1
|
Ding C, Yang D, Feldmeyer D. Adenosinergic Modulation of Layer 6 Microcircuitry in the Medial Prefrontal Cortex Is Specific to Presynaptic Cell Type. J Neurosci 2024; 44:e1606232023. [PMID: 38429106 PMCID: PMC11007316 DOI: 10.1523/jneurosci.1606-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 12/12/2023] [Accepted: 12/13/2023] [Indexed: 03/03/2024] Open
Abstract
Adenosinergic modulation in the PFC is recognized for its involvement in various behavioral aspects including sleep homoeostasis, decision-making, spatial working memory and anxiety. While the principal cells of layer 6 (L6) exhibit a significant morphological diversity, the detailed cell-specific regulatory mechanisms of adenosine in L6 remain unexplored. Here, we quantitatively analyzed the morphological and electrophysiological parameters of L6 neurons in the rat medial prefrontal cortex (mPFC) using whole-cell recordings combined with morphological reconstructions. We were able to identify two different morphological categories of excitatory neurons in the mPFC of both juvenile and young adult rats with both sexes. These categories were characterized by a leading dendrite that was oriented either upright (toward the pial surface) or inverted (toward the white matter). These two excitatory neuron subtypes exhibited different electrophysiological and synaptic properties. Adenosine at a concentration of 30 µM indiscriminately suppressed connections with either an upright or an inverted presynaptic excitatory neuron. However, using lower concentrations of adenosine (10 µM) revealed that synapses originating from L6 upright neurons have a higher sensitivity to adenosine-induced inhibition of synaptic release. Adenosine receptor activation causes a reduction in the probability of presynaptic neurotransmitter release that could be abolished by specifically blocking A1 adenosine receptors (A1ARs) using 8-cyclopentyltheophylline (CPT). Our results demonstrate a differential expression level of A1ARs at presynaptic sites of two functionally and morphologically distinct subpopulations of L6 principal neurons, suggesting the intricate functional role of adenosine in neuronal signaling in the brain.
Collapse
Affiliation(s)
- Chao Ding
- Research Center Juelich, Institute of Neuroscience and Medicine 10, Research Center Juelich, Juelich 52425, Germany
| | - Danqing Yang
- Research Center Juelich, Institute of Neuroscience and Medicine 10, Research Center Juelich, Juelich 52425, Germany
- Department of Psychiatry, Psychotherapy, and Psychosomatics, RWTH Aachen University Hospital, Aachen 52074, Germany
| | - Dirk Feldmeyer
- Research Center Juelich, Institute of Neuroscience and Medicine 10, Research Center Juelich, Juelich 52425, Germany
- Department of Psychiatry, Psychotherapy, and Psychosomatics, RWTH Aachen University Hospital, Aachen 52074, Germany
- Jülich-Aachen Research Alliance, Translational Brain Medicine (JARA Brain), Aachen 52074, Germany
| |
Collapse
|
2
|
Abstract
Cortical layer 6b is considered by many to be a remnant of the subplate that forms during early stages of neocortical development, but its role in the adult is not well understood. Its neuronal complement has only recently become the subject of systematic studies, and its axonal projections and synaptic input structures have remained largely unexplored despite decades of research into neocortical function. In recent years, however, layer 6b (L6b) has attracted increasing attention and its functional role is beginning to be elucidated. In this review, I will attempt to provide an overview of what is currently known about the excitatory and inhibitory neurons in this layer, their pre- and postsynaptic connectivity, and their functional implications. Similarities and differences between different cortical areas will be highlighted. Finally, layer 6b neurons are highly responsive to several neuropeptides such as orexin/hypocretin, neurotensin and cholecystokinin, in some cases exclusively. They are also strongly controlled by neurotransmitters such as acetylcholine and norepinephrine. The interaction of these neuromodulators with L6b microcircuitry and its functional consequences will also be discussed.
Collapse
Affiliation(s)
- Dirk Feldmeyer
- Research Centre Jülich, Institute of Neuroscience and Medicine 10 (INM-10), Jülich, Germany
- Department of Psychiatry, Psychotherapy, and Psychosomatics, RWTH Aachen University Hospital, Aachen, Germany
- Jülich-Aachen Research Alliance, Translational Brain Medicine (JARA Brain), Aachen, Germany
| |
Collapse
|
3
|
de Kock CPJ, Feldmeyer D. Shared and divergent principles of synaptic transmission between cortical excitatory neurons in rodent and human brain. Front Synaptic Neurosci 2023; 15:1274383. [PMID: 37731775 PMCID: PMC10508294 DOI: 10.3389/fnsyn.2023.1274383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 08/21/2023] [Indexed: 09/22/2023] Open
Abstract
Information transfer between principal neurons in neocortex occurs through (glutamatergic) synaptic transmission. In this focussed review, we provide a detailed overview on the strength of synaptic neurotransmission between pairs of excitatory neurons in human and laboratory animals with a specific focus on data obtained using patch clamp electrophysiology. We reach two major conclusions: (1) the synaptic strength, measured as unitary excitatory postsynaptic potential (or uEPSP), is remarkably consistent across species, cortical regions, layers and/or cell-types (median 0.5 mV, interquartile range 0.4-1.0 mV) with most variability associated with the cell-type specific connection studied (min 0.1-max 1.4 mV), (2) synaptic function cannot be generalized across human and rodent, which we exemplify by discussing the differences in anatomical and functional properties of pyramidal-to-pyramidal connections within human and rodent cortical layers 2 and 3. With only a handful of studies available on synaptic transmission in human, it is obvious that much remains unknown to date. Uncovering the shared and divergent principles of synaptic transmission across species however, will almost certainly be a pivotal step toward understanding human cognitive ability and brain function in health and disease.
Collapse
Affiliation(s)
- Christiaan P. J. de Kock
- Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Dirk Feldmeyer
- Research Center Juelich, Institute of Neuroscience and Medicine, Jülich, Germany
- Department of Psychiatry, Psychotherapy, and Psychosomatics, RWTH Aachen University Hospital, Aachen, Germany
- Jülich-Aachen Research Alliance, Translational Brain Medicine (JARA Brain), Aachen, Germany
| |
Collapse
|
4
|
Qi G, Feldmeyer D. Cell-Type Specific Neuromodulation of Excitatory and Inhibitory Neurons via Muscarinic Acetylcholine Receptors in Layer 4 of Rat Barrel Cortex. Front Neural Circuits 2022; 16:843025. [PMID: 35250496 PMCID: PMC8894850 DOI: 10.3389/fncir.2022.843025] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 01/27/2022] [Indexed: 11/25/2022] Open
Abstract
The neuromodulator acetylcholine (ACh) plays an important role in arousal, attention, vigilance, learning and memory. ACh is released during different behavioural states and affects the brain microcircuit by regulating neuronal and synaptic properties. Here, we investigated how a low concentration of ACh (30 μM) affects the intrinsic properties of electrophysiologically and morphologically identified excitatory and inhibitory neurons in layer 4 (L4) of rat barrel cortex. ACh altered the membrane potential of L4 neurons in a heterogeneous manner. Nearly all L4 regular spiking (RS) excitatory neurons responded to bath-application of ACh with a M4 muscarinic ACh receptor-mediated hyperpolarisation. In contrast, in the majority of L4 fast spiking (FS) and non-fast spiking (nFS) interneurons 30 μM ACh induced a depolarisation while the remainder showed a hyperpolarisation or no response. The ACh-induced depolarisation of L4 FS interneurons was much weaker than that in L4 nFS interneurons. There was no clear difference in the response to ACh for three morphological subtypes of L4 FS interneurons. However, in four morpho-electrophysiological subtypes of L4 nFS interneurons, VIP+-like interneurons showed the strongest ACh-induced depolarisation; occasionally, even action potential firing was elicited. The ACh-induced depolarisation in L4 FS interneurons was exclusively mediated by M1 muscarinic ACh receptors; in L4 nFS interneurons it was mainly mediated by M1 and/or M3/5 muscarinic ACh receptors. In a subset of L4 nFS interneurons, a co-operative activation of muscarinic and nicotinic ACh receptors was also observed. The present study demonstrates that low-concentrations of ACh affect different L4 neuron types in a cell-type specific way. These effects result from a specific expression of different muscarinic and/or nicotinic ACh receptors on the somatodendritic compartments of L4 neurons. This suggests that even at low concentrations ACh may tune the excitability of L4 excitatory and inhibitory neurons and their synaptic microcircuits differentially depending on the behavioural state during which ACh is released.
Collapse
Affiliation(s)
- Guanxiao Qi
- Institute of Neuroscience and Medicine, INM-10, Reseach Centre Jülich, Jülich, Germany
- *Correspondence: Guanxiao Qi,
| | - Dirk Feldmeyer
- Institute of Neuroscience and Medicine, INM-10, Reseach Centre Jülich, Jülich, Germany
- Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Aachen, Germany
- Jülich-Aachen Research Alliance-Brain, Translational Brain Medicine, Aachen, Germany
- Dirk Feldmeyer,
| |
Collapse
|
5
|
Yang D, Qi G, Ding C, Feldmeyer D. Layer 6A Pyramidal Cell Subtypes Form Synaptic Microcircuits with Distinct Functional and Structural Properties. Cereb Cortex 2021; 32:2095-2111. [PMID: 34628499 PMCID: PMC9113278 DOI: 10.1093/cercor/bhab340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 08/03/2021] [Accepted: 08/25/2021] [Indexed: 11/27/2022] Open
Abstract
Neocortical layer 6 plays a crucial role in sensorimotor co-ordination and integration through functionally segregated circuits linking intracortical and subcortical areas. We performed whole-cell recordings combined with morphological reconstructions to identify morpho-electric types of layer 6A pyramidal cells (PCs) in rat barrel cortex. Cortico-thalamic (CT), cortico-cortical (CC), and cortico-claustral (CCla) PCs were classified based on their distinct morphologies and have been shown to exhibit different electrophysiological properties. We demonstrate that these three types of layer 6A PCs innervate neighboring excitatory neurons with distinct synaptic properties: CT PCs establish weak facilitating synapses onto other L6A PCs; CC PCs form synapses of moderate efficacy, while synapses made by putative CCla PCs display the highest release probability and a marked short-term depression. For excitatory-inhibitory synaptic connections in layer 6, both the presynaptic PC type and the postsynaptic interneuron type govern the dynamic properties of the respective synaptic connections. We have identified a functional division of local layer 6A excitatory microcircuits which may be responsible for the differential temporal engagement of layer 6 feed-forward and feedback networks. Our results provide a basis for further investigations on the long-range CC, CT, and CCla pathways.
Collapse
Affiliation(s)
- Danqing Yang
- Research Center Juelich, Institute of Neuroscience and Medicine 10, 52425 Juelich, Germany
| | - Guanxiao Qi
- Research Center Juelich, Institute of Neuroscience and Medicine 10, 52425 Juelich, Germany
| | - Chao Ding
- Research Center Juelich, Institute of Neuroscience and Medicine 10, 52425 Juelich, Germany
| | - Dirk Feldmeyer
- Research Center Juelich, Institute of Neuroscience and Medicine 10, 52425 Juelich, Germany.,RWTH Aachen University Hospital, Dept of Psychiatry, Psychotherapy, and Psychosomatics, 52074 Aachen, Germany.,Jülich-Aachen Research Alliance, Translational Brain Medicine (JARA Brain), Aachen, Germany
| |
Collapse
|
6
|
Barz CS, Garderes PM, Ganea DA, Reischauer S, Feldmeyer D, Haiss F. Functional and Structural Properties of Highly Responsive Somatosensory Neurons in Mouse Barrel Cortex. Cereb Cortex 2021; 31:4533-4553. [PMID: 33963394 PMCID: PMC8408454 DOI: 10.1093/cercor/bhab104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 03/12/2021] [Accepted: 03/24/2021] [Indexed: 11/14/2022] Open
Abstract
Sparse population activity is a well-known feature of supragranular sensory neurons in neocortex. The mechanisms underlying sparseness are not well understood because a direct link between the neurons activated in vivo, and their cellular properties investigated in vitro has been missing. We used two-photon calcium imaging to identify a subset of neurons in layer L2/3 (L2/3) of mouse primary somatosensory cortex that are highly active following principal whisker vibrotactile stimulation. These high responders (HRs) were then tagged using photoconvertible green fluorescent protein for subsequent targeting in the brain slice using intracellular patch-clamp recordings and biocytin staining. This approach allowed us to investigate the structural and functional properties of HRs that distinguish them from less active control cells. Compared to less responsive L2/3 neurons, HRs displayed increased levels of stimulus-evoked and spontaneous activity, elevated noise and spontaneous pairwise correlations, and stronger coupling to the population response. Intrinsic excitability was reduced in HRs, while we found no evidence for differences in other electrophysiological and morphological parameters. Thus, the choice of which neurons participate in stimulus encoding may be determined largely by network connectivity rather than by cellular structure and function.
