1
|
Xavier AM, Lin Q, Kang CJ, Cheadle L. A single-cell transcriptomic atlas of sensory-dependent gene expression in developing mouse visual cortex. Development 2025; 152:dev204244. [PMID: 40018816 DOI: 10.1242/dev.204244] [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: 07/12/2024] [Accepted: 02/20/2025] [Indexed: 03/01/2025]
Abstract
Sensory experience drives the maturation of neural circuits during postnatal brain development through molecular mechanisms that remain to be fully elucidated. One likely mechanism involves the sensory-dependent expression of genes that encode direct mediators of circuit remodeling within developing cells. To identify potential drivers of sensory-dependent synaptic development, we generated a single-nucleus RNA sequencing dataset describing the transcriptional responses of cells in the mouse visual cortex to sensory deprivation or to stimulation during a developmental window when visual input is necessary for circuit refinement. We sequenced 118,529 nuclei across 16 neuronal and non-neuronal cell types isolated from control, sensory deprived and sensory stimulated mice, identifying 1268 sensory-induced genes within the developing brain. While experience elicited transcriptomic changes in all cell types, excitatory neurons in layer 2/3 exhibited the most robust changes, and the sensory-induced genes in these cells are poised to strengthen synapse-to-nucleus crosstalk and to promote cell type-specific axon guidance pathways. Altogether, we expect this dataset to significantly broaden our understanding of the molecular mechanisms through which sensory experience shapes neural circuit wiring in the developing brain.
Collapse
Affiliation(s)
- Andre M Xavier
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Qianyu Lin
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Chris J Kang
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Lucas Cheadle
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
- Howard Hughes Medical Institute, Cold Spring Harbor, NY 11724, USA
| |
Collapse
|
2
|
Sonoda T, Stephany CÉ, Kelley K, Kang D, Wu R, Uzgare MR, Fagiolini M, Greenberg ME, Chen C. Experience influences the refinement of feature selectivity in the mouse primary visual thalamus. Neuron 2025; 113:1352-1362.e4. [PMID: 40112812 DOI: 10.1016/j.neuron.2025.02.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 01/15/2025] [Accepted: 02/20/2025] [Indexed: 03/22/2025]
Abstract
Neurons exhibit selectivity for specific features: a property essential for extracting and encoding relevant information in the environment. This feature selectivity is thought to be modifiable by experience at the level of the cortex. Here, we demonstrate that selective exposure to a feature during development can alter the population representation of that feature in the primary visual thalamus. This thalamic plasticity is not due to changes in corticothalamic inputs and is blocked in mutant mice that exhibit deficits in retinogeniculate refinement, suggesting that plasticity is a direct result of changes in feedforward connectivity. Notably, experience-dependent changes in thalamic feature selectivity also occur in adult animals, although these changes are transient, unlike in juvenile animals, where they are long lasting. These results reveal an unexpected degree of plasticity in the visual thalamus and show that salient environmental features can be encoded in thalamic circuits during a discrete developmental window.
Collapse
Affiliation(s)
- Takuma Sonoda
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA
| | - Céleste-Élise Stephany
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA
| | - Kaleb Kelley
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA
| | - Di Kang
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA
| | - Rui Wu
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA; Harvard-MIT Health Sciences and Technology Program, Harvard Medical School, Boston, MA 02115, USA
| | - Meghna R Uzgare
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA
| | - Michela Fagiolini
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA
| | | | - Chinfei Chen
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA; Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
| |
Collapse
|
3
|
Pan M, Ye J, Yan Y, Chen A, Li X, Jiang X, Wang W, Meng X, Chen S, Gu Y, Shi X. Experience-dependent plasticity of multiple receptive field properties in lateral geniculate binocular neurons during the critical period. Front Cell Neurosci 2025; 19:1574505. [PMID: 40357170 PMCID: PMC12066550 DOI: 10.3389/fncel.2025.1574505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2025] [Accepted: 04/07/2025] [Indexed: 05/15/2025] Open
Abstract
The visual thalamus serves as a critical hub for feature preprocessing in visual processing pathways. Emerging evidence demonstrates that experience-dependent plasticity can be revealed by monocular deprivation (MD) in the dorsolateral geniculate nucleus (dLGN) of the thalamus. However, whether and how this thalamic plasticity induces changes in multiple receptive field properties and the potential mechanisms remain unclear. Using in vivo electrophysiology, here we show that binocular neurons in the dLGN of 4-day MD mice starting at P28 undergo a significant ocular dominance (OD) shift during the critical period. This OD plasticity could be attributed to the potentiation of ipsilateral eye responses but not to the depression of deprived eye responses, contrasting with conventional observations in the primary visual cortex (V1). The direction and orientation selectivity of ipsilateral eye responses, but not of contralateral eye responses in these neurons, were dramatically reduced. Developmental analysis revealed pre-critical and critical period-associated changes in densities of both GABA positive neurons and GABAA receptor α1 subunit (GABRA1) positive neurons. However, early compensatory inhibition from V1 feedback in P18 MD mice maintained network stability with no changes in OD and feature selectivity. Mechanistically, pharmacological activation of GABAA receptors rescued the MD-induced OD shifts and feature selectivity impairments in critical period MD mice, operating independently of the V1 feedback. Furthermore, under different contrast levels and spatial frequencies, these critical period-associated changes in receptive field properties still indicate alterations in ipsilateral eye responses alone. Together, these findings provide novel insights into the developmental mechanisms of thalamic sensory processing, highlighting the thalamus as an active participant in experience-dependent visual plasticity rather than merely a passive relay station. The identified GABA-mediated plasticity mechanisms offer potential therapeutic targets for visual system disorders.
