirazi P. Challenging the point neuron dogma: FS basket cells as 2-stage nonlinear integrators. Nat Commun 2019; 10:3664. [PMID: 31413258 PMCID: PMC6694133 DOI: 10.1038/s41467-019-11537-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 07/15/2019] [Indexed: 12/16/2022] Open
Abstract
Interneurons are critical for the proper functioning of neural circuits. While often morphologically complex, their dendrites have been ignored for decades, treating them as linear point neurons. Exciting new findings reveal complex, non-linear dendritic computations that call for a new theory of interneuron arithmetic. Using detailed biophysical models, we predict that dendrites of FS basket cells in both hippocampus and prefrontal cortex come in two flavors: supralinear, supporting local sodium spikes within large-volume branches and sublinear, in small-volume branches. Synaptic activation of varying sets of these dendrites leads to somatic firing variability that cannot be fully explained by the point neuron reduction. Instead, a 2-stage artificial neural network (ANN), with sub- and supralinear hidden nodes, captures most of the variance. Reduced neuronal circuit modeling suggest that this bi-modal, 2-stage integration in FS basket cells confers substantial resource savings in memory encoding as well as the linking of memories across time.
Collapse
Affiliation(s)
- Alexandra Tzilivaki
- Institute of Molecular Biology and Biotechnology (IMBB), Foundation for Research and Technology Hellas (FORTH), Heraklion, 70013, Greece
- Department of Biology, University of Crete, Heraklion, 70013, Greece
- Einstein Center for Neurosciences Berlin, Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health, NeuroCure Cluster of Excellence, Charitéplatz 1, 10117, Berlin, Germany
| | - George Kastellakis
- Institute of Molecular Biology and Biotechnology (IMBB), Foundation for Research and Technology Hellas (FORTH), Heraklion, 70013, Greece
| | - Panayiota Poirazi
- Institute of Molecular Biology and Biotechnology (IMBB), Foundation for Research and Technology Hellas (FORTH), Heraklion, 70013, Greece.
| |
Collapse
|
16
|
Optogenetic approaches to study the mammalian brain. Curr Opin Struct Biol 2019; 57:157-163. [PMID: 31082625 DOI: 10.1016/j.sbi.2019.04.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 03/30/2019] [Accepted: 04/05/2019] [Indexed: 12/24/2022]
Abstract
Optogenetics has revolutionized neurobiological research by allowing to disentangle intricate neuronal circuits at a spatio-temporal precision unmatched by other techniques. Here, we review current advances of optogenetic applications in mammals, especially focusing on freely moving animals. State-of-the-art strategies allow the targeted expression of opsins in neuronal subpopulations, defined either by genetic cell type or neuronal projection pattern. Optogenetic manipulations of these subpopulations become particularly powerful when combined with behavioral paradigms and neurophysiological readout techniques. Thereby, specific roles can be assigned to identified cells. All-optical approaches with the opportunity to write complex three dimensional patterns into neuronal networks have recently emerged. While clinical implications of the new tool set seem tempting, we emphasize here the role of optogenetics for basic research.
Collapse
|
17
|
Francavilla R, Villette V, Martel O, Topolnik L. Calcium Dynamics in Dendrites of Hippocampal CA1 Interneurons in Awake Mice. Front Cell Neurosci 2019; 13:98. [PMID: 30930750 PMCID: PMC6428725 DOI: 10.3389/fncel.2019.00098] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 02/27/2019] [Indexed: 11/19/2022] Open
Abstract
Hippocampal inhibitory interneurons exhibit a large diversity of dendritic Ca2+ mechanisms that are involved in the induction of Hebbian and anti-Hebbian synaptic plasticity. High resolution imaging techniques allowed examining somatic Ca2+ signals and, accordingly, the recruitment of hippocampal interneurons in awake behaving animals. However, little is still known about dendritic Ca2+ activity in interneurons during different behavioral states. Here, we used two-photon Ca2+ imaging in mouse hippocampal CA1 interneurons to reveal Ca2+ signal patterns in interneuron dendrites during animal locomotion and immobility. Despite overall variability in dendritic Ca2+ transients (CaTs) across different cells and dendritic branches, we report consistent behavior state-dependent organization of Ca2+ signaling in interneurons. As such, spreading regenerative CaTs dominated in dendrites during locomotion, whereas both spreading and localized Ca2+ signals were seen during immobility. Thus, these data indicate that while animal locomotion is associated with widespread Ca2+ elevations in interneuron dendrites that may reflect regenerative activity, local CaTs that may be related to synaptic activity become apparent during animal quiet state.
Collapse
Affiliation(s)
- Ruggiero Francavilla
- Department of Biochemistry, Microbiology and Bio-informatics, Faculty of Science and Engineering, Neuroscience Axis, CHU de Québec Research Center (CHUL), Laval University, Québec, PQ, Canada
| | - Vincent Villette
- Department of Biochemistry, Microbiology and Bio-informatics, Faculty of Science and Engineering, Neuroscience Axis, CHU de Québec Research Center (CHUL), Laval University, Québec, PQ, Canada
| | - Olivier Martel
- Department of Biochemistry, Microbiology and Bio-informatics, Faculty of Science and Engineering, Neuroscience Axis, CHU de Québec Research Center (CHUL), Laval University, Québec, PQ, Canada
| | - Lisa Topolnik
- Department of Biochemistry, Microbiology and Bio-informatics, Faculty of Science and Engineering, Neuroscience Axis, CHU de Québec Research Center (CHUL), Laval University, Québec, PQ, Canada
| |
Collapse
|
18
|
Pálfi D, Chiovini B, Szalay G, Kaszás A, Turi GF, Katona G, Ábrányi-Balogh P, Szőri M, Potor A, Frigyesi O, Lukácsné Haveland C, Szadai Z, Madarász M, Vasanits-Zsigrai A, Molnár-Perl I, Viskolcz B, Csizmadia IG, Mucsi Z, Rózsa B. High efficiency two-photon uncaging coupled by the correction of spontaneous hydrolysis. Org Biomol Chem 2019; 16:1958-1970. [PMID: 29497727 DOI: 10.1039/c8ob00025e] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two-photon (TP) uncaging of neurotransmitter molecules is the method of choice to mimic and study the subtleties of neuronal communication either in the intact brain or in slice preparations. However, the currently available caged materials are just at the limit of their usability and have several drawbacks. The local and focal nature of their use may for example be jeopardized by a high spontaneous hydrolysis rate of the commercially available compounds with increased photochemical release rate. Here, using quantum chemical modelling we show the mechanisms of hydrolysis and two-photon activation, and synthesized more effective caged compounds. Furthermore, we have developed a new enzymatic elimination method removing neurotransmitters inadvertently escaping from their compound during experiment. This method, usable both in one and two-photon experiments, allows for the use of materials with an increased rate of photochemical release. The efficiency of the new compound and the enzymatic method and of the new compound are demonstrated in neurophysiological experiments.
Collapse
Affiliation(s)
- Dénes Pálfi
- Two-Photon Measurement Technology Research Group, The Faculty of Information Technology, Pázmány Péter Catholic University, Práter str 50, H-1083 Budapest, Hungary
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Ronzitti E, Emiliani V, Papagiakoumou E. Methods for Three-Dimensional All-Optical Manipulation of Neural Circuits. Front Cell Neurosci 2018; 12:469. [PMID: 30618626 PMCID: PMC6304748 DOI: 10.3389/fncel.2018.00469] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 11/19/2018] [Indexed: 12/18/2022] Open
Abstract
Optical means for modulating and monitoring neuronal activity, have provided substantial insights to neurophysiology and toward our understanding of how the brain works. Optogenetic actuators, calcium or voltage imaging probes and other molecular tools, combined with advanced microscopies have allowed an "all-optical" readout and modulation of neural circuits. Completion of this remarkable work is evolving toward a three-dimensional (3D) manipulation of neural ensembles at a high spatiotemporal resolution. Recently, original optical methods have been proposed for both activating and monitoring neurons in a 3D space, mainly through optogenetic compounds. Here, we review these methods and anticipate possible combinations among them.
