1
|
Martinetti LE, Autio DM, Crandall SR. Motor Control of Distinct Layer 6 Corticothalamic Feedback Circuits. eNeuro 2024; 11:ENEURO.0255-24.2024. [PMID: 38926084 PMCID: PMC11236587 DOI: 10.1523/eneuro.0255-24.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Accepted: 06/20/2024] [Indexed: 06/28/2024] Open
Abstract
Layer 6 corticothalamic (L6 CT) neurons provide massive input to the thalamus, and these feedback connections enable the cortex to influence its own sensory input by modulating thalamic excitability. However, the functional role(s) feedback serves during sensory processing is unclear. One hypothesis is that CT feedback is under the control of extrasensory signals originating from higher-order cortical areas, yet we know nothing about the mechanisms of such control. It is also unclear whether such regulation is specific to CT neurons with distinct thalamic connectivity. Using mice (either sex) combined with in vitro electrophysiology techniques, optogenetics, and retrograde labeling, we describe studies of vibrissal primary motor cortex (vM1) influences on different CT neurons in the vibrissal primary somatosensory cortex (vS1) with distinct intrathalamic axonal projections. We found that vM1 inputs are highly selective, evoking stronger postsynaptic responses in CT neurons projecting to the dual ventral posterior medial nucleus (VPm) and posterior medial nucleus (POm) located in lower L6a than VPm-only-projecting CT cells in upper L6a. A targeted analysis of the specific cells and synapses involved revealed that the greater responsiveness of Dual CT neurons was due to their distinctive intrinsic membrane properties and synaptic mechanisms. These data demonstrate that vS1 has at least two discrete L6 CT subcircuits distinguished by their thalamic projection patterns, intrinsic physiology, and functional connectivity with vM1. Our results also provide insights into how a distinct CT subcircuit may serve specialized roles specific to contextual modulation of tactile-related sensory signals in the somatosensory thalamus during active vibrissa movements.
Collapse
Affiliation(s)
- Luis E Martinetti
- Neuroscience Program, Michigan State University, East Lansing, Michigan 48824
| | - Dawn M Autio
- Department of Physiology, Michigan State University, East Lansing, Michigan 48824
| | - Shane R Crandall
- Neuroscience Program, Michigan State University, East Lansing, Michigan 48824
- Department of Physiology, Michigan State University, East Lansing, Michigan 48824
| |
Collapse
|
2
|
Martinetti LE, Autio DM, Crandall SR. Motor Control of Distinct Layer 6 Corticothalamic Feedback Circuits. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.22.590613. [PMID: 38712153 PMCID: PMC11071411 DOI: 10.1101/2024.04.22.590613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Layer 6 corticothalamic (L6 CT) neurons provide massive input to the thalamus, and these feedback connections enable the cortex to influence its own sensory input by modulating thalamic excitability. However, the functional role(s) feedback serves during sensory processing is unclear. One hypothesis is that CT feedback is under the control of extra-sensory signals originating from higher-order cortical areas, yet we know nothing about the mechanisms of such control. It is also unclear whether such regulation is specific to CT neurons with distinct thalamic connectivity. Using mice (either sex) combined with in vitro electrophysiology techniques, optogenetics, and retrograde labeling, we describe studies of vibrissal primary motor cortex (vM1) influences on different CT neurons in the vibrissal primary somatosensory cortex (vS1) with distinct intrathalamic axonal projections. We found that vM1 inputs are highly selective, evoking stronger postsynaptic responses in Dual ventral posterior medial nucleus (VPm) and posterior medial nucleus (POm) projecting CT neurons located in lower L6a than VPm-only projecting CT cells in upper L6a. A targeted analysis of the specific cells and synapses involved revealed that the greater responsiveness of Dual CT neurons was due to their distinctive intrinsic membrane properties and synaptic mechanisms. These data demonstrate that vS1 has at least two discrete L6 CT subcircuits distinguished by their thalamic projection patterns, intrinsic physiology, and functional connectivity with vM1. Our results also provide insights into how a distinct CT subcircuit may serve specialized roles specific to contextual modulation of tactile-related sensory signals in the somatosensory thalamus during active vibrissa movements.
Collapse
Affiliation(s)
| | - Dawn M. Autio
- Department of Physiology, Michigan State University, East Lansing, MI 48824
| | - Shane R. Crandall
- Neuroscience Program, Michigan State University, East Lansing, MI 48824
- Department of Physiology, Michigan State University, East Lansing, MI 48824
| |
Collapse
|
3
|
Zhang T, Wu Z, Li L, Ren J, Zhang Z, Wang G. CPPLS-MLP: a method for constructing cell-cell communication networks and identifying related highly variable genes based on single-cell sequencing and spatial transcriptomics data. Brief Bioinform 2024; 25:bbae198. [PMID: 38678387 PMCID: PMC11056015 DOI: 10.1093/bib/bbae198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 03/08/2024] [Accepted: 04/10/2024] [Indexed: 04/30/2024] Open
Abstract
In the growth and development of multicellular organisms, the immune processes of the immune system and the maintenance of the organism's internal environment, cell communication plays a crucial role. It exerts a significant influence on regulating internal cellular states such as gene expression and cell functionality. Currently, the mainstream methods for studying intercellular communication are focused on exploring the ligand-receptor-transcription factor and ligand-receptor-subunit scales. However, there is relatively limited research on the association between intercellular communication and highly variable genes (HVGs). As some HVGs are closely related to cell communication, accurately identifying these HVGs can enhance the accuracy of constructing cell communication networks. The rapid development of single-cell sequencing (scRNA-seq) and spatial transcriptomics technologies provides a data foundation for exploring the relationship between intercellular communication and HVGs. Therefore, we propose CPPLS-MLP, which can identify HVGs closely related to intercellular communication and further analyze the impact of Multiple Input Multiple Output cellular communication on the differential expression of these HVGs. By comparing with the commonly used method CCPLS for constructing intercellular communication networks, we validated the superior performance of our method in identifying cell-type-specific HVGs and effectively analyzing the influence of neighboring cell types on HVG expression regulation. Source codes for the CPPLS_MLP R, python packages and the related scripts are available at 'CPPLS_MLP Github [https://github.com/wuzhenao/CPPLS-MLP]'.
Collapse
Affiliation(s)
- Tianjiao Zhang
- College of Computer and Control Engineering, Northeast Forestry University Harbin, 150040, China
| | - Zhenao Wu
- College of Computer and Control Engineering, Northeast Forestry University Harbin, 150040, China
| | - Liangyu Li
- College of Computer and Control Engineering, Northeast Forestry University Harbin, 150040, China
| | - Jixiang Ren
- College of Computer and Control Engineering, Northeast Forestry University Harbin, 150040, China
| | - Ziheng Zhang
- College of Computer and Control Engineering, Northeast Forestry University Harbin, 150040, China
| | - Guohua Wang
- College of Computer and Control Engineering, Northeast Forestry University Harbin, 150040, China
- Faculty of Computing, Harbin Institute of Technology Harbin, 150001, China
| |
Collapse
|
4
|
Usui N. Possible roles of deep cortical neurons and oligodendrocytes in the neural basis of human sociality. Anat Sci Int 2024; 99:34-47. [PMID: 38010534 PMCID: PMC10771383 DOI: 10.1007/s12565-023-00747-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 10/17/2023] [Indexed: 11/29/2023]
Abstract
Sociality is an instinctive property of organisms that live in relation to others and is a complex characteristic of higher order brain functions. However, the evolution of the human brain to acquire higher order brain functions, such as sociality, and the neural basis for executing these functions and their control mechanisms are largely unknown. Several studies have attempted to evaluate how human sociality was acquired during the course of evolution and the mechanisms controlling sociality from a neurodevelopment viewpoint. This review discusses these findings in the context of human brain evolution and the pathophysiology of autism spectrum disorder (ASD). Comparative genomic studies of postmortem primate brains have demonstrated human-specific regulatory mechanisms underlying higher order brain functions, providing evidence for the contribution of oligodendrocytes to human brain function. Functional analyses of the causative genes of ASD in animal models have demonstrated that the neural basis of social behavior is associated with layer 6 (L6) of the neocortex and oligodendrocytes. These findings demonstrate that both neurons and oligodendrocytes contribute to the neural basis and molecular mechanisms underlying human brain evolution and social functioning. This review provides novel insights into sociability and the corresponding neural bases of brain disorders and evolution.
Collapse
Affiliation(s)
- Noriyoshi Usui
- Department of Neuroscience and Cell Biology, Graduate School of Medicine, Osaka University, Suita, 565-0871, Japan.
- Omics Center, Center of Medical Innovation and Translational Research, Graduate School of Medicine, Osaka University, Suita, 565-0871, Japan.
- United Graduate School of Child Development, Osaka University, Suita, 565-0871, Japan.
- Global Center for Medical Engineering and Informatics, Osaka University, Suita, 565-0871, Japan.
- Addiction Research Unit, Osaka Psychiatric Research Center, Osaka Psychiatric Medical Center, Osaka, 541-8567, Japan.
| |
Collapse
|
5
|
Aguado J, Amarilla AA, Taherian Fard A, Albornoz EA, Tyshkovskiy A, Schwabenland M, Chaggar HK, Modhiran N, Gómez-Inclán C, Javed I, Baradar AA, Liang B, Peng L, Dharmaratne M, Pietrogrande G, Padmanabhan P, Freney ME, Parry R, Sng JDJ, Isaacs A, Khromykh AA, Valenzuela Nieto G, Rojas-Fernandez A, Davis TP, Prinz M, Bengsch B, Gladyshev VN, Woodruff TM, Mar JC, Watterson D, Wolvetang EJ. Senolytic therapy alleviates physiological human brain aging and COVID-19 neuropathology. NATURE AGING 2023; 3:1561-1575. [PMID: 37957361 PMCID: PMC10724067 DOI: 10.1038/s43587-023-00519-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 10/03/2023] [Indexed: 11/15/2023]
Abstract
Aging is a major risk factor for neurodegenerative diseases, and coronavirus disease 2019 (COVID-19) is linked to severe neurological manifestations. Senescent cells contribute to brain aging, but the impact of virus-induced senescence on neuropathologies is unknown. Here we show that senescent cells accumulate in aged human brain organoids and that senolytics reduce age-related inflammation and rejuvenate transcriptomic aging clocks. In postmortem brains of patients with severe COVID-19 we observed increased senescent cell accumulation compared with age-matched controls. Exposure of human brain organoids to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induced cellular senescence, and transcriptomic analysis revealed a unique SARS-CoV-2 inflammatory signature. Senolytic treatment of infected brain organoids blocked viral replication and prevented senescence in distinct neuronal populations. In human-ACE2-overexpressing mice, senolytics improved COVID-19 clinical outcomes, promoted dopaminergic neuron survival and alleviated viral and proinflammatory gene expression. Collectively our results demonstrate an important role for cellular senescence in driving brain aging and SARS-CoV-2-induced neuropathology, and a therapeutic benefit of senolytic treatments.
Collapse
Affiliation(s)
- Julio Aguado
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St Lucia, Queensland, Australia.