Collapse
Affiliation(s)
- Meng Pan
- Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Eye Institute, Tianjin Eye Hospital, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
| | - Jingjing Ye
- Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Eye Institute, Tianjin Eye Hospital, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
| | - Yijing Yan
- Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Eye Institute, Tianjin Eye Hospital, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
| | - Ailin Chen
- Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Eye Institute, Tianjin Eye Hospital, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
| | - Xinyu Li
- Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Eye Institute, Tianjin Eye Hospital, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
| | - Xin Jiang
- Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Eye Institute, Tianjin Eye Hospital, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
- School of Medicine, Nankai University, Tianjin, China
| | - Wei Wang
- Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Eye Institute, Tianjin Eye Hospital, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
| | - Xin Meng
- Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Eye Institute, Tianjin Eye Hospital, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
| | - Shujian Chen
- Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Eye Institute, Tianjin Eye Hospital, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
| | - Yu Gu
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Xuefeng Shi
- Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Eye Institute, Tianjin Eye Hospital, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
- School of Medicine, Nankai University, Tianjin, China
| |
Collapse
|
4
|
Nagappan-Chettiar S, Burbridge TJ, Umemori H. Activity-Dependent Synapse Refinement: From Mechanisms to Molecules. Neuroscientist 2024; 30:673-689. [PMID: 37140155 PMCID: PMC11584027 DOI: 10.1177/10738584231170167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The refinement of immature neuronal networks into efficient mature ones is critical to nervous system development and function. This process of synapse refinement is driven by the neuronal activity-dependent competition of converging synaptic inputs, resulting in the elimination of weak inputs and the stabilization of strong ones. Neuronal activity, whether in the form of spontaneous activity or experience-evoked activity, is known to drive synapse refinement in numerous brain regions. More recent studies are now revealing the manner and mechanisms by which neuronal activity is detected and converted into molecular signals that appropriately regulate the elimination of weaker synapses and stabilization of stronger ones. Here, we highlight how spontaneous activity and evoked activity instruct neuronal activity-dependent competition during synapse refinement. We then focus on how neuronal activity is transformed into the molecular cues that determine and execute synapse refinement. A comprehensive understanding of the mechanisms underlying synapse refinement can lead to novel therapeutic strategies in neuropsychiatric diseases characterized by aberrant synaptic function.
Collapse
Affiliation(s)
- Sivapratha Nagappan-Chettiar
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Timothy J. Burbridge
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Hisashi Umemori
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| |
Collapse
|
5
|
Rogerson-Wood L, Goldsbury CS, Sawatari A, Leamey CA. An early enriched experience drives targeted microglial engulfment of miswired neural circuitry during a restricted postnatal period. Glia 2024; 72:1217-1235. [PMID: 38511347 DOI: 10.1002/glia.24522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 02/17/2024] [Accepted: 02/27/2024] [Indexed: 03/22/2024]
Abstract
Brain function is critically dependent on correct circuit assembly. Microglia are well-known for their important roles in immunological defense and neural plasticity, but whether they can also mediate experience-induced correction of miswired circuitry is unclear. Ten-m3 knockout (KO) mice display a pronounced and stereotyped visuotopic mismapping of ipsilateral retinal inputs in their visual thalamus, providing a useful model to probe circuit correction mechanisms. Environmental enrichment (EE) commenced around birth, but not later in life, can drive a partial correction of the most mismapped retinal inputs in Ten-m3 KO mice. Here, we assess whether enrichment unlocks the capacity for microglia to selectively engulf and remove miswired circuitry, and the timing of this effect. Expression of the microglial-associated lysosomal protein CD68 showed a clear enrichment-driven, spatially restricted change which had not commenced at postnatal day (P)18, was evident at P21, more robust at P25, and had ceased by P30. This was observed specifically at the corrective pruning site and was absent at a control site. An engulfment assay at the corrective pruning site in P25 mice showed EE-driven microglial-uptake of the mismapped axon terminals. This was temporally and spatially specific, as no enrichment-driven microglial engulfment was seen in P18 KO mice, nor the control locus. The timecourse of the EE-driven corrective pruning as determined anatomically, aligned with this pattern of microglia reactivity and engulfment. Collectively, these findings show experience can drive targeted microglial engulfment of miswired neural circuitry during a restricted postnatal window. This may have important therapeutic implications for neurodevelopmental conditions involving aberrant neural connectivity.