Collapse
Affiliation(s)
| | | | - Eirini Papagiakoumou
- Wavefront Engineering Microscopy Group, Photonics Department, Institut de la Vision, Sorbonne Université, Inserm S968, CNRS UMR7210, Paris, France
| |
Collapse
|
20
|
Sakaki KDR, Coleman P, Toth TD, Guerrier C, Haas K. Automating Event-detection of Brain Neuron Synaptic Activity and Action Potential Firing in vivo using a Random-access Multiphoton Laser Scanning Microscope for Real-time Analysis. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2018; 2018:1-7. [PMID: 30440280 DOI: 10.1109/embc.2018.8512983] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Determining how a neuron computes requires an understanding of the complex spatiotemporal relationship between its input (e.g. synaptic input as a result of external stimuli) and action potential output. Recent advances in in vivo, laser-scanning multiphoton technology, known as random-access microscopy (RAM), can capture this relationship by imaging fluorescent light, emitted from calcium-sensitive biosensors responding to synaptic and action potential firing in a neuron's full dendritic arbor and cell body. Ideally, a continuous output of fluorescent intensities from the neuron would be converted to a binary output (`event', 'or no-event'). These binary events can be used to correlate temporal and spatial associations between the input and output. However, neurons contain hundreds-to-thousands of synapses on the dendritic arbors generating an enormous quantity of data composed of physiological signals, which vary greatly in shape and size. Thus, automating data-processing tasks is essential to support high-throughput analysis for real-time/post-processing operations and to improve operators' comprehension of the data used to decipher neuron computations. Here, we describe an automated software algorithm to detect brain neuron events in real-time using an acousto-optic, multiphoton, laser scanning RAM developed in our laboratory. The fluorescent light intensities, from a genetically encoded, calcium biosensor (GCAMP 6m), are measured by our RAM system and are input to our 'event-detector', which converts them to a binary output meant for real-time applications. We evaluate three algorithms for this purpose: exponentially weighted moving average, cumulative sum, and template matching; present each algorithm's performance; and discuss user-feasibility of each. We validated our system in vivo, using the visual circuit of the Xenopus laevis.
Collapse
|
21
|
Differential Dendritic Integration of Synaptic Potentials and Calcium in Cerebellar Interneurons. Neuron 2017; 91:837-850. [PMID: 27537486 DOI: 10.1016/j.neuron.2016.07.029] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2016] [Revised: 05/25/2016] [Accepted: 06/23/2016] [Indexed: 11/20/2022]
Abstract
Dendritic voltage integration determines the transformation of synaptic inputs into output firing, while synaptic calcium integration drives plasticity mechanisms thought to underlie memory storage. Dendritic calcium integration has been shown to follow the same synaptic input-output relationship as dendritic voltage, but whether similar operations apply to neurons exhibiting sublinear voltage integration is unknown. We examined the properties and cellular mechanisms of these dendritic operations in cerebellar molecular layer interneurons using dendritic voltage and calcium imaging, in combination with synaptic stimulation or glutamate uncaging. We show that, while synaptic potentials summate sublinearly, concomitant dendritic calcium signals summate either linearly or supralinearly depending on the number of synapses activated. The supralinear dendritic calcium triggers a branch-specific, short-term suppression of neurotransmitter release that alters the pattern of synaptic activation. Thus, differential voltage and calcium integration permits dynamic regulation of neuronal input-output transformations without altering intrinsic nonlinear integration mechanisms.
Collapse
|
22
|
Ji N, Freeman J, Smith SL. Technologies for imaging neural activity in large volumes. Nat Neurosci 2017; 19:1154-64. [PMID: 27571194 DOI: 10.1038/nn.4358] [Citation(s) in RCA: 149] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 07/14/2016] [Indexed: 02/08/2023]
Abstract
Neural circuitry has evolved to form distributed networks that act dynamically across large volumes. Conventional microscopy collects data from individual planes and cannot sample circuitry across large volumes at the temporal resolution relevant to neural circuit function and behaviors. Here we review emerging technologies for rapid volume imaging of neural circuitry. We focus on two critical challenges: the inertia of optical systems, which limits image speed, and aberrations, which restrict the image volume. Optical sampling time must be long enough to ensure high-fidelity measurements, but optimized sampling strategies and point-spread function engineering can facilitate rapid volume imaging of neural activity within this constraint. We also discuss new computational strategies for processing and analyzing volume imaging data of increasing size and complexity. Together, optical and computational advances are providing a broader view of neural circuit dynamics and helping elucidate how brain regions work in concert to support behavior.
Collapse
Affiliation(s)
- Na Ji
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, USA
| | - Jeremy Freeman
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, USA
| | - Spencer L Smith
- Department of Cell Biology and Physiology, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA.,Neuroscience Center, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA.,Carolina Institute for Developmental Disabilities, University of North Carolina School of Medicine, Chapel Hill, North Carolina
| |
Collapse
|
23
|
Szalay G, Judák L, Katona G, Ócsai K, Juhász G, Veress M, Szadai Z, Fehér A, Tompa T, Chiovini B, Maák P, Rózsa B. Fast 3D Imaging of Spine, Dendritic, and Neuronal Assemblies in Behaving Animals. Neuron 2016; 92:723-738. [PMID: 27773582 PMCID: PMC5167293 DOI: 10.1016/j.neuron.2016.10.002] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2015] [Revised: 07/19/2016] [Accepted: 09/20/2016] [Indexed: 11/19/2022]
Abstract
Understanding neural computation requires methods such as 3D acousto-optical (AO) scanning that can simultaneously read out neural activity on both the somatic and dendritic scales. AO point scanning can increase measurement speed and signal-to-noise ratio (SNR) by several orders of magnitude, but high optical resolution requires long point-to-point switching time, which limits imaging capability. Here we present a novel technology, 3D DRIFT AO scanning, which can extend each scanning point to small 3D lines, surfaces, or volume elements for flexible and fast imaging of complex structures simultaneously in multiple locations. Our method was demonstrated by fast 3D recording of over 150 dendritic spines with 3D lines, over 100 somata with squares and cubes, or multiple spiny dendritic segments with surface and volume elements, including in behaving animals. Finally, a 4-fold improvement in total excitation efficiency resulted in about 500 × 500 × 650 μm scanning volume with genetically encoded calcium indicators (GECIs).
Collapse
Affiliation(s)
- Gergely Szalay
- Laboratory of 3D Functional Network and Dendritic Imaging, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest 1083, Hungary
| | - Linda Judák
- Laboratory of 3D Functional Network and Dendritic Imaging, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest 1083, Hungary
| | - Gergely Katona
- Laboratory of 3D Functional Network and Dendritic Imaging, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest 1083, Hungary; MTA-PPKE ITK-NAP B-2p Measurement Technology Group, Faculty of Information Technology, Pázmány Péter Catholic University, Budapest 1083, Hungary
| | - Katalin Ócsai
- MTA-PPKE ITK-NAP B-2p Measurement Technology Group, Faculty of Information Technology, Pázmány Péter Catholic University, Budapest 1083, Hungary
| | - Gábor Juhász
- Laboratory of 3D Functional Network and Dendritic Imaging, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest 1083, Hungary; MTA-PPKE ITK-NAP B-2p Measurement Technology Group, Faculty of Information Technology, Pázmány Péter Catholic University, Budapest 1083, Hungary
| | - Máté Veress
- Department of Atomic Physics, Budapest University of Technology and Economics, Budapest 1111, Hungary
| | - Zoltán Szadai
- Laboratory of 3D Functional Network and Dendritic Imaging, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest 1083, Hungary; Two-Photon Laboratory, Faculty of Information Technology, Pázmány Péter Catholic University, Budapest 1083, Hungary
| | - András Fehér
- Department of Atomic Physics, Budapest University of Technology and Economics, Budapest 1111, Hungary
| | - Tamás Tompa
- Laboratory of 3D Functional Network and Dendritic Imaging, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest 1083, Hungary; Two-Photon Laboratory, Faculty of Information Technology, Pázmány Péter Catholic University, Budapest 1083, Hungary
| | - Balázs Chiovini
- Laboratory of 3D Functional Network and Dendritic Imaging, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest 1083, Hungary; Two-Photon Laboratory, Faculty of Information Technology, Pázmány Péter Catholic University, Budapest 1083, Hungary
| | - Pál Maák
- Department of Atomic Physics, Budapest University of Technology and Economics, Budapest 1111, Hungary
| | - Balázs Rózsa
- Laboratory of 3D Functional Network and Dendritic Imaging, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest 1083, Hungary; Two-Photon Laboratory, Faculty of Information Technology, Pázmány Péter Catholic University, Budapest 1083, Hungary.