| | - Alberto A Amarilla
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Queensland, Australia
| | - Atefeh Taherian Fard
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St Lucia, Queensland, Australia
| | - Eduardo A Albornoz
- School of Biomedical Sciences, Faculty of Medicine, University of Queensland, St Lucia, Queensland, Australia
| | - Alexander Tyshkovskiy
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia
| | - Marius Schwabenland
- Institute of Neuropathology and Center for Basics in NeuroModulation, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Harman K Chaggar
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St Lucia, Queensland, Australia
| | - Naphak Modhiran
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St Lucia, Queensland, Australia
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Queensland, Australia
| | - Cecilia Gómez-Inclán
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St Lucia, Queensland, Australia
| | - Ibrahim Javed
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St Lucia, Queensland, Australia
- Centre for Pharmaceutical Innovation, School of Pharmacy and Medical Sciences, UniSA Clinical and Health Sciences, The University of South Australia, Adelaide, South Australia, Australia
| | - Alireza A Baradar
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St Lucia, Queensland, Australia
| | - Benjamin Liang
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Queensland, Australia
| | - Lianli Peng
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St Lucia, Queensland, Australia
| | - Malindrie Dharmaratne
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St Lucia, Queensland, Australia
| | - Giovanni Pietrogrande
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St Lucia, Queensland, Australia
| | - Pranesh Padmanabhan
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, University of Queensland, Brisbane, Queensland, Australia
| | - Morgan E Freney
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Queensland, Australia
| | - Rhys Parry
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Queensland, Australia
| | - Julian D J Sng
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Queensland, Australia
| | - Ariel Isaacs
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Queensland, Australia
| | - Alexander A Khromykh
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Queensland, Australia
- Australian Infectious Disease Research Centre, Global Virus Network Centre of Excellence, Brisbane, Queensland, Australia
| | - Guillermo Valenzuela Nieto
- Institute of Medicine, Faculty of Medicine & Center for Interdisciplinary Studies on the Nervous System, CISNE, Universidad Austral de Chile, Valdivia, Chile
| | - Alejandro Rojas-Fernandez
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Berking Biotechnology, Valdivia, Chile
| | - Thomas P Davis
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St Lucia, Queensland, Australia
| | - Marco Prinz
- Institute of Neuropathology and Center for Basics in NeuroModulation, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Signalling Research Centers BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| | - Bertram Bengsch
- Signalling Research Centers BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
- Faculty of Medicine, Clinic for Internal Medicine II, Gastroenterology, Hepatology, Endocrinology, and Infectious Disease, University Medical Center Freiburg, Freiburg, Germany
| | - Vadim N Gladyshev
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Trent M Woodruff
- School of Biomedical Sciences, Faculty of Medicine, University of Queensland, St Lucia, Queensland, Australia
| | - Jessica C Mar
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St Lucia, Queensland, Australia
| | - Daniel Watterson
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Queensland, Australia
| | - Ernst J Wolvetang
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St Lucia, Queensland, Australia
| |
Collapse
|
6
|
Hayden DJ, Finnie PSB, Thomazeau A, Li AY, Cooke SF, Bear MF. Electrophysiological Signatures of Visual Recognition Memory across All Layers of Mouse V1. J Neurosci 2023; 43:7307-7321. [PMID: 37714707 PMCID: PMC10621768 DOI: 10.1523/jneurosci.0090-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 08/31/2023] [Accepted: 09/05/2023] [Indexed: 09/17/2023] Open
Abstract
In mouse primary visual cortex (V1), familiar stimuli evoke significantly altered responses when compared with novel stimuli. This stimulus-selective response plasticity (SRP) was described originally as an increase in the magnitude of visual evoked potentials (VEPs) elicited in layer 4 (L4) by familiar phase-reversing grating stimuli. SRP is dependent on NMDA receptors (NMDARs) and has been hypothesized to reflect potentiation of thalamocortical (TC) synapses in L4. However, recent evidence indicates that the synaptic modifications that manifest as SRP do not occur on L4 principal cells. To shed light on where and how SRP is induced and expressed in male and female mice, the present study had three related aims: (1) to confirm that NMDAR are required specifically in glutamatergic principal neurons of V1, (2) to investigate the consequences of deleting NMDAR specifically in L6, and (3) to use translaminar electrophysiological recordings to characterize SRP expression in different layers of V1. We find that knock-out (KO) of NMDAR in L6 principal neurons disrupts SRP. Current-source density (CSD) analysis of the VEP depth profile shows augmentation of short latency current sinks in layers 3, 4, and 6 in response to phase reversals of familiar stimuli. Multiunit recordings demonstrate that increased peak firing occurs in response to phase reversals of familiar stimuli across all layers, but that activity between phase reversals is suppressed. Together, these data reveal important aspects of the underlying phenomenology of SRP and generate new hypotheses for the expression of experience-dependent plasticity in V1.SIGNIFICANCE STATEMENT Repeated exposure to stimuli that portend neither reward nor punishment leads to behavioral habituation, enabling organisms to dedicate attention to novel or otherwise significant features of the environment. The neural basis of this process, which is so often dysregulated in neurologic and psychiatric disorders, remains poorly understood. Learning and memory of stimulus familiarity can be studied in mouse visual cortex by measuring electrophysiological responses to simple phase-reversing grating stimuli. The current study advances knowledge of this process by documenting changes in visual evoked potentials (VEPs), neuronal spiking activity, and oscillations in the local field potentials (LFPs) across all layers of mouse visual cortex. In addition, we identify a key contribution of a specific population of neurons in layer 6 (L6) of visual cortex.
Collapse
Affiliation(s)
- Dustin J Hayden
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Peter S B Finnie
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Aurore Thomazeau
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Alyssa Y Li
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
- Biochemistry Program, Wellesley College, Wellesley, Massachusetts 02481
| | - Samuel F Cooke
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Mark F Bear
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| |
Collapse
|
7
|
Galazo MJ, Sweetser DA, Macklis JD. Tle4 controls both developmental acquisition and early post-natal maturation of corticothalamic projection neuron identity. Cell Rep 2023; 42:112957. [PMID: 37561632 PMCID: PMC10542749 DOI: 10.1016/j.celrep.2023.112957] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 04/21/2023] [Accepted: 07/25/2023] [Indexed: 08/12/2023] Open
Abstract
Identities of distinct neuron subtypes are specified during embryonic development, then maintained during post-natal maturation. In cerebral cortex, mechanisms controlling early acquisition of neuron-subtype identities have become increasingly understood. However, mechanisms controlling neuron-subtype identity stability during post-natal maturation are largely unexplored. We identify that Tle4 is required for both early acquisition and post-natal stability of corticothalamic neuron-subtype identity. Embryonically, Tle4 promotes acquisition of corticothalamic identity and blocks emergence of core characteristics of subcerebral/corticospinal projection neuron identity, including gene expression and connectivity. During the first post-natal week, when corticothalamic innervation is ongoing, Tle4 is required to stabilize corticothalamic neuron identity, limiting interference from differentiation programs of developmentally related neuron classes. We identify a deacetylation-based epigenetic mechanism by which TLE4 controls Fezf2 expression level by corticothalamic neurons. This contributes to distinction of cortical output subtypes and ensures identity stability for appropriate maturation of corticothalamic neurons.
Collapse
Affiliation(s)
- Maria J Galazo
- Department of Stem Cell and Regenerative Biology, and Center for Brain Science, Harvard University, Cambridge, MA 02138, USA
| | - David A Sweetser
- Department of Pediatrics, Divisions of Pediatric Hematology/Oncology and Medical Genetics, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Jeffrey D Macklis
- Department of Stem Cell and Regenerative Biology, and Center for Brain Science, Harvard University, Cambridge, MA 02138, USA.
| |
Collapse
|
8
|
Issa LK, Sekaran NVC, Llano DA. Highly branched and complementary distributions of layer 5 and layer 6 auditory corticofugal axons in mouse. Cereb Cortex 2023; 33:9566-9582. [PMID: 37386697 PMCID: PMC10431747 DOI: 10.1093/cercor/bhad227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 06/05/2023] [Accepted: 06/06/2023] [Indexed: 07/01/2023] Open
Abstract
The auditory cortex exerts a powerful, yet heterogeneous, effect on subcortical targets. Auditory corticofugal projections emanate from layers 5 and 6 and have complementary physiological properties. While several studies suggested that layer 5 corticofugal projections branch widely, others suggested that multiple independent projections exist. Less is known about layer 6; no studies have examined whether the various layer 6 corticofugal projections are independent. Therefore, we examined branching patterns of layers 5 and 6 auditory corticofugal neurons, using the corticocollicular system as an index, using traditional and novel approaches. We confirmed that dual retrograde injections into the mouse inferior colliculus and auditory thalamus co-labeled subpopulations of layers 5 and 6 auditory cortex neurons. We then used an intersectional approach to relabel layer 5 or 6 corticocollicular somata and found that both layers sent extensive branches to multiple subcortical structures. Using a novel approach to separately label layers 5 and 6 axons in individual mice, we found that layers 5 and 6 terminal distributions partially spatially overlapped and that giant terminals were only found in layer 5-derived axons. Overall, the high degree of branching and complementarity in layers 5 and 6 axonal distributions suggest that corticofugal projections should be considered as 2 widespread systems, rather than collections of individual projections.
Collapse
Affiliation(s)
- Lina K Issa
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana—Champaign, Champaign, IL, United States
- Beckman Institute for Advanced Science and Technology, Urbana, IL, United States
| | - Nathiya V C Sekaran
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana—Champaign, Champaign, IL, United States
- Beckman Institute for Advanced Science and Technology, Urbana, IL, United States
| | - Daniel A Llano
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana—Champaign, Champaign, IL, United States
- Beckman Institute for Advanced Science and Technology, Urbana, IL, United States
- Department of Biomedical and Translational Sciences, Carle Illinois College of Medicine, Urbana, IL, United States
- Department of Speech and Hearing Science, University of Illinois at Urbana-Champaign, Champaign, IL, United States
| |
Collapse
|
9
|
Ziegler K, Folkard R, Gonzalez AJ, Burghardt J, Antharvedi-Goda S, Martin-Cortecero J, Isaías-Camacho E, Kaushalya S, Tan LL, Kuner T, Acuna C, Kuner R, Mease RA, Groh A. Primary somatosensory cortex bidirectionally modulates sensory gain and nociceptive behavior in a layer-specific manner. Nat Commun 2023; 14:2999. [PMID: 37225702 DOI: 10.1038/s41467-023-38798-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 05/16/2023] [Indexed: 05/26/2023] Open
Abstract
The primary somatosensory cortex (S1) is a hub for body sensation of both innocuous and noxious signals, yet its role in somatosensation versus pain is debated. Despite known contributions of S1 to sensory gain modulation, its causal involvement in subjective sensory experiences remains elusive. Here, in mouse S1, we reveal the involvement of cortical output neurons in layers 5 (L5) and 6 (L6) in the perception of innocuous and noxious somatosensory signals. We find that L6 activation can drive aversive hypersensitivity and spontaneous nocifensive behavior. Linking behavior to neuronal mechanisms, we find that L6 enhances thalamic somatosensory responses, and in parallel, strongly suppresses L5 neurons. Directly suppressing L5 reproduced the pronociceptive phenotype induced by L6 activation, suggesting an anti-nociceptive function for L5 output. Indeed, L5 activation reduced sensory sensitivity and reversed inflammatory allodynia. Together, these findings reveal a layer-specific and bidirectional role for S1 in modulating subjective sensory experiences.
Collapse
Affiliation(s)
- Katharina Ziegler
- Medical Biophysics, Institute for Physiology and Pathophysiology, Heidelberg University, Heidelberg, Germany
| | - Ross Folkard
- Medical Biophysics, Institute for Physiology and Pathophysiology, Heidelberg University, Heidelberg, Germany
| | - Antonio J Gonzalez
- Medical Biophysics, Institute for Physiology and Pathophysiology, Heidelberg University, Heidelberg, Germany
| | - Jan Burghardt
- Medical Biophysics, Institute for Physiology and Pathophysiology, Heidelberg University, Heidelberg, Germany
| | - Sailaja Antharvedi-Goda
- Medical Biophysics, Institute for Physiology and Pathophysiology, Heidelberg University, Heidelberg, Germany
| | - Jesus Martin-Cortecero
- Medical Biophysics, Institute for Physiology and Pathophysiology, Heidelberg University, Heidelberg, Germany
| | - Emilio Isaías-Camacho
- Medical Biophysics, Institute for Physiology and Pathophysiology, Heidelberg University, Heidelberg, Germany
| | - Sanjeev Kaushalya
- Department of Molecular Pharmacology, Institute for Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Linette Liqi Tan
- Department of Molecular Pharmacology, Institute for Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Thomas Kuner
- Institute for Anatomy and Cell Biology, Heidelberg University, Heidelberg, Germany
| | - Claudio Acuna
- Chica and Heinz Schaller Research Group, Institute for Anatomy and Cell Biology, Heidelberg University, Heidelberg, Germany
| | - Rohini Kuner
- Department of Molecular Pharmacology, Institute for Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Rebecca Audrey Mease
- Medical Biophysics, Institute for Physiology and Pathophysiology, Heidelberg University, Heidelberg, Germany.
| | - Alexander Groh
- Medical Biophysics, Institute for Physiology and Pathophysiology, Heidelberg University, Heidelberg, Germany.
| |
Collapse
|
10
|
Brunelle DL, Llano DA. Role of auditory-somatosensory corticothalamic circuit integration in analgesia. Cell Calcium 2023; 111:102717. [PMID: 36931195 PMCID: PMC10755628 DOI: 10.1016/j.ceca.2023.102717] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 03/07/2023] [Accepted: 03/10/2023] [Indexed: 03/14/2023]
Abstract
Our sensory environment is permeated by a diverse array of auditory and somatosensory stimuli. The pairing of acoustic signals with concurrent or forthcoming tactile cues are abundant in everyday life and various survival contexts across species, thus deeming the ability to integrate sensory inputs arising from the combination of these stimuli as crucial. The corticothalamic system plays a critical role in orchestrating the construction, integration and distribution of the information extracted from these sensory modalities. In this mini-review, we provide a circuit-level description of the auditory corticothalamic pathway in conjunction with adjacent corticothalamic somatosensory projections. Although the extent of the functional interactions shared by these pathways is not entirely elucidated, activation of each of these systems appears to modulate sensory perception in the complementary domain. Several specific issues are reviewed. Under certain environmental noise conditions, the spectral information of a sound could induce modulations in nociception and even induce analgesia. We begin by discussing recent findings by Zhou et al. (2022) implicating the corticothalamic system in mediating sound-induced analgesia. Next, we describe relevant components of the corticothalamic pathway's functional organization. Additionally, we describe an emerging body of literature pointing to intrathalamic circuitry being optimal for controlling and selecting sensory signals across modalities, with the thalamic reticular nucleus being a candidate mechanism for directing cross-modal interactions. Finally, Ca2+ bursting in thalamic neurons evoked by the thalamic reticular nucleus is explored.
Collapse
Affiliation(s)
- Dimitri L Brunelle
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States of America
| | - Daniel A Llano
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States of America; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States of America; Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States of America.
| |
Collapse
|
11
|
Liu Z, He B, Wang X, Peng J, Sun Q, Luo C. Deep cortical microinfarction induced by femtosecond laser in mice: Long-term secondary pathological changes in corresponding superficial cortex. Neurosci Lett 2023; 802:137170. [PMID: 36898650 DOI: 10.1016/j.neulet.2023.137170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 02/19/2023] [Accepted: 03/06/2023] [Indexed: 03/11/2023]
Abstract
BACKGROUND AND PURPOSE Previous studies have explored the clinical consequences of cortical microinfarction, mainly age-related cognitive decline. However, functional impairment of deep cortical microinfarction remains poorly understood. Based on anatomical knowledge and previous research, we infer that damage to the deep cortex may lead to cognitive deficits and communication impairment between the superficial cortex and thalamus. This study aimed to develop a new model of deep cortical microinfarction based on femtosecond laser ablation of a perforating artery. METHODS Twenty-eight mice were anesthetized with isoflurane, and a cranial window was thinned using a microdrill. Intensively focused femtosecond laser pulses were used to produce perforating arteriolar occlusions and ischemic brain damage was examined using histological analysis. RESULTS Occlusion of different perforating arteries induced different types of cortical microinfarctions. Blocking the perforating artery, which enters the cerebral cortex vertically and has no branches within 300 μm below, can result in deep cortical microinfarction. Moreover, this model showed neuronal loss and microglial activation in the lesions as well as dysplasia of nerve fibers and β-amyloid deposition in the corresponding superficial cortex. CONCLUSIONS We present here a new model of deep cortical microinfarction in mice, in which specific perforating arteries are selectively occluded by a femtosecond laser, and we preliminarily observe several long-term effects related to cognition. This animal model is helpful in investigating the pathophysiology of deep cerebral microinfarction. However, further clinical and experimental studies are required to explore deep cortical microinfarctions in greater molecular and physiological detail.
Collapse
Affiliation(s)
- Zhoujing Liu
- Department of Neurology, The Seventh Affiliated Hospital, Sun Yat-Sen University, No. 628 Zhenyuan Road, Shenzhen 518017, China
| | - Baixuan He
- Department of Neurology, Sun Yat-sen Memorial Hospital, Sun Yat-Sen University, No. 107 Yan Jiang West Road, Guangzhou 510120, China
| | - Xuemin Wang
- Department of Neurology, The Seventh Affiliated Hospital, Sun Yat-Sen University, No. 628 Zhenyuan Road, Shenzhen 518017, China
| | - Jiamin Peng
- Department of Neurology, The Seventh Affiliated Hospital, Sun Yat-Sen University, No. 628 Zhenyuan Road, Shenzhen 518017, China
| | - Qiaosong Sun
- Department of Neurology, The Seventh Affiliated Hospital, Sun Yat-Sen University, No. 628 Zhenyuan Road, Shenzhen 518017, China.
| | - Chuanming Luo
- Department of Neurology, The Seventh Affiliated Hospital, Sun Yat-Sen University, No. 628 Zhenyuan Road, Shenzhen 518017, China.
| |
Collapse
|
12
|
English G, Ghasemi Nejad N, Sommerfelt M, Yanik MF, von der Behrens W. Bayesian surprise shapes neural responses in somatosensory cortical circuits. Cell Rep 2023; 42:112009. [PMID: 36701237 DOI: 10.1016/j.celrep.2023.112009] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 09/16/2022] [Accepted: 12/31/2022] [Indexed: 01/26/2023] Open
Abstract
Numerous psychophysical studies show that Bayesian inference governs sensory decision-making; however, the specific neural circuitry underlying this probabilistic mechanism remains unclear. We record extracellular neural activity along the somatosensory pathway of mice while delivering sensory stimulation paradigms designed to isolate the response to the surprise generated by Bayesian inference. Our results demonstrate that laminar cortical circuits in early sensory areas encode Bayesian surprise. Systematic sensitivity to surprise is not identified in the somatosensory thalamus, rather emerging in the primary (S1) and secondary (S2) somatosensory cortices. Multiunit spiking activity and evoked potentials in layer 6 of these regions exhibit the highest sensitivity to surprise. Gamma power in S1 layer 2/3 exhibits an NMDAR-dependent scaling with surprise, as does alpha power in layers 2/3 and 6 of S2. These results show a precise spatiotemporal neural representation of Bayesian surprise and suggest that Bayesian inference is a fundamental component of cortical processing.
Collapse
Affiliation(s)
- Gwendolyn English
- Institute of Neuroinformatics, ETH Zurich & University of Zurich, 8057 Zurich, Switzerland; ZNZ Neuroscience Center Zurich, ETH Zurich & University of Zurich, 8057 Zurich, Switzerland.
| | - Newsha Ghasemi Nejad
- Institute of Neuroinformatics, ETH Zurich & University of Zurich, 8057 Zurich, Switzerland; ZNZ Neuroscience Center Zurich, ETH Zurich & University of Zurich, 8057 Zurich, Switzerland
| | - Marcel Sommerfelt
- Institute of Neuroinformatics, ETH Zurich & University of Zurich, 8057 Zurich, Switzerland
| | - Mehmet Fatih Yanik
- Institute of Neuroinformatics, ETH Zurich & University of Zurich, 8057 Zurich, Switzerland; ZNZ Neuroscience Center Zurich, ETH Zurich & University of Zurich, 8057 Zurich, Switzerland
| | - Wolfger von der Behrens
- Institute of Neuroinformatics, ETH Zurich & University of Zurich, 8057 Zurich, Switzerland; ZNZ Neuroscience Center Zurich, ETH Zurich & University of Zurich, 8057 Zurich, Switzerland.
| |
Collapse
|
13
|
Hayden DJ, Finnie PSB, Thomazeau A, Li AY, Cooke SF, Bear MF. Electrophysiological signatures of visual recognition memory across all layers of mouse V1. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.25.524429. [PMID: 36747661 PMCID: PMC9900851 DOI: 10.1101/2023.01.25.524429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
In mouse primary visual cortex (V1), familiar stimuli evoke significantly altered responses when compared to novel stimuli. This stimulus-selective response plasticity (SRP) was described originally as an increase in the magnitude of visual evoked potentials (VEPs) elicited in layer (L) 4 by familiar phase-reversing grating stimuli. SRP is dependent on NMDA receptors (NMDAR) and has been hypothesized to reflect potentiation of thalamocortical synapses in L4. However, recent evidence indicates that the synaptic modifications that manifest as SRP do not occur on L4 principal cells. To shed light on where and how SRP is induced and expressed, the present study had three related aims: (1) to confirm that NMDAR are required specifically in glutamatergic principal neurons of V1, (2) to investigate the consequences of deleting NMDAR specifically in L6, and (3) to use translaminar electrophysiological recordings to characterize SRP expression in different layers of V1. We find that knockout of NMDAR in L6 principal neurons disrupts SRP. Current-source density analysis of the VEP depth profile shows augmentation of short latency current sinks in layers 3, 4 and 6 in response to phase reversals of familiar stimuli. Multiunit recordings demonstrate that increased peak firing occurs to in response to phase reversals of familiar stimuli across all layers, but that activity between phase reversals is suppressed. Together, these data reveal important aspects of the underlying phenomenology of SRP and generate new hypotheses for the expression of experience-dependent plasticity in V1. Significance Statement Repeated exposure to stimuli that portend neither reward nor punishment leads to behavioral habituation, enabling organisms to dedicate attention to novel or otherwise significant features of the environment. The neural basis of this process, which is so often dysregulated in neurological and psychiatric disorders, remains poorly understood. Learning and memory of stimulus familiarity can be studied in mouse visual cortex by measuring electrophysiological responses to simple phase-reversing grating stimuli. The current study advances knowledge of this process by documenting changes in visual evoked potentials, neuronal spiking activity, and oscillations in the local field potentials across all layers of mouse visual cortex. In addition, we identify a key contribution of a specific population of neurons in layer 6 of visual cortex.
Collapse
|
14
|
Chan RW, Cron GO, Asaad M, Edelman BJ, Lee HJ, Adesnik H, Feinberg D, Lee JH. Distinct local and brain-wide networks are activated by optogenetic stimulation of neurons specific to each layer of motor cortex. Neuroimage 2022; 263:119640. [PMID: 36176220 PMCID: PMC10025169 DOI: 10.1016/j.neuroimage.2022.119640] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 09/13/2022] [Accepted: 09/19/2022] [Indexed: 11/20/2022] Open
Abstract
Primary motor cortex (M1) consists of a stack of interconnected but distinct layers (L1-L6) which affect motor control through large-scale networks. However, the brain-wide functional influence of each layer is poorly understood. We sought to expand our knowledge of these layers' circuitry by combining Cre-driver mouse lines, optogenetics, fMRI, and electrophysiology. Neuronal activities initiated in Drd3 neurons (within L2/3) were mainly confined within M1, while stimulation of Scnn1a, Rbp4, and Ntsr1 neurons (within L4, L5, and L6, respectively) evoked distinct responses in M1 and motor-related subcortical regions, including striatum and motor thalamus. We also found that fMRI responses from targeted stimulations correlated with both local field potentials (LFPs) and spike changes. This study represents a step forward in our understanding of how different layers of primary motor cortex are embedded in brain-wide circuitry.
Collapse
Affiliation(s)
- Russell W Chan
- Department of Neurology and Neurological Sciences, Stanford University, CA 94305, USA
| | - Greg O Cron
- Department of Neurology and Neurological Sciences, Stanford University, CA 94305, USA
| | - Mazen Asaad
- Department of Molecular and Cellular Physiology, Stanford University, CA 94305, USA
| | - Bradley J Edelman
- Department of Neurology and Neurological Sciences, Stanford University, CA 94305, USA
| | - Hyun Joo Lee
- Department of Neurology and Neurological Sciences, Stanford University, CA 94305, USA
| | - Hillel Adesnik
- Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720, USA
| | - David Feinberg
- Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720, USA
| | - Jin Hyung Lee
- Department of Neurology and Neurological Sciences, Stanford University, CA 94305, USA; Department of Bioengineering, Stanford University, CA 94305, USA; Department of Neurosurgery, Stanford University, CA 94305, USA; Department of Electrical Engineering, Stanford University, CA 94305, USA.
| |
Collapse
|
15
|
Dash S, Autio DM, Crandall SR. State-Dependent Modulation of Activity in Distinct Layer 6 Corticothalamic Neurons in Barrel Cortex of Awake Mice. J Neurosci 2022; 42:6551-6565. [PMID: 35863890 PMCID: PMC9410757 DOI: 10.1523/jneurosci.2219-21.2022] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 06/17/2022] [Accepted: 07/15/2022] [Indexed: 11/21/2022] Open
Abstract
Layer 6 corticothalamic (L6 CT) neurons are in a strategic position to control sensory input to the neocortex, yet we understand very little about their functions. Apart from studying their anatomic, physiological, and synaptic properties, most recent efforts have focused on the activity-dependent influences CT cells can exert on thalamic and cortical neurons through causal optogenetic manipulations. However, few studies have attempted to study them during behavior. To address this gap, we performed juxtacellular recordings from optogenetically identified CT neurons in whisker-related primary somatosensory cortex (wS1) of awake, head-fixed mice (either sex) free to rest quietly or self-initiate bouts of whisking and locomotion. We found a rich diversity of response profiles exhibited by CT cells. Their spiking patterns were either modulated by whisking-related behavior (∼28%) or not (∼72%). Whisking-responsive neurons exhibited both increases (activated-type) and decreases in firing rates (suppressed-type) that aligned with whisking onset better than locomotion. We also encountered responsive neurons with preceding modulations in firing rate before whisking onset. Overall, whisking better explained these changes in rates than overall changes in arousal. Whisking-unresponsive CT cells were generally quiet, with many having low spontaneous firing rates (sparse-type) and others being completely silent (silent-type). Remarkably, the sparse firing CT population preferentially spiked at the state transition point when pupil diameter constricted, and the mouse entered quiet wakefulness. Thus, our results demonstrate that L6 CT cells in wS1 show diverse spiking patterns, perhaps subserving distinct functional roles related to precisely timed responses during complex behaviors and transitions between discrete waking states.SIGNIFICANCE STATEMENT Layer 6 corticothalamic neurons provide a massive input to the sensory thalamus and local connectivity within cortex, but their role in thalamocortical processing remains unclear because of difficulty accessing and isolating their activity. Although several recent optogenetic studies reveal that the net influence of corticothalamic actions, suppression versus enhancement, depends critically on the rate these neurons fire, the factors that influence their spiking are poorly understood, particularly during wakefulness. Using the well-established Ntsr1-Cre line to target this elusive population in the whisker somatosensory cortex of awake mice, we found that corticothalamic neurons show diverse state-related responses and modulations in firing rate. These results suggest separate corticothalamic populations can differentially influence thalamocortical excitability during rapid state transitions in awake, behaving animals.
Collapse
Affiliation(s)
- Suryadeep Dash
- Department of Physiology, Michigan State University, East Lansing, Michigan 48824
| | - Dawn M Autio
- Department of Physiology, Michigan State University, East Lansing, Michigan 48824
| | - Shane R Crandall
- Department of Physiology, Michigan State University, East Lansing, Michigan 48824
| |
Collapse
|
16
|
Uygun DS, Basheer R. Circuits and components of delta wave regulation. Brain Res Bull 2022; 188:223-232. [PMID: 35738502 DOI: 10.1016/j.brainresbull.2022.06.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 06/07/2022] [Accepted: 06/14/2022] [Indexed: 11/02/2022]
Abstract
Sleep is vital and the deepest stages of sleep occur within Non-rapid-eye-movement sleep (NREM), defined by high electroencephalographic power in the delta (~0.5-4Hz) wave frequency range. Delta waves are thought to facilitate a myriad of physical and mental health functions. This review aims to comprehensively cover the historical and recent advances in the understanding of the mechanisms orchestrating NREM delta waves. We discuss a complete neurocircuit - focusing on one leg of the circuit at a time - and delve deeply into the molecular mechanistic components that contribute to NREM delta wave regulation. We also discuss the relatively localized nature in which these mechanisms have been defined, and how likely they might generalize across distinct sensory and higher order modalities in the brain.
Collapse
Affiliation(s)
- David S Uygun
- VA Boston Healthcare System and Harvard Medical School, Dept. of Psychiatry, West Roxbury, MA; 02132.
| | - Radhika Basheer
- VA Boston Healthcare System and Harvard Medical School, Dept. of Psychiatry, West Roxbury, MA; 02132.
| |
Collapse
|
17
|
Marin IA, Gutman-Wei AY, Chew KS, Raissi AJ, Djurisic M, Shatz CJ. The nonclassical MHC class I Qa-1 expressed in layer 6 neurons regulates activity-dependent plasticity via microglial CD94/NKG2 in the cortex. Proc Natl Acad Sci U S A 2022; 119:e2203965119. [PMID: 35648829 PMCID: PMC9191652 DOI: 10.1073/pnas.2203965119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 04/20/2022] [Indexed: 12/30/2022] Open
Abstract
During developmental critical periods, circuits are sculpted by a process of activity-dependent competition. The molecular machinery involved in regulating the complex process of responding to different levels of activity is now beginning to be identified. Here, we show that the nonclassical major histocompatibility class I (MHCI) molecule Qa-1 is expressed in the healthy brain in layer 6 corticothalamic neurons. In the visual cortex, Qa-1 expression begins during the critical period for ocular dominance (OD) plasticity and is regulated by neuronal activity, suggesting a role in regulating activity-dependent competition. Indeed, in mice lacking Qa-1, OD plasticity is perturbed. Moreover, signaling through CD94/NKG2, a known cognate Qa-1 heterodimeric receptor in the immune system, is implicated: selectively targeting this interaction phenocopies the plasticity perturbation observed in Qa-1 knockouts. In the cortex, CD94/NKG2 is expressed by microglial cells, which undergo activity-dependent changes in their morphology in a Qa-1–dependent manner. Our study thus reveals a neuron–microglial interaction dependent upon a nonclassical MHCI molecule expressed in L6 neurons, which regulates plasticity in the visual cortex. These results also point to an unexpected function for the Qa-1/HLA-E (ligand) and CD94/NKG2 (receptor) interaction in the nervous system, in addition to that described in the immune system.
Collapse
Affiliation(s)
- Ioana A. Marin
- Department of Biology, Stanford University, Stanford, CA 94035
- Department of Neurobiology, Stanford University, Stanford, CA 94035
| | - Alan Y. Gutman-Wei
- Department of Biology, Stanford University, Stanford, CA 94035
- Department of Neurobiology, Stanford University, Stanford, CA 94035
| | - Kylie S. Chew
- Department of Biology, Stanford University, Stanford, CA 94035
- Department of Neurobiology, Stanford University, Stanford, CA 94035
| | - Aram J. Raissi
- Department of Biology, Stanford University, Stanford, CA 94035
- Department of Neurobiology, Stanford University, Stanford, CA 94035
| | - Maja Djurisic
- Department of Biology, Stanford University, Stanford, CA 94035
- Department of Neurobiology, Stanford University, Stanford, CA 94035
| | - Carla J. Shatz
- Department of Biology, Stanford University, Stanford, CA 94035
- Department of Neurobiology, Stanford University, Stanford, CA 94035
| |
Collapse
|
18
|
Tian D, Izumi SI. Transcranial Magnetic Stimulation and Neocortical Neurons: The Micro-Macro Connection. Front Neurosci 2022; 16:866245. [PMID: 35495053 PMCID: PMC9039343 DOI: 10.3389/fnins.2022.866245] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 02/28/2022] [Indexed: 12/20/2022] Open
Abstract
Understanding the operation of cortical circuits is an important and necessary task in both neuroscience and neurorehabilitation. The functioning of the neocortex results from integrative neuronal activity, which can be probed non-invasively by transcranial magnetic stimulation (TMS). Despite a clear indication of the direct involvement of cortical neurons in TMS, no explicit connection model has been made between the microscopic neuronal landscape and the macroscopic TMS outcome. Here we have performed an integrative review of multidisciplinary evidence regarding motor cortex neurocytology and TMS-related neurophysiology with the aim of elucidating the micro–macro connections underlying TMS. Neurocytological evidence from animal and human studies has been reviewed to describe the landscape of the cortical neurons covering the taxonomy, morphology, circuit wiring, and excitatory–inhibitory balance. Evidence from TMS studies in healthy humans is discussed, with emphasis on the TMS pulse and paradigm selectivity that reflect the underlying neural circuitry constitution. As a result, we propose a preliminary neuronal model of the human motor cortex and then link the TMS mechanisms with the neuronal model by stimulus intensity, direction of induced current, and paired-pulse timing. As TMS bears great developmental potential for both a probe and modulator of neural network activity and neurotransmission, the connection model will act as a foundation for future combined studies of neurocytology and neurophysiology, as well as the technical advances and application of TMS.
Collapse
Affiliation(s)
- Dongting Tian
- Department of Physical Medicine and Rehabilitation, Tohoku University Graduates School of Medicine, Sendai, Japan
- *Correspondence: Dongting Tian,
| | - Shin-Ichi Izumi
- Department of Physical Medicine and Rehabilitation, Tohoku University Graduates School of Medicine, Sendai, Japan
- Graduate School of Biomedical Engineering, Tohoku University, Sendai, Japan
- Shin-Ichi Izumi,
| |
Collapse
|
19
|
Spacek MA, Crombie D, Bauer Y, Born G, Liu X, Katzner S, Busse L. Robust effects of corticothalamic feedback and behavioral state on movie responses in mouse dLGN. eLife 2022; 11:e70469. [PMID: 35315775 PMCID: PMC9020820 DOI: 10.7554/elife.70469] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 03/13/2022] [Indexed: 11/13/2022] Open
Abstract
Neurons in the dorsolateral geniculate nucleus (dLGN) of the thalamus receive a substantial proportion of modulatory inputs from corticothalamic (CT) feedback and brain stem nuclei. Hypothesizing that these modulatory influences might be differentially engaged depending on the visual stimulus and behavioral state, we performed in vivo extracellular recordings from mouse dLGN while optogenetically suppressing CT feedback and monitoring behavioral state by locomotion and pupil dilation. For naturalistic movie clips, we found CT feedback to consistently increase dLGN response gain and promote tonic firing. In contrast, for gratings, CT feedback effects on firing rates were mixed. For both stimulus types, the neural signatures of CT feedback closely resembled those of behavioral state, yet effects of behavioral state on responses to movies persisted even when CT feedback was suppressed. We conclude that CT feedback modulates visual information on its way to cortex in a stimulus-dependent manner, but largely independently of behavioral state.
Collapse
Affiliation(s)
- Martin A Spacek
- Division of Neurobiology, Faculty of Biology, LMU MunichPlanegg-MartinsriedGermany
| | - Davide Crombie
- Division of Neurobiology, Faculty of Biology, LMU MunichPlanegg-MartinsriedGermany
- Graduate School of Systemic Neurosciences, LMU MunichMunichGermany
| | - Yannik Bauer
- Division of Neurobiology, Faculty of Biology, LMU MunichPlanegg-MartinsriedGermany
- Graduate School of Systemic Neurosciences, LMU MunichMunichGermany
| | - Gregory Born
- Division of Neurobiology, Faculty of Biology, LMU MunichPlanegg-MartinsriedGermany
- Graduate School of Systemic Neurosciences, LMU MunichMunichGermany
| | - Xinyu Liu
- Division of Neurobiology, Faculty of Biology, LMU MunichPlanegg-MartinsriedGermany
- Graduate School of Systemic Neurosciences, LMU MunichMunichGermany
| | - Steffen Katzner
- Division of Neurobiology, Faculty of Biology, LMU MunichPlanegg-MartinsriedGermany
| | - Laura Busse
- Division of Neurobiology, Faculty of Biology, LMU MunichPlanegg-MartinsriedGermany
- Bernstein Centre for Computational NeuroscienceMunichGermany
| |
Collapse
|
20
|
Montgomery DP, Hayden DJ, Chaloner FA, Cooke SF, Bear MF. Stimulus-Selective Response Plasticity in Primary Visual Cortex: Progress and Puzzles. Front Neural Circuits 2022; 15:815554. [PMID: 35173586 PMCID: PMC8841555 DOI: 10.3389/fncir.2021.815554] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 12/29/2021] [Indexed: 11/23/2022] Open
Abstract
Stimulus-selective response plasticity (SRP) is a robust and lasting modification of primary visual cortex (V1) that occurs in response to exposure to novel visual stimuli. It is readily observed as a pronounced increase in the magnitude of visual evoked potentials (VEPs) recorded in response to phase-reversing grating stimuli in neocortical layer 4. The expression of SRP at the individual neuron level is equally robust, but the qualities vary depending on the neuronal type and how activity is measured. This form of plasticity is highly selective for stimulus features such as stimulus orientation, spatial frequency, and contrast. Several key insights into the significance and underlying mechanisms of SRP have recently been made. First, it occurs concomitantly and shares core mechanisms with behavioral habituation, indicating that SRP reflects the formation of long-term familiarity that can support recognition of innocuous stimuli. Second, SRP does not manifest within a recording session but only emerges after an off-line period of several hours that includes sleep. Third, SRP requires not only canonical molecular mechanisms of Hebbian synaptic plasticity within V1, but also the opposing engagement of two key subclasses of cortical inhibitory neuron: the parvalbumin- and somatostatin-expressing GABAergic interneurons. Fourth, pronounced shifts in the power of cortical oscillations from high frequency (gamma) to low frequency (alpha/beta) oscillations provide respective readouts of the engagement of these inhibitory neuronal subtypes following familiarization. In this article we will discuss the implications of these findings and the outstanding questions that remain to gain a deeper understanding of this striking form of experience-dependent plasticity.
Collapse
Affiliation(s)
- Daniel P. Montgomery
- Department of Brain and Cognitive Sciences, The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Dustin J. Hayden
- Department of Brain and Cognitive Sciences, The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Francesca A. Chaloner
- MRC Centre for Neurodevelopmental Disorders (CNDD), King’s College London, London, United Kingdom
- Department of Basic and Clinical Neuroscience, The Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
| | - Samuel F. Cooke
- MRC Centre for Neurodevelopmental Disorders (CNDD), King’s College London, London, United Kingdom
- Department of Basic and Clinical Neuroscience, The Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
| | - Mark F. Bear
- Department of Brain and Cognitive Sciences, The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, United States
| |
Collapse
|
21
|
Hage TA, Bosma-Moody A, Baker CA, Kratz MB, Campagnola L, Jarsky T, Zeng H, Murphy GJ. Synaptic connectivity to L2/3 of primary visual cortex measured by two-photon optogenetic stimulation. eLife 2022; 11:71103. [PMID: 35060903 PMCID: PMC8824465 DOI: 10.7554/elife.71103] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 01/19/2022] [Indexed: 12/04/2022] Open
Abstract
Understanding cortical microcircuits requires thorough measurement of physiological properties of synaptic connections formed within and between diverse subclasses of neurons. Towards this goal, we combined spatially precise optogenetic stimulation with multicellular recording to deeply characterize intralaminar and translaminar monosynaptic connections to supragranular (L2/3) neurons in the mouse visual cortex. The reliability and specificity of multiphoton optogenetic stimulation were measured across multiple Cre lines, and measurements of connectivity were verified by comparison to paired recordings and targeted patching of optically identified presynaptic cells. With a focus on translaminar pathways, excitatory and inhibitory synaptic connections from genetically defined presynaptic populations were characterized by their relative abundance, spatial profiles, strength, and short-term dynamics. Consistent with the canonical cortical microcircuit, layer 4 excitatory neurons and interneurons within L2/3 represented the most common sources of input to L2/3 pyramidal cells. More surprisingly, we also observed strong excitatory connections from layer 5 intratelencephalic neurons and potent translaminar inhibition from multiple interneuron subclasses. The hybrid approach revealed convergence to and divergence from excitatory and inhibitory neurons within and across cortical layers. Divergent excitatory connections often spanned hundreds of microns of horizontal space. In contrast, divergent inhibitory connections were more frequently measured from postsynaptic targets near each other.
Collapse
Affiliation(s)
- Travis A Hage
- Electrophysiology, Allen Institute for Brain Science
| | | | | | - Megan B Kratz
- Electrophysiology, Allen Institute for Brain Science
| | | | - Tim Jarsky
- Synaptic Physiology, Allen Institute for Brain Science
| | - Hongkui Zeng
- Synaptic Physiology, Allen Institute for Brain Science
| | - Gabe J Murphy
- Synaptic Physiology, Allen Institute for Brain Science
| |
Collapse
|
22
|
Kim J, Kim DW, Lee A, Mason M, Jouroukhin Y, Woo H, Yolken RH, Pletnikov MV. Homeostatic regulation of neuronal excitability by probiotics in male germ-free mice. J Neurosci Res 2021; 100:444-460. [PMID: 34935171 DOI: 10.1002/jnr.24999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 11/10/2021] [Accepted: 11/27/2021] [Indexed: 11/08/2022]
Abstract
Emerging evidence indicates that probiotics can influence the gut-brain axis to ameliorate somatic and behavioral symptoms associated with brain disorders. However, whether probiotics have effects on the electrophysiological activities of individual neurons in the brain has not been evaluated at a single-neuron resolution, and whether the neuronal effects of probiotics depend on the gut microbiome status have yet to be tested. Thus, we conducted whole-cell patch-clamp recording-assisted electrophysiological characterizations of the neuronal effects of probiotics in male germ-free (GF) mice with and without gut microbiome colonization. Two weeks of treatment with probiotics (Lactobacillus rhamnosus and Bifidobacterium animalis) significantly and selectively increased the intrinsic excitability of hippocampal CA1 pyramidal neurons, whereas reconstituting gut microbiota in GF mice reversed the effects of the probiotics leading to a decreased intrinsic excitability in hippocampal neurons. This bidirectional modulation of neuronal excitability by probiotics was observed in hippocampal neurons with corresponding basal membrane property and action potential waveform changes. However, unlike the hippocampus, the amygdala excitatory neurons did not show any electrophysiological changes to the probiotic treatment in either GF or conventionalized GF mice. Our findings demonstrate for the first time how probiotic treatment can have a significant influence on the electrophysiological properties of neurons, bidirectionally modulating their intrinsic excitability in a gut microbiota and brain area-specific manner.
Collapse
Affiliation(s)
- Juhyun Kim
- Department of Psychiatry and Behavioral Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Dong Won Kim
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Adrian Lee
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Madisen Mason
- Department of Biology, University of New Mexico, Albuquerque, NM, USA
| | - Yan Jouroukhin
- Department of Psychiatry and Behavioral Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Hyewon Woo
- Department of Psychiatry and Behavioral Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Pediatrics, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Robert H Yolken
- Department of Psychiatry and Behavioral Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Stanley Division of Developmental Neurovirology, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Mikhail V Pletnikov
- Department of Psychiatry and Behavioral Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Physiology and Biophysics, Jacobs School of Medicine & Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
| |
Collapse
|
23
|
Breuer TM, Krieger P. Sensory deprivation leads to subpopulation-specific changes in layer 6 corticothalamic cells. Eur J Neurosci 2021; 55:566-588. [PMID: 34927292 DOI: 10.1111/ejn.15572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 12/12/2021] [Accepted: 12/14/2021] [Indexed: 12/01/2022]
Abstract
The effect of sensory deprivation on anatomical and physiological properties in two genetically defined types of layer 6 corticothalamic pyramidal cells in mouse somatosensory barrel cortex was investigated using in vitro electrophysiology. The two types analysed were the L6-Ntsr1 subtype, found preferentially in the upper region of layer 6 and projecting to both ventral posterior medial nucleus of the thalamus and posterior medial nucleus of the thalamus, and the L6-Drd1a subtype, located mostly in the lower regions of layer 6 and projecting to posterior medial nucleus. We found that the apical dendrite in L6-Ntsr1 cells is longer and more branched, compared to L6-Drd1a cells, and that the increase in firing frequency with increasing current stimulation is steeper in L6-Drd1a cells. Sensory deprivation was achieved clipping one row of whiskers from birth until the day of experiment (16 ± 2 days). Mice of this age are actively exploring. In L6-Ntsr1, but not in L6-Drd1a cells, sensory deprivation decreased apical and basal dendrite outgrowth, and calcium influx evoked by backpropagating action potentials. These results contribute to the ongoing functional characterisation of corticothalamic layer 6 cells and indicate differences in the postnatal cortical refinement of two distinct corticothalamic circuits.
Collapse
Affiliation(s)
| | - Patrik Krieger
- Department of Systems Neuroscience, Faculty of Medicine; Ruhr University Bochum, Germany
| |
Collapse
|
24
|
Kirchgessner MA, Franklin AD, Callaway EM. Distinct "driving" versus "modulatory" influences of different visual corticothalamic pathways. Curr Biol 2021; 31:5121-5137.e7. [PMID: 34614389 PMCID: PMC8665059 DOI: 10.1016/j.cub.2021.09.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 07/25/2021] [Accepted: 09/08/2021] [Indexed: 02/04/2023]
Abstract
Higher-order (HO) thalamic nuclei interact extensively and reciprocally with the cerebral cortex. These corticothalamic (CT) interactions are thought to be important for sensation and perception, attention, and many other important brain functions. CT projections to HO thalamic nuclei, such as the visual pulvinar, originate from two different excitatory populations in cortical layers 5 and 6, whereas first-order nuclei (such as the dorsolateral geniculate nucleus; dLGN) only receive layer 6 CT input. It has been proposed that these layer 5 and layer 6 CT pathways have different functional influences on the HO thalamus, but this has never been directly tested. By optogenetically inactivating different CT populations in the primary visual cortex (V1) and recording single-unit activity from V1, dLGN, and pulvinar of awake mice, we demonstrate that layer 5, but not layer 6, CT projections drive visual responses in the pulvinar, even while both pathways provide retinotopic, baseline excitation to their thalamic targets. Inactivating the superior colliculus also suppressed visual responses in the same subregion of the pulvinar, demonstrating that cortical layer 5 and subcortical inputs both contribute to HO visual thalamic activity-even at the level of putative single neurons. Altogether, these results indicate a functional division of "driver" and "modulator" CT pathways from V1 to the visual thalamus in vivo.
Collapse
Affiliation(s)
- Megan A Kirchgessner
- Systems Neurobiology Laboratories, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA; Neurosciences Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Alexis D Franklin
- Systems Neurobiology Laboratories, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Edward M Callaway
- Systems Neurobiology Laboratories, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA; Neurosciences Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA.
| |
Collapse
|
25
|
Whilden CM, Chevée M, An SY, Brown SP. The synaptic inputs and thalamic projections of two classes of layer 6 corticothalamic neurons in primary somatosensory cortex of the mouse. J Comp Neurol 2021; 529:3751-3771. [PMID: 33908623 PMCID: PMC8551307 DOI: 10.1002/cne.25163] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 04/14/2021] [Accepted: 04/19/2021] [Indexed: 12/11/2022]
Abstract
Although corticothalamic neurons (CThNs) represent the largest source of synaptic input to thalamic neurons, their role in regulating thalamocortical interactions remains incompletely understood. CThNs in sensory cortex have historically been divided into two types, those with cell bodies in Layer 6 (L6) that project back to primary sensory thalamic nuclei and those with cell bodies in Layer 5 (L5) that project to higher-order thalamic nuclei and subcortical structures. Recently, diversity among L6 CThNs has increasingly been appreciated. In the rodent somatosensory cortex, two major classes of L6 CThNs have been identified: one projecting to the ventral posterior medial nucleus (VPM-only L6 CThNs) and one projecting to both VPM and the posterior medial nucleus (VPM/POm L6 CThNs). Using rabies-based tracing methods in mice, we asked whether these L6 CThN populations integrate similar synaptic inputs. We found that both types of L6 CThNs received local input from somatosensory cortex and thalamic input from VPM and POm. However, VPM/POm L6 CThNs received significantly more input from a number of additional cortical areas, higher order thalamic nuclei, and subcortical structures. We also found that the two types of L6 CThNs target different functional regions within the thalamic reticular nucleus (TRN). Together, our results indicate that these two types of L6 CThNs represent distinct information streams in the somatosensory cortex and suggest that VPM-only L6 CThNs regulate, via their more restricted circuits, sensory responses related to a cortical column while VPM/POm L6 CThNs, which are integrated into more widespread POm-related circuits, relay contextual information.
Collapse
Affiliation(s)
- Courtney Michelle Whilden
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Program in Neuroscience, Harvard Medical School, Boston, Massachusetts, USA
| | - Maxime Chevée
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Biochemistry, Cellular and Molecular Biology Graduate Program, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, USA
| | - Seong Yeol An
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Solange Pezon Brown
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Kavli Neuroscience Discovery Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| |
Collapse
|
26
|
Adibi M, Lampl I. Sensory Adaptation in the Whisker-Mediated Tactile System: Physiology, Theory, and Function. Front Neurosci 2021; 15:770011. [PMID: 34776857 PMCID: PMC8586522 DOI: 10.3389/fnins.2021.770011] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 09/30/2021] [Indexed: 12/03/2022] Open
Abstract
In the natural environment, organisms are constantly exposed to a continuous stream of sensory input. The dynamics of sensory input changes with organism's behaviour and environmental context. The contextual variations may induce >100-fold change in the parameters of the stimulation that an animal experiences. Thus, it is vital for the organism to adapt to the new diet of stimulation. The response properties of neurons, in turn, dynamically adjust to the prevailing properties of sensory stimulation, a process known as "neuronal adaptation." Neuronal adaptation is a ubiquitous phenomenon across all sensory modalities and occurs at different stages of processing from periphery to cortex. In spite of the wealth of research on contextual modulation and neuronal adaptation in visual and auditory systems, the neuronal and computational basis of sensory adaptation in somatosensory system is less understood. Here, we summarise the recent finding and views about the neuronal adaptation in the rodent whisker-mediated tactile system and further summarise the functional effect of neuronal adaptation on the response dynamics and encoding efficiency of neurons at single cell and population levels along the whisker-mediated touch system in rodents. Based on direct and indirect pieces of evidence presented here, we suggest sensory adaptation provides context-dependent functional mechanisms for noise reduction in sensory processing, salience processing and deviant stimulus detection, shift between integration and coincidence detection, band-pass frequency filtering, adjusting neuronal receptive fields, enhancing neural coding and improving discriminability around adapting stimuli, energy conservation, and disambiguating encoding of principal features of tactile stimuli.
Collapse
Affiliation(s)
- Mehdi Adibi
- Department of Physiology and Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
- Department of Neuroscience and Padova Neuroscience Center (PNC), University of Padova, Padova, Italy
| | - Ilan Lampl
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel
| |
Collapse
|
27
|
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] [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
|
28
|
Gutman-Wei AY, Brown SP. Mechanisms Underlying Target Selectivity for Cell Types and Subcellular Domains in Developing Neocortical Circuits. Front Neural Circuits 2021; 15:728832. [PMID: 34630048 PMCID: PMC8497978 DOI: 10.3389/fncir.2021.728832] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 08/25/2021] [Indexed: 11/25/2022] Open
Abstract
The cerebral cortex contains numerous neuronal cell types, distinguished by their molecular identity as well as their electrophysiological and morphological properties. Cortical function is reliant on stereotyped patterns of synaptic connectivity and synaptic function among these neuron types, but how these patterns are established during development remains poorly understood. Selective targeting not only of different cell types but also of distinct postsynaptic neuronal domains occurs in many brain circuits and is directed by multiple mechanisms. These mechanisms include the regulation of axonal and dendritic guidance and fine-scale morphogenesis of pre- and postsynaptic processes, lineage relationships, activity dependent mechanisms and intercellular molecular determinants such as transmembrane and secreted molecules, many of which have also been implicated in neurodevelopmental disorders. However, many studies of synaptic targeting have focused on circuits in which neuronal processes target different lamina, such that cell-type-biased connectivity may be confounded with mechanisms of laminar specificity. In the cerebral cortex, each cortical layer contains cell bodies and processes from intermingled neuronal cell types, an arrangement that presents a challenge for the development of target-selective synapse formation. Here, we address progress and future directions in the study of cell-type-biased synaptic targeting in the cerebral cortex. We highlight challenges to identifying developmental mechanisms generating stereotyped patterns of intracortical connectivity, recent developments in uncovering the determinants of synaptic target selection during cortical synapse formation, and current gaps in the understanding of cortical synapse specificity.
Collapse
Affiliation(s)
- Alan Y. Gutman-Wei
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Solange P. Brown
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, United States
- Kavli Neuroscience Discovery Institute, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| |
Collapse
|
29
|
Martinetti LE, Bonekamp KE, Autio DM, Kim HH, Crandall SR. Short-Term Facilitation of Long-Range Corticocortical Synapses Revealed by Selective Optical Stimulation. Cereb Cortex 2021; 32:1932-1949. [PMID: 34519352 PMCID: PMC9070351 DOI: 10.1093/cercor/bhab325] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 08/10/2021] [Accepted: 08/11/2021] [Indexed: 11/14/2022] Open
Abstract
Short-term plasticity regulates the strength of central synapses as a function of previous activity. In the neocortex, direct synaptic interactions between areas play a central role in cognitive function, but the activity-dependent regulation of these long-range corticocortical connections and their impact on a postsynaptic target neuron is unclear. Here, we use an optogenetic strategy to study the connections between mouse primary somatosensory and motor cortex. We found that short-term facilitation was strong in both corticocortical synapses, resulting in far more sustained responses than local intracortical and thalamocortical connections. A major difference between pathways was that the synaptic strength and magnitude of facilitation were distinct for individual excitatory cells located across all cortical layers and specific subtypes of GABAergic neurons. Facilitation was dependent on the presynaptic calcium sensor synaptotagmin-7 and altered by several optogenetic approaches. Current-clamp recordings revealed that during repetitive activation, the short-term dynamics of corticocortical synapses enhanced the excitability of layer 2/3 pyramidal neurons, increasing the probability of spiking with activity. Furthermore, the properties of the connections linking primary with secondary somatosensory cortex resemble those between somatosensory-motor areas. These short-term changes in transmission properties suggest long-range corticocortical synapses are specialized for conveying information over relatively extended periods.
Collapse
Affiliation(s)
| | | | - Dawn M Autio
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA
| | - Hye-Hyun Kim
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA
| | | |
Collapse
|
30
|
Antunes FM, Malmierca MS. Corticothalamic Pathways in Auditory Processing: Recent Advances and Insights From Other Sensory Systems. Front Neural Circuits 2021; 15:721186. [PMID: 34489648 PMCID: PMC8418311 DOI: 10.3389/fncir.2021.721186] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Accepted: 07/28/2021] [Indexed: 11/24/2022] Open
Abstract
The corticothalamic (CT) pathways emanate from either Layer 5 (L5) or 6 (L6) of the neocortex and largely outnumber the ascending, thalamocortical pathways. The CT pathways provide the anatomical foundations for an intricate, bidirectional communication between thalamus and cortex. They act as dynamic circuits of information transfer with the ability to modulate or even drive the response properties of target neurons at each synaptic node of the circuit. L6 CT feedback pathways enable the cortex to shape the nature of its driving inputs, by directly modulating the sensory message arriving at the thalamus. L5 CT pathways can drive the postsynaptic neurons and initiate a transthalamic corticocortical circuit by which cortical areas communicate with each other. For this reason, L5 CT pathways place the thalamus at the heart of information transfer through the cortical hierarchy. Recent evidence goes even further to suggest that the thalamus via CT pathways regulates functional connectivity within and across cortical regions, and might be engaged in cognition, behavior, and perceptual inference. As descending pathways that enable reciprocal and context-dependent communication between thalamus and cortex, we venture that CT projections are particularly interesting in the context of hierarchical perceptual inference formulations such as those contemplated in predictive processing schemes, which so far heavily rely on cortical implementations. We discuss recent proposals suggesting that the thalamus, and particularly higher order thalamus via transthalamic pathways, could coordinate and contextualize hierarchical inference in cortical hierarchies. We will explore these ideas with a focus on the auditory system.
Collapse
Affiliation(s)
- Flora M. Antunes
- Cognitive and Auditory Neuroscience Laboratory (CANELAB), Institute of Neuroscience of Castilla y León (INCYL), University of Salamanca, Salamanca, Spain
- Institute for Biomedical Research of Salamanca, University of Salamanca, Salamanca, Spain
| | - Manuel S. Malmierca
- Cognitive and Auditory Neuroscience Laboratory (CANELAB), Institute of Neuroscience of Castilla y León (INCYL), University of Salamanca, Salamanca, Spain
- Institute for Biomedical Research of Salamanca, University of Salamanca, Salamanca, Spain
- Department of Cell Biology and Pathology, School of Medicine, University of Salamanca, Salamanca, Spain
| |
Collapse
|
31
|
Homma NY, Bajo VM. Lemniscal Corticothalamic Feedback in Auditory Scene Analysis. Front Neurosci 2021; 15:723893. [PMID: 34489635 PMCID: PMC8417129 DOI: 10.3389/fnins.2021.723893] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 07/30/2021] [Indexed: 12/15/2022] Open
Abstract
Sound information is transmitted from the ear to central auditory stations of the brain via several nuclei. In addition to these ascending pathways there exist descending projections that can influence the information processing at each of these nuclei. A major descending pathway in the auditory system is the feedback projection from layer VI of the primary auditory cortex (A1) to the ventral division of medial geniculate body (MGBv) in the thalamus. The corticothalamic axons have small glutamatergic terminals that can modulate thalamic processing and thalamocortical information transmission. Corticothalamic neurons also provide input to GABAergic neurons of the thalamic reticular nucleus (TRN) that receives collaterals from the ascending thalamic axons. The balance of corticothalamic and TRN inputs has been shown to refine frequency tuning, firing patterns, and gating of MGBv neurons. Therefore, the thalamus is not merely a relay stage in the chain of auditory nuclei but does participate in complex aspects of sound processing that include top-down modulations. In this review, we aim (i) to examine how lemniscal corticothalamic feedback modulates responses in MGBv neurons, and (ii) to explore how the feedback contributes to auditory scene analysis, particularly on frequency and harmonic perception. Finally, we will discuss potential implications of the role of corticothalamic feedback in music and speech perception, where precise spectral and temporal processing is essential.
Collapse
Affiliation(s)
- Natsumi Y. Homma
- Center for Integrative Neuroscience, University of California, San Francisco, San Francisco, CA, United States
- Coleman Memorial Laboratory, Department of Otolaryngology – Head and Neck Surgery, University of California, San Francisco, San Francisco, CA, United States
| | - Victoria M. Bajo
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| |
Collapse
|
32
|
Meng X, Solarana K, Bowen Z, Liu J, Nagode DA, Sheikh A, Winkowski DE, Kao JPY, Kanold PO. Transient Subgranular Hyperconnectivity to L2/3 and Enhanced Pairwise Correlations During the Critical Period in the Mouse Auditory Cortex. Cereb Cortex 2021; 30:1914-1930. [PMID: 31667495 DOI: 10.1093/cercor/bhz213] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 08/20/2019] [Accepted: 08/20/2019] [Indexed: 11/13/2022] Open
Abstract
During the critical period, neuronal connections are shaped by sensory experience. While the basis for this temporarily heightened plasticity remains unclear, shared connections introducing activity correlations likely play a key role. Thus, we investigated the changing intracortical connectivity in primary auditory cortex (A1) over development. In adult, layer 2/3 (L2/3) neurons receive ascending inputs from layer 4 (L4) and also receive few inputs from subgranular layer 5/6 (L5/6). We measured the spatial pattern of intracortical excitatory and inhibitory connections to L2/3 neurons in slices of mouse A1 across development using laser-scanning photostimulation. Before P11, L2/3 cells receive most excitatory input from within L2/3. Excitatory inputs from L2/3 and L4 increase after P5 and peak during P9-16. L5/6 inputs increase after P5 and provide most input during P12-16, the peak of the critical period. Inhibitory inputs followed a similar pattern. Functional circuit diversity in L2/3 emerges after P16. In vivo two-photon imaging shows low pairwise signal correlations in neighboring neurons before P11, which peak at P15-16 and decline after. Our results suggest that the critical period is characterized by high pairwise activity correlations and that transient hyperconnectivity of specific circuits, in particular those originating in L5/6, might play a key role.
Collapse
Affiliation(s)
- Xiangying Meng
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Krystyna Solarana
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Zac Bowen
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Ji Liu
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Daniel A Nagode
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Aminah Sheikh
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Daniel E Winkowski
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Joseph P Y Kao
- Center for Biomedical Engineering and Technology, and Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Patrick O Kanold
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| |
Collapse
|
33
|
Lindström SH, Sundberg SC, Larsson M, Andersson FK, Broman J, Granseth B. VGluT1 Deficiency Impairs Visual Attention and Reduces the Dynamic Range of Short-Term Plasticity at Corticothalamic Synapses. Cereb Cortex 2021; 30:1813-1829. [PMID: 31711131 PMCID: PMC7132919 DOI: 10.1093/cercor/bhz204] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 08/08/2019] [Accepted: 08/13/2019] [Indexed: 12/17/2022] Open
Abstract
The most common excitatory neurotransmitter in the central nervous system, glutamate, is loaded into synaptic vesicles by vesicular glutamate transporters (VGluTs). The primary isoforms, VGluT1 and 2, are expressed in complementary patterns throughout the brain and correlate with short-term synaptic plasticity. VGluT1 deficiency is observed in certain neurological disorders, and hemizygous (VGluT1+/−) mice display increased anxiety and depression, altered sensorimotor gating, and impairments in learning and memory. The synaptic mechanisms underlying these behavioral deficits are unknown. Here, we show that VGluT1+/− mice had decreased visual processing speeds during a sustained visual-spatial attention task. Furthermore, in vitro recordings of corticothalamic (CT) synapses revealed dramatic reductions in short-term facilitation, increased initial release probability, and earlier synaptic depression in VGluT1+/− mice. Our electron microscopy results show that VGluT1 concentration is reduced at CT synapses of hemizygous mice, but other features (such as vesicle number and active zone size) are unchanged. We conclude that VGluT1-haploinsuficiency decreases the dynamic range of gain modulation provided by CT feedback to the thalamus, and this deficiency contributes to the observed attentional processing deficit. We further hypothesize that VGluT1 concentration regulates release probability by applying a “brake” to an unidentified presynaptic protein that typically acts as a positive regulator of release.
Collapse
Affiliation(s)
- Sarah H Lindström
- Department of Clinical and Experimental Medicine, Division of Neurobiology, Linköping University, Linköping, 58185, Sweden
| | - Sofie C Sundberg
- Department of Clinical and Experimental Medicine, Division of Neurobiology, Linköping University, Linköping, 58185, Sweden
| | - Max Larsson
- Department of Clinical and Experimental Medicine, Division of Neurobiology, Linköping University, Linköping, 58185, Sweden
| | - Fredrik K Andersson
- Department of Clinical and Experimental Medicine, Division of Neurobiology, Linköping University, Linköping, 58185, Sweden
| | - Jonas Broman
- Department of Clinical and Experimental Medicine, Division of Neurobiology, Linköping University, Linköping, 58185, Sweden
| | - Björn Granseth
- Department of Clinical and Experimental Medicine, Division of Neurobiology, Linköping University, Linköping, 58185, Sweden
| |
Collapse
|
34
|
Ibrahim BA, Murphy CA, Yudintsev G, Shinagawa Y, Banks MI, Llano DA. Corticothalamic gating of population auditory thalamocortical transmission in mouse. eLife 2021; 10:e56645. [PMID: 34028350 PMCID: PMC8186908 DOI: 10.7554/elife.56645] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 05/23/2021] [Indexed: 12/12/2022] Open
Abstract
The mechanisms that govern thalamocortical transmission are poorly understood. Recent data have shown that sensory stimuli elicit activity in ensembles of cortical neurons that recapitulate stereotyped spontaneous activity patterns. Here, we elucidate a possible mechanism by which gating of patterned population cortical activity occurs. In this study, sensory-evoked all-or-none cortical population responses were observed in the mouse auditory cortex in vivo and similar stochastic cortical responses were observed in a colliculo-thalamocortical brain slice preparation. Cortical responses were associated with decreases in auditory thalamic synaptic inhibition and increases in thalamic synchrony. Silencing of corticothalamic neurons in layer 6 (but not layer 5) or the thalamic reticular nucleus linearized the cortical responses, suggesting that layer 6 corticothalamic feedback via the thalamic reticular nucleus was responsible for gating stochastic cortical population responses. These data implicate a corticothalamic-thalamic reticular nucleus circuit that modifies thalamic neuronal synchronization to recruit populations of cortical neurons for sensory representations.
Collapse
Affiliation(s)
- Baher A Ibrahim
- Department of Molecular and Integrative Physiology, University of IllinoisUrbana-ChampaignUnited States
- Beckman Institute for Advanced Science and Technology, University of IllinoisUrbana-ChampaignUnited States
| | - Caitlin A Murphy
- Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin-MadisonWisconsin-MadisonUnited States
- Department of Anesthesiology, School of Medicine and Public Health, University of Wisconsin-MadisonWisconsin-MadisonUnited States
| | - Georgiy Yudintsev
- Neuroscience Program, University of IllinoisUrbana-ChampaignUnited States
| | - Yoshitaka Shinagawa
- Department of Molecular and Integrative Physiology, University of IllinoisUrbana-ChampaignUnited States
| | - Matthew I Banks
- Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin-MadisonWisconsin-MadisonUnited States
- Department of Anesthesiology, School of Medicine and Public Health, University of Wisconsin-MadisonWisconsin-MadisonUnited States
| | - Daniel A Llano
- Department of Molecular and Integrative Physiology, University of IllinoisUrbana-ChampaignUnited States
- Beckman Institute for Advanced Science and Technology, University of IllinoisUrbana-ChampaignUnited States
- Neuroscience Program, University of IllinoisUrbana-ChampaignUnited States
- College of Medicine, University of IllinoisUrbana-ChampaignUnited States
| |
Collapse
|
35
|
Delineating the organization of projection neuron subsets in primary visual cortex with multiple fluorescent rabies virus tracing. Brain Struct Funct 2021; 226:951-961. [PMID: 33710409 DOI: 10.1007/s00429-021-02250-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 03/01/2021] [Indexed: 10/21/2022]
Abstract
The impressive functions of the brain rely on an extensive connectivity matrix between specific neurons, the architecture of which is frequently characterized by one brain nucleus/region connecting to multiple targets, either via collaterals of the same projection neuron or several, differentially specified neurons. Delineating the fine architecture of projection neuron subsets in a specific brain region could greatly facilitate its circuit, computational, and functional resolution. Here, we developed multiple fluorescent rabies viruses (RV) to delineate the fine organization of corticothalamic projection neuron subsets in the primary visual cortex (V1). By simultaneously retrograde labeling multiple distinct subsets of corticothalamic projection neurons in V1 from their target nuclei in thalamus (dLGN, LP, LD), we observed that V1-dLGN corticothalamic projection neurons were densely concentrated in layer VI, except for several sparsely scattered neurons in layer V, while V1-LP and V1-LD corticothalamic projection neurons were localized to both layers V and VI. Meanwhile, we observed a fraction of V1 corticothalamic projection neurons targeting two thalamic nuclei, which was further confirmed by fMOST whole-brain imaging. The multiple fluorescent RV tracing tools can be extensively applied to resolve the architecture of projection neuron subsets in certain brain regions, with a strong potential to delineate the computational and functional organization of these brain regions.
Collapse
|
36
|
Burns TF, Rajan R. Sensing and processing whisker deflections in rodents. PeerJ 2021; 9:e10730. [PMID: 33665005 PMCID: PMC7906041 DOI: 10.7717/peerj.10730] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 12/17/2020] [Indexed: 11/20/2022] Open
Abstract
The classical view of sensory information mainly flowing into barrel cortex at layer IV, moving up for complex feature processing and lateral interactions in layers II and III, then down to layers V and VI for output and corticothalamic feedback is becoming increasingly undermined by new evidence. We review the neurophysiology of sensing and processing whisker deflections, emphasizing the general processing and organisational principles present along the entire sensory pathway—from the site of physical deflection at the whiskers to the encoding of deflections in the barrel cortex. Many of these principles support the classical view. However, we also highlight the growing number of exceptions to these general principles, which complexify the system and which investigators should be mindful of when interpreting their results. We identify gaps in the literature for experimentalists and theorists to investigate, not just to better understand whisker sensation but also to better understand sensory and cortical processing.
Collapse
Affiliation(s)
- Thomas F Burns
- Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Ramesh Rajan
- Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| |
Collapse
|
37
|
Sensory Neurobiology: A New Crossroads Deep in the Cortex. Curr Biol 2021; 31:R133-R135. [PMID: 33561413 DOI: 10.1016/j.cub.2020.12.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Self-generated movements elicit concomitant sensory responses that are beneficial to ignore. Combining state-of-the-art physiology, behavior, and anatomy, a new study discovers a neural crossroads in the deepest layer of auditory cortex where pre-lick ramping activity suppresses peri-lick sound responses across layers.
Collapse
|
38
|
Clayton KK, Williamson RS, Hancock KE, Tasaka GI, Mizrahi A, Hackett T, Polley DB. Auditory Corticothalamic Neurons Are Recruited by Motor Preparatory Inputs. Curr Biol 2021; 31:310-321.e5. [PMID: 33157020 PMCID: PMC7855066 DOI: 10.1016/j.cub.2020.10.027] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 10/06/2020] [Accepted: 10/08/2020] [Indexed: 12/22/2022]
Abstract
Corticothalamic (CT) neurons comprise the largest component of the descending sensory corticofugal pathway, but their contributions to brain function and behavior remain an unsolved mystery. To address the hypothesis that layer 6 (L6) CTs may be activated by extra-sensory inputs prior to anticipated sounds, we performed optogenetically targeted single-unit recordings and two-photon imaging of Ntsr1-Cre+ L6 CT neurons in the primary auditory cortex (A1) while mice were engaged in an active listening task. We found that L6 CTs and other L6 units began spiking hundreds of milliseconds prior to orofacial movements linked to sound presentation and reward, but not to other movements such as locomotion, which were not linked to an explicit behavioral task. Rabies tracing of monosynaptic inputs to A1 L6 CT neurons revealed a narrow strip of cholinergic and non-cholinergic projection neurons in the external globus pallidus, suggesting a potential source of motor-related input. These findings identify new pathways and local circuits for motor modulation of sound processing and suggest a new role for CT neurons in active sensing.
Collapse
Affiliation(s)
- Kameron K. Clayton
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, Boston MA 02114 USA
| | - Ross S. Williamson
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, Boston MA 02114 USA
- Dept. Otolaryngology, Harvard Medical School, Boston MA 02114 US
| | - Kenneth E. Hancock
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, Boston MA 02114 USA
- Dept. Otolaryngology, Harvard Medical School, Boston MA 02114 US
| | - Gen-ichi Tasaka
- The Edmond and Lily Safra Center for Brain Sciences, Dept. Neurobiology, Hebrew University of Jerusalem, Jerusalem ISR
| | - Adi Mizrahi
- The Edmond and Lily Safra Center for Brain Sciences, Dept. Neurobiology, Hebrew University of Jerusalem, Jerusalem ISR
| | - Troy Hackett
- Dept. Hearing and Speech Sciences, Vanderbilt University Medical Center, Nashville TN, 37203 USA
| | - Daniel B Polley
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, Boston MA 02114 USA
- Dept. Otolaryngology, Harvard Medical School, Boston MA 02114 US
| |
Collapse
|
39
|
Abstract
The physiological response properties of neurons in the visual system are inherited mainly from feedforward inputs. Interestingly, feedback inputs often outnumber feedforward inputs. Although they are numerous, feedback connections are weaker, slower, and considered to be modulatory, in contrast to fast, high-efficacy feedforward connections. Accordingly, the functional role of feedback in visual processing has remained a fundamental mystery in vision science. At the core of this mystery are questions about whether feedback circuits regulate spatial receptive field properties versus temporal responses among target neurons, or whether feedback serves a more global role in arousal or attention. These proposed functions are not mutually exclusive, and there is compelling evidence to support multiple functional roles for feedback. In this review, the role of feedback in vision will be explored mainly from the perspective of corticothalamic feedback. Further generalized principles of feedback applicable to corticocortical connections will also be considered.
Collapse
Affiliation(s)
- Farran Briggs
- Departments of Neuroscience and Brain and Cognitive Sciences, Del Monte Institute for Neuroscience, and Center for Visual Science, University of Rochester, Rochester, New York 14642, USA;
| |
Collapse
|
40
|
Frandolig JE, Matney CJ, Lee K, Kim J, Chevée M, Kim SJ, Bickert AA, Brown SP. The Synaptic Organization of Layer 6 Circuits Reveals Inhibition as a Major Output of a Neocortical Sublamina. Cell Rep 2020; 28:3131-3143.e5. [PMID: 31533036 DOI: 10.1016/j.celrep.2019.08.048] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 06/24/2019] [Accepted: 08/13/2019] [Indexed: 12/21/2022] Open
Abstract
The canonical cortical microcircuit has principally been defined by interlaminar excitatory connections among the six layers of the neocortex. However, excitatory neurons in layer 6 (L6), a layer whose functional organization is poorly understood, form relatively rare synaptic connections with other cortical excitatory neurons. Here, we show that the vast majority of parvalbumin inhibitory neurons in a sublamina within L6 send axons through the cortical layers toward the pia. These interlaminar inhibitory neurons receive local synaptic inputs from both major types of L6 excitatory neurons and receive stronger input from thalamocortical afferents than do neighboring pyramidal neurons. The distribution of these interlaminar interneurons and their synaptic connectivity further support a functional subdivision within the standard six layers of the cortex. Positioned to integrate local and long-distance inputs in this sublayer, these interneurons generate an inhibitory interlaminar output. These findings call for a revision to the canonical cortical microcircuit.
Collapse
Affiliation(s)
- Jaclyn Ellen Frandolig
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Chanel Joylae Matney
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Kihwan Lee
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Juhyun Kim
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Maxime Chevée
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Biochemistry, Cellular, and Molecular Biology Graduate Program, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Su-Jeong Kim
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Aaron Andrew Bickert
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Solange Pezon Brown
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Kavli Neuroscience Discovery Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| |
Collapse
|
41
|
Staiger JF, Petersen CCH. Neuronal Circuits in Barrel Cortex for Whisker Sensory Perception. Physiol Rev 2020; 101:353-415. [PMID: 32816652 DOI: 10.1152/physrev.00019.2019] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The array of whiskers on the snout provides rodents with tactile sensory information relating to the size, shape and texture of objects in their immediate environment. Rodents can use their whiskers to detect stimuli, distinguish textures, locate objects and navigate. Important aspects of whisker sensation are thought to result from neuronal computations in the whisker somatosensory cortex (wS1). Each whisker is individually represented in the somatotopic map of wS1 by an anatomical unit named a 'barrel' (hence also called barrel cortex). This allows precise investigation of sensory processing in the context of a well-defined map. Here, we first review the signaling pathways from the whiskers to wS1, and then discuss current understanding of the various types of excitatory and inhibitory neurons present within wS1. Different classes of cells can be defined according to anatomical, electrophysiological and molecular features. The synaptic connectivity of neurons within local wS1 microcircuits, as well as their long-range interactions and the impact of neuromodulators, are beginning to be understood. Recent technological progress has allowed cell-type-specific connectivity to be related to cell-type-specific activity during whisker-related behaviors. An important goal for future research is to obtain a causal and mechanistic understanding of how selected aspects of tactile sensory information are processed by specific types of neurons in the synaptically connected neuronal networks of wS1 and signaled to downstream brain areas, thus contributing to sensory-guided decision-making.
Collapse
Affiliation(s)
- Jochen F Staiger
- University Medical Center Göttingen, Institute for Neuroanatomy, Göttingen, Germany; and Laboratory of Sensory Processing, Faculty of Life Sciences, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Carl C H Petersen
- University Medical Center Göttingen, Institute for Neuroanatomy, Göttingen, Germany; and Laboratory of Sensory Processing, Faculty of Life Sciences, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| |
Collapse
|
42
|
Bennett M. An Attempt at a Unified Theory of the Neocortical Microcircuit in Sensory Cortex. Front Neural Circuits 2020; 14:40. [PMID: 32848632 PMCID: PMC7416357 DOI: 10.3389/fncir.2020.00040] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 06/15/2020] [Indexed: 11/13/2022] Open
Abstract
The neocortex performs a wide range of functions, including working memory, sensory perception, and motor planning. Despite this diversity in function, evidence suggests that the neocortex is made up of repeating subunits ("macrocolumns"), each of which is largely identical in circuitry. As such, the specific computations performed by these macrocolumns are of great interest to neuroscientists and AI researchers. Leading theories of this microcircuit include models of predictive coding, hierarchical temporal memory (HTM), and Adaptive Resonance Theory (ART). However, these models have not yet explained: (1) how microcircuits learn sequences input with delay (i.e., working memory); (2) how networks of columns coordinate processing on precise timescales; or (3) how top-down attention modulates sensory processing. I provide a theory of the neocortical microcircuit that extends prior models in all three ways. Additionally, this theory provides a novel working memory circuit that extends prior models to support simultaneous multi-item storage without disrupting ongoing sensory processing. I then use this theory to explain the functional origin of a diverse set of experimental findings, such as cortical oscillations.
Collapse
Affiliation(s)
- Max Bennett
- Independent Researcher, New York, NY, United States
| |
Collapse
|
43
|
Induction of BDNF Expression in Layer II/III and Layer V Neurons of the Motor Cortex Is Essential for Motor Learning. J Neurosci 2020; 40:6289-6308. [PMID: 32651187 PMCID: PMC7424868 DOI: 10.1523/jneurosci.0288-20.2020] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 06/09/2020] [Accepted: 06/25/2020] [Indexed: 12/16/2022] Open
Abstract
Motor learning depends on synaptic plasticity between corticostriatal projections and striatal medium spiny neurons. Retrograde tracing from the dorsolateral striatum reveals that both layer II/III and V neurons in the motor cortex express BDNF as a potential regulator of plasticity in corticostriatal projections in male and female mice. The number of these BDNF-expressing cortical neurons and levels of BDNF protein are highest in juvenile mice when adult motor patterns are shaped, while BDNF levels in the adult are low. When mice are trained by physical exercise in the adult, BDNF expression in motor cortex is reinduced, especially in layer II/III projection neurons. Reduced expression of cortical BDNF in 3-month-old mice results in impaired motor learning while space memory is preserved. These findings suggest that activity regulates BDNF expression differentially in layers II/III and V striatal afferents from motor cortex and that cortical BDNF is essential for motor learning. SIGNIFICANCE STATEMENT Motor learning in mice depends on corticostriatal BDNF supply, and regulation of BDNF expression during motor learning is highest in corticostriatal projection neurons in cortical layer II/III.
Collapse
|
44
|
Vecchia D, Beltramo R, Vallone F, Chéreau R, Forli A, Molano-Mazón M, Bawa T, Binini N, Moretti C, Holtmaat A, Panzeri S, Fellin T. Temporal Sharpening of Sensory Responses by Layer V in the Mouse Primary Somatosensory Cortex. Curr Biol 2020; 30:1589-1599.e10. [PMID: 32169206 PMCID: PMC7198976 DOI: 10.1016/j.cub.2020.02.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 01/16/2020] [Accepted: 02/03/2020] [Indexed: 01/14/2023]
Abstract
The timing of stimulus-evoked spikes encodes information about sensory stimuli. Here we studied the neural circuits controlling this process in the mouse primary somatosensory cortex. We found that brief optogenetic activation of layer V pyramidal cells just after whisker deflection modulated the membrane potential of neurons and interrupted their long-latency whisker responses, increasing their accuracy in encoding whisker deflection time. In contrast, optogenetic inhibition of layer V during either passive whisker deflection or active whisking decreased accuracy in encoding stimulus or touch time, respectively. Suppression of layer V pyramidal cells increased reaction times in a texture discrimination task. Moreover, two-color optogenetic experiments revealed that cortical inhibition was efficiently recruited by layer V stimulation and that it mainly involved activation of parvalbumin-positive rather than somatostatin-positive interneurons. Layer V thus performs behaviorally relevant temporal sharpening of sensory responses through circuit-specific recruitment of cortical inhibition.
Collapse
Affiliation(s)
- Dania Vecchia
- Optical Approaches to Brain Function Laboratory, Istituto Italiano di Tecnologia, 16163 Genova, Italy; Neural Coding Laboratory, Istituto Italiano di Tecnologia, 16163 Genova and 38068 Rovereto, Italy
| | - Riccardo Beltramo
- Optical Approaches to Brain Function Laboratory, Istituto Italiano di Tecnologia, 16163 Genova, Italy
| | - Fabio Vallone
- Neural Coding Laboratory, Istituto Italiano di Tecnologia, 16163 Genova and 38068 Rovereto, Italy
| | - Ronan Chéreau
- Department of Basic Neurosciences, Geneva University Neurocenter, Faculty of Medicine, University of Geneva, 1206 Geneva, Switzerland
| | - Angelo Forli
- Optical Approaches to Brain Function Laboratory, Istituto Italiano di Tecnologia, 16163 Genova, Italy; Neural Coding Laboratory, Istituto Italiano di Tecnologia, 16163 Genova and 38068 Rovereto, Italy
| | - Manuel Molano-Mazón
- Neural Coding Laboratory, Istituto Italiano di Tecnologia, 16163 Genova and 38068 Rovereto, Italy; Neural Computation Laboratory, Center for Neuroscience and Cognitive Systems @UniTn, Istituto Italiano di Tecnologia, 38068 Rovereto, Italy
| | - Tanika Bawa
- Department of Basic Neurosciences, Geneva University Neurocenter, Faculty of Medicine, University of Geneva, 1206 Geneva, Switzerland
| | - Noemi Binini
- Optical Approaches to Brain Function Laboratory, Istituto Italiano di Tecnologia, 16163 Genova, Italy; Neural Coding Laboratory, Istituto Italiano di Tecnologia, 16163 Genova and 38068 Rovereto, Italy
| | - Claudio Moretti
- Optical Approaches to Brain Function Laboratory, Istituto Italiano di Tecnologia, 16163 Genova, Italy; Neural Coding Laboratory, Istituto Italiano di Tecnologia, 16163 Genova and 38068 Rovereto, Italy
| | - Anthony Holtmaat
- Department of Basic Neurosciences, Geneva University Neurocenter, Faculty of Medicine, University of Geneva, 1206 Geneva, Switzerland
| | - Stefano Panzeri
- Neural Coding Laboratory, Istituto Italiano di Tecnologia, 16163 Genova and 38068 Rovereto, Italy; Neural Computation Laboratory, Center for Neuroscience and Cognitive Systems @UniTn, Istituto Italiano di Tecnologia, 38068 Rovereto, Italy
| | - Tommaso Fellin
- Optical Approaches to Brain Function Laboratory, Istituto Italiano di Tecnologia, 16163 Genova, Italy; Neural Coding Laboratory, Istituto Italiano di Tecnologia, 16163 Genova and 38068 Rovereto, Italy.
| |
Collapse
|
45
|
Fong MF, Finnie PS, Kim T, Thomazeau A, Kaplan ES, Cooke SF, Bear MF. Distinct Laminar Requirements for NMDA Receptors in Experience-Dependent Visual Cortical Plasticity. Cereb Cortex 2020; 30:2555-2572. [PMID: 31832634 PMCID: PMC7174998 DOI: 10.1093/cercor/bhz260] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 08/23/2019] [Accepted: 09/17/2019] [Indexed: 11/13/2022] Open
Abstract
Primary visual cortex (V1) is the locus of numerous forms of experience-dependent plasticity. Restricting visual stimulation to one eye at a time has revealed that many such forms of plasticity are eye-specific, indicating that synaptic modification occurs prior to binocular integration of thalamocortical inputs. A common feature of these forms of plasticity is the requirement for NMDA receptor (NMDAR) activation in V1. We therefore hypothesized that NMDARs in cortical layer 4 (L4), which receives the densest thalamocortical input, would be necessary for all forms of NMDAR-dependent and input-specific V1 plasticity. We tested this hypothesis in awake mice using a genetic approach to selectively delete NMDARs from L4 principal cells. We found, unexpectedly, that both stimulus-selective response potentiation and potentiation of open-eye responses following monocular deprivation (MD) persist in the absence of L4 NMDARs. In contrast, MD-driven depression of deprived-eye responses was impaired in mice lacking L4 NMDARs, as was L4 long-term depression in V1 slices. Our findings reveal a crucial requirement for L4 NMDARs in visual cortical synaptic depression, and a surprisingly negligible role for them in cortical response potentiation. These results demonstrate that NMDARs within distinct cellular subpopulations support different forms of experience-dependent plasticity.
Collapse
Affiliation(s)
- Ming-fai Fong
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Peter Sb Finnie
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Taekeun Kim
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Aurore Thomazeau
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Eitan S Kaplan
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA 98101, USA
| | - Samuel F Cooke
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Maurice Wohl Institute for Clinical Neuroscience, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London SE5 8AF, UK
- The Medical Research Council Centre for Neurodevelopmental Disorders (MRC CNDD), King's College London, London SE5 8AF, UK
| | - Mark F Bear
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| |
Collapse
|
46
|
Guo K, Yamawaki N, Barrett JM, Tapies M, Shepherd GMG. Cortico-Thalamo-Cortical Circuits of Mouse Forelimb S1 Are Organized Primarily as Recurrent Loops. J Neurosci 2020; 40:2849-2858. [PMID: 32075900 PMCID: PMC7117898 DOI: 10.1523/jneurosci.2277-19.2020] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 01/29/2020] [Accepted: 01/30/2020] [Indexed: 11/21/2022] Open
Abstract
Cortical projections to the thalamus arise from corticothalamic (CT) neurons in layer 6 and pyramidal tract-type (PT) neurons in layer 5B. We dissected the excitatory synaptic connections in the somatosensory thalamus formed by CT and PT neurons of the primary somatosensory (S1) cortex, focusing on mouse forelimb S1. Mice of both sexes were studied. The CT neurons in S1 synaptically excited S1-projecting thalamocortical (TC) neurons in subregions of both the ventral posterior lateral and posterior (PO) nuclei, forming a pair of recurrent cortico-thalamo-cortical (C-T-C) loops. The PT neurons in S1 also formed a recurrent loop with S1-projecting TC neurons in the same subregion of the PO. The PT neurons in the adjacent primary motor (M1) cortex formed a separate recurrent loop with M1-projecting TC neurons in a nearby subregion of the PO. Collectively, our results reveal that C-T-C circuits of mouse forelimb S1 are primarily organized as multiple cortical cell-type-specific and thalamic subnucleus-specific recurrent loops, with both CT and PT neurons providing the strongest excitatory input to TC neurons that project back to S1. The findings, together with those of related studies of C-T-C circuits, thus suggest that recurrently projecting thalamocortical neurons are the principal targets of cortical excitatory input to the mouse somatosensory and motor thalamus.SIGNIFICANCE STATEMENT Bidirectional cortical communication with the thalamus is considered an important aspect of sensorimotor integration for active touch in the somatosensory system, but the cellular organization of the circuits mediating this process is not well understood. We used an approach combining cell-type-specific anterograde optogenetic excitation with single-cell recordings targeted to retrogradely labeled thalamocortical neurons to dissect these circuits. The findings reveal a consistent pattern: cortical projections to the somatosensory thalamus target thalamocortical neurons that project back to the same cortical area. Commonalities of these findings to previous descriptions of related circuits in other areas suggest that cortico-thalamo-cortical circuits may generally be organized primarily as recurrent loops.
Collapse
Affiliation(s)
- KuangHua Guo
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611
| | - Naoki Yamawaki
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611
| | - John M Barrett
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611
| | - Martinna Tapies
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611
| | - Gordon M G Shepherd
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611
| |
Collapse
|
47
|
Kast RJ, Wu HH, Levitt P. Developmental Connectivity and Molecular Phenotypes of Unique Cortical Projection Neurons that Express a Synapse-Associated Receptor Tyrosine Kinase. Cereb Cortex 2020; 29:189-201. [PMID: 29190358 DOI: 10.1093/cercor/bhx318] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 11/01/2017] [Indexed: 12/15/2022] Open
Abstract
The complex circuitry and cell-type diversity of the cerebral cortex are required for its high-level functions. The mechanisms underlying the diversification of cortical neurons during prenatal development have received substantial attention, but understanding of neuronal heterogeneity is more limited during later periods of cortical circuit maturation. To address this knowledge gap, connectivity analysis and molecular phenotyping of cortical neuron subtypes that express the developing synapse-enriched MET receptor tyrosine kinase were performed. Experiments used a MetGFP transgenic mouse line, combined with coexpression analysis of class-specific molecular markers and retrograde connectivity mapping. The results reveal that MET is expressed by a minor subset of subcerebral and a larger number of intratelencephalic projection neurons. Remarkably, MET is excluded from most layer 6 corticothalamic neurons. These findings are particularly relevant for understanding the maturation of discrete cortical circuits, given converging evidence that MET influences dendritic elaboration and glutamatergic synapse maturation. The data suggest that classically defined cortical projection classes can be further subdivided based on molecular characteristics that likely influence synaptic maturation and circuit wiring. Additionally, given that MET is classified as a high confidence autism risk gene, the data suggest that projection neuron subpopulations may be differentially vulnerable to disorder-associated genetic variation.
Collapse
Affiliation(s)
- Ryan J Kast
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, USA.,Department of Pediatrics, The Saban Research Institute, Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.,The Institute for the Developing Mind, The Saban Research Institute, Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Hsiao-Huei Wu
- Department of Pediatrics, The Saban Research Institute, Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.,The Institute for the Developing Mind, The Saban Research Institute, Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Pat Levitt
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, USA.,Department of Pediatrics, The Saban Research Institute, Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.,The Institute for the Developing Mind, The Saban Research Institute, Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| |
Collapse
|
48
|
Layer 6b Is Driven by Intracortical Long-Range Projection Neurons. Cell Rep 2020; 30:3492-3505.e5. [DOI: 10.1016/j.celrep.2020.02.044] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 09/20/2019] [Accepted: 02/10/2020] [Indexed: 01/03/2023] Open
|
49
|
In Vivo Two-photon Calcium Imaging in Dendrites of Rabies Virus-labeled V1 Corticothalamic Neurons. Neurosci Bull 2019; 36:545-553. [PMID: 31808041 DOI: 10.1007/s12264-019-00452-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 10/04/2019] [Indexed: 01/20/2023] Open
Abstract
Monitoring neuronal activity in vivo is critical to understanding the physiological or pathological functions of the brain. Two-photon Ca2+ imaging in vivo using a cranial window and specific neuronal labeling enables real-time, in situ, and long-term imaging of the living brain. Here, we constructed a recombinant rabies virus containing the Ca2+ indicator GCaMP6s along with the fluorescent protein DsRed2 as a baseline reference to ensure GCaMP6s signal reliability. This functional tracer was applied to retrogradely label specific V1-thalamus circuits and detect spontaneous Ca2+ activity in the dendrites of V1 corticothalamic neurons by in vivo two-photon Ca2+ imaging. Notably, we were able to record single-spine spontaneous Ca2+ activity in specific circuits. Distinct spontaneous Ca2+ dynamics in dendrites of V1 corticothalamic neurons were found for different V1-thalamus circuits. Our method can be applied to monitor Ca2+ dynamics in specific input circuits in vivo, and contribute to functional studies of defined neural circuits and the dissection of functional circuit connections.
Collapse
|
50
|
Pauzin FP, Schwarz N, Krieger P. Activation of Corticothalamic Layer 6 Cells Decreases Angular Tuning in Mouse Barrel Cortex. Front Neural Circuits 2019; 13:67. [PMID: 31736714 PMCID: PMC6838007 DOI: 10.3389/fncir.2019.00067] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 09/30/2019] [Indexed: 01/21/2023] Open
Abstract
In the mouse whisker system, the contribution of L6 corticothalamic cells (L6 CT) to cortical and thalamic processing of the whisker deflection direction was investigated. A genetically defined population of L6 CT cells project to infragranular GABAergic interneurons that hyperpolarize neurons in somatosensory barrel cortex (BC). Optogenetic activation of these neurons switched BC to an adapted mode in which excitatory cells lost their angular tuning. In contrast, however, this was not the case with a general activation of inhibitory interneurons via optogenetic activation of Gad2-expressing cells. The decrease in angular tuning, when L6 CT cells were activated, was due to changes in cortical inhibition, and not inherited from changes in the thalamic output. Furthermore, L6 CT driven cortical inhibition, but not the general activation of GABAergic interneurons, abolished adaptation to whisker responses. In the present study, evidence is presented that a subpopulation of L6 CT activates a specific circuit of GABAergic interneurons that will predispose neocortex toward processing of tactile information requiring multiple whisker touches, such as in a texture discrimination task.
Collapse
Affiliation(s)
- François Philippe Pauzin
- Department of Systems Neuroscience, Faculty of Medicine, Ruhr University Bochum, Bochum, Germany
| | - Nadja Schwarz
- Department of Systems Neuroscience, Faculty of Medicine, Ruhr University Bochum, Bochum, Germany
| | - Patrik Krieger
- Department of Systems Neuroscience, Faculty of Medicine, Ruhr University Bochum, Bochum, Germany
| |
Collapse
|