Collapse
Affiliation(s)
- Lara Rogerson-Wood
- School of Medical Sciences (Neuroscience theme), Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia
| | - Claire S Goldsbury
- School of Medical Sciences (Neuroscience theme), Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia
| | - Atomu Sawatari
- School of Medical Sciences (Neuroscience theme), Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia
| | - Catherine A Leamey
- School of Medical Sciences (Neuroscience theme), Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia
| |
Collapse
|
6
|
Xavier AM, Lin Q, Kang CJ, Cheadle L. A single-cell transcriptomic atlas of sensory-dependent gene expression in developing mouse visual cortex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.25.600673. [PMID: 38979325 PMCID: PMC11230371 DOI: 10.1101/2024.06.25.600673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Sensory experience drives the refinement and maturation of neural circuits during postnatal brain development through molecular mechanisms that remain to be fully elucidated. One likely mechanism involves the sensory-dependent expression of genes that encode direct mediators of circuit remodeling within developing cells. However, while studies in adult systems have begun to uncover crucial roles for sensory-induced genes in modifying circuit connectivity, the gene programs induced by brain cells in response to sensory experience during development remain to be fully characterized. Here, we present a single-nucleus RNA-sequencing dataset describing the transcriptional responses of cells in mouse visual cortex to sensory deprivation or sensory stimulation during a developmental window when visual input is necessary for circuit refinement. We sequenced 118,529 individual nuclei across sixteen neuronal and non-neuronal cortical cell types isolated from control, sensory deprived, and sensory stimulated mice, identifying 1,268 unique sensory-induced genes within the developing brain. To demonstrate the utility of this resource, we compared the architecture and ontology of sensory-induced gene programs between cell types, annotated transcriptional induction and repression events based upon RNA velocity, and discovered Neurexin and Neuregulin signaling networks that underlie cell-cell interactions via CellChat . We find that excitatory neurons, especially layer 2/3 pyramidal neurons, are highly sensitive to sensory stimulation, and that the sensory-induced genes in these cells are poised to strengthen synapse-to-nucleus crosstalk by heightening protein serine/threonine kinase activity. Altogether, we expect this dataset to significantly broaden our understanding of the molecular mechanisms through which sensory experience shapes neural circuit wiring in the developing brain.
Collapse
|
7
|
Maillard AM, Romascano D, Villalón-Reina JE, Moreau CA, Almeida Osório JM, Richetin S, Junod V, Yu P, Misic B, Thompson PM, Fornari E, Gygax MJ, Jacquemont S, Chabane N, Rodríguez-Herreros B. Pervasive alterations of intra-axonal volume and network organization in young children with a 16p11.2 deletion. Transl Psychiatry 2024; 14:95. [PMID: 38355713 PMCID: PMC10866898 DOI: 10.1038/s41398-024-02810-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 12/04/2023] [Accepted: 01/29/2024] [Indexed: 02/16/2024] Open
Abstract
Reciprocal Copy Number Variants (CNVs) at the 16p11.2 locus confer high risk for autism spectrum disorder (ASD) and other neurodevelopmental disorders (NDDs). Morphometric MRI studies have revealed large and pervasive volumetric alterations in carriers of a 16p11.2 deletion. However, the specific neuroanatomical mechanisms underlying such alterations, as well as their developmental trajectory, are still poorly understood. Here we explored differences in microstructural brain connectivity between 24 children carrying a 16p11.2 deletion and 66 typically developing (TD) children between 2 and 8 years of age. We found a large pervasive increase of intra-axonal volume widespread over a high number of white matter tracts. Such microstructural alterations in 16p11.2 deletion children were already present at an early age, and led to significant changes in the global efficiency and integration of brain networks mainly associated to language, motricity and socio-emotional behavior, although the widespread pattern made it unlikely to represent direct functional correlates. Our results shed light on the neuroanatomical basis of the previously reported increase of white matter volume, and align well with analogous evidence of altered axonal diameter and synaptic function in 16p11.2 mice models. We provide evidence of a prevalent mechanistic deviation from typical maturation of brain structural connectivity associated with a specific biological risk to develop ASD. Future work is warranted to determine how this deviation contributes to the emergence of symptoms observed in young children diagnosed with ASD and other NDDs.
Collapse
Affiliation(s)
- Anne M Maillard
- Service des Troubles du Spectre de l'Autisme et apparentés, Département de psychiatrie, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - David Romascano
- Service des Troubles du Spectre de l'Autisme et apparentés, Département de psychiatrie, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Julio E Villalón-Reina
- Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California (USC), Marina del Rey, CA, USA
| | - Clara A Moreau
- Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California (USC), Marina del Rey, CA, USA
| | - Joana M Almeida Osório
- Service des Troubles du Spectre de l'Autisme et apparentés, Département de psychiatrie, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Sonia Richetin
- Service des Troubles du Spectre de l'Autisme et apparentés, Département de psychiatrie, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Vincent Junod
- Unité de Neurologie et neuroréhabilitation pédiatrique, Département femme-mère-enfant, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Paola Yu
- Service des Troubles du Spectre de l'Autisme et apparentés, Département de psychiatrie, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Bratislav Misic
- Department of Neurology and Neurosurgery, Montréal Neurological Institute, Montréal, QC, H3A 2B4, Canada
- McConnell Brain Imaging Center, McGill University, Montréal, QC, H3A 2B4, Canada
| | - Paul M Thompson
- Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California (USC), Marina del Rey, CA, USA
| | - Eleonora Fornari
- Biomedical Imaging Center (CIBM), Department of Radiology, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Marine Jequier Gygax
- Service des Troubles du Spectre de l'Autisme et apparentés, Département de psychiatrie, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Sébastien Jacquemont
- Sainte Justine Hospital Research Center, Montréal, QC, Canada
- Department of Pediatrics, University of Montréal, Montreal, QC, Canada
| | - Nadia Chabane
- Service des Troubles du Spectre de l'Autisme et apparentés, Département de psychiatrie, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Borja Rodríguez-Herreros
- Service des Troubles du Spectre de l'Autisme et apparentés, Département de psychiatrie, Lausanne University Hospital (CHUV), Lausanne, Switzerland.