Collapse
Affiliation(s)
- C S Barz
- Institute of Neuroscience and Medicine, INM-10, Research Centre Jülich, 52425 Jülich, Germany.,Department of Psychiatry, Psychotherapy and Psychosomatics, Medical School, RWTH Aachen University, 52074 Aachen, Germany.,Jülich-Aachen Research Alliance - Translational Brain Medicine, 52074 Aachen, Germany.,IZKF Aachen, Medical School, RWTH Aachen University, 52074 Aachen, Germany
| | - P M Garderes
- IZKF Aachen, Medical School, RWTH Aachen University, 52074 Aachen, Germany.,Department of Neuropathology, Medical School, RWTH Aachen University, 52074 Aachen, Germany.,Department of Ophthalmology, Medical School, RWTH Aachen University, 52074 Aachen, Germany.,Unit of Neural Circuits Dynamics and Decision Making, Institut Pasteur, 75015 Paris, France
| | - D A Ganea
- IZKF Aachen, Medical School, RWTH Aachen University, 52074 Aachen, Germany.,Department of Neuropathology, Medical School, RWTH Aachen University, 52074 Aachen, Germany.,Department of Ophthalmology, Medical School, RWTH Aachen University, 52074 Aachen, Germany.,Biomedical Department, University of Basel, 4056 Basel, Switzerland
| | - S Reischauer
- Medical Clinic I, (Cardiology/Angiology) and Campus Kerckhoff, Justus-Liebig-University Giessen, 35390 Giessen Germany.,Department of Developmental Genetics, Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany.,Cardio-Pulmonary Institute (CPI), 35392 Giessen, Germany
| | - D Feldmeyer
- Institute of Neuroscience and Medicine, INM-10, Research Centre Jülich, 52425 Jülich, Germany.,Department of Psychiatry, Psychotherapy and Psychosomatics, Medical School, RWTH Aachen University, 52074 Aachen, Germany.,Jülich-Aachen Research Alliance - Translational Brain Medicine, 52074 Aachen, Germany
| | - F Haiss
- IZKF Aachen, Medical School, RWTH Aachen University, 52074 Aachen, Germany.,Department of Neuropathology, Medical School, RWTH Aachen University, 52074 Aachen, Germany.,Department of Ophthalmology, Medical School, RWTH Aachen University, 52074 Aachen, Germany.,Unit of Neural Circuits Dynamics and Decision Making, Institut Pasteur, 75015 Paris, France
| |
Collapse
|
7
|
Yuste R, Hawrylycz M, Aalling N, Aguilar-Valles A, Arendt D, Armañanzas R, Ascoli GA, Bielza C, Bokharaie V, Bergmann TB, Bystron I, Capogna M, Chang Y, Clemens A, de Kock CPJ, DeFelipe J, Dos Santos SE, Dunville K, Feldmeyer D, Fiáth R, Fishell GJ, Foggetti A, Gao X, Ghaderi P, Goriounova NA, Güntürkün O, Hagihara K, Hall VJ, Helmstaedter M, Herculano-Houzel S, Hilscher MM, Hirase H, Hjerling-Leffler J, Hodge R, Huang J, Huda R, Khodosevich K, Kiehn O, Koch H, Kuebler ES, Kühnemund M, Larrañaga P, Lelieveldt B, Louth EL, Lui JH, Mansvelder HD, Marin O, Martinez-Trujillo J, Chameh HM, Mohapatra AN, Munguba H, Nedergaard M, Němec P, Ofer N, Pfisterer UG, Pontes S, Redmond W, Rossier J, Sanes JR, Scheuermann RH, Serrano-Saiz E, Staiger JF, Somogyi P, Tamás G, Tolias AS, Tosches MA, García MT, Wozny C, Wuttke TV, Liu Y, Yuan J, Zeng H, Lein E. A community-based transcriptomics classification and nomenclature of neocortical cell types. Nat Neurosci 2021; 23:1456-1468. [PMID: 32839617 PMCID: PMC7683348 DOI: 10.1038/s41593-020-0685-8] [Citation(s) in RCA: 137] [Impact Index Per Article: 45.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
To understand the function of cortical circuits, it is necessary to catalog their cellular diversity. Past attempts to do so using anatomical, physiological or molecular features of cortical cells have not resulted in a unified taxonomy of neuronal or glial cell types, partly due to limited data. Single-cell transcriptomics is enabling, for the first time, systematic high-throughput measurements of cortical cells and generation of datasets that hold the promise of being complete, accurate and permanent. Statistical analyses of these data reveal clusters that often correspond to cell types previously defined by morphological or physiological criteria and that appear conserved across cortical areas and species. To capitalize on these new methods, we propose the adoption of a transcriptome-based taxonomy of cell types for mammalian neocortex. This classification should be hierarchical and use a standardized nomenclature. It should be based on a probabilistic definition of a cell type and incorporate data from different approaches, developmental stages and species. A community-based classification and data aggregation model, such as a knowledge graph, could provide a common foundation for the study of cortical circuits. This community-based classification, nomenclature and data aggregation could serve as an example for cell type atlases in other parts of the body.
Collapse
Affiliation(s)
| | | | | | | | - Detlev Arendt
- European Molecular Biology Laboratory, Heidelberg, Germany
| | - Ruben Armañanzas
- George Mason University, Fairfax, VA, USA.,BrainScope Company Inc., Bethesda, MD, USA
| | | | | | - Vahid Bokharaie
- Max Planck Institute for Biological Cybernetics, Tübingen, Germany
| | | | | | - Marco Capogna
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - YoonJeung Chang
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | | | | | | | | | | | | | - Richárd Fiáth
- Research Centre for Natural Sciences, Budapest, Hungary
| | | | | | - Xuefan Gao
- European Molecular Biology Laboratory, Hamburg, Germany
| | - Parviz Ghaderi
- École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | | | | | - Kenta Hagihara
- Friedrich Miescher Institute for Biological Research, Basel, Switzerland
| | | | | | | | - Markus M Hilscher
- Karolinska Institutet, Stockholm, Sweden.,Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Solna, Sweden
| | | | | | | | - Josh Huang
- Cold Spring Harbor Laboratory, Laurel Hollow, NY, USA
| | - Rafiq Huda
- WM Keck Center for Collaborative Neuroscience, Department of Cell Biology and Neuroscience, Rutgers University - New Brunswick, Piscataway, NJ, USA
| | | | - Ole Kiehn
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
| | | | - Eric S Kuebler
- Robarts Research Institute, Western University, London, Ontario, Canada
| | | | | | | | | | - Jan H Lui
- Stanford University, Stanford, CA, USA
| | | | | | - Julio Martinez-Trujillo
- Schulich School of Medicine and Dentistry, Departments of Physiology, Pharmacology and Psychiatry, University of Western Ontario, London, Ontario, Canada
| | | | | | | | | | | | | | | | | | | | | | | | - Richard H Scheuermann
- J. Craig Venter Institute, La Jolla, CA, USA.,Department of Pathology, University of California, San Diego, CA, USA
| | | | - Jochen F Staiger
- Institute for Neuroanatomy, University of Göttingen, Göttingen, Germany
| | | | | | | | | | | | - Christian Wozny
- University of Strathclyde, Glasgow, UK.,MSH Medical School, Hamburg, Germany
| | - Thomas V Wuttke
- Departments of Neurosurgery and of Neurology and Epileptology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Yong Liu
- University of Copenhagen, Copenhagen, Denmark
| | - Juan Yuan
- Karolinska Institutet, Stockholm, Sweden
| | - Hongkui Zeng
- Allen Institute for Brain Science, Seattle, WA, USA.
| | - Ed Lein
- Allen Institute for Brain Science, Seattle, WA, USA.
| |
Collapse
|
8
|
Ding C, Emmenegger V, Schaffrath K, Feldmeyer D. Layer-Specific Inhibitory Microcircuits of Layer 6 Interneurons in Rat Prefrontal Cortex. Cereb Cortex 2021; 31:32-47. [PMID: 32829414 PMCID: PMC7727376 DOI: 10.1093/cercor/bhaa201] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 06/06/2020] [Accepted: 07/02/2020] [Indexed: 12/15/2022] Open
Abstract
GABAergic interneurons in different cortical areas play important roles in diverse higher-order cognitive functions. The heterogeneity of interneurons is well characterized in different sensory cortices, in particular in primary somatosensory and visual cortex. However, the structural and functional properties of the medial prefrontal cortex (mPFC) interneurons have received less attention. In this study, a cluster analysis based on axonal projection patterns revealed four distinct clusters of L6 interneurons in rat mPFC: Cluster 1 interneurons showed axonal projections similar to Martinotti-like cells extending to layer 1, cluster 2 displayed translaminar projections mostly to layer 5, and cluster 3 interneuron axons were confined to the layer 6, whereas those of cluster 4 interneurons extend also into the white matter. Correlations were found between neuron location and axonal distribution in all clusters. Moreover, all cluster 1 L6 interneurons showed a monotonically adapting firing pattern with an initial high-frequency burst. All cluster 2 interneurons were fast-spiking, while neurons in cluster 3 and 4 showed heterogeneous firing patterns. Our data suggest that L6 interneurons that have distinct morphological and physiological characteristics are likely to innervate different targets in mPFC and thus play differential roles in the L6 microcircuitry and in mPFC-associated functions.
Collapse
Affiliation(s)
- Chao Ding
- Institute of Neuroscience and Medicine, INM-10 Function of Cortical Microcircuits Group, Research Centre Jülich, 52425 Jülich, Germany
| | - Vishalini Emmenegger
- Institute of Neuroscience and Medicine, INM-10 Function of Cortical Microcircuits Group, Research Centre Jülich, 52425 Jülich, Germany
- Department of Biosystems Science and Engineering, ETH Zürich, Basel, Switzerland
| | - Kim Schaffrath
- Institute of Neuroscience and Medicine, INM-10 Function of Cortical Microcircuits Group, Research Centre Jülich, 52425 Jülich, Germany
- Department of Ophthalmology, RWTH Aachen University Hospital, Medical School, 52074 Aachen, Germany
| | - Dirk Feldmeyer
- Institute of Neuroscience and Medicine, INM-10 Function of Cortical Microcircuits Group, Research Centre Jülich, 52425 Jülich, Germany
- Department of Psychiatry, Psychotherapy and Psychosomatics, Medical School, RWTH Aachen University Hospital, 52074 Aachen, Germany
- JARA-Translational Brain Medicine, 52074 Aachen, Germany
| |
Collapse
|
9
|
Affiliation(s)
- Dirk Feldmeyer
- Institute of Neuroscience and Medicine 10 (INM-10), Research Centre Jülich, Jülich, Germany.,Department of Psychiatry, Psychotherapy and Psychosomatics, Medical School, RWTH Aachen University Hospital, Aachen, Germany
| | - John F Wesseling
- Instituto de Neurociencias, CSIC-UMH, San Juan de Alicante, Spain
| | - P Jesper Sjöström
- Centre for Research in Neuroscience, Brain Repair and Integrative Neuroscience Program, Department of Medicine, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, QC, Canada
| |
Collapse
|
10
|
Yang D, Ding C, Qi G, Feldmeyer D. Cholinergic and Adenosinergic Modulation of Synaptic Release. Neuroscience 2020; 456:114-130. [PMID: 32540364 DOI: 10.1016/j.neuroscience.2020.06.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 05/29/2020] [Accepted: 06/01/2020] [Indexed: 01/14/2023]
Abstract
In this review we will discuss the effect of two neuromodulatory transmitters, acetylcholine (ACh) and adenosine, on the synaptic release probability and short-term synaptic plasticity. ACh and adenosine differ fundamentally in the way they are released into the extracellular space. ACh is released mostly from synaptic terminals and axonal bouton of cholinergic neurons in the basal forebrain (BF). Its mode of action on synaptic release probability is complex because it activate both ligand-gated ion channels, so-called nicotinic ACh receptors and G-protein coupled muscarinic ACh receptors. In contrast, adenosine is released from both neurons and glia via nucleoside transporters or diffusion over the cell membrane in a non-vesicular, non-synaptic fashion; its receptors are exclusively G-protein coupled receptors. We show that ACh and adenosine effects are highly specific for an identified synaptic connection and depend mostly on the presynaptic but also on the postsynaptic receptor type and discuss the functional implications of these differences.
Collapse
Affiliation(s)
- Danqing Yang
- Research Centre Juelich, Institute of Neuroscience and Medicine 10, Leo-Brandt-Strasse, Juelich, Germany
| | - Chao Ding
- Research Centre Juelich, Institute of Neuroscience and Medicine 10, Leo-Brandt-Strasse, Juelich, Germany
| | - Guanxiao Qi
- Research Centre Juelich, Institute of Neuroscience and Medicine 10, Leo-Brandt-Strasse, Juelich, Germany
| | - Dirk Feldmeyer
- Research Centre Juelich, Institute of Neuroscience and Medicine 10, Leo-Brandt-Strasse, Juelich, Germany; RWTH Aachen University Hospital, Pauwelsstrasse 30, Aachen, Germany; Jülich-Aachen Research Alliance Brain - JARA Brain, Germany.
| |
Collapse
|
11
|
Qi G, Yang D, Ding C, Feldmeyer D. Unveiling the Synaptic Function and Structure Using Paired Recordings From Synaptically Coupled Neurons. Front Synaptic Neurosci 2020; 12:5. [PMID: 32116641 PMCID: PMC7026682 DOI: 10.3389/fnsyn.2020.00005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 01/22/2020] [Indexed: 11/24/2022] Open
Abstract
Synaptic transmission between neurons is the basic mechanism for information processing in cortical microcircuits. To date, paired recording from synaptically coupled neurons is the most widely used method which allows a detailed functional characterization of unitary synaptic transmission at the cellular and synaptic level in combination with a structural characterization of both pre- and postsynaptic neurons at the light and electron microscopic level. In this review, we will summarize the many applications of paired recordings to investigate synaptic function and structure. Paired recordings have been used to study the detailed electrophysiological and anatomical properties of synaptically coupled cell pairs within a synaptic microcircuit; this is critical in order to understand the connectivity rules and dynamic properties of synaptic transmission. Paired recordings can also be adopted for quantal analysis of an identified synaptic connection and to study the regulation of synaptic transmission by neuromodulators such as acetylcholine, the monoamines, neuropeptides, and adenosine etc. Taken together, paired recordings from synaptically coupled neurons will remain a very useful approach for a detailed characterization of synaptic transmission not only in the rodent brain but also that of other species including humans.