| |
Collapse
|
24
|
Phillips WS, Herly M, Del Negro CA, Rekling JC. Organotypic slice cultures containing the preBötzinger complex generate respiratory-like rhythms. J Neurophysiol 2015; 115:1063-70. [PMID: 26655824 DOI: 10.1152/jn.00904.2015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 12/02/2015] [Indexed: 02/08/2023] Open
Abstract
Study of acute brain stem slice preparations in vitro has advanced our understanding of the cellular and synaptic mechanisms of respiratory rhythm generation, but their inherent limitations preclude long-term manipulation and recording experiments. In the current study, we have developed an organotypic slice culture preparation containing the preBötzinger complex (preBötC), the core inspiratory rhythm generator of the ventrolateral brain stem. We measured bilateral synchronous network oscillations, using calcium-sensitive fluorescent dyes, in both ventrolateral (presumably the preBötC) and dorsomedial regions of slice cultures at 7-43 days in vitro. These calcium oscillations appear to be driven by periodic bursts of inspiratory neuronal activity, because whole cell recordings from ventrolateral neurons in culture revealed inspiratory-like drive potentials, and no oscillatory activity was detected from glial fibrillary associated protein-expressing astrocytes in cultures. Acute slices showed a burst frequency of 10.9 ± 4.2 bursts/min, which was not different from that of brain stem slice cultures (13.7 ± 10.6 bursts/min). However, slice cocultures that include two cerebellar explants placed along the dorsolateral border of the brainstem displayed up to 193% faster burst frequency (22.4 ± 8.3 bursts/min) and higher signal amplitude (340%) compared with acute slices. We conclude that preBötC-containing slice cultures retain inspiratory-like rhythmic function and therefore may facilitate lines of experimentation that involve extended incubation (e.g., genetic transfection or chronic drug exposure) while simultaneously being amenable to imaging and electrophysiology at cellular, synaptic, and network levels.
Collapse
Affiliation(s)
- Wiktor S Phillips
- Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark; and Department of Applied Science, The College of William and Mary, Williamsburg, Virginia
| | - Mikkel Herly
- Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark; and
| | | | - Jens C Rekling
- Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark; and
| |
Collapse
|
25
|
Kummer M, Kirmse K, Witte OW, Haueisen J, Holthoff K. Method to quantify accuracy of position feedback signals of a three-dimensional two-photon laser-scanning microscope. BIOMEDICAL OPTICS EXPRESS 2015; 6:3678-93. [PMID: 26504620 PMCID: PMC4605029 DOI: 10.1364/boe.6.003678] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 07/24/2015] [Accepted: 07/24/2015] [Indexed: 05/10/2023]
Abstract
Two-photon laser-scanning microscopy enables to record neuronal network activity in three-dimensional space while maintaining single-cellular resolution. One of the proposed approaches combines galvanometric x-y scanning with piezo-driven objective movements and employs hardware feedback signals for position monitoring. However, readily applicable methods to quantify the accuracy of those feedback signals are currently lacking. Here we provide techniques based on contact-free laser reflection and laser triangulation for the quantification of positioning accuracy of each spatial axis. We found that the lateral feedback signals are sufficiently accurate (defined as <2.5 µm) for a wide range of scan trajectories and frequencies. We further show that axial positioning accuracy does not only depend on objective acceleration and mass but also its geometry. We conclude that the introduced methods allow a reliable quantification of position feedback signals in a cost-efficient, easy-to-install manner and should be applicable for a wide range of two-photon laser scanning microscopes.
Collapse
Affiliation(s)
- Michael Kummer
- Experimentelle Neurologie, Hans-Berger-Klinik für Neurologie, Universitätsklinikum Jena, Erlanger Allee 101, D-07747 Jena, Germany
| | - Knut Kirmse
- Experimentelle Neurologie, Hans-Berger-Klinik für Neurologie, Universitätsklinikum Jena, Erlanger Allee 101, D-07747 Jena, Germany
| | - Otto W. Witte
- Experimentelle Neurologie, Hans-Berger-Klinik für Neurologie, Universitätsklinikum Jena, Erlanger Allee 101, D-07747 Jena, Germany
| | - Jens Haueisen
- Institut für Biomedizinische Technik und Informatik, Technische Universität Ilmenau Gustav-Kirchhoff Str. 2, D-98693 Ilmenau, Germany
| | - Knut Holthoff
- Experimentelle Neurologie, Hans-Berger-Klinik für Neurologie, Universitätsklinikum Jena, Erlanger Allee 101, D-07747 Jena, Germany
| |
Collapse
|
26
|
Wertz A, Trenholm S, Yonehara K, Hillier D, Raics Z, Leinweber M, Szalay G, Ghanem A, Keller G, Rózsa B, Conzelmann KK, Roska B. PRESYNAPTIC NETWORKS. Single-cell-initiated monosynaptic tracing reveals layer-specific cortical network modules. Science 2015; 349:70-4. [PMID: 26138975 DOI: 10.1126/science.aab1687] [Citation(s) in RCA: 145] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Individual cortical neurons can selectively respond to specific environmental features, such as visual motion or faces. How this relates to the selectivity of the presynaptic network across cortical layers remains unclear. We used single-cell-initiated, monosynaptically restricted retrograde transsynaptic tracing with rabies viruses expressing GCaMP6s to image, in vivo, the visual motion-evoked activity of individual layer 2/3 pyramidal neurons and their presynaptic networks across layers in mouse primary visual cortex. Neurons within each layer exhibited similar motion direction preferences, forming layer-specific functional modules. In one-third of the networks, the layer modules were locked to the direction preference of the postsynaptic neuron, whereas for other networks the direction preference varied by layer. Thus, there exist feature-locked and feature-variant cortical networks.
Collapse
Affiliation(s)
- Adrian Wertz
- Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Stuart Trenholm
- Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Keisuke Yonehara
- Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Daniel Hillier
- Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Zoltan Raics
- Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Marcus Leinweber
- Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Gergely Szalay
- Two-Photon Imaging Center, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - Alexander Ghanem
- Max von Pettenkofer-Institute and Gene Center, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Georg Keller
- Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Balázs Rózsa
- Two-Photon Imaging Center, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - Karl-Klaus Conzelmann
- Max von Pettenkofer-Institute and Gene Center, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Botond Roska
- Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland. Department of Ophthalmology, University of Basel, Basel, Switzerland.
| |
Collapse
|
27
|
Quantitation of various indolinyl caged glutamates as their o-phthalaldehyde derivatives by high performance liquid chromatography coupled with tandem spectroscopic detections: Derivatization, stoichiometry and stability studies. J Chromatogr A 2015; 1394:81-8. [DOI: 10.1016/j.chroma.2015.03.039] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2015] [Revised: 03/15/2015] [Accepted: 03/17/2015] [Indexed: 11/23/2022]
|
28
|
Bartley AF, Dobrunz LE. Short-term plasticity regulates the excitation/inhibition ratio and the temporal window for spike integration in CA1 pyramidal cells. Eur J Neurosci 2015; 41:1402-15. [PMID: 25903384 DOI: 10.1111/ejn.12898] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 02/27/2015] [Accepted: 03/16/2015] [Indexed: 12/21/2022]
Abstract
Many neurodevelopmental and neuropsychiatric disorders involve an imbalance between excitation and inhibition caused by synaptic alterations. The proper excitation/inhibition (E/I) balance is especially critical in CA1 pyramidal cells, because they control hippocampal output. Activation of Schaffer collateral axons causes direct excitation of CA1 pyramidal cells, quickly followed by disynaptic feedforward inhibition, stemming from synaptically induced firing of GABAergic interneurons. Both excitatory and inhibitory synapses are modulated by short-term plasticity, potentially causing dynamic tuning of the E/I ratio. However, the effects of short-term plasticity on the E/I ratio in CA1 pyramidal cells are not yet known. To determine this, we recorded disynaptic inhibitory postsynaptic currents and the E/I ratio in CA1 pyramidal cells in acute hippocampal slices from juvenile mice. We found that, whereas inhibitory synapses had paired-pulse depression, disynaptic inhibition instead had paired-pulse facilitation (≤ 200-ms intervals), caused by increased recruitment of feedforward interneurons. Although enhanced disynaptic inhibition helped to constrain paired-pulse facilitation of excitation, the E/I ratio was still larger on the second pulse, increasing pyramidal cell spiking. Surprisingly, this occurred without compromising the precision of spike timing. The E/I balance regulates the temporal spike integration window from multiple inputs; here, we showed that paired-pulse stimulation can broaden the spike integration window. Together, our findings show that the combined effects of short-term plasticity of disynaptic inhibition and monosynaptic excitation alter the E/I balance in CA1 pyramidal cells, leading to dynamic modulation of spike probability and the spike integration window. Short-term plasticity is therefore an important mechanism for modulating signal processing of hippocampal output.