| |
Collapse
|
8
|
Kerschensteiner D, Feller MB. Mapping the Retina onto the Brain. Cold Spring Harb Perspect Biol 2024; 16:a041512. [PMID: 38052498 PMCID: PMC10835620 DOI: 10.1101/cshperspect.a041512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2023]
Abstract
Vision begins in the retina, which extracts salient features from the environment and encodes them in the spike trains of retinal ganglion cells (RGCs), the output neurons of the eye. RGC axons innervate diverse brain areas (>50 in mice) to support perception, guide behavior, and mediate influences of light on physiology and internal states. In recent years, complete lists of RGC types (∼45 in mice) have been compiled, detailed maps of their dendritic connections drawn, and their light responses surveyed at scale. We know less about the RGCs' axonal projection patterns, which map retinal information onto the brain. However, some organizing principles have emerged. Here, we review the strategies and mechanisms that govern developing RGC axons and organize their innervation of retinorecipient brain areas.
Collapse
Affiliation(s)
- Daniel Kerschensteiner
- Department of Ophthalmology and Visual Sciences
- Department of Neuroscience
- Department of Biomedical Engineering, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | - Marla B Feller
- Department of Molecular and Cell Biology
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, California 94720, USA
| |
Collapse
|
9
|
Qin Y, Ahmadlou M, Suhai S, Neering P, de Kraker L, Heimel JA, Levelt CN. Thalamic regulation of ocular dominance plasticity in adult visual cortex. eLife 2023; 12:RP88124. [PMID: 37796249 PMCID: PMC10554735 DOI: 10.7554/elife.88124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/06/2023] Open
Abstract
Experience-dependent plasticity in the adult visual system is generally thought of as a cortical process. However, several recent studies have shown that perceptual learning or monocular deprivation can also induce plasticity in the adult dorsolateral geniculate nucleus (dLGN) of the thalamus. How plasticity in the thalamus and cortex interact in the adult visual system is ill-understood. To assess the influence of thalamic plasticity on plasticity in primary visual cortex (V1), we made use of our previous finding that during the critical period ocular dominance (OD) plasticity occurs in dLGN and requires thalamic synaptic inhibition. Using multielectrode recordings we find that this is also true in adult mice, and that in the absence of thalamic inhibition and plasticity, OD plasticity in adult V1 is absent. To study the influence of V1 on thalamic plasticity, we silenced V1 and show that during the critical period, but not in adulthood, the OD shift in dLGN is partially caused by feedback from V1. We conclude that during adulthood the thalamus plays an unexpectedly dominant role in experience-dependent plasticity in V1. Our findings highlight the importance of considering the thalamus as a potential source of plasticity in learning events that are typically thought of as cortical processes.
Collapse
Affiliation(s)
- Yi Qin
- Molecular Visual Plasticity Group, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and SciencesAmsterdamNetherlands
- University of StrasbourgStrasbourgFrance
| | - Mehran Ahmadlou
- Circuits, Structure and Function Group, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and SciencesAmsterdamNetherlands
| | - Samuel Suhai
- Molecular Visual Plasticity Group, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and SciencesAmsterdamNetherlands
| | - Paul Neering
- Molecular Visual Plasticity Group, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and SciencesAmsterdamNetherlands
| | - Leander de Kraker
- Molecular Visual Plasticity Group, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and SciencesAmsterdamNetherlands
| | - J Alexander Heimel
- Circuits, Structure and Function Group, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and SciencesAmsterdamNetherlands
| | - Christiaan N Levelt
- Molecular Visual Plasticity Group, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and SciencesAmsterdamNetherlands
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, VU University AmsterdamAmsterdamNetherlands
| |
Collapse
|
10
|
Ueta Y, Miyata M. Functional and structural synaptic remodeling mechanisms underlying somatotopic organization and reorganization in the thalamus. Neurosci Biobehav Rev 2023; 152:105332. [PMID: 37524138 DOI: 10.1016/j.neubiorev.2023.105332] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 05/09/2023] [Accepted: 07/27/2023] [Indexed: 08/02/2023]
Abstract
The somatosensory system organizes the topographic representation of body maps, termed somatotopy, at all levels of an ascending hierarchy. Postnatal maturation of somatotopy establishes optimal somatosensation, whereas deafferentation in adults reorganizes somatotopy, which underlies pathological somatosensation, such as phantom pain and complex regional pain syndrome. Here, we focus on the mouse whisker somatosensory thalamus to study how sensory experience shapes the fine topography of afferent connectivity during the critical period and what mechanisms remodel it and drive a large-scale somatotopic reorganization after peripheral nerve injury. We will review our findings that, following peripheral nerve injury in adults, lemniscal afferent synapses onto thalamic neurons are remodeled back to immature configuration, as if the critical period reopens. The remodeling process is initiated with local activation of microglia in the brainstem somatosensory nucleus downstream to injured nerves and heterosynaptically controlled by input from GABAergic and cortical neurons to thalamic neurons. These fruits of thalamic studies complement well-studied cortical mechanisms of somatotopic organization and reorganization and unveil potential intervention points in treating pathological somatosensation.