Collapse
Affiliation(s)
- Guanxiao Qi
- Institute of Neuroscience and Medicine, INM-10, Jülich Research Centre, Jülich, Germany
| | - Danqing Yang
- Institute of Neuroscience and Medicine, INM-10, Jülich Research Centre, Jülich, Germany
| | - Chao Ding
- Institute of Neuroscience and Medicine, INM-10, Jülich Research Centre, Jülich, Germany
| | - Dirk Feldmeyer
- Institute of Neuroscience and Medicine, INM-10, Jülich Research Centre, Jülich, Germany.,Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University Hospital, Aachen, Germany.,Jülich-Aachen Research Alliance, Translational Brain Medicine (JARA Brain), Aachen, Germany
| |
Collapse
|
12
|
Emmenegger V, Qi G, Wang H, Feldmeyer D. Morphological and Functional Characterization of Non-fast-Spiking GABAergic Interneurons in Layer 4 Microcircuitry of Rat Barrel Cortex. Cereb Cortex 2019; 28:1439-1457. [PMID: 29329401 PMCID: PMC6093438 DOI: 10.1093/cercor/bhx352] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Indexed: 12/23/2022] Open
Abstract
GABAergic interneurons are notorious for their heterogeneity, despite constituting a small fraction of the neuronal population in the neocortex. Classification of interneurons is crucial for understanding their widespread cortical functions as they provide a complex and dynamic network, balancing excitation and inhibition. Here, we investigated different types of non-fast-spiking (nFS) interneurons in Layer 4 (L4) of rat barrel cortex using whole-cell patch-clamp recordings with biocytin-filling. Based on a quantitative analysis on a combination of morphological and electrophysiological parameters, we identified 5 distinct types of L4 nFS interneurons: 1) trans-columnar projecting interneurons, 2) locally projecting non-Martinotti-like interneurons, 3) supra-granular projecting Martinotti-like interneurons, 4) intra-columnar projecting VIP-like interneurons, and 5) locally projecting neurogliaform-like interneurons. Trans-columnar projecting interneurons are one of the most striking interneuron types, which have not been described so far in Layer 4. They feature extensive axonal collateralization not only in their home barrel but also in adjacent barrels. Furthermore, we identified that most of the L4 nFS interneurons express somatostatin, while few are positive for the transcription factor Prox1. The morphological and electrophysiological characterization of different L4 nFS interneuron types presented here provides insights into their synaptic connectivity and functional role in cortical information processing.
Collapse
Affiliation(s)
- Vishalini Emmenegger
- Institute of Neuroscience and Medicine, INM-2 and INM-10, Research Centre Jülich, Jülich, Germany
- Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Aachen, Germany
- Department of Biosystems Sciences and Engineering, Bio Engineering Lab, ETH Zürich, Basel, Switzerland
| | - Guanxiao Qi
- Institute of Neuroscience and Medicine, INM-2 and INM-10, Research Centre Jülich, Jülich, Germany
| | - Haijun Wang
- Institute of Neuroscience and Medicine, INM-2 and INM-10, Research Centre Jülich, Jülich, Germany
- Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Aachen, Germany
- School of Electronic Engineering, Nanjing Xiaozhuang University, Nanjing, P.R. China
| | - Dirk Feldmeyer
- Institute of Neuroscience and Medicine, INM-2 and INM-10, Research Centre Jülich, Jülich, Germany
- Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Aachen, Germany
- Jülich Aachen Research Alliance, Translational Brain Medicine (JARA Brain), Aachen, Germany
- Address correspondence to Dirk Feldmeyer, Institute of Neuroscience and Medicine (INM-2), Research Centre Jülich, D-52425 Jülich, Germany.
| |
Collapse
|
13
|
Yang D, Günter R, Qi G, Radnikow G, Feldmeyer D. Muscarinic and Nicotinic Modulation of Neocortical Layer 6A Synaptic Microcircuits Is Cooperative and Cell-Specific. Cereb Cortex 2019; 30:3528-3542. [PMID: 32026946 PMCID: PMC7233001 DOI: 10.1093/cercor/bhz324] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 12/02/2019] [Accepted: 12/05/2019] [Indexed: 12/27/2022] Open
Abstract
Acetylcholine (ACh) is known to regulate cortical activity during different behavioral states, for example, wakefulness and attention. Here we show a differential expression of muscarinic ACh receptors (mAChRs) and nicotinic ACh receptors (nAChRs) in different layer 6A (L6A) pyramidal cell (PC) types of somatosensory cortex. At low concentrations, ACh induced a persistent hyperpolarization in corticocortical (CC) but a depolarization in corticothalamic (CT) L6A PCs via M 4 and M1 mAChRs, respectively. At ~ 1 mM, ACh depolarized exclusively CT PCs via α4β2 subunit-containing nAChRs without affecting CC PCs. Miniature EPSC frequency in CC PCs was decreased by ACh but increased in CT PCs. In synaptic connections with a presynaptic CC PC, glutamate release was suppressed via M4 mAChR activation but enhanced by nAChRs via α4β2 nAChRs when the presynaptic neuron was a CT PC. Thus, in L6A, the interaction of mAChRs and nAChRs results in an altered excitability and synaptic release, effectively strengthening CT output while weakening CC synaptic signaling.
Collapse
Affiliation(s)
- Danqing Yang
- Institute of Neuroscience and Medicine (INM-10), Function of Neuronal Microcircuits, Research Centre Jülich, D-52425 Jülich, Germany
| | - Robert Günter
- Institute of Neuroscience and Medicine (INM-10), Function of Neuronal Microcircuits, Research Centre Jülich, D-52425 Jülich, Germany
| | - Guanxiao Qi
- Institute of Neuroscience and Medicine (INM-10), Function of Neuronal Microcircuits, Research Centre Jülich, D-52425 Jülich, Germany
| | - Gabriele Radnikow
- Institute of Neuroscience and Medicine (INM-10), Function of Neuronal Microcircuits, Research Centre Jülich, D-52425 Jülich, Germany
| | - Dirk Feldmeyer
- Institute of Neuroscience and Medicine (INM-10), Function of Neuronal Microcircuits, Research Centre Jülich, D-52425 Jülich, Germany.,Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, D-52074 Aachen, Germany.,Jülich Aachen Research Alliance, Translational Brain Medicine (JARA Brain), D-52074 Aachen, Germany
| |
Collapse
|
14
|
Qi G, van Aerde K, Abel T, Feldmeyer D. Adenosine Differentially Modulates Synaptic Transmission of Excitatory and Inhibitory Microcircuits in Layer 4 of Rat Barrel Cortex. Cereb Cortex 2018; 27:4411-4422. [PMID: 27522071 DOI: 10.1093/cercor/bhw243] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2016] [Accepted: 07/15/2016] [Indexed: 12/27/2022] Open
Abstract
Adenosine is considered to be a key regulator of sleep homeostasis by promoting slow-wave sleep through inhibition of the brain's arousal centers. However, little is known about the effect of adenosine on neuronal network activity at the cellular level in the neocortex. Here, we show that adenosine differentially modulates synaptic transmission between different types of neurons in cortical layer 4 (L4) through activation of pre- and/or postsynaptically located adenosine A1 receptors. In recurrent excitatory connections between L4 spiny neurons, adenosine suppresses synaptic transmission through activation of both pre- and postsynaptic A1 receptors. In reciprocal excitatory and inhibitory connections between L4 spiny neurons and interneurons, adenosine strongly suppresses excitatory transmission via activating presynaptic A1 receptors but only slightly suppresses inhibitory transmission via activating postsynaptic A1 receptors. Adenosine has no effect on inhibitory transmission between L4 interneurons. The effect of adenosine is concentration dependent and first visible at a concentration of 1 μM. The effect of adenosine is blocked by the specific A1 receptor antagonist, 8-cyclopentyltheophylline or the nonspecific adenosine receptor antagonist, caffeine. By differentially affecting excitatory and inhibitory synaptic transmission, adenosine changes the excitation-inhibition balance and causes an overall shift to lower excitability in L4 primary somatosensory (barrel) cortical microcircuits.
Collapse
Affiliation(s)
- Guanxiao Qi
- Institute of Neuroscience and Medicine, INM-2, Research Centre Jülich, D-52425 Jülich, Germany
| | - Karlijn van Aerde
- Institute of Neuroscience and Medicine, INM-2, Research Centre Jülich, D-52425 Jülich, Germany.,Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3508 AB Utrecht, The Netherlands
| | - Ted Abel
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Dirk Feldmeyer
- Institute of Neuroscience and Medicine, INM-2, Research Centre Jülich, D-52425 Jülich, Germany.,Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, D-52074 Aachen, Germany.,Jülich-Aachen Research Alliance-Brain, Translational Brain Medicine, D-52074 Aachen, Germany
| |
Collapse
|
15
|
Marx M, Qi G, Hanganu-Opatz IL, Kilb W, Luhmann HJ, Feldmeyer D. Neocortical Layer 6B as a Remnant of the Subplate - A Morphological Comparison. Cereb Cortex 2018; 27:1011-1026. [PMID: 26637449 DOI: 10.1093/cercor/bhv279] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The fate of the subplate (SP) is still a matter of debate. The SP and layer 6 (which is ontogenetically the oldest and innermost neocortical lamina) develop coincidentally. Yet, the function of sublamina 6B is largely unknown. It has been suggested that it consists partly of neurons from the transient SP, however, experimental evidence for this hypothesis is still missing. To obtain first insights into the neuronal complement of layer 6B in the somatosensory rat barrel cortex, we used biocytin stainings of SP neurons (aged 0-4 postnatal days, PND) and layer 6B neurons (PND 11-35) obtained during in vitro whole-cell patch-clamp recordings. Neurons were reconstructed for a quantitative characterization of their axonal and dendritic morphology. An unsupervised cluster analysis revealed that the SP and layer 6B consist of heterogeneous but comparable neuronal cell populations. Both contain 5 distinct spine-bearing cell types whose relative fractions change with increasing age. Pyramidal cells were more prominent in layer 6B, whereas non-pyramidal neurons were less frequent. Because of the high morphological similarity of SP and layer 6B neurons, we suggest that layer 6B consists of persistent non-pyramidal neurons from the SP and cortical L6B pyramidal neurons.
Collapse
Affiliation(s)
- Manuel Marx
- Institute of Neuroscience and Medicine, INM-2, Research Centre Jülich, D-52428 Jülich, Germany.,Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, D-52074 Aachen, Germany
| | - Guanxiao Qi
- Institute of Neuroscience and Medicine, INM-2, Research Centre Jülich, D-52428 Jülich, Germany
| | - Ileana L Hanganu-Opatz
- Developmental Neurophysiology, Institute of Neuroanatomy, Centre for Molecular Neurobiology Hamburg (ZMNH), D-20251 Hamburg, Germany
| | - Werner Kilb
- Institute of Physiology, University Medical Centre of the Johannes Gutenberg-University Mainz, D-55128 Mainz, Germany
| | - Heiko J Luhmann
- Institute of Physiology, University Medical Centre of the Johannes Gutenberg-University Mainz, D-55128 Mainz, Germany
| | - Dirk Feldmeyer
- Institute of Neuroscience and Medicine, INM-2, Research Centre Jülich, D-52428 Jülich, Germany.,Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, D-52074 Aachen, Germany.,Jülich Aachen Research Alliance, Translational Brain Medicine (JARA Brain), D-52074 Aachen, Germany
| |
Collapse
|
16
|
Radnikow G, Feldmeyer D. Layer- and Cell Type-Specific Modulation of Excitatory Neuronal Activity in the Neocortex. Front Neuroanat 2018; 12:1. [PMID: 29440997 PMCID: PMC5797542 DOI: 10.3389/fnana.2018.00001] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 01/04/2018] [Indexed: 01/08/2023] Open
Abstract
From an anatomical point of view the neocortex is subdivided into up to six layers depending on the cortical area. This subdivision has been described already by Meynert and Brodmann in the late 19/early 20. century and is mainly based on cytoarchitectonic features such as the size and location of the pyramidal cell bodies. Hence, cortical lamination is originally an anatomical concept based on the distribution of excitatory neuron. However, it has become apparent in recent years that apart from the layer-specific differences in morphological features, many functional properties of neurons are also dependent on cortical layer or cell type. Such functional differences include changes in neuronal excitability and synaptic activity by neuromodulatory transmitters. Many of these neuromodulators are released from axonal afferents from subcortical brain regions while others are released intrinsically. In this review we aim to describe layer- and cell-type specific differences in the effects of neuromodulator receptors in excitatory neurons in layers 2–6 of different cortical areas. We will focus on the neuromodulator systems using adenosine, acetylcholine, dopamine, and orexin/hypocretin as examples because these neuromodulator systems show important differences in receptor type and distribution, mode of release and functional mechanisms and effects. We try to summarize how layer- and cell type-specific neuromodulation may affect synaptic signaling in cortical microcircuits.