Collapse
Affiliation(s)
- Aundrea F Bartley
- Department of Neurobiology, Civitan International Research Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, 1825 University Blvd, SHEL 902, Birmingham, AL, 35294, USA
| | - Lynn E Dobrunz
- Department of Neurobiology, Civitan International Research Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, 1825 University Blvd, SHEL 902, Birmingham, AL, 35294, USA
| |
Collapse
|
29
|
Tran-Van-Minh A, Cazé RD, Abrahamsson T, Cathala L, Gutkin BS, DiGregorio DA. Contribution of sublinear and supralinear dendritic integration to neuronal computations. Front Cell Neurosci 2015; 9:67. [PMID: 25852470 PMCID: PMC4371705 DOI: 10.3389/fncel.2015.00067] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 02/13/2015] [Indexed: 12/25/2022] Open
Abstract
Nonlinear dendritic integration is thought to increase the computational ability of neurons. Most studies focus on how supralinear summation of excitatory synaptic responses arising from clustered inputs within single dendrites result in the enhancement of neuronal firing, enabling simple computations such as feature detection. Recent reports have shown that sublinear summation is also a prominent dendritic operation, extending the range of subthreshold input-output (sI/O) transformations conferred by dendrites. Like supralinear operations, sublinear dendritic operations also increase the repertoire of neuronal computations, but feature extraction requires different synaptic connectivity strategies for each of these operations. In this article we will review the experimental and theoretical findings describing the biophysical determinants of the three primary classes of dendritic operations: linear, sublinear, and supralinear. We then review a Boolean algebra-based analysis of simplified neuron models, which provides insight into how dendritic operations influence neuronal computations. We highlight how neuronal computations are critically dependent on the interplay of dendritic properties (morphology and voltage-gated channel expression), spiking threshold and distribution of synaptic inputs carrying particular sensory features. Finally, we describe how global (scattered) and local (clustered) integration strategies permit the implementation of similar classes of computations, one example being the object feature binding problem.
Collapse
Affiliation(s)
- Alexandra Tran-Van-Minh
- Unit of Dynamic Neuronal Imaging, Department of Neuroscience, CNRS UMR 3571, Institut Pasteur Paris, France
| | - Romain D Cazé
- Group for Neural Theory, LNC INSERM U960, Institut d'Etude de la Cognition de l'Ecole normale supérieure, Ecole normale supérieure Paris, France ; Department of Bioengineering, Imperial College London London, UK
| | - Therése Abrahamsson
- Unit of Dynamic Neuronal Imaging, Department of Neuroscience, CNRS UMR 3571, Institut Pasteur Paris, France ; Center for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital Montreal, QC, Canada
| | - Laurence Cathala
- Sorbonne Universités, UPMC Univ Paris 6, UMR 8256 B2A, Team Brain Development, Repair and Aging Paris, France
| | - Boris S Gutkin
- Group for Neural Theory, LNC INSERM U960, Institut d'Etude de la Cognition de l'Ecole normale supérieure, Ecole normale supérieure Paris, France ; Federal Research University Higher School of Economics Moscow, Russia
| | - David A DiGregorio
- Unit of Dynamic Neuronal Imaging, Department of Neuroscience, CNRS UMR 3571, Institut Pasteur Paris, France
| |
Collapse
|
30
|
Ujfalussy BB, Makara JK, Branco T, Lengyel M. Dendritic nonlinearities are tuned for efficient spike-based computations in cortical circuits. eLife 2015; 4:e10056. [PMID: 26705334 PMCID: PMC4912838 DOI: 10.7554/elife.10056] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 12/23/2015] [Indexed: 01/27/2023] Open
Abstract
Cortical neurons integrate thousands of synaptic inputs in their dendrites in highly nonlinear ways. It is unknown how these dendritic nonlinearities in individual cells contribute to computations at the level of neural circuits. Here, we show that dendritic nonlinearities are critical for the efficient integration of synaptic inputs in circuits performing analog computations with spiking neurons. We developed a theory that formalizes how a neuron's dendritic nonlinearity that is optimal for integrating synaptic inputs depends on the statistics of its presynaptic activity patterns. Based on their in vivo preynaptic population statistics (firing rates, membrane potential fluctuations, and correlations due to ensemble dynamics), our theory accurately predicted the responses of two different types of cortical pyramidal cells to patterned stimulation by two-photon glutamate uncaging. These results reveal a new computational principle underlying dendritic integration in cortical neurons by suggesting a functional link between cellular and systems--level properties of cortical circuits.
Collapse
Affiliation(s)
- Balázs B Ujfalussy
- Computational and Biological Learning Lab, Department of Engineering, University of Cambridge, Cambridge, United Kingdom,Wigner Research Centre for Physics, Hungarian Academy of Sciences, Budapest, Hungary,MRC Laboratory of Molecular Biology, Cambridge, United Kingdom,Lendület Laboratory of Neuronal Signaling, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary,
| | - Judit K Makara
- Lendület Laboratory of Neuronal Signaling, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary,Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Tiago Branco
- MRC Laboratory of Molecular Biology, Cambridge, United Kingdom,Wolfson Institute for Biomedical Research, University College London, London, United Kingdom
| | - Máté Lengyel
- Computational and Biological Learning Lab, Department of Engineering, University of Cambridge, Cambridge, United Kingdom,Department of Cognitive Science, Central European University, Budapest, Hungary
| |
Collapse
|
31
|
Amatrudo JM, Olson JP, Agarwal HK, Ellis-Davies GCR. Caged compounds for multichromic optical interrogation of neural systems. Eur J Neurosci 2014; 41:5-16. [PMID: 25471355 DOI: 10.1111/ejn.12785] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 10/06/2014] [Accepted: 10/13/2014] [Indexed: 01/16/2023]
Abstract
Caged compounds are widely used by neurophysiologists to study many aspects of cellular signaling in glia and neurons. Biologically inert before irradiation, they can be loaded into cells via patch pipette or topically applied in situ to a defined concentration; photolysis releases the caged compound in a very rapid and spatially defined way. As caged compounds are exogenous optical probes, they include not only natural products such neurotransmitters, calcium and IP3 but non-natural products such as fluorophores, drugs and antibodies. In this Technical Spotlight we provide a short introduction to the uncaging technique by discussing the nitroaromatic caging chromophores most widely used in such experiments [e.g. α-carboxy-ortho-nitrobenyl (CNB), dimethoxynitrobenzyl (DMNB), 4-methoxy-7-nitroindolinyl (MNI) and 4-carboxymethoxy-7-nitroindolinyl (CDNI)]. We show that recently developed caging chromophores [rutheniumbipyridial (RuBi) and 7-diethylaminocoumarin (DEAC)450] that are photolyzed with blue light (~ 430-480 nm range) can be combined with traditional nitroaromatic caged compounds to enable two-color optical probing of neuronal function. For example, one-photon uncaging of either RuBi-GABA or DEAC450-GABA with a 473-nm laser is facile, and can block nonlinear currents (dendritic spikes or action potentials) evoked by two-photon uncaging of CDNI-Glu at 720 nm. We also show that two-photon uncaging of DEAC450-Glu and CDNI-GABA at 900 and 720 nm, respectively, can be used to fire and block action potentials. Our experiments illustrate that recently developed chromophores have taken uncaging out of the 'monochrome era', in which it has existed since 1978, so as to enable multichromic interrogation of neuronal function with single-synapse precision.
Collapse
Affiliation(s)
- Joseph M Amatrudo
- Department of Neuroscience, Mount Sinai School of Medicine, New York, NY, 10029, USA
| | | | | | | |
Collapse
|
32
|
Oikonomou KD, Singh MB, Sterjanaj EV, Antic SD. Spiny neurons of amygdala, striatum, and cortex use dendritic plateau potentials to detect network UP states. Front Cell Neurosci 2014; 8:292. [PMID: 25278841 PMCID: PMC4166350 DOI: 10.3389/fncel.2014.00292] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Accepted: 09/01/2014] [Indexed: 11/25/2022] Open
Abstract
Spiny neurons of amygdala, striatum, and cerebral cortex share four interesting features: (1) they are the most abundant cell type within their respective brain area, (2) covered by thousands of thorny protrusions (dendritic spines), (3) possess high levels of dendritic NMDA conductances, and (4) experience sustained somatic depolarizations in vivo and in vitro (UP states). In all spiny neurons of the forebrain, adequate glutamatergic inputs generate dendritic plateau potentials (“dendritic UP states”) characterized by (i) fast rise, (ii) plateau phase lasting several hundred milliseconds, and (iii) abrupt decline at the end of the plateau phase. The dendritic plateau potential propagates toward the cell body decrementally to induce a long-lasting (longer than 100 ms, most often 200–800 ms) steady depolarization (∼20 mV amplitude), which resembles a neuronal UP state. Based on voltage-sensitive dye imaging, the plateau depolarization in the soma is precisely time-locked to the regenerative plateau potential taking place in the dendrite. The somatic plateau rises after the onset of the dendritic voltage transient and collapses with the breakdown of the dendritic plateau depolarization. We hypothesize that neuronal UP states in vivo reflect the occurrence of dendritic plateau potentials (dendritic UP states). We propose that the somatic voltage waveform during a neuronal UP state is determined by dendritic plateau potentials. A mammalian spiny neuron uses dendritic plateau potentials to detect and transform coherent network activity into a ubiquitous neuronal UP state. The biophysical properties of dendritic plateau potentials allow neurons to quickly attune to the ongoing network activity, as well as secure the stable amplitudes of successive UP states.