Collapse
Affiliation(s)
- Yoshifumi Ueta
- Division of Neurophysiology, Department of Physiology, School of Medicine, Tokyo Women's Medical University, Tokyo 162-8666, Japan
| | - Mariko Miyata
- Division of Neurophysiology, Department of Physiology, School of Medicine, Tokyo Women's Medical University, Tokyo 162-8666, Japan.
| |
Collapse
|
11
|
An Early Enriched Experience Drives an Activated Microglial Profile at Site of Corrective Neuroplasticity in Ten-m3 Knock-Out Mice. eNeuro 2023; 10:ENEURO.0162-22.2022. [PMID: 36635245 PMCID: PMC9831145 DOI: 10.1523/eneuro.0162-22.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 09/29/2022] [Accepted: 10/09/2022] [Indexed: 12/15/2022] Open
Abstract
Environmental enrichment (EE) is beneficial for brain development and function, but our understanding of its capacity to drive circuit repair, the underlying mechanisms, and how this might vary with age remains limited. Ten-m3 knock-out (KO) mice exhibit a dramatic and stereotyped mistargeting of ipsilateral retinal inputs to the thalamus, resulting in visual deficits. We have recently shown a previously unexpected capacity for EE during early postnatal life (from birth for six weeks) to drive the partial elimination of miswired axonal projections, along with a recovery of visually mediated behavior, but the timeline of this repair was unclear. Here, we reveal that with just 3.5 weeks of EE from birth, Ten-m3 KOs exhibit a partial behavioral rescue, accompanied by pruning of the most profoundly miswired retinogeniculate terminals. Analysis suggests that the pruning is underway at this time point, providing an ideal opportunity to probe potential mechanisms. With the shorter EE-period, we found a localized increase in microglial density and activation profile within the identified geniculate region where corrective pruning was observed. No comparable response to EE was found in age-matched wild-type (WT) mice. These findings identify microglia as a potential mechanistic link through which EE drives the elimination of miswired neural circuits during early postnatal development. Activity driven, atypical recruitment of microglia to prune aberrant connectivity and restore function may have important therapeutic implications for neurodevelopmental disorders such as autistic spectrum disorder.
Collapse
|
12
|
Li N, Liu Q, Zhang Y, Yang Z, Shi X, Gu Y. Cortical feedback modulates distinct critical period development in mouse visual thalamus. iScience 2022; 26:105752. [PMID: 36590174 PMCID: PMC9794980 DOI: 10.1016/j.isci.2022.105752] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 11/15/2022] [Accepted: 12/03/2022] [Indexed: 12/12/2022] Open
Abstract
In primary visual cortex (V1), critical period for ocular dominance (OD) plasticity is a well-defined developmental stage to shape neuronal circuits based on visual experience. Recent studies showed that V1-like OD plasticity existed in mouse dorsal lateral geniculate nucleus (dLGN). It is still unclear what the exact time window is and how neural circuits contribute to OD plasticity in dLGN. Using in vivo electrophysiology, we defined a critical period for OD plasticity in dLGN from eye opening to puberty. There also existed an innate process of OD formation from contralateral to equal bias in dLGN binocular neurons. Instant V1 inactivation with muscimol had no effect on OD bias or plasticity. Short-term V1 inactivation with N-methyl-d-aspartate reversed the formation of equal OD bias, while long-term V1 inactivation retained dLGN development to an immature stage.
Collapse
Affiliation(s)
- Na Li
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Qiong Liu
- School of Life Sciences, Westlake University, Hangzhou 310000, China
| | - Yimu Zhang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Zhongyi Yang
- School of Basic Medicine, Fudan University, Shanghai 200032, China
| | - Xuefeng Shi
- Tianjin Eye Hospital, Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Eye Institute, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin 300020, China
- Institute of Ophthalmology, Nankai University, Tianjin 300020, China
- Corresponding author
| | - Yu Gu
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
- Corresponding author
| |
Collapse
|
13
|
Whitt JL, Ewall G, Chakraborty D, Adegbesan A, Lee R, Kanold PO, Lee HK. Visual Deprivation Selectively Reduces Thalamic Reticular Nucleus-Mediated Inhibition of the Auditory Thalamus in Adults. J Neurosci 2022; 42:7921-7930. [PMID: 36261269 PMCID: PMC9617613 DOI: 10.1523/jneurosci.2032-21.2022] [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: 10/08/2021] [Revised: 08/19/2022] [Accepted: 08/24/2022] [Indexed: 11/21/2022] Open
Abstract
Sensory loss leads to widespread cross-modal plasticity across brain areas to allow the remaining senses to guide behavior. While multimodal sensory interactions are often attributed to higher-order sensory areas, cross-modal plasticity has been observed at the level of synaptic changes even across primary sensory cortices. In particular, vision loss leads to widespread circuit adaptation in the primary auditory cortex (A1) even in adults. Here we report using mice of both sexes in which cross-modal plasticity occurs even earlier in the sensory-processing pathway at the level of the thalamus in a modality-selective manner. A week of visual deprivation reduced inhibitory synaptic transmission from the thalamic reticular nucleus (TRN) to the primary auditory thalamus (MGBv) without changes to the primary visual thalamus (dLGN). The plasticity of TRN inhibition to MGBv was observed as a reduction in postsynaptic gain and short-term depression. There was no observable plasticity of the cortical feedback excitatory synaptic transmission from the primary visual cortex to dLGN or TRN and A1 to MGBv, which suggests that the visual deprivation-induced plasticity occurs predominantly at the level of thalamic inhibition. We provide evidence that visual deprivation-induced change in the short-term depression of TRN inhibition to MGBv involves endocannabinoid CB1 receptors. TRN inhibition is considered critical for sensory gating, selective attention, and multimodal performances; hence, its plasticity has implications for sensory processing. Our results suggest that selective disinhibition and altered short-term dynamics of TRN inhibition in the spared thalamic nucleus support cross-modal plasticity in the adult brain.SIGNIFICANCE STATEMENT Losing vision triggers adaptation of the brain to enhance the processing of the remaining senses, which can be observed as better auditory performance in blind subjects. We previously found that depriving vision of adult rodents produces widespread circuit reorganization in the primary auditory cortex and enhances auditory processing at a neural level. Here we report that visual deprivation-induced plasticity in adults occurs much earlier in the auditory pathway, at the level of thalamic inhibition. Sensory processing is largely gated at the level of the thalamus via strong cortical feedback inhibition mediated through the thalamic reticular nucleus (TRN). We found that TRN inhibition of the auditory thalamus is selectively reduced by visual deprivation, thus playing a role in adult cross-modal plasticity.
Collapse
Affiliation(s)
- Jessica L Whitt
- Zanvyl-Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, Maryland 21218
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Gabrielle Ewall
- Zanvyl-Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, Maryland 21218
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Darpan Chakraborty
- Zanvyl-Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, Maryland 21218
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Ayorinde Adegbesan
- Zanvyl-Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, Maryland 21218
| | - Rachel Lee
- Zanvyl-Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, Maryland 21218
| | - Patrick O Kanold
- Department of Biomedical Engineering, Whiting School of Engineering and Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
- Kavli Neuroscience Discovery Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Hey-Kyoung Lee
- Zanvyl-Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, Maryland 21218
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
- Kavli Neuroscience Discovery Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| |
Collapse
|
14
|
Pumo GM, Kitazawa T, Rijli FM. Epigenetic and Transcriptional Regulation of Spontaneous and Sensory Activity Dependent Programs During Neuronal Circuit Development. Front Neural Circuits 2022; 16:911023. [PMID: 35664458 PMCID: PMC9158562 DOI: 10.3389/fncir.2022.911023] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 04/28/2022] [Indexed: 11/13/2022] Open
Abstract
Spontaneous activity generated before the onset of sensory transduction has a key role in wiring developing sensory circuits. From axonal targeting, to synapse formation and elimination, to the balanced integration of neurons into developing circuits, this type of activity is implicated in a variety of cellular processes. However, little is known about its molecular mechanisms of action, especially at the level of genome regulation. Conversely, sensory experience-dependent activity implements well-characterized transcriptional and epigenetic chromatin programs that underlie heterogeneous but specific genomic responses that shape both postnatal circuit development and neuroplasticity in the adult. In this review, we focus on our knowledge of the developmental processes regulated by spontaneous activity and the underlying transcriptional mechanisms. We also review novel findings on how chromatin regulates the specificity and developmental induction of the experience-dependent program, and speculate their relevance for our understanding of how spontaneous activity may act at the genomic level to instruct circuit assembly and prepare developing neurons for sensory-dependent connectivity refinement and processing.
Collapse
Affiliation(s)
- Gabriele M. Pumo
- Laboratory of Neurodevelopmental Epigenetics, Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
- Department Biozentrum, University of Basel, Basel, Switzerland
| | - Taro Kitazawa
- Laboratory of Neurodevelopmental Epigenetics, Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Filippo M. Rijli
- Laboratory of Neurodevelopmental Epigenetics, Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
- Department Biozentrum, University of Basel, Basel, Switzerland
| |
Collapse
|
15
|
Sokhadze G, Campbell PW, Charalambakis N, Govindaiah G, Guido W, McGee AW. Cre driver mouse lines for thalamocortical circuit mapping. J Comp Neurol 2022; 530:1049-1063. [PMID: 34545582 PMCID: PMC9891227 DOI: 10.1002/cne.25248] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 08/16/2021] [Accepted: 09/07/2021] [Indexed: 02/04/2023]
Abstract
Subpopulations of neurons and associated neural circuits can be targeted in mice with genetic tools in a highly selective manner for visualization and manipulation. However, there are not well-defined Cre "driver" lines that target the expression of Cre recombinase to thalamocortical (TC) neurons. Here, we characterize three Cre driver lines for the nuclei of the dorsal thalamus: Oligodendrocyte transcription factor 3 (Olig3)-Cre, histidine decarboxylase (HDC)-Cre, and corticotropin-releasing hormone (CRH)-Cre. We examined the postnatal distribution of Cre expression for each of these lines with the Cre-dependent reporter CAG-tdTomato (Ai9). Cre-dependent expression of tdTomato reveals that Olig3-Cre expresses broadly within the thalamus, including TC neurons and interneurons, while HDC-Cre and CRH-Cre each have unique patterns of expression restricted to TC neurons within and across the sensory relay nuclei of the dorsal thalamus. Cre expression is present by the time of natural birth in all three lines, underscoring their utility for developmental studies. To demonstrate the utility of these Cre drivers for studying sensory TC circuitry, we targeted the expression of channelrhodopsin-2 to thalamus from the CAG-COP4*H134R/EYFP (Ai32) allele with either HDC-Cre or CRH-Cre. Optogenetic activation of TC afferents in primary visual cortex was sufficient to measure frequency-dependent depression. Thus, these Cre drivers provide selective Cre-dependent gene expression in thalamus suitable for both anatomical and functional studies.
Collapse
Affiliation(s)
- Guela Sokhadze
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky, USA
| | - Peter W Campbell
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky, USA
| | - Naomi Charalambakis
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky, USA
| | - Gubbi Govindaiah
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky, USA
| | - William Guido
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky, USA
| | - Aaron W McGee
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky, USA
| |
Collapse
|
16
|
Midorikawa M. Pathway-specific maturation of presynaptic functions of the somatosensory thalamus. Neurosci Res 2022; 181:1-8. [DOI: 10.1016/j.neures.2022.04.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 04/25/2022] [Accepted: 04/27/2022] [Indexed: 02/05/2023]
|
17
|
Bhandari A, Ward TW, Smith J, Van Hook MJ. Structural and functional plasticity in the dorsolateral geniculate nucleus of mice following bilateral enucleation. Neuroscience 2022; 488:44-59. [PMID: 35131394 PMCID: PMC8960354 DOI: 10.1016/j.neuroscience.2022.01.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Accepted: 01/31/2022] [Indexed: 02/08/2023]
Abstract
Within the nervous system, plasticity mechanisms attempt to stabilize network activity following disruption by injury, disease, or degeneration. Optic nerve injury and age-related diseases can induce homeostatic-like responses in adulthood. We tested this possibility in the thalamocortical (TC) neurons in the dorsolateral geniculate nucleus (dLGN) using patch-clamp electrophysiology, optogenetics, immunostaining, and single-cell dendritic analysis following loss of visual input via bilateral enucleation. We observed progressive loss of vGlut2-positive retinal terminals in the dLGN indicating degeneration post-enucleation that was coincident with changes in microglial morphology indicative of microglial activation. Consistent with the decline of vGlut2 puncta, we also observed loss of retinogeniculate (RG) synaptic function assessed using optogenetic activation of RG axons while performing whole-cell voltage clamp recordings from TC neurons in brain slices. Surprisingly, we did not detect any significant changes in the frequency of miniature post-synaptic currents (mEPSCs) or corticothalamic feedback synapses. Analysis of TC neuron dendritic structure from single-cell dye fills revealed a gradual loss of dendrites proximal to the soma, where TC neurons receive the bulk of RG inputs. Finally, analysis of action potential firing demonstrated that TC neurons have increased excitability following enucleation, firing more action potentials in response to depolarizing current injections. Our findings show that degeneration of the retinal axons/optic nerve and loss of RG synaptic inputs induces structural and functional changes in TC neurons, consistent with neuronal attempts at compensatory plasticity in the dLGN.
Collapse
|
18
|
Stacy AK, Van Hooser SD. Development of Functional Properties in the Early Visual System: New Appreciations of the Roles of Lateral Geniculate Nucleus. Curr Top Behav Neurosci 2022; 53:3-35. [PMID: 35112333 DOI: 10.1007/7854_2021_297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
In the years following Hubel and Wiesel's first reports on ocular dominance plasticity and amblyopia, much attention has been focused on understanding the role of cortical circuits in developmental and experience-dependent plasticity. Initial studies found few differences between retinal ganglion cells and neurons in the lateral geniculate nucleus and uncovered little evidence for an impact of altered visual experience on the functional properties of lateral geniculate nucleus neurons. In the last two decades, however, studies have revealed that the connectivity between the retina and lateral geniculate nucleus is much richer than was previously appreciated, even revealing visual plasticity - including ocular dominance plasticity - in lateral geniculate nucleus neurons. Here we review the development of the early visual system and the impact of experience with a distinct focus on recent discoveries about lateral geniculate nucleus, its connectivity, and evidence for its plasticity and rigidity during development.
Collapse
Affiliation(s)
- Andrea K Stacy
- Department of Biology, Brandeis University, Waltham, MA, USA
| | | |
Collapse
|
19
|
Lešták J. NEUROTRANSMISSION IN VISUAL ANALYZER AND BIONIC EYE. A REVIEW. CESKA A SLOVENSKA OFTALMOLOGIE : CASOPIS CESKE OFTALMOLOGICKE SPOLECNOSTI A SLOVENSKE OFTALMOLOGICKE SPOLECNOSTI 2021; 77:55-59. [PMID: 33985334 DOI: 10.31348/2020/28] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS The aim of the work is to point out the transmission of electrical voltage changes in the visual analyser and thus the efficiency of the bionic eye. MATERIAL AND METHODS The review deals with the question of the transmission of electrical changes in visual path voltage under physiological and pathological conditions. In particular, it points to feedback autoregulatory damage not only of primarily altered cellular structures, but of all other, both horizontally and vertically localized. Based on the results of functional magnetic resonance imaging and electrophysiological methods, it shows the pathology of the entire visual pathway in three eye diseases: retinitis pigmentosa, age-related macular degeneration and glaucoma. RESULTS The thesis also provides an overview of possible systems that are used to replace lost vision, from epiretinal, subretinal, suprachoroidal implants, through stimulation of the optic nerve, corpus geniculatum laterale to the visual cortex. CONCLUSION Due to the pathology of neurotransmission, bionic eye systems cannot be expected to be restored after stabilization of binocular functions.
Collapse
|
20
|
An activity-dependent determinant of synapse elimination in the mammalian brain. Neuron 2021; 109:1333-1349.e6. [PMID: 33770504 DOI: 10.1016/j.neuron.2021.03.006] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/26/2021] [Accepted: 03/04/2021] [Indexed: 01/06/2023]
Abstract
To establish functional neural circuits in the brain, synaptic connections are refined by neural activity during development, where active connections are maintained and inactive ones are eliminated. However, the molecular signals that regulate synapse refinement remain to be elucidated. When we inactivate a subset of neurons in the mouse cingulate cortex, their callosal connections are eliminated through activity-dependent competition. Using this system, we identify JAK2 tyrosine kinase as a key regulator of inactive synapse elimination. We show that JAK2 is necessary and sufficient for elimination of inactive connections; JAK2 is activated at inactive synapses in response to signals from other active synapses; STAT1, a substrate of JAK2, mediates inactive synapse elimination; JAK2 signaling is critical for physiological refinement of synapses during normal development; and JAK2 regulates synapse refinement in multiple brain regions. We propose that JAK2 is an activity-dependent switch that serves as a determinant of inactive synapse elimination.
Collapse
|
21
|
Jager P, Moore G, Calpin P, Durmishi X, Salgarella I, Menage L, Kita Y, Wang Y, Kim DW, Blackshaw S, Schultz SR, Brickley S, Shimogori T, Delogu A. Dual midbrain and forebrain origins of thalamic inhibitory interneurons. eLife 2021; 10:e59272. [PMID: 33522480 PMCID: PMC7906600 DOI: 10.7554/elife.59272] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Accepted: 01/31/2021] [Indexed: 12/12/2022] Open
Abstract
The ubiquitous presence of inhibitory interneurons in the thalamus of primates contrasts with the sparsity of interneurons reported in mice. Here, we identify a larger than expected complexity and distribution of interneurons across the mouse thalamus, where all thalamic interneurons can be traced back to two developmental programmes: one specified in the midbrain and the other in the forebrain. Interneurons migrate to functionally distinct thalamocortical nuclei depending on their origin: the abundant, midbrain-derived class populates the first and higher order sensory thalamus while the rarer, forebrain-generated class is restricted to some higher order associative regions. We also observe that markers for the midbrain-born class are abundantly expressed throughout the thalamus of the New World monkey marmoset. These data therefore reveal that, despite the broad variability in interneuron density across mammalian species, the blueprint of the ontogenetic organisation of thalamic interneurons of larger-brained mammals exists and can be studied in mice.
Collapse
Affiliation(s)
- Polona Jager
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King’s College LondonLondonUnited Kingdom
| | - Gerald Moore
- Department of Bioengineering, Imperial College LondonLondonUnited Kingdom
- Department of Life Sciences and Centre for Neurotechnology, Imperial College LondonLondonUnited Kingdom
| | - Padraic Calpin
- Department of Physics and Astronomy, University College LondonLondonUnited Kingdom
| | - Xhuljana Durmishi
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King’s College LondonLondonUnited Kingdom
| | - Irene Salgarella
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King’s College LondonLondonUnited Kingdom
| | - Lucy Menage
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King’s College LondonLondonUnited Kingdom
| | | | - Yan Wang
- RIKEN, Center for Brain Science (CBS)SaitamaJapan
| | - Dong Won Kim
- The Solomon H. Snyder Department of Neuroscience, School of Medicine, Johns Hopkins UniversityBaltimoreUnited States
| | - Seth Blackshaw
- The Solomon H. Snyder Department of Neuroscience, School of Medicine, Johns Hopkins UniversityBaltimoreUnited States
| | - Simon R Schultz
- Department of Bioengineering, Imperial College LondonLondonUnited Kingdom
| | - Stephen Brickley
- Department of Life Sciences and Centre for Neurotechnology, Imperial College LondonLondonUnited Kingdom
| | | | - Alessio Delogu
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King’s College LondonLondonUnited Kingdom
| |
Collapse
|
22
|
Song M, Jang J, Kim G, Paik SB. Projection of Orthogonal Tiling from the Retina to the Visual Cortex. Cell Rep 2021; 34:108581. [PMID: 33406438 DOI: 10.1016/j.celrep.2020.108581] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 10/22/2020] [Accepted: 12/09/2020] [Indexed: 10/22/2022] Open
Abstract
In higher mammals, the primary visual cortex (V1) is organized into diverse tuning maps of visual features. The topography of these maps intersects orthogonally, but it remains unclear how such a systematic relationship can develop