Collapse
Affiliation(s)
- Gabriele Radnikow
- Research Centre Jülich, Institute of Neuroscience and Medicine, INM-10, Jülich, Germany
| | - Dirk Feldmeyer
- Research Centre Jülich, Institute of Neuroscience and Medicine, INM-10, Jülich, Germany.,Department of Psychiatry, Psychotherapy and Psychosomatics, Medical School, RWTH Aachen University, Aachen, Germany.,Jülich-Aachen Research Alliance - Translational Brain Medicine, Jülich, Germany
| |
Collapse
|
17
|
Feldmeyer D, Qi G, Emmenegger V, Staiger JF. Inhibitory interneurons and their circuit motifs in the many layers of the barrel cortex. Neuroscience 2017; 368:132-151. [PMID: 28528964 DOI: 10.1016/j.neuroscience.2017.05.027] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Revised: 05/11/2017] [Accepted: 05/12/2017] [Indexed: 10/19/2022]
Abstract
Recent years have seen substantial progress in studying the structural and functional properties of GABAergic interneurons and their roles in the neuronal networks of barrel cortex. Although GABAergic interneurons represent only about 12% of the total number of neocortical neurons, they are extremely diverse with respect to their structural and functional properties. It has become clear that barrel cortex interneurons not only serve the maintenance of an appropriate excitation/inhibition balance but also are directly involved in sensory processing. In this review we present different interneuron types and their axonal projection pattern framework in the context of the laminar and columnar organization of the barrel cortex. The main focus is here on the most prominent interneuron types, i.e. basket cells, chandelier cells, Martinotti cells, bipolar/bitufted cells and neurogliaform cells, but interneurons with more unusual axonal domains will also be mentioned. We describe their developmental origin, their classification with respect to molecular, morphological and intrinsic membrane and synaptic properties. Most importantly, we will highlight the most prominent circuit motifs these interneurons are involved in and in which way they serve feed-forward inhibition, feedback inhibition and disinhibition. Finally, this will be put into context to their functional roles in sensory signal perception and processing in the whisker system and beyond.
Collapse
Affiliation(s)
- Dirk Feldmeyer
- Institute of Neuroscience and Medicine, INM-2, Research Center Jülich, D-52425 Jülich, Germany; Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, D-52074 Aachen, Germany; Jülich Aachen Research Alliance, Translational Brain Medicine (JARA Brain), D-52074 Aachen, Germany.
| | - Guanxiao Qi
- Institute of Neuroscience and Medicine, INM-2, Research Center Jülich, D-52425 Jülich, Germany
| | - Vishalini Emmenegger
- Institute of Neuroscience and Medicine, INM-2, Research Center Jülich, D-52425 Jülich, Germany; Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, D-52074 Aachen, Germany
| | - Jochen F Staiger
- Institute for Neuroanatomy, University Medical Center Göttingen, Georg-August-University, Göttingen D-37075, Germany.
| |
Collapse
|
18
|
Schoch H, Kreibich AS, Ferri SL, White RS, Bohorquez D, Banerjee A, Port RG, Dow HC, Cordero L, Pallathra AA, Kim H, Li H, Bilker WB, Hirano S, Schultz RT, Borgmann-Winter K, Hahn CG, Feldmeyer D, Carlson GC, Abel T, Brodkin ES. Sociability Deficits and Altered Amygdala Circuits in Mice Lacking Pcdh10, an Autism Associated Gene. Biol Psychiatry 2017; 81:193-202. [PMID: 27567313 PMCID: PMC5161717 DOI: 10.1016/j.biopsych.2016.06.008] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 05/03/2016] [Accepted: 06/01/2016] [Indexed: 12/20/2022]
Abstract
BACKGROUND Behavioral symptoms in individuals with autism spectrum disorder (ASD) have been attributed to abnormal neuronal connectivity, but the molecular bases of these behavioral and brain phenotypes are largely unknown. Human genetic studies have implicated PCDH10, a member of the δ2 subfamily of nonclustered protocadherin genes, in ASD. PCDH10 expression is enriched in the basolateral amygdala, a brain region implicated in the social deficits of ASD. Previous reports indicate that Pcdh10 plays a role in axon outgrowth and glutamatergic synapse elimination, but its roles in social behaviors and amygdala neuronal connectivity are unknown. We hypothesized that haploinsufficiency of Pcdh10 would reduce social approach behavior and alter the structure and function of amygdala circuits. METHODS Mice lacking one copy of Pcdh10 (Pcdh10+/-) and wild-type littermates were assessed for social approach and other behaviors. The lateral/basolateral amygdala was assessed for dendritic spine number and morphology, and amygdala circuit function was studied using voltage-sensitive dye imaging. Expression of Pcdh10 and N-methyl-D-aspartate receptor (NMDAR) subunits was assessed in postsynaptic density fractions of the amygdala. RESULTS Male Pcdh10+/- mice have reduced social approach behavior, as well as impaired gamma synchronization, abnormal spine morphology, and reduced levels of NMDAR subunits in the amygdala. Social approach deficits in Pcdh10+/- male mice were rescued with acute treatment with the NMDAR partial agonist d-cycloserine. CONCLUSIONS Our studies reveal that male Pcdh10+/- mice have synaptic and behavioral deficits, and establish Pcdh10+/- mice as a novel genetic model for investigating neural circuitry and behavioral changes relevant to ASD.
Collapse
Affiliation(s)
- Hannah Schoch
- Cell and Molecular Biology Graduate Group, Perelman School of Medicine at the University of Pennsylvania, Smilow Center for Translational Research, Room 10-170, Building 421, 3400 Civic Center Boulevard, Philadelphia, PA 19104-6168, USA
| | - Arati S. Kreibich
- Center for Neurobiology and Behavior, Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Translational Research Laboratory, 125 South 31 Street, Room 2220, Philadelphia, PA 19104-3403, USA
| | - Sarah L. Ferri
- Department of Biology, University of Pennsylvania, Smilow Center for Translational Research, Room 10-133, Building 421, 3400 Civic Center Boulevard, Philadelphia, PA 19104-6168, USA
| | - Rachel S. White
- Center for Neurobiology and Behavior, Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Translational Research Laboratory, 125 South 31 Street, Room 2220, Philadelphia, PA 19104-3403, USA
| | - Dominique Bohorquez
- Center for Neurobiology and Behavior, Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Translational Research Laboratory, 125 South 31 Street, Room 2220, Philadelphia, PA 19104-3403, USA
| | - Anamika Banerjee
- Center for Neurobiology and Behavior, Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Translational Research Laboratory, 125 South 31 Street, Room 2220, Philadelphia, PA 19104-3403, USA
| | - Russell G. Port
- Center for Neurobiology and Behavior, Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Translational Research Laboratory, 125 South 31 Street, Room 2220, Philadelphia, PA 19104-3403, USA
| | - Holly C. Dow
- Center for Neurobiology and Behavior, Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Translational Research Laboratory, 125 South 31 Street, Room 2220, Philadelphia, PA 19104-3403, USA
| | - Lucero Cordero
- Center for Neurobiology and Behavior, Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Translational Research Laboratory, 125 South 31 Street, Room 2220, Philadelphia, PA 19104-3403, USA
| | - Ashley A. Pallathra
- Center for Neurobiology and Behavior, Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Translational Research Laboratory, 125 South 31 Street, Room 2220, Philadelphia, PA 19104-3403, USA
| | - Hyong Kim
- Center for Neurobiology and Behavior, Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Translational Research Laboratory, 125 South 31 Street, Room 2220, Philadelphia, PA 19104-3403, USA
| | - Honghze Li
- Department of Biostatistics and Epidemiology, Perelman School of Medicine at the University of Pennsylvania, 215 Blockley Hall, 423 Guardian Drive, Philadelphia, PA 19104-6021, USA
| | - Warren B. Bilker
- Department of Biostatistics and Epidemiology, Perelman School of Medicine at the University of Pennsylvania, 215 Blockley Hall, 423 Guardian Drive, Philadelphia, PA 19104-6021, USA
| | - Shinji Hirano
- Department of Cell Biology, Kansai Medical University, 2-5-1 Shinmachi, Hirakata City, Osaka 573-1010, Japan
| | - Robert T. Schultz
- Center for Autism Research, Children’s Hospital of Philadelphia, and Departments of Pediatrics and Psychiatry, Perelman School of Medicine, University of Pennsylvania, 3535 Market Street, Philadelphia, PA 19104, USA
| | - Karin Borgmann-Winter
- Center for Neurobiology and Behavior, Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Translational Research Laboratory, 125 South 31 Street, Room 2220, Philadelphia, PA 19104-3403, USA,Department of Child and Adolescent Psychiatry, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Chang-Gyu Hahn
- Center for Neurobiology and Behavior, Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Translational Research Laboratory, 125 South 31 Street, Room 2220, Philadelphia, PA 19104-3403, USA
| | - Dirk Feldmeyer
- Forschungzentrum Julich, Institute of Neuroscience and Medicine, INM-2, D-52425, Julich, Germany,RWTH Aachen University, Medical School, Department of Psychiatry, Psychotherapy and Psychosomatics, D-52074 Aachen, Germany
| | - Gregory C. Carlson
- Center for Neurobiology and Behavior, Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Translational Research Laboratory, 125 South 31 Street, Room 2220, Philadelphia, PA 19104-3403, USA
| | - Ted Abel
- Department of Biology, University of Pennsylvania, Smilow Center for Translational Research, Room 10-133, Building 421, 3400 Civic Center Boulevard, Philadelphia, PA 19104-6168, USA
| | - Edward S. Brodkin
- Center for Neurobiology and Behavior, Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Translational Research Laboratory, 125 South 31 Street, Room 2220, Philadelphia, PA 19104-3403, USA
| |
Collapse
|
19
|
Barth A, Burkhalter A, Callaway EM, Connors BW, Cauli B, DeFelipe J, Feldmeyer D, Freund T, Kawaguchi Y, Kisvarday Z, Kubota Y, McBain C, Oberlaender M, Rossier J, Rudy B, Staiger JF, Somogyi P, Tamas G, Yuste R. Comment on "Principles of connectivity among morphologically defined cell types in adult neocortex". Science 2016; 353:1108. [PMID: 27609882 DOI: 10.1126/science.aaf5663] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 08/03/2016] [Indexed: 01/15/2023]
Abstract
Jiang et al (Research Article, 27 November 2015, aac9462) describe detailed experiments that substantially add to the knowledge of cortical microcircuitry and are unique in the number of connections reported and the quality of interneuron reconstruction. The work appeals to experts and laypersons because of the notion that it unveils new principles and provides a complete description of cortical circuits. We provide a counterbalance to the authors' claims to give those less familiar with the minutiae of cortical circuits a better sense of the contributions and the limitations of this study.