Collapse
Affiliation(s)
- Katerina D Oikonomou
- Department of Neuroscience, University of Connecticut Health Center Farmington, CT, USA
| | - Mandakini B Singh
- Department of Neuroscience, University of Connecticut Health Center Farmington, CT, USA
| | - Enas V Sterjanaj
- Department of Neuroscience, University of Connecticut Health Center Farmington, CT, USA
| | - Srdjan D Antic
- Department of Neuroscience, University of Connecticut Health Center Farmington, CT, USA
| |
Collapse
|
33
|
Grein S, Stepniewski M, Reiter S, Knodel MM, Queisser G. 1D-3D hybrid modeling-from multi-compartment models to full resolution models in space and time. Front Neuroinform 2014; 8:68. [PMID: 25120463 PMCID: PMC4114301 DOI: 10.3389/fninf.2014.00068] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Accepted: 06/28/2014] [Indexed: 12/03/2022] Open
Abstract
Investigation of cellular and network dynamics in the brain by means of modeling and simulation has evolved into a highly interdisciplinary field, that uses sophisticated modeling and simulation approaches to understand distinct areas of brain function. Depending on the underlying complexity, these models vary in their level of detail, in order to cope with the attached computational cost. Hence for large network simulations, single neurons are typically reduced to time-dependent signal processors, dismissing the spatial aspect of each cell. For single cell or networks with relatively small numbers of neurons, general purpose simulators allow for space and time-dependent simulations of electrical signal processing, based on the cable equation theory. An emerging field in Computational Neuroscience encompasses a new level of detail by incorporating the full three-dimensional morphology of cells and organelles into three-dimensional, space and time-dependent, simulations. While every approach has its advantages and limitations, such as computational cost, integrated and methods-spanning simulation approaches, depending on the network size could establish new ways to investigate the brain. In this paper we present a hybrid simulation approach, that makes use of reduced 1D-models using e.g., the NEURON simulator—which couples to fully resolved models for simulating cellular and sub-cellular dynamics, including the detailed three-dimensional morphology of neurons and organelles. In order to couple 1D- and 3D-simulations, we present a geometry-, membrane potential- and intracellular concentration mapping framework, with which graph- based morphologies, e.g., in the swc- or hoc-format, are mapped to full surface and volume representations of the neuron and computational data from 1D-simulations can be used as boundary conditions for full 3D simulations and vice versa. Thus, established models and data, based on general purpose 1D-simulators, can be directly coupled to the emerging field of fully resolved, highly detailed 3D-modeling approaches. We present the developed general framework for 1D/3D hybrid modeling and apply it to investigate electrically active neurons and their intracellular spatio-temporal calcium dynamics.
Collapse
Affiliation(s)
- Stephan Grein
- Computational Neuroscience, Goethe Center for Scientific Computing, Computer Science and Mathematics, Goethe University Frankfurt am Main, Germany
| | - Martin Stepniewski
- Computational Neuroscience, Goethe Center for Scientific Computing, Computer Science and Mathematics, Goethe University Frankfurt am Main, Germany
| | - Sebastian Reiter
- Simulation and Modelling, Goethe Center for Scientific Computing, Computer Science and Mathematics, Goethe University Frankfurt am Main, Germany
| | - Markus M Knodel
- Simulation and Modelling, Goethe Center for Scientific Computing, Computer Science and Mathematics, Goethe University Frankfurt am Main, Germany
| | - Gillian Queisser
- Computational Neuroscience, Goethe Center for Scientific Computing, Computer Science and Mathematics, Goethe University Frankfurt am Main, Germany
| |
Collapse
|
34
|
Kerekes BP, Tóth K, Kaszás A, Chiovini B, Szadai Z, Szalay G, Pálfi D, Bagó A, Spitzer K, Rózsa B, Ulbert I, Wittner L. Combined two-photon imaging, electrophysiological, and anatomical investigation of the human neocortex in vitro. NEUROPHOTONICS 2014; 1:011013. [PMID: 26157969 PMCID: PMC4478968 DOI: 10.1117/1.nph.1.1.011013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 08/19/2014] [Accepted: 08/20/2014] [Indexed: 05/06/2023]
Abstract
Spontaneous synchronous population activity (SPA) can be detected by electrophysiological methods in cortical slices of epileptic patients, maintained in a physiological medium in vitro. In order to gain additional spatial information about the network mechanisms involved in the SPA generation, we combined electrophysiological studies with two-photon imaging. Neocortical slices prepared from postoperative tissue of epileptic and tumor patients were maintained in a dual perfusion chamber in a physiological incubation medium. SPA was recorded with a 24-channel extracellular linear microelectrode covering all neocortical layers. After identifying the electrophysiologically active regions of the slice, bolus loading of neuronal and glial markers was applied on the tissue. SPA-related [Formula: see text] transients were detected in a large population of neighboring neurons with two-photon microscopy, simultaneous with extracellular SPA and intracellular whole-cell patch-clamp recordings. The intracellularly recorded cells were filled for subsequent anatomy. The cells were reconstructed in three dimensions and examined with light- and transmission electron microscopy. Combining high spatial resolution two-photon [Formula: see text] imaging techniques and high temporal resolution extra- and intracellular electrophysiology with cellular anatomy may permit a deeper understanding of the structural and functional properties of the human neocortex.
Collapse
Affiliation(s)
- Bálint Péter Kerekes
- Pázmány Péter Catholic University, Faculty of Information Technology and Bionics, H-1083 Budapest, Práter utca 50/a, Hungary
- Research Centre for Natural Sciences, Hungarian Academy of Sciences, Institute of Cognitive Neuroscience and Psychology, Budapest, Hungary
| | - Kinga Tóth
- Research Centre for Natural Sciences, Hungarian Academy of Sciences, Institute of Cognitive Neuroscience and Psychology, Budapest, Hungary
| | - Attila Kaszás
- Pázmány Péter Catholic University, Faculty of Information Technology and Bionics, H-1083 Budapest, Práter utca 50/a, Hungary
- Two-Photon Imaging Center, Hungarian Academy of Sciences, Institute of Experimental Medicine, Budapest, Hungary
| | - Balázs Chiovini
- Pázmány Péter Catholic University, Faculty of Information Technology and Bionics, H-1083 Budapest, Práter utca 50/a, Hungary
- Two-Photon Imaging Center, Hungarian Academy of Sciences, Institute of Experimental Medicine, Budapest, Hungary
| | - Zoltán Szadai
- Pázmány Péter Catholic University, Faculty of Information Technology and Bionics, H-1083 Budapest, Práter utca 50/a, Hungary
- Two-Photon Imaging Center, Hungarian Academy of Sciences, Institute of Experimental Medicine, Budapest, Hungary
| | - Gergely Szalay
- Two-Photon Imaging Center, Hungarian Academy of Sciences, Institute of Experimental Medicine, Budapest, Hungary
| | - Dénes Pálfi
- Pázmány Péter Catholic University, Faculty of Information Technology and Bionics, H-1083 Budapest, Práter utca 50/a, Hungary
- Two-Photon Imaging Center, Hungarian Academy of Sciences, Institute of Experimental Medicine, Budapest, Hungary
| | - Attila Bagó
- National Institute of Clinical Neuroscience, Department of Neurooncology, Budapest, Hungary
| | - Klaudia Spitzer
- Two-Photon Imaging Center, Hungarian Academy of Sciences, Institute of Experimental Medicine, Budapest, Hungary
| | - Balázs Rózsa
- Pázmány Péter Catholic University, Faculty of Information Technology and Bionics, H-1083 Budapest, Práter utca 50/a, Hungary
- Two-Photon Imaging Center, Hungarian Academy of Sciences, Institute of Experimental Medicine, Budapest, Hungary
| | - István Ulbert
- Pázmány Péter Catholic University, Faculty of Information Technology and Bionics, H-1083 Budapest, Práter utca 50/a, Hungary
- Research Centre for Natural Sciences, Hungarian Academy of Sciences, Institute of Cognitive Neuroscience and Psychology, Budapest, Hungary
- Address all correspondence to: István Ulbert, E-mail:
| | - Lucia Wittner
- Research Centre for Natural Sciences, Hungarian Academy of Sciences, Institute of Cognitive Neuroscience and Psychology, Budapest, Hungary
- National Institute of Clinical Neuroscience, Department of Neurooncology, Budapest, Hungary
| |
Collapse
|
35
|
Dendritic calcium nonlinearities switch the direction of synaptic plasticity in fast-spiking interneurons. J Neurosci 2014; 34:3864-77. [PMID: 24623765 DOI: 10.1523/jneurosci.2253-13.2014] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Postsynaptic calcium (Ca2+) nonlinearities allow neuronal coincidence detection and site-specific plasticity. Whether such events exist in dendrites of interneurons and play a role in regulation of synaptic efficacy remains unknown. Here, we used a combination of whole-cell patch-clamp recordings and two-photon Ca2+ imaging to reveal Ca2+ nonlinearities associated with synaptic integration in dendrites of mouse hippocampal CA1 fast-spiking interneurons. Local stimulation of distal dendritic branches within stratum oriens/alveus elicited fast Ca2+ transients, which showed a steep sigmoidal relationship to stimulus intensity. Supralinear Ca2+ events required Ca2+ entry through AMPA receptors with a subsequent Ca2+ release from internal stores. To investigate the functional significance of supralinear Ca2+ signals, we examined activity-dependent fluctuations in transmission efficacy triggered by Ca2+ signals of different amplitudes at excitatory synapses of interneurons. Subthreshold theta-burst stimulation (TBS) produced small amplitude postsynaptic Ca2+ transients and triggered long-term potentiation. In contrast, the suprathreshold TBS, which was associated with the generation of supralinear Ca2+ events, triggered long-term depression. Blocking group I/II metabotropic glutamate receptors (mGluRs) during suprathreshold TBS resulted in a slight reduction of supralinear Ca2+ events and induction of short-term depression. In contrast, blocking internal stores and supralinear Ca2+ signals during suprathreshold TBS switched the direction of plasticity from depression back to potentiation. These data reveal a novel type of supralinear Ca2+ events at synapses lacking the GluA2 AMPA subtype of glutamate receptors and demonstrate a general mechanism by which Ca2+ -permeable AMPA receptors, together with internal stores and mGluRs, control the direction of plasticity at interneuron excitatory synapses.
Collapse
|
36
|
Chiovini B, Turi G, Katona G, Kaszás A, Pálfi D, Maák P, Szalay G, Szabó M, Szabó G, Szadai Z, Káli S, Rózsa B. Dendritic Spikes Induce Ripples in Parvalbumin Interneurons during Hippocampal Sharp Waves. Neuron 2014; 82:908-24. [DOI: 10.1016/j.neuron.2014.04.004] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/18/2014] [Indexed: 12/21/2022]
|
37
|
Jadi MP, Behabadi BF, Poleg-Polsky A, Schiller J, Mel BW. An Augmented Two-Layer Model Captures Nonlinear Analog Spatial Integration Effects in Pyramidal Neuron Dendrites. PROCEEDINGS OF THE IEEE. INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS 2014; 102:1. [PMID: 25554708 PMCID: PMC4279447 DOI: 10.1109/jproc.2014.2312671] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
In pursuit of the goal to understand and eventually reproduce the diverse functions of the brain, a key challenge lies in reverse engineering the peculiar biology-based "technology" that underlies the brain's remarkable ability to process and store information. The basic building block of the nervous system is the nerve cell, or "neuron," yet after more than 100 years of neurophysiological study and 60 years of modeling, the information processing functions of individual neurons, and the parameters that allow them to engage in so many different types of computation (sensory, motor, mnemonic, executive, etc.) remain poorly understood. In this paper, we review both historical and recent findings that have led to our current understanding of the analog spatial processing capabilities of dendrites, the major input structures of neurons, with a focus on the principal cell type of the neocortex and hippocampus, the pyramidal neuron (PN). We encapsulate our current understanding of PN dendritic integration in an abstract layered model whose spatially sensitive branch-subunits compute multidimensional sigmoidal functions. Unlike the 1-D sigmoids found in conventional neural network models, multidimensional sigmoids allow the cell to implement a rich spectrum of nonlinear modulation effects directly within their dendritic trees.
Collapse
Affiliation(s)
- Monika P Jadi
- Computational Neurobiology Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037 USA
| | | | - Alon Poleg-Polsky
- Synaptic Physiology Section, National Institute of Neurobiological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892 USA
| | - Jackie Schiller
- Department of Physiology, Technion Medical School, Haifa 31096, Israel
| | - Bartlett W Mel
- Department of Biomedical Engineering and Neuroscience Graduate Program, University of Southern California, Los Angeles, CA 90089 USA
| |
Collapse
|
38
|
Mechanisms underlying subunit independence in pyramidal neuron dendrites. Proc Natl Acad Sci U S A 2013; 111:498-503. [PMID: 24357611 DOI: 10.1073/pnas.1217645111] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Pyramidal neuron (PN) dendrites compartmentalize voltage signals and can generate local spikes, which has led to the proposal that their dendrites act as independent computational subunits within a multilayered processing scheme. However, when a PN is strongly activated, back-propagating action potentials (bAPs) sweeping outward from the soma synchronize dendritic membrane potentials many times per second. How PN dendrites maintain the independence of their voltage-dependent computations, despite these repeated voltage resets, remains unknown. Using a detailed compartmental model of a layer 5 PN, and an improved method for quantifying subunit independence that incorporates a more accurate model of dendritic integration, we first established that the output of each dendrite can be almost perfectly predicted by the intensity and spatial configuration of its own synaptic inputs, and is nearly invariant to the rate of bAP-mediated "cross-talk" from other dendrites over a 100-fold range. Then, through an analysis of conductance, voltage, and current waveforms within the model cell, we identify three biophysical mechanisms that together help make independent dendritic computation possible in a firing neuron, suggesting that a major subtype of neocortical neuron has been optimized for layered, compartmentalized processing under in-vivo-like spiking conditions.
Collapse
|
39
|
Fernández-Alfonso T, Nadella KMNS, Iacaruso MF, Pichler B, Roš H, Kirkby PA, Silver RA. Monitoring synaptic and neuronal activity in 3D with synthetic and genetic indicators using a compact acousto-optic lens two-photon microscope. J Neurosci Methods 2013; 222:69-81. [PMID: 24200507 PMCID: PMC3889102 DOI: 10.1016/j.jneumeth.2013.10.021] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 10/22/2013] [Accepted: 10/26/2013] [Indexed: 11/15/2022]
Abstract
We expand the utility of acousto-optic lens (AOL) 3D 2P microscopy. We show rapid, simultaneous monitoring of synaptic inputs distributed in 3D. First use of genetically encoded indicators with AOL 3D functional imaging. Measurement of sensory-evoked neuronal population activity in 3D in vivo. Strategies for improving the measurement of the timing of neuronal signals.
Background Two-photon microscopy is widely used to study brain function, but conventional microscopes are too slow to capture the timing of neuronal signalling and imaging is restricted to one plane. Recent development of acousto-optic-deflector-based random access functional imaging has improved the temporal resolution, but the utility of these technologies for mapping 3D synaptic activity patterns and their performance at the excitation wavelengths required to image genetically encoded indicators have not been investigated. New method Here, we have used a compact acousto-optic lens (AOL) two-photon microscope to make high speed [Ca2+] measurements from spines and dendrites distributed in 3D with different excitation wavelengths (800–920 nm). Results We show simultaneous monitoring of activity from many synaptic inputs distributed over the 3D arborisation of a neuronal dendrite using both synthetic as well as genetically encoded indicators. We confirm the utility of AOL-based imaging for fast in vivo recordings by measuring, simultaneously, visually evoked responses in 100 neurons distributed over a 150 μm focal depth range. Moreover, we explore ways to improve the measurement of timing of neuronal activation by choosing specific regions within the cell soma. Comparison with existing methods These results establish that AOL-based 3D random access two-photon microscopy has a wider range of neuroscience applications than previously shown. Conclusions Our findings show that the compact AOL microscope design has the speed, spatial resolution, sensitivity and wavelength flexibility to measure 3D patterns of synaptic and neuronal activity on individual trials.
Collapse
Affiliation(s)
- Tomás Fernández-Alfonso
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK.
| | - K M Naga Srinivas Nadella
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK.
| | - M Florencia Iacaruso
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK.
| | - Bruno Pichler
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK.
| | - Hana Roš
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK.
| | - Paul A Kirkby
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK.
| | - R Angus Silver
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK.
| |
Collapse
|
40
|
Chen JL, Pfäffli OA, Voigt FF, Margolis DJ, Helmchen F. Online correction of licking-induced brain motion during two-photon imaging with a tunable lens. J Physiol 2013; 591:4689-98. [PMID: 23940380 DOI: 10.1113/jphysiol.2013.259804] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Two-photon calcium imaging in awake, head-fixed animals enables the measurement of neuronal activity during behaviour. Often, licking for the retrieval of water reward is used as a measurable report of the animal's decision during reward-driven behaviour. However, licking behaviour can induce severe motion artifacts that interfere with two-photon imaging of cellular activity. Here, we describe a simple method for the online correction of licking-induced focus shifts for two-photon calcium imaging of neocortical neurons in the head-fixed mouse. We found that licking causes a stereotyped drop of neocortical tissue, shifting neurons up to 20 μm out of focus. Based on the measurement of licking with a piezo film sensor, we developed a feedback model, which provides a corrective signal for fast optical focus adjustments with an electrically tunable lens. Using online correction with this feedback model, we demonstrate a reduction of licking-related focus changes below 3 μm, minimizing motion artifact contamination of cellular calcium signals. Focus correction with a tunable lens is a simple and effective method to improve the ability to monitor neuronal activity during reward-based behaviour.
Collapse
Affiliation(s)
- Jerry L Chen
- J. L. Chen: University of Zurich, Brain Research Institute, Winterthurerstrasse 190, 55H64, Zurich, CH-8057, Switzerland.
| | | | | | | | | |
Collapse
|
41
|
Chen TW, Wardill TJ, Sun Y, Pulver SR, Renninger SL, Baohan A, Schreiter ER, Kerr RA, Orger MB, Jayaraman V, Looger LL, Svoboda K, Kim DS. Ultrasensitive fluorescent proteins for imaging neuronal activity. Nature 2013; 499:295-300. [PMID: 23868258 PMCID: PMC3777791 DOI: 10.1038/nature12354] [Citation(s) in RCA: 4111] [Impact Index Per Article: 373.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Accepted: 06/04/2013] [Indexed: 12/15/2022]
Abstract
Fluorescent calcium sensors are widely used to image neural activity. Using structure-based mutagenesis and neuron-based screening, we developed a family of ultra-sensitive protein calcium sensors (GCaMP6) that outperformed other sensors in cultured neurons and in zebrafish, flies, and mice in vivo. In layer 2/3 pyramidal neurons of the mouse visual cortex, GCaMP6 reliably detected single action potentials in neuronal somata and orientation-tuned synaptic calcium transients in individual dendritic spines. The orientation tuning of structurally persistent spines was largely stable over timescales of weeks. Orientation tuning averaged across spine populations predicted the tuning of their parent cell. Although the somata of GABAergic neurons showed little orientation tuning, their dendrites included highly tuned dendritic segments (5 - 40 micrometers long). GCaMP6 sensors thus provide new windows into the organization and dynamics of neural circuits over multiple spatial and temporal scales.
Collapse
Affiliation(s)
- Tsai-Wen Chen
- Janelia Farm Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, Virginia 20147, USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Langer D, van 't Hoff M, Keller AJ, Nagaraja C, Pfäffli OA, Göldi M, Kasper H, Helmchen F. HelioScan: a software framework for controlling in vivo microscopy setups with high hardware flexibility, functional diversity and extendibility. J Neurosci Methods 2013; 215:38-52. [PMID: 23416135 DOI: 10.1016/j.jneumeth.2013.02.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Revised: 02/05/2013] [Accepted: 02/06/2013] [Indexed: 10/27/2022]
Abstract
Intravital microscopy such as in vivo imaging of brain dynamics is often performed with custom-built microscope setups controlled by custom-written software to meet specific requirements. Continuous technological advancement in the field has created a need for new control software that is flexible enough to support the biological researcher with innovative imaging techniques and provide the developer with a solid platform for quickly and easily implementing new extensions. Here, we introduce HelioScan, a software package written in LabVIEW, as a platform serving this dual role. HelioScan is designed as a collection of components that can be flexibly assembled into microscope control software tailored to the particular hardware and functionality requirements. Moreover, HelioScan provides a software framework, within which new functionality can be implemented in a quick and structured manner. A specific HelioScan application assembles at run-time from individual software components, based on user-definable configuration files. Due to its component-based architecture, HelioScan can exploit synergies of multiple developers working in parallel on different components in a community effort. We exemplify the capabilities and versatility of HelioScan by demonstrating several in vivo brain imaging modes, including camera-based intrinsic optical signal imaging for functional mapping of cortical areas, standard two-photon laser-scanning microscopy using galvanometric mirrors, and high-speed in vivo two-photon calcium imaging using either acousto-optic deflectors or a resonant scanner. We recommend HelioScan as a convenient software framework for the in vivo imaging community.
Collapse
Affiliation(s)
- Dominik Langer
- Brain Research Institute, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | | | | | | | | | | | | | | |
Collapse
|
43
|
Ellis-Davies GC. A chemist and biologist talk to each other about caged neurotransmitters. Beilstein J Org Chem 2013; 9:64-73. [PMID: 23399979 PMCID: PMC3566830 DOI: 10.3762/bjoc.9.8] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2012] [Accepted: 12/07/2012] [Indexed: 11/23/2022] Open
Abstract
Caged compounds are small organic molecules that can be photoactivated with brief pulses of light. They are widely used to study a great variety of biological processes by physiologists, cell biologists and neuroscientists. Initially made and invented by biologists in the late 1970s, they are now made mostly by chemists, often without any dialogue with the end users, the biologists. The idea for this review is to stimulate interaction between the two communities to further the creative development and application of these powerful optical probes.
Collapse
Affiliation(s)
- Graham Cr Ellis-Davies
- Department of Neuroscience, Mount Sinai School of Medicine, One Gustave Levy Place, New York, NY 10029, USA
| |
Collapse
|
44
|
Camiré O, Topolnik L. Functional compartmentalisation and regulation of postsynaptic Ca2+ transients in inhibitory interneurons. Cell Calcium 2012; 52:339-46. [DOI: 10.1016/j.ceca.2012.05.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Revised: 05/01/2012] [Accepted: 05/02/2012] [Indexed: 01/14/2023]
|
45
|
Budd JML, Kisvárday ZF. Communication and wiring in the cortical connectome. Front Neuroanat 2012; 6:42. [PMID: 23087619 PMCID: PMC3472565 DOI: 10.3389/fnana.2012.00042] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Accepted: 09/24/2012] [Indexed: 11/23/2022] Open
Abstract
In cerebral cortex, the huge mass of axonal wiring that carries information between near and distant neurons is thought to provide the neural substrate for cognitive and perceptual function. The goal of mapping the connectivity of cortical axons at different spatial scales, the cortical connectome, is to trace the paths of information flow in cerebral cortex. To appreciate the relationship between the connectome and cortical function, we need to discover the nature and purpose of the wiring principles underlying cortical connectivity. A popular explanation has been that axonal length is strictly minimized both within and between cortical regions. In contrast, we have hypothesized the existence of a multi-scale principle of cortical wiring where to optimize communication there is a trade-off between spatial (construction) and temporal (routing) costs. Here, using recent evidence concerning cortical spatial networks we critically evaluate this hypothesis at neuron, local circuit, and pathway scales. We report three main conclusions. First, the axonal and dendritic arbor morphology of single neocortical neurons may be governed by a similar wiring principle, one that balances the conservation of cellular material and conduction delay. Second, the same principle may be observed for fiber tracts connecting cortical regions. Third, the absence of sufficient local circuit data currently prohibits any meaningful assessment of the hypothesis at this scale of cortical organization. To avoid neglecting neuron and microcircuit levels of cortical organization, the connectome framework should incorporate more morphological description. In addition, structural analyses of temporal cost for cortical circuits should take account of both axonal conduction and neuronal integration delays, which appear mostly of the same order of magnitude. We conclude the hypothesized trade-off between spatial and temporal costs may potentially offer a powerful explanation for cortical wiring patterns.
Collapse
Affiliation(s)
- Julian M. L. Budd
- Department of Informatics, University of SussexFalmer, East Sussex, UK
| | - Zoltán F. Kisvárday
- Laboratory for Cortical Systems Neuroscience, Department of Anatomy, Histology and Embryology, University of DebrecenDebrecen, Hungary
| |
Collapse
|
46
|
Oikonomou KD, Short SM, Rich MT, Antic SD. Extrasynaptic glutamate receptor activation as cellular bases for dynamic range compression in pyramidal neurons. Front Physiol 2012; 3:334. [PMID: 22934081 PMCID: PMC3429100 DOI: 10.3389/fphys.2012.00334] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Accepted: 07/30/2012] [Indexed: 12/02/2022] Open
Abstract
Repetitive synaptic stimulation overcomes the ability of astrocytic processes to clear glutamate from the extracellular space, allowing some dendritic segments to become submerged in a pool of glutamate, for a brief period of time. This dynamic arrangement activates extrasynaptic NMDA receptors located on dendritic shafts. We used voltage-sensitive and calcium-sensitive dyes to probe dendritic function in this glutamate-rich location. An excess of glutamate in the extrasynaptic space was achieved either by repetitive synaptic stimulation or by glutamate iontophoresis onto the dendrites of pyramidal neurons. Two successive activations of synaptic inputs produced a typical NMDA spike, whereas five successive synaptic inputs produced characteristic plateau potentials, reminiscent of cortical UP states. While NMDA spikes were coupled with brief calcium transients highly restricted to the glutamate input site, the dendritic plateau potentials were accompanied by calcium influx along the entire dendritic branch. Once initiated, the glutamate-mediated dendritic plateau potentials could not be interrupted by negative voltage pulses. Activation of extrasynaptic NMDA receptors in cellular compartments void of spines is sufficient to initiate and support plateau potentials. The only requirement for sustained depolarizing events is a surplus of free glutamate near a group of extrasynaptic receptors. Highly non-linear dendritic spikes (plateau potentials) are summed in a highly sublinear fashion at the soma, revealing the cellular bases of signal compression in cortical circuits. Extrasynaptic NMDA receptors provide pyramidal neurons with a function analogous to a dynamic range compression in audio engineering. They limit or reduce the volume of “loud sounds” (i.e., strong glutamatergic inputs) and amplify “quiet sounds” (i.e., glutamatergic inputs that barely cross the dendritic threshold for local spike initiation). Our data also explain why consecutive cortical UP states have uniform amplitudes in a given neuron.
Collapse
Affiliation(s)
- Katerina D Oikonomou
- Department of Neuroscience, University of Connecticut Health Center Farmington, CT, USA
| | | | | | | |
Collapse
|
47
|
Duchemin S, Boily M, Sadekova N, Girouard H. The complex contribution of NOS interneurons in the physiology of cerebrovascular regulation. Front Neural Circuits 2012; 6:51. [PMID: 22907993 PMCID: PMC3414732 DOI: 10.3389/fncir.2012.00051] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Accepted: 07/19/2012] [Indexed: 12/23/2022] Open
Abstract
Following the discovery of the vasorelaxant properties of nitric oxide (NO) by Furchgott and Ignarro, the finding by Bredt and coll. of a constitutively expressed NO synthase in neurons (nNOS) led to the presumption that neuronal NO may control cerebrovascular functions. Consequently, numerous studies have sought to determine whether neuraly-derived NO is involved in the regulation of cerebral blood flow (CBF). Anatomically, axons, dendrites, or somata of NO neurons have been found to contact the basement membrane of blood vessels or perivascular astrocytes in all segments of the cortical microcirculation. Functionally, various experimental approaches support a role of neuronal NO in the maintenance of resting CBF as well as in the vascular response to neuronal activity. Since decades, it has been assumed that neuronal NO simply diffuses to the local blood vessels and produce vasodilation through a cGMP-PKG dependent mechanism. However, NO is not the sole mediator of vasodilation in the cerebral microcirculation and is known to interact with a myriad of signaling pathways also involved in vascular control. In addition, cerebrovascular regulation is the result of a complex orchestration between all components of the neurovascular unit (i.e., neuronal, glial, and vascular cells) also known to produce NO. In this review article, the role of NO interneuron in the regulation of cortical microcirculation will be discussed in the context of the neurovascular unit.
Collapse
Affiliation(s)
- Sonia Duchemin
- Department of Pharmacology, Université de Montréal Montreal, QC, Canada
| | | | | | | |
Collapse
|
48
|
Calcium-permeable AMPA receptors provide a common mechanism for LTP in glutamatergic synapses of distinct hippocampal interneuron types. J Neurosci 2012; 32:6511-6. [PMID: 22573673 DOI: 10.1523/jneurosci.0206-12.2012] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Glutamatergic synapses on some hippocampal GABAergic interneurons exhibit activity-induced long-term potentiation (LTP). Interneuron types within the CA1 area expressing mutually exclusive molecular markers differ in LTP responses. Potentiation that depends on calcium-permeable (CP) AMPA receptors has been characterized in oriens-lacunosum moleculare (O-LM) interneurons, which express parvalbumin and somatostatin (SM). However, it is unknown how widely CP-AMPAR-dependent plasticity is expressed among different GABAergic interneuron types. Here we examine synaptic plasticity in rat hippocampal O-LM cells and two other interneuron types expressing either nitric oxide synthase (NOS) or cholecystokinin (CCK), which are known to be physiologically and developmentally distinct. We report similar CP-AMPAR-dependent LTP in NOS-immunopositive ivy cells and SM-expressing O-LM cells to afferent fiber theta burst stimulation. The potentiation in both cell types is induced at postsynaptic membrane potentials below firing threshold, and induction is blocked by intense spiking simultaneously with afferent stimulation. The strong inward rectification and calcium permeability of AMPARs is explained by a low level of GluA2 subunit mRNA expression. LTP is not elicited in CCK-expressing Schaffer collateral-associated cells, which lack CP-AMPARs and express high levels of the GluA2 subunit. The results show that CP-AMPAR-mediated synaptic potentiation is common in hippocampal interneuron types and occurs in interneurons of both feedforward and feedback inhibitory pathways.
Collapse
|
49
|
Huang Y, Williams JC, Johnson SM. Brain slice on a chip: opportunities and challenges of applying microfluidic technology to intact tissues. LAB ON A CHIP 2012; 12:2103-2117. [PMID: 22534786 DOI: 10.1039/c2lc21142d] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Isolated brain tissue, especially brain slices, are valuable experimental tools for studying neuronal function at the network, cellular, synaptic, and single channel levels. Neuroscientists have refined the methods for preserving brain slice viability and function and converged on principles that strongly resemble the approach taken by engineers in developing microfluidic devices. With respect to brain slices, microfluidic technology may 1) overcome the traditional limitations of conventional interface and submerged slice chambers and improve oxygen/nutrient penetration into slices, 2) provide better spatiotemporal control over solution flow/drug delivery to specific slice regions, and 3) permit successful integration with modern optical and electrophysiological techniques. In this review, we highlight the unique advantages of microfluidic devices for in vitro brain slice research, describe recent advances in the integration of microfluidic devices with optical and electrophysiological instrumentation, and discuss clinical applications of microfluidic technology as applied to brain slices and other non-neuronal tissues. We hope that this review will serve as an interdisciplinary guide for both neuroscientists studying brain tissue in vitro and engineers as they further develop microfluidic chamber technology for neuroscience research.
Collapse
Affiliation(s)
- Yu Huang
- University of Wisconsin-Madison, Department of Biomedical Engineering, Madison, WI 53706, USA
| | | | | |
Collapse
|
50
|
Jadi M, Polsky A, Schiller J, Mel BW. Location-dependent effects of inhibition on local spiking in pyramidal neuron dendrites. PLoS Comput Biol 2012; 8:e1002550. [PMID: 22719240 PMCID: PMC3375251 DOI: 10.1371/journal.pcbi.1002550] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Accepted: 04/24/2012] [Indexed: 11/18/2022] Open
Abstract
Cortical computations are critically dependent on interactions between pyramidal neurons (PNs) and a menagerie of inhibitory interneuron types. A key feature distinguishing interneuron types is the spatial distribution of their synaptic contacts onto PNs, but the location-dependent effects of inhibition are mostly unknown, especially under conditions involving active dendritic responses. We studied the effect of somatic vs. dendritic inhibition on local spike generation in basal dendrites of layer 5 PNs both in neocortical slices and in simple and detailed compartmental models, with equivalent results: somatic inhibition divisively suppressed the amplitude of dendritic spikes recorded at the soma while minimally affecting dendritic spike thresholds. In contrast, distal dendritic inhibition raised dendritic spike thresholds while minimally affecting their amplitudes. On-the-path dendritic inhibition modulated both the gain and threshold of dendritic spikes depending on its distance from the spike initiation zone. Our findings suggest that cortical circuits could assign different mixtures of gain vs. threshold inhibition to different neural pathways, and thus tailor their local computations, by managing their relative activation of soma- vs. dendrite-targeting interneurons.
Collapse
Affiliation(s)
- Monika Jadi
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, United States of America.
| | | | | | | |
Collapse
|