Collapse
Affiliation(s)
- Alison Barth
- 159C Mellon Institute, Department of Biological Sciences, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, USA
| | - Andreas Burkhalter
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Edward M Callaway
- Systems Neurobiology Laboratories, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
| | - Barry W Connors
- Department of Neuroscience, Division of Biology and Medicine, Brown University, Providence, RI 02912, USA
| | - Bruno Cauli
- Neuroscience Paris Seine (NPS), Cortical Network and Neurovascular Coupling (CNNC), CNRS UMR 8246, Inserm U 1130, UPMC UM 119, Université Pierre et Marie Curie, 9 Quai Saint Bernard, 75005 Paris, France
| | - Javier DeFelipe
- Laboratorio Cajal de Circuitos Corticales, Centro de Tecnologia Biomedica, Universidad Politecnica de Madrid, Campus Montegancedo S/N, Pozuelo de Alarcon, 28223 Madrid, Spain. Instituto Cajal (CSIC), Avenida Doctor Arce 37, 28002 Madrid, Spain
| | - Dirk Feldmeyer
- Institut für Neurowissenschaften und Medizin (INM-2), Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Tamas Freund
- Department of Cellular and Network Neurobiology, Laboratory of Cerebral Cortex Research, Institute of Experimental Medicine, Hungarian Academy of Sciences, H-1450 Budapest, POB 67, Hungary
| | - Yasuo Kawaguchi
- Division of Cerebral Circuitry, National Institute for Physiological Sciences, 5-1 Myodaiji-Higashiyama, Okazaki, Aichi 444-8787, Japan
| | - Zoltan Kisvarday
- University of Debrecen, Department of Anatomy, Histology, Embryology, Laboratory for Cortical Systems Neuroscience, Nagyerdei krt. 98, 4012 Debrecen, Hungary
| | - Yoshiyuki Kubota
- Division of Cerebral Circuitry, National Institute for Physiological Sciences, 5-1 Myodaiji-Higashiyama, Okazaki, Aichi 444-8787, Japan
| | - Chris McBain
- Laboratory of Cellular and Synaptic Neurophysiology, National Institute of Child Health and Human Development, 35 Convent Drive MSC3715, Bethesda, MD 20892, USA
| | - Marcel Oberlaender
- Max Planck Institute for Biological Cybernetics, Computational Neuroanatomy Group, D-72076 Tubingen, Germany
| | - Jean Rossier
- Neuroscience Paris Seine, Univerisité Pierre et Marie Curie (UPMC) Paris VI, 7-9 Quai Saint Bernard, 75005 Paris, France
| | - Bernardo Rudy
- Neuroscience Institute, Department of Anesthesiology, Perioperative Care, and Pain Medicine, New York University School of Medicine, Smilow Research Center, 522 First Avenue, New York, NY 10016, USA.
| | - Jochen F Staiger
- University Medicine Goettingen, Center for Anatomy, Institute for Neuroanatomy, Kreuzbergring 36, D-37075 Goettingen, Germany.
| | - Peter Somogyi
- Medical Research Council Brain Network Dynamics Unit, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3TH, UK
| | - Gabor Tamas
- Research Group for Cortical Microcircuits of the Hungarian Academy of Sciences, Department of Physiology, Anatomy and Neuroscience, University of Szeged, Közép Fasor 52, Szeged, H-6726 Hungary
| | - Rafael Yuste
- Kavli institute of Brain Science, Columbia University, Department of Biological Sciences, West 120 Street, New York, NY 10027, USA
| |
Collapse
|
20
|
Barz CS, Bessaih T, Abel T, Feldmeyer D, Contreras D. Altered resonance properties of somatosensory responses in mice deficient for the schizophrenia risk gene Neuregulin 1. Brain Struct Funct 2015; 221:4383-4398. [PMID: 26721794 DOI: 10.1007/s00429-015-1169-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Accepted: 12/01/2015] [Indexed: 12/20/2022]
Abstract
To reveal the neuronal underpinnings of sensory processing deficits in patients with schizophrenia, previous studies have investigated brain activity in response to sustained sensory stimulation at various frequencies. This paradigm evoked neural activity at the stimulation frequency and harmonics thereof. During visual and auditory stimulation that elicited enhanced or 'resonant' responses in healthy controls, patients with schizophrenia displayed reduced activity. The present study sought to elucidate the cellular basis of disease-related deficits in sensory resonance properties using mice heterozygous for the schizophrenia susceptibility gene Neuregulin 1 (NRG1). We applied repetitive whisker stimulation at 1-15 Hz, a range relevant to whisking behavior in mice, and measured cellular activity in the primary somatosensory cortex. At frequencies where control mice displayed enhancements in measures of response magnitude and precision, NRG1 (+/-) mutants showed reductions. Our results demonstrate for the first time a link between a mutation of a schizophrenia risk gene and altered neuronal resonance properties in sensory cortex.
Collapse
Affiliation(s)
- Claudia S Barz
- Function of Cortical Microcircuits Group, Institute for Neuroscience and Medicine, Research Centre Jülich, Leo-Brandt-Str., 52425, Jülich, Germany.
- Department of Psychiatry, Psychotherapy and Psychosomatics, Medical School, RWTH Aachen University, Pauwelsstr. 30, 52074, Aachen, Germany.
- Department of Neuropathology, Medical School, RWTH Aachen University, Aachen, Germany.
- Department of Ophthalmology, Medical School, RWTH Aachen University, Aachen, Germany.
- IZKF Aachen, Medical School, RWTH Aachen University, Aachen, Germany.
| | - Thomas Bessaih
- Sorbonne Universités, UPMC Univ Paris 06, UM CR18, Neuroscience Paris Seine, Paris, France
- INSERM, UMR-S 1130, Neuroscience Paris Seine, Paris, France
- CNRS, UMR 8246, Neuroscience Paris Seine, Paris, France
- Université Pierre et Marie Curie, Laboratoire Neuroscience Paris Seine, 9 quai Staint Bernard, Bat B, 5e etage, Case courrier 16, 75005, Paris, France
| | - Ted Abel
- Department of Biology, University of Pennsylvania, Philadelphia, USA
- 10-133 Smilow Center for Translational Research, 3400 Civic Center Boulevard, Building 421, Philadelphia, PA, 19104, USA
| | - Dirk Feldmeyer
- Function of Cortical Microcircuits Group, Institute for Neuroscience and Medicine, Research Centre Jülich, Leo-Brandt-Str., 52425, Jülich, Germany
- Department of Psychiatry, Psychotherapy and Psychosomatics, Medical School, RWTH Aachen University, Pauwelsstr. 30, 52074, Aachen, Germany
- Jülich Aachen Research Alliance (JARA)-Translational Brain Medicine, Aachen, Germany
| | - Diego Contreras
- Department of Neuroscience, School of Medicine, University of Pennsylvania, 215 Stemmler Hall, Philadelphia, PA, 19104-6074, USA
| |
Collapse
|
21
|
Abstract
Synaptic connections between identified fast-spiking (FS), parvalbumin (PV)-positive interneurons, and excitatory spiny neurons in layer 4 (L4) of the barrel cortex were investigated using patch-clamp recordings and simultaneous biocytin fillings. Three distinct clusters of FS L4 interneurons were identified based on their axonal morphology relative to the barrel column suggesting that these neurons do not constitute a homogeneous interneuron population. One L4 FS interneuron type had an axonal domain strictly confined to a L4 barrel and was therefore named "barrel-confined inhibitory interneuron" (BIn). BIns established reliable inhibitory synaptic connections with L4 spiny neurons at a high connectivity rate of 67%, of which 69% were reciprocal. Unitary IPSPs at these connections had a mean amplitude of 0.9 ± 0.8 mV with little amplitude variation and weak short-term synaptic depression. We found on average 3.7 ± 1.3 putative inhibitory synaptic contacts that were not restricted to perisomatic areas. In conclusion, we characterized a novel type of barrel cortex interneuron in the major thalamo-recipient layer 4 forming dense synaptic networks with L4 spiny neurons. These networks constitute an efficient and powerful inhibitory feedback system, which may serve to rapidly reset the barrel microcircuitry following sensory activation.
Collapse
Affiliation(s)
- Christian Koelbl
- Department of Cell Physiology, Max Planck Institute of Medical Research, Jahnstr. 20, D-69120 Heidelberg, Germany
- Current address: Section of Cardiovascular Medicine, Boston University Medical Center, 88 East Newton Street, Boston, MA 02118, USA
| | - Moritz Helmstaedter
- Department of Cell Physiology, Max Planck Institute of Medical Research, Jahnstr. 20, D-69120 Heidelberg, Germany
- Current address: Structure of Neocortical Circuits Group, Max Planck Institute of Neurobiology, Am Klopferspitz 18, D-82152 Martinsried, Germany
| | - Joachim Lübke
- Institute for Neuroscience and Medicine, INM-2, Research Centre Jülich, Leo-Brandt-Str., D-52425 Jülich, Germany
- Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Pauwelstr. 30, D-52074 Aachen, Germany
- Jülich-Aachen Research Alliance, Translational Brain Medicine (JARA-Brain), D-52074, Aachen, Germany
| | - Dirk Feldmeyer
- Institute for Neuroscience and Medicine, INM-2, Research Centre Jülich, Leo-Brandt-Str., D-52425 Jülich, Germany
- Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Pauwelstr. 30, D-52074 Aachen, Germany
- Jülich-Aachen Research Alliance, Translational Brain Medicine (JARA-Brain), D-52074, Aachen, Germany
| |
Collapse
|
22
|
Qi G, Feldmeyer D. Dendritic Target Region-Specific Formation of Synapses Between Excitatory Layer 4 Neurons and Layer 6 Pyramidal Cells. Cereb Cortex 2015; 26:1569-1579. [PMID: 25595180 DOI: 10.1093/cercor/bhu334] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Excitatory connections between neocortical layer 4 (L4) and L6 are part of the corticothalamic feedback microcircuitry. Here we studied the intracortical element of this feedback loop, the L4 spiny neuron-to-L6 pyramidal cell connection. We found that the distribution of synapses onto both putative corticothalamic (CT) and corticocortical (CC) L6 pyramidal cells (PCs) depends on the presynaptic L4 neuron type but is independent of the postsynaptic L6 PC type. L4 spiny stellate cells establish synapses on distal apical tuft dendrites of L6 PCs and elicit slow unitary excitatory postsynaptic potentials (uEPSPs) in L6 somata. In contrast, the majority of L4 star pyramidal neurons target basal and proximal apical oblique dendrites of L6 PCs and show fast uEPSPs. Compartmental modeling suggests that the slow uEPSP time course is primarily the result of dendritic filtering. This suggests that the dendritic target specificity of the 2 L4 spiny neuron types is due to their different axonal projection patterns across cortical layers. The preferential dendritic targeting by different L4 neuron types may facilitate the generation of dendritic Ca(2+) or Na(+) action potentials in L6 PCs; this could play a role in synaptic gain modulation in the corticothalamic pathway.
Collapse
Affiliation(s)
- Guanxiao Qi
- Institute of Neuroscience and Medicine, INM-2, Research Centre Jülich, D-52425 Jülich, Germany
| | - Dirk Feldmeyer
- Institute of Neuroscience and Medicine, INM-2, Research Centre Jülich, D-52425 Jülich, Germany.,Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, D-52074 Aachen, Germany.,Jülich-Aachen Research Alliance-Brain, Translational Brain Medicine, D-52074 Aachen, Germany
| |
Collapse
|
23
|
Qi G, Radnikow G, Feldmeyer D. Electrophysiological and morphological characterization of neuronal microcircuits in acute brain slices using paired patch-clamp recordings. J Vis Exp 2015:52358. [PMID: 25650985 DOI: 10.3791/52358] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The combination of patch clamp recordings from two (or more) synaptically coupled neurons (paired recordings) in acute brain slice preparations with simultaneous intracellular biocytin filling allows a correlated analysis of their structural and functional properties. With this method it is possible to identify and characterize both pre- and postsynaptic neurons by their morphology and electrophysiological response pattern. Paired recordings allow studying the connectivity patterns between these neurons as well as the properties of both chemical and electrical synaptic transmission. Here, we give a step-by-step description of the procedures required to obtain reliable paired recordings together with an optimal recovery of the neuron morphology. We will describe how pairs of neurons connected via chemical synapses or gap junctions are identified in brain slice preparations. We will outline how neurons are reconstructed to obtain their 3D morphology of the dendritic and axonal domain and how synaptic contacts are identified and localized. We will also discuss the caveats and limitations of the paired recording technique, in particular those associated with dendritic and axonal truncations during the preparation of brain slices because these strongly affect connectivity estimates. However, because of the versatility of the paired recording approach it will remain a valuable tool in characterizing different aspects of synaptic transmission at identified neuronal microcircuits in the brain.
Collapse
Affiliation(s)
- Guanxiao Qi
- Institute of Neuroscience and Medicine (INM-2), Research Centre Jülich
| | - Gabriele Radnikow
- Institute of Neuroscience and Medicine (INM-2), Research Centre Jülich
| | - Dirk Feldmeyer
- Institute of Neuroscience and Medicine (INM-2), Research Centre Jülich; Department of Psychiatry, Psychotherapy and Psychosomatics, Medical Faculty, JARA, RWTH Aachen University;
| |
Collapse
|
24
|
Feldmeyer D. S1 microcircuits. Scholarpedia 2015. [DOI: 10.4249/scholarpedia.7458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
|
25
|
Barz CS, Bessaih T, Abel T, Feldmeyer D, Contreras D. Sensory encoding in Neuregulin 1 mutants. Brain Struct Funct 2014; 221:1067-81. [PMID: 25515311 DOI: 10.1007/s00429-014-0955-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 12/02/2014] [Indexed: 10/24/2022]
Abstract
Schizophrenic patients show altered sensory perception as well as changes in electrical and magnetic brain responses to sustained, frequency-modulated sensory stimulation. Both the amplitude and temporal precision of the neural responses differ in patients as compared to control subjects, and these changes are most pronounced for stimulation at gamma frequencies (20-40 Hz). In addition, patients display enhanced spontaneous gamma oscillations, which has been interpreted as 'neural noise' that may interfere with normal stimulus processing. To investigate electrophysiological markers of aberrant sensory processing in a model of schizophrenia, we recorded neuronal activity in primary somatosensory cortex of mice heterozygous for the schizophrenia susceptibility gene Neuregulin 1. Sensory responses to sustained 20-70 Hz whisker stimulation were analyzed with respect to firing rates, spike precision (phase locking) and gamma oscillations, and compared to baseline conditions. The mutants displayed elevated spontaneous firing rates, a reduced gain in sensory-evoked spiking and gamma activity, and reduced spike precision of 20-40 Hz responses. These findings present the first in vivo evidence of the linkage between a genetic marker and altered stimulus encoding, thus suggesting a novel electrophysiological endophenotype of schizophrenia.
Collapse
Affiliation(s)
- Claudia S Barz
- Department of Psychiatry, Psychotherapy and Psychosomatics, Medical School, RWTH Aachen University, Aachen, Germany. .,Department of Neuropathology, Medical School, RWTH Aachen University, Aachen, Germany. .,Department of Ophthalmology, Medical School, RWTH Aachen University, Aachen, Germany. .,IZKF Aachen, Medical School, RWTH Aachen University, Aachen, Germany.
| | - Thomas Bessaih
- Sorbonne Universités, UPMC Univ Paris 06, UM 119, Neuroscience Paris Seine (NPS), Paris, 75005, France.,CNRS, UMR 8246, NPS, Paris, 75005, France.,INSERM, U1130, NPS, Paris, 75005, France
| | - Ted Abel
- Department of Biology, University of Pennsylvania, Philadelphia, USA.,Smilow Center for Translational Research, Philadelphia, USA
| | - Dirk Feldmeyer
- Department of Psychiatry, Psychotherapy and Psychosomatics, Medical School, RWTH Aachen University, Aachen, Germany.,Jülich Aachen Research Alliance (JARA) - Translational Brain Medicine, Aachen, Germany
| | - Diego Contreras
- Department of Neuroscience, School of Medicine, University of Pennsylvania, Philadelphia, USA
| |
Collapse
|
26
|
Sarid L, Feldmeyer D, Gidon A, Sakmann B, Segev I. Contribution of intracolumnar layer 2/3-to-layer 2/3 excitatory connections in shaping the response to whisker deflection in rat barrel cortex. Cereb Cortex 2013; 25:849-58. [PMID: 24165834 PMCID: PMC4379993 DOI: 10.1093/cercor/bht268] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
This computational study integrates anatomical and physiological data to assess the functional role of the lateral excitatory connections between layer 2/3 (L2/3) pyramidal cells (PCs) in shaping their response during early stages of intracortical processing of a whisker deflection (WD). Based on in vivo and in vitro recordings, and 3D reconstructions of connected pairs of L2/3 PCs, our model predicts that: 1) AMPAR and NMDAR conductances/synapse are 0.52 ± 0.24 and 0.40 ± 0.34 nS, respectively; 2) following WD, connection between L2/3 PCs induces a composite EPSPs of 7.6 ± 1.7 mV, well below the threshold for action potential (AP) initiation; 3) together with the excitatory feedforward L4-to-L2/3 connection, WD evoked a composite EPSP of 16.3 ± 3.5 mV and a probability of 0.01 to generate an AP. When considering the variability in L4 spiny neurons responsiveness, it increased to 17.8 ± 11.2 mV; this 3-fold increase in the SD yielded AP probability of 0.35; 4) the interaction between L4-to-L2/3 and L2/3-to-L2/3 inputs is highly nonlinear; 5) L2/3 dendritic morphology significantly affects L2/3 PCs responsiveness. We conclude that early stages of intracortical signaling of WD are dominated by a combination of feedforward L4-L2/3 and L2/3-L2/3 lateral connections.
Collapse
Affiliation(s)
- Leora Sarid
- Department of Neurobiology, Institute of Life Sciences, Jerusalem Il-91904, Israel
| | - Dirk Feldmeyer
- Institute for Neuroscience and Medicine, INM-2 Research Centre Jülich, Jülich D-52425, Germany Department of Psychiatry, Psychotherapy, and Psychosomatics, RWTH Aachen University, Aachen D-52074, Germany Jülich-Aachen Research Alliance (JARA)-Brain, Aachen D-52074, Germany
| | - Albert Gidon
- Department of Neurobiology, Institute of Life Sciences, Jerusalem Il-91904, Israel
| | - Bert Sakmann
- Digital Neuroanatomy, Max Planck Florida Institute, Jupiter, FL 33458-2906, USA
| | - Idan Segev
- Department of Neurobiology, Institute of Life Sciences, Jerusalem Il-91904, Israel Interdisciplinary Center for Neural Computation, Hebrew University, Jerusalem Il-91904, Israel and Edmond and Lily Safra Center for Brain Sciences, Jerusalem Il-91904, Israel
| |
Collapse
|
27
|
van Aerde KI, Feldmeyer D. Morphological and physiological characterization of pyramidal neuron subtypes in rat medial prefrontal cortex. ACTA ACUST UNITED AC 2013; 25:788-805. [PMID: 24108807 DOI: 10.1093/cercor/bht278] [Citation(s) in RCA: 101] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
The medial prefrontal cortex (mPFC) has been implicated in cognitive and executive processes including decision making, working memory and behavioral flexibility. Cortical processing depends on the interaction between distinct neuronal cell types in different cortical layers. To better understand cortical processing in the rat mPFC, we studied the diversity of pyramidal neurons using in vitro whole-cell patch clamp recordings and biocytin staining of neurons, followed by morphological analysis. Using unsupervised cluster analysis for the objective grouping of neurons, we identified more than 10 different pyramidal subtypes spread across the different cortical layers. Layer 2 pyramidal neurons possessed a unique morphology with wide apical dendritic field spans and a narrow basal field span. Layer 3 contained the only subtype that showed a burst of action potentials upon current injection. Layer 5 pyramidal neurons showed the largest voltage sags. Finally, pyramidal neurons in layer 6 (L6) showed a great variety in their morphology with 39% of L6 neurons possessing tall apical dendrites that extend into layer 1. Future experiments on the functional role of the mPFC should take into account the great diversity of pyramidal neurons.
Collapse
Affiliation(s)
- Karlijn I van Aerde
- Forschungszentrum Jülich, Institute of Neuroscience and Medicine, INM-2, D-52425 Jülich, Germany Current address: Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Science, 1105 BA Amsterdam, The Netherlands
| | - Dirk Feldmeyer
- Forschungszentrum Jülich, Institute of Neuroscience and Medicine, INM-2, D-52425 Jülich, Germany Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Medical School, D-52074 Aachen, Germany Jülich Aachen Research Alliance, Translational Brain Medicine (JARA-Brain), D-52074 Aachen, Germany
| |
Collapse
|
28
|
Abstract
The neuromodulator adenosine is widely considered to be a key regulator of sleep homeostasis and an indicator of sleep need. Although the effect of adenosine on subcortical areas has been previously described, the effects on cortical neurons have not been addressed systematically to date. To that purpose, we performed in vitro whole-cell patch-clamp recordings and biocytin staining of pyramidal neurons and interneurons throughout all layers of rat prefrontal and somatosensory cortex, followed by morphological analysis. We found that adenosine, via the A1 receptor, exerts differential effects depending on neuronal cell type and laminar location. Interneurons and pyramidal neurons in layer 2 and a subpopulation of layer 3 pyramidal neurons that displayed regular spiking were insensitive to adenosine application, whereas other pyramidal cells in layers 3-6 were hyperpolarized (range 1.2-10.8 mV). Broad tufted pyramidal neurons with little spike adaptation showed a small adenosine response, whereas slender tufted pyramidal neurons with substantial adaptation showed a bigger response. These studies of the action of adenosine at the postsynaptic level may contribute to the understanding of the changes in cortical circuit functioning that take place between sleep and awakening.
Collapse
Affiliation(s)
- Karlijn I van Aerde
- Forschungszentrum Jülich, Institute of Neuroscience and Medicine, INM-2, D-52425 Jülich, Germany Current address: Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Science, 1105 BA Amsterdam, The Netherlands
| | - Guanxiao Qi
- Forschungszentrum Jülich, Institute of Neuroscience and Medicine, INM-2, D-52425 Jülich, Germany Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Medical School, D-52074 Aachen, Germany
| | - Dirk Feldmeyer
- Forschungszentrum Jülich, Institute of Neuroscience and Medicine, INM-2, D-52425 Jülich, Germany Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Medical School, D-52074 Aachen, Germany JARA-Translational Brain Medicine, Aachen, Germany
| |
Collapse
|
29
|
|
30
|
DeFelipe J, López-Cruz PL, Benavides-Piccione R, Bielza C, Larrañaga P, Anderson S, Burkhalter A, Cauli B, Fairén A, Feldmeyer D, Fishell G, Fitzpatrick D, Freund TF, González-Burgos G, Hestrin S, Hill S, Hof PR, Huang J, Jones EG, Kawaguchi Y, Kisvárday Z, Kubota Y, Lewis DA, Marín O, Markram H, McBain CJ, Meyer HS, Monyer H, Nelson SB, Rockland K, Rossier J, Rubenstein JLR, Rudy B, Scanziani M, Shepherd GM, Sherwood CC, Staiger JF, Tamás G, Thomson A, Wang Y, Yuste R, Ascoli GA. New insights into the classification and nomenclature of cortical GABAergic interneurons. Nat Rev Neurosci 2013; 14:202-16. [PMID: 23385869 PMCID: PMC3619199 DOI: 10.1038/nrn3444] [Citation(s) in RCA: 553] [Impact Index Per Article: 50.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A systematic classification and accepted nomenclature of neuron types is much needed but is currently lacking. This article describes a possible taxonomical solution for classifying GABAergic interneurons of the cerebral cortex based on a novel, web-based interactive system that allows experts to classify neurons with pre-determined criteria. Using Bayesian analysis and clustering algorithms on the resulting data, we investigated the suitability of several anatomical terms and neuron names for cortical GABAergic interneurons. Moreover, we show that supervised classification models could automatically categorize interneurons in agreement with experts' assignments. These results demonstrate a practical and objective approach to the naming, characterization and classification of neurons based on community consensus.
Collapse
Affiliation(s)
- Javier DeFelipe
- Laboratorio Cajal de Circuitos Corticales, Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, Campus Montegancedo S/N, Pozuelo de Alarcón, 28223 Madrid, Spain.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Abstract
Neocortical lamina 6B (L6B) is a largely unexplored layer with a very heterogeneous cellular composition. To date, only little is known about L6B neurons on a systematic and quantitative basis. We investigated the morphological and electrophysiological properties of excitatory L6B neurons in the rat somatosensory barrel cortex using whole-cell patch-clamp recordings and simultaneous biocytin fillings. Subsequent histological processing and computer-assisted 3D reconstructions provided the basis for a classification of excitatory L6B neurons according to their structural and functional characteristics. Three distinct clusters of excitatory L6B neurons were identified: (C1) pyramidal neurons with an apical dendrite pointing towards the pial surface, (C2) neurons with a prominent, “apical”-like dendrite not oriented towards the pia, and (C3) multipolar spiny neurons without any preferential dendritic orientation. The second group could be further subdivided into three categories termed inverted, “tangentially” oriented and “horizontally” oriented neurons. Furthermore, based on the axonal domain two subcategories of L6B pyramidal cells were identified that had either a more barrel-column confined or an extended axonal field. The classification of excitatory L6B neurons provided here may serve as a basis for future studies on the structure, function, and synaptic connectivity of L6B neurons.
Collapse
Affiliation(s)
- Manuel Marx
- Research Center Jülich, Institute of Neuroscience and Medicine (INM-2), D-52425 Jülich, Germany,
| | - Dirk Feldmeyer
- Research Center Jülich, Institute of Neuroscience and Medicine (INM-2), D-52425 Jülich, Germany,
- Department of Psychiatry, Psychotherapy and Psychosomatics, Medical School, RWTH Aachen University, D-52074 Aachen, Germany and
- Jülich Aachen Research Alliance, Translational Brain Medicine (JARA Brain), D-52074 Aachen, Germany
| |
Collapse
|
32
|
Abstract
Neocortical areas are believed to be organized into vertical modules, the cortical columns, and the horizontal layers 1–6. In the somatosensory barrel cortex these columns are defined by the readily discernible barrel structure in layer 4. Information processing in the neocortex occurs along vertical and horizontal axes, thereby linking individual barrel-related columns via axons running through the different cortical layers of the barrel cortex. Long-range signaling occurs within the neocortical layers but also through axons projecting through the white matter to other neocortical areas and subcortical brain regions. Because of the ease of identification of barrel-related columns, the rodent barrel cortex has become a prototypical system to study the interactions between different neuronal connections within a sensory cortical area and between this area and other cortical as well subcortical regions. Such interactions will be discussed specifically for the feed-forward and feedback loops between the somatosensory and the somatomotor cortices as well as the different thalamic nuclei. In addition, recent advances concerning the morphological characteristics of excitatory neurons and their impact on the synaptic connectivity patterns and signaling properties of neuronal microcircuits in the whisker-related somatosensory cortex will be reviewed. In this context, their relationship between the structural properties of barrel-related columns and their function as a module in vertical synaptic signaling in the whisker-related cortical areas will be discussed.
Collapse
Affiliation(s)
- Dirk Feldmeyer
- Institute of Neuroscience and Medicine, INM-2, Research Centre Jülich Jülich, Germany
| |
Collapse
|
33
|
|
34
|
Abstract
In the neocortex, most excitatory, glutamatergic synapses are established during the first 4-5 weeks after birth. During this period profound changes in the properties of synaptic transmission occur. Excitatory postsynaptic potentials (EPSPs) at immature synaptic connections are profoundly and progressively reduced in response to moderate to high frequency (5-100 Hz) stimulation. With maturation, this frequency-dependent depression becomes progressively weaker and may eventually transform into a weak to moderate EPSP facilitation. In parallel to changes in the short-term plasticity, a reduction in the synaptic reliability occurs at most glutamatergic neocortical synapses: immature synapses show a high probability of neurotransmitter release as indicated by their low failure rate and small EPSP amplitude variation. This high reliability is reduced in mature synapses, which show considerably higher failure rates and more variable EPSP amplitudes. During early neocortical development synaptic vesicle pools are not yet fully differentiated and their replenishment may be slow, thus resulting in EPSP amplitude depression. The decrease in the probability of neurotransmitter release may be the result of an altered Ca(2+) control in the presynaptic terminal with a reduced Ca(2+) influx and/or a higher Ca(2+) buffering capacity. This may lead to a lower synaptic reliability and a weaker short-term synaptic depression with maturation.
Collapse
Affiliation(s)
- Dirk Feldmeyer
- Research Centre Jülich, Institute for Neuroscience and Medicine, INM-2, Juelich, Germany.
| | | |
Collapse
|
35
|
Helmstaedter M, Sakmann B, Feldmeyer D. Neuronal Correlates of Local, Lateral, and Translaminar Inhibition with Reference to Cortical Columns. Cereb Cortex 2008; 19:926-37. [DOI: 10.1093/cercor/bhn141] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|
36
|
Helmstaedter M, Sakmann B, Feldmeyer D. L2/3 Interneuron Groups Defined by Multiparameter Analysis of Axonal Projection, Dendritic Geometry, and Electrical Excitability. Cereb Cortex 2008; 19:951-62. [DOI: 10.1093/cercor/bhn130] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
|
37
|
Helmstaedter M, Sakmann B, Feldmeyer D. The Relation between Dendritic Geometry, Electrical Excitability, and Axonal Projections of L2/3 Interneurons in Rat Barrel Cortex. Cereb Cortex 2008; 19:938-50. [DOI: 10.1093/cercor/bhn138] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
|
38
|
Frick A, Feldmeyer D, Sakmann B. Postnatal development of synaptic transmission in local networks of L5A pyramidal neurons in rat somatosensory cortex. J Physiol 2007; 585:103-16. [PMID: 17916610 DOI: 10.1113/jphysiol.2007.141788] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The probability of synaptic transmitter release determines the spread of excitation and the possible range of computations at unitary connections. To investigate whether synaptic properties between neocortical pyramidal neurons change during the assembly period of cortical circuits, whole-cell voltage recordings were made simultaneously from two layer 5A (L5A) pyramidal neurons within the cortical columns of rat barrel cortex. We found that synaptic transmission between L5A pyramidal neurons is very reliable between 2 and 3 weeks of postnatal development with a mean unitary EPSP amplitude of approximately 1.2 mV, but becomes less efficient and fails more frequently in the more mature cortex of approximately 4 weeks of age with a mean unitary EPSP amplitude of 0.65 mV. Coefficient of variation and failure rate increase as the unitary EPSP amplitude decreases during development. The paired-pulse ratio (PPR) of synaptic efficacy at 10 Hz changes from 0.7 to 1.04. Despite the overall increase in PPR, short-term plasticity displays a large variability at 4 weeks, ranging from strong depression to strong facilitation (PPR, range 0.6-2.1), suggesting the potential for use-dependent modifications at this intracortical synapse. In conclusion, the transmitter release probability at the L5A-L5A connection is developmentally regulated in such a way that in juvenile animals excitation by single action potentials is efficiently transmitted, whereas in the more mature cortex synapses might be endowed with a diversity of filtering characteristics.
Collapse
Affiliation(s)
- Andreas Frick
- Abteilung Zellphysiologie, Max-Planck-Institut für Medizinische Forschung, Jahnstrasse 29, 69120 Heidelberg, Germany.
| | | | | |
Collapse
|
39
|
Sarid L, Bruno R, Sakmann B, Segev I, Feldmeyer D. Modeling a layer 4-to-layer 2/3 module of a single column in rat neocortex: interweaving in vitro and in vivo experimental observations. Proc Natl Acad Sci U S A 2007; 104:16353-8. [PMID: 17913876 PMCID: PMC2000451 DOI: 10.1073/pnas.0707853104] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We report a step in constructing an in silico model of a neocortical column, focusing on the synaptic connection between layer 4 (L4) spiny neurons and L2/3 pyramidal cells in rat barrel cortex. It is based first on a detailed morphological and functional characterization of synaptically connected pairs of L4-L2/3 neurons from in vitro recordings and second, on in vivo recordings of voltage responses of L2/3 pyramidal cells to current pulses and to whisker deflection. In vitro data and a detailed compartmental model of L2/3 pyramidal cells enabled us to extract their specific membrane resistivity ( approximately 16,000 ohms x cm(2)) and capacitance ( approximately 0.8 microF/cm(2)) and the spatial distribution of L4-L2/3 synaptic contacts. The average peak conductance per L4 synaptic contact is 0.26 nS for the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid and 0.2 nS for NMDA receptors. The in vivo voltage response for current steps was then used to calibrate the model for in vivo conditions in the Down state. Consequently, the effect of a single whisker deflection was modeled by converging, on average, 350 +/- 20 L4 axons onto the modeled L2/3 pyramidal cell. Based on values of synaptic conductance, the spatial distribution of L4 synapses on L2/3 dendrites, and the average in vivo spiking probability of L4 spiny neurons, the model predicts that the feed-forward L4-L2/3 connection on its own does not fire the L2/3 neuron. With a broader distribution in the number of L4 neurons or with slight synchrony among them, the L2/3 model does spike with low probability.
Collapse
Affiliation(s)
- Leora Sarid
- *Department of Neurobiology, Institute of Life Sciences, Jerusalem Il-91904, Israel
| | - Randy Bruno
- Department of Cell Physiology, Max Planck Institute for Medical Research, D-69120 Heidelberg, Germany; and
| | - Bert Sakmann
- Department of Cell Physiology, Max Planck Institute for Medical Research, D-69120 Heidelberg, Germany; and
- To whom correspondence may be addressed. E-mail: or
| | - Idan Segev
- *Department of Neurobiology, Institute of Life Sciences, Jerusalem Il-91904, Israel
- Interdisciplinary Center for Neural Computation, Hebrew University, Jerusalem Il-91904, Israel
- To whom correspondence may be addressed. E-mail: or
| | - Dirk Feldmeyer
- Institute of Neuroscience and Biophysics, INB-3 Research Centre Jülich, D-52425 Jülich, Germany
| |
Collapse
|
40
|
Helmstaedter M, de Kock CPJ, Feldmeyer D, Bruno RM, Sakmann B. Reconstruction of an average cortical column in silico. ACTA ACUST UNITED AC 2007; 55:193-203. [PMID: 17822776 DOI: 10.1016/j.brainresrev.2007.07.011] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2007] [Revised: 07/06/2007] [Accepted: 07/06/2007] [Indexed: 11/28/2022]
Abstract
The characterization of individual neurons by Golgi and Cajal has been the basis of neuroanatomy for a century. A new challenge is to anatomically describe, at cellular resolution, complete local circuits that can drive behavior. In this essay, we review the possibilities to obtain a model cortical column by using in vitro and in vivo pair recordings, followed by anatomical reconstructions of the projecting and target cells. These pairs establish connection modules that eventually may be useful to synthesize an average cortical column in silico. Together with data on sensory evoked neuronal activity measured in vivo, this will allow to model the anatomical and functional cellular basis of behavior based on more realistic assumptions than previously attempted.
Collapse
Affiliation(s)
- M Helmstaedter
- Department of Cell Physiology, Max-Planck-Institut für Medizinische Forschung, Jahnstrasse 29, Heidelberg, Germany
| | | | | | | | | |
Collapse
|
41
|
Frick A, Feldmeyer D, Helmstaedter M, Sakmann B. Monosynaptic connections between pairs of L5A pyramidal neurons in columns of juvenile rat somatosensory cortex. Cereb Cortex 2007; 18:397-406. [PMID: 17548800 DOI: 10.1093/cercor/bhm074] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Layer 5 (L5) of somatosensory cortex is a major gateway for projections to intra- and subcortical brain regions. This layer is further divided into 5A and 5B characterized by relatively separate afferent and efferent connections. Little is known about the organization of connections within L5A of neocortical columns. We therefore used paired recordings to probe the anatomy and physiology of monosynaptic connections between L5A pyramidal neurons within the barrel columns of somatosensory cortex in acute slices of approximately 3-week-old rats. Post hoc reconstruction and calculation of the axodendritic overlap of pre- and postsynaptic neurons, together with identification of putative synaptic contacts (3.5 per connection), indicated a preferred innervation domain in the proximal dendritic region. Synaptic transmission was reliable (failure rate <2%) and had a low variability (coefficient of variation of 0.3). Unitary excitatory postsynaptic potential (EPSP) amplitudes varied 30-fold with a mean of 1.2 mV and displayed depression over a wide range of frequencies (2-100 Hz) during bursts of presynaptic firing. A single L5A pyramidal neuron was estimated to target approximately 270 other pyramidal neurons within the same layer of its home barrel column, suggesting a mechanism of feed-forward excitation by which synchronized single action potentials are efficiently transmitted within L5A of juvenile cortex.
Collapse
Affiliation(s)
- Andreas Frick
- Abteilung Zellphysiologie, Max-Planck-Institut für Medizinische Forschung, D-69120 Heidelberg, Germany.
| | | | | | | |
Collapse
|
42
|
Lübke J, Feldmeyer D. Excitatory signal flow and connectivity in a cortical column: focus on barrel cortex. Brain Struct Funct 2007; 212:3-17. [PMID: 17717695 DOI: 10.1007/s00429-007-0144-2] [Citation(s) in RCA: 139] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2007] [Accepted: 05/08/2007] [Indexed: 10/23/2022]
Abstract
A basic feature of the neocortex is its organization in functional, vertically oriented columns, recurring modules of signal processing and a system of transcolumnar long-range horizontal connections. These columns, together with their network of neurons, present in all sensory cortices, are the cellular substrate for sensory perception in the brain. Cortical columns contain thousands of neurons and span all cortical layers. They receive input from other cortical areas and subcortical brain regions and in turn their neurons provide output to various areas of the brain. The modular concept presumes that the neuronal network in a cortical column performs basic signal transformations, which are then integrated with the activity in other networks and more extended brain areas. To understand how sensory signals from the periphery are transformed into electrical activity in the neocortex it is essential to elucidate the spatial-temporal dynamics of cortical signal processing and the underlying neuronal 'microcircuits'. In the last decade the 'barrel' field in the rodent somatosensory cortex, which processes sensory information arriving from the mysticial vibrissae, has become a quite attractive model system because here the columnar structure is clearly visible. In the neocortex and in particular the barrel cortex, numerous neuronal connections within or between cortical layers have been studied both at the functional and structural level. Besides similarities, clear differences with respect to both physiology and morphology of synaptic transmission and connectivity were found. It is therefore necessary to investigate each neuronal connection individually, in order to develop a realistic model of neuronal connectivity and organization of a cortical column. This review attempts to summarize recent advances in the study of individual microcircuits and their functional relevance within the framework of a cortical column, with emphasis on excitatory signal flow.
Collapse
Affiliation(s)
- Joachim Lübke
- Research Centre Jülich, Institute of Neurosciences and Biophysics INB-3, Leo-Brandt-Str, 52425 Jülich, Germany
| | | |
Collapse
|
43
|
Abstract
Synaptically coupled layer 2/3 (L2/3) pyramidal neurones located above the same layer 4 barrel ('barrel-related') were investigated using dual whole-cell voltage recordings in acute slices of rat somatosensory cortex. Recordings were followed by reconstructions of biocytin-filled neurones. The onset latency of unitary EPSPs was 1.1 +/- 0.4 ms, the 20-80% rise time was 0.7 +/- 0.2 ms, the average amplitude was 1.0 +/- 0.7 mV and the decay time constant was 15.7 +/- 4.5 ms. The coefficient of variation (c.v.) of unitary EPSP amplitudes decreased with increasing EPSP peak and was 0.33 +/- 0.18. Bursts of APs in the presynaptic pyramidal cell resulted in EPSPs that, over a wide range of frequencies (5-100 Hz), displayed amplitude depression. Anatomically the barrel-related pyramidal cells in the lower half of layer 2/3 have a long apical dendrite with a small terminal tuft, while pyramidal cells in the upper half of layer 2/3 have shorter and often more 'irregularly' shaped apical dendrites that branch profusely in layer 1. The number of putative excitatory synaptic contacts established by the axonal collaterals of a L2/3 pyramidal cell with a postsynaptic pyramidal cell in the same column varied between 2 and 4, with an average of 2.8 +/- 0.7 (n = 8 pairs). Synaptic contacts were established predominantly on the basal dendrites at a mean geometric distance of 91 +/- 47 mum from the pyramidal cell soma. L2/3-to-L2/3 connections formed a blob-like innervation domain containing 2.8 mm of the presynaptic axon collaterals with a bouton density of 0.3 boutons per mum axon. Within the supragranular layers of its home column a single L2/3 pyramidal cell established about 900 boutons suggesting that 270 pyramidal cells in layer 2/3 are innervated by an individual pyramidal cell. In turn, a single pyramidal cell received synaptic inputs from 270 other L2/3 pyramidal cells. The innervation domain of L2/3-to-L2/3 connections superimposes almost exactly with that of L4-to-L2/3 connections. This suggests that synchronous feed-forward excitation of L2/3 pyramidal cells arriving from layer 4 could be potentially amplified in layer 2/3 by feedback excitation within a column and then relayed to the neighbouring columns.
Collapse
Affiliation(s)
- Dirk Feldmeyer
- Institut für Neurowissenschaften und Biophysik, AG Zelluläre Neurobiologie-Medizin, Forschungszentrum Jülich GmbH, Leo-Brandt-Strasse, D-52425 Jülich, Germany.
| | | | | |
Collapse
|
44
|
Feldmeyer D, Roth A, Sakmann B. Monosynaptic connections between pairs of spiny stellate cells in layer 4 and pyramidal cells in layer 5A indicate that lemniscal and paralemniscal afferent pathways converge in the infragranular somatosensory cortex. J Neurosci 2006; 25:3423-31. [PMID: 15800197 PMCID: PMC6724912 DOI: 10.1523/jneurosci.5227-04.2005] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Monosynaptic interlaminar connections between spiny stellate cells in layer 4 (L4), the main cortical recipient layer for thalamic projections, and pyramidal cells in layer 5A (L5A), one of the main cortical output layers, were examined anatomically and functionally by paired recordings in acute brain slices. The somata of pairs forming interlaminar L4-to-L5A connections were located predominantly close to or directly under the barrel-septum wall in layer 4. Superposition of spiny stellate axon arbors and L5A pyramidal cell dendritic arbors suggested an innervation domain underneath an L4 barrel wall. Functionally, the L4-to-L5A connections were of high reliability and relatively low efficacy, with a unitary EPSP amplitude of 0.6 mV, and the connectivity was moderately high (one in seven pairs tested was connected). The EPSP amplitude was weakly depressing (paired-pulse ratio of approximately 0.8) during repetitive presynaptic action potentials at 10 Hz. The existence of monosynaptic L4-to-L5A connections indicates that the specific "lemniscal" thalamic input from the ventro-basal nucleus of the thalamus to the cortex and the more unspecific "paralemniscal" afferent thalamic projections from the posterior medial nucleus of the thalamus merge already at an initial stage of cortical signal processing. These monosynaptic connections establish a monosynaptic coupling of the input to the cortex and its output, thereby effectively bypassing the supragranular layers.
Collapse
Affiliation(s)
- Dirk Feldmeyer
- Zelluläre Neurobiologie, Institut für Medizin, Forschungszentrum Jülich, D-52425 Jülich, Germany.
| | | | | |
Collapse
|
45
|
Abstract
The number of vesicles released at excitatory synapses and the number of release sites per synaptic connection are key determinants of information processing in the cortex, yet they remain uncertain. Here we show that the number of functional release sites and the number of anatomically identified synaptic contacts are equal at connections between spiny stellate and pyramidal cells in rat barrel cortex. Moreover, our results indicate that the amount of transmitter released per synaptic contact is independent of release probability and the intrinsic release probability is high. These properties suggest that connections between layer 4 and layer 2/3 are tuned for reliable transmission of spatially distributed, timing-based signals.
Collapse
Affiliation(s)
- R Angus Silver
- Department of Physiology, University College London, Gower Street, London WC1E 6BT, U.K.
| | | | | | | |
Collapse
|
46
|
Lübke J, Roth A, Feldmeyer D, Sakmann B. Morphometric analysis of the columnar innervation domain of neurons connecting layer 4 and layer 2/3 of juvenile rat barrel cortex. Cereb Cortex 2003; 13:1051-63. [PMID: 12967922 DOI: 10.1093/cercor/13.10.1051] [Citation(s) in RCA: 178] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We have investigated the dendritic and axonal morphology of connected pairs of L4 spiny neurons and L2/3 pyramidal cells in rat barrel cortex. The 'projection' field of the axons of L4 spiny neurons in layers 2/3, 4 and 5 has a width of 400-500 microm thereby defining an anatomical barrel-column. In layer 2/3, the averaged axonal 'projection' field of L4 spiny neurons together with the dendritic 'receptive' field of the connected L2/3 pyramidal cells form a mostly column-restricted anatomical L4-to-L2/3 'innervation domain' that extends 300-400 microm and includes mostly basal dendrites. In the L4-to-L2/3 innervation domain a single L4 spiny neuron contacts approximately 300-400 pyramidal cells while in the L4-to-L4 innervation domain it contacts approximately 200 other L4 spiny neurons. Similarly approximately 300-400 L4 spiny neurons converge onto a single pyramidal cell and approximately 200 L4 spiny neurons innervate another L4 spiny neuron. The L2/3 pyramidal cell axon has a vertical projection field spanning all cortical layers, and a long-range horizontal field in layers 2/3 (width 1,100-1,200 microm) and 5 (700-800 microm) projecting across column borders. The results suggest that the flow of excitation within a barrel-column is determined by the largely columnar confinement of the L4-to-L4 and L4-to-L2/3 innervation domains. A whisker deflection activates approximately 140 L4 spiny neurons that will generate EPSPs in most barrel-related L2/3 pyramidal cells of a principal whisker column. The translaminar synaptic transmission to layer 2/3 and the axonal projection fields of L2/3 pyramidal cells are the major determinants of the dynamic, multi-columnar map in which a single whisker deflection is represented in the cortex.
Collapse
Affiliation(s)
- Joachim Lübke
- Anatomisches Institut der Albert-Ludwigs-Universität Freiburg, Albertstrasse 17, D-79104 Freiburg, Germany
| | | | | | | |
Collapse
|
47
|
Feldmeyer D, Lübke J, Silver RA, Sakmann B. Synaptic connections between layer 4 spiny neurone-layer 2/3 pyramidal cell pairs in juvenile rat barrel cortex: physiology and anatomy of interlaminar signalling within a cortical column. J Physiol 2002; 538:803-22. [PMID: 11826166 PMCID: PMC2290091 DOI: 10.1113/jphysiol.2001.012959] [Citation(s) in RCA: 335] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2001] [Accepted: 09/28/2001] [Indexed: 11/08/2022] Open
Abstract
Whole-cell voltage recordings were obtained from 64 synaptically coupled excitatory layer 4 (L4) spiny neurones and L2/3 pyramidal cells in acute slices of the somatosensory cortex ('barrel' cortex) of 17- to 23-days-old rats. Single action potentials (APs) in the L4 spiny neurone evoked single unitary EPSPs in the L2/3 pyramidal cell with a peak amplitude of 0.7 +/- 0.6 mV. The average latency was 2.1 +/- 0.6 ms, the rise time was 0.8 +/- 0.3 ms and the decay time constant was 12.7 +/- 3.5 ms. The percentage of failures of an AP in a L4 spiny neurone to evoke a unitary EPSP in the L2/3 pyramidal cell was 4.9 +/- 8.8 % and the coefficient of variation (c.v.) of the unitary EPSP amplitude was 0.27 +/- 0.13. Both c.v. and percentage of failures decreased with increased average EPSP amplitude. Postsynaptic glutamate receptors (GluRs) in L2/3 pyramidal cells were of the N-methyl-D-aspartate (NMDA) receptor (NMDAR) and the non-NMDAR type. At -60 mV in the presence of extracellular Mg2+ (1 mM), 29 +/- 15 % of the EPSP voltage-time integral was blocked by NMDAR antagonists. In 0 Mg2+, the NMDAR/AMPAR ratio of the EPSC was 0.50 +/- 0.29, about half the value obtained for L4 spiny neurone connections. Burst stimulation of L4 spiny neurones showed that EPSPs in L2/3 pyramidal cells depressed over a wide range of frequencies (1-100 s(-1) ). However, at higher frequencies (30 s(-1)) EPSP summation overcame synaptic depression so that the summed EPSP was larger than the first EPSP amplitude in the train. The number of putative synaptic contacts established by the axonal collaterals of the L4 projection neurone with the target neurone in layer 2/3 varied between 4 and 5, with an average of 4.5 +/- 0.5 (n = 13 pairs). Synapses were established on basal dendrites of the pyramidal cell. Their mean geometric distance from the pyramidal cell soma was 67 +/- 34 microm (range, 16-196 microm). The results suggest that each connected L4 spiny neurone produces a weak but reliable EPSP in the pyramidal cell. Therefore transmission of signals to layer 2/3 is likely to have a high threshold requiring simultaneous activation of many L4 neurons, implying that L4 spiny neurone to L2/3 pyramidal cell synapses act as a gate for the lateral spread of excitation in layer 2/3.
Collapse
Affiliation(s)
- Dirk Feldmeyer
- Max-Planck Institut für Medizinische Forschung, Abteilung Zellphysiologie, Jahnstrasse 29, D-69120 Heidelberg, Germany.
| | | | | | | |
Collapse
|
48
|
Venance L, Rozov A, Blatow M, Burnashev N, Feldmeyer D, Monyer H. Connexin expression in electrically coupled postnatal rat brain neurons. Proc Natl Acad Sci U S A 2000; 97:10260-5. [PMID: 10944183 PMCID: PMC27858 DOI: 10.1073/pnas.160037097] [Citation(s) in RCA: 204] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Electrical coupling by gap junctions is an important form of cell-to-cell communication in early brain development. Whereas glial cells remain electrically coupled at postnatal stages, adult vertebrate neurons were thought to communicate mainly via chemical synapses. There is now accumulating evidence that in certain neuronal cell populations the capacity for electrical signaling by gap junction channels is still present in the adult. Here we identified electrically coupled pairs of neurons between postnatal days 12 and 18 in rat visual cortex, somatosensory cortex, and hippocampus. Notably, coupling was found both between pairs of inhibitory neurons and between inhibitory and excitatory neurons. Molecular analysis by single-cell reverse transcription-PCR revealed a differential expression pattern of connexins in these identified neurons.
Collapse
Affiliation(s)
- L Venance
- Department of Clinical Neurobiology, University Hospital for Neurology, Im Neuenheimer Feld 364, and Max-Planck-Institut für Medizinische Forschung, Jahnstrasse 29, D-69120 Heidelberg, Germany
| | | | | | | | | | | |
Collapse
|
49
|
Lübke J, Egger V, Sakmann B, Feldmeyer D. Columnar organization of dendrites and axons of single and synaptically coupled excitatory spiny neurons in layer 4 of the rat barrel cortex. J Neurosci 2000; 20:5300-11. [PMID: 10884314 PMCID: PMC6772349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023] Open
Abstract
Cortical columns are the functional units of the neocortex that are particularly prominent in the "barrel" field of the somatosensory cortex. Here we describe the morphology of two classes of synaptically coupled excitatory neurons in layer 4 of the barrel cortex, spiny stellate, and star pyramidal cells, respectively. Within a single barrel, their somata tend to be organized in clusters. The dendritic arbors are largely confined to layer 4, except for the distal part of the apical dendrite of star pyramidal neurons that extends into layer 2/3. In contrast, the axon of both types of neurons spans the cortex from layer 1 to layer 6. The most prominent axonal projections are those to layers 4 and 2/3 where they are largely restricted to a single cortical column. In layers 5 and 6, a small fraction of axon collaterals projects also across cortical columns. Consistent with the dense axonal projection to layers 4 and 2/3, the total number and density of boutons per unit axonal length was also highest there. Electron microscopy combined with GABA postimmunogold labeling revealed that most (>90%) of the synaptic contacts were established on dendritic spines and shafts of excitatory neurons in layers 4 and 2/3. The largely columnar organization of dendrites and axons of both cell types, combined with the preferential and dense projections within cortical layers 4 and 2/3, suggests that spiny stellate and star pyramidal neurons of layer 4 serve to amplify thalamic input and relay excitation vertically within a single cortical column.
Collapse
Affiliation(s)
- J Lübke
- Anatomisches Institut I, Albert-Ludwigs-Universität Freiburg, D-79104 Freiburg, Germany.
| | | | | | | |
Collapse
|
50
|
Higuchi M, Maas S, Single FN, Hartner J, Rozov A, Burnashev N, Feldmeyer D, Sprengel R, Seeburg PH. Point mutation in an AMPA receptor gene rescues lethality in mice deficient in the RNA-editing enzyme ADAR2. Nature 2000; 406:78-81. [PMID: 10894545 DOI: 10.1038/35017558] [Citation(s) in RCA: 711] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
RNA editing by site-selective deamination of adenosine to inosine alters codons and splicing in nuclear transcripts, and therefore protein function. ADAR2 (refs 7, 8) is a candidate mammalian editing enzyme that is widely expressed in brain and other tissues, but its RNA substrates are unknown. Here we have studied ADAR2-mediated RNA editing by generating mice that are homozygous for a targeted functional null allele. Editing in ADAR2-/- mice was substantially reduced at most of 25 positions in diverse transcripts; the mutant mice became prone to seizures and died young. The impaired phenotype appeared to result entirely from a single underedited position, as it reverted to normal when both alleles for the underedited transcript were substituted with alleles encoding the edited version exonically. The critical position specifies an ion channel determinant, the Q/R site, in AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate) receptor GluR-B pre-messenger RNA. We conclude that this transcript is the physiologically most important substrate of ADAR2.
Collapse
Affiliation(s)
- M Higuchi
- Department of Molecular Neurobiology, Max-Planck Institute for Medical Research, Heidelberg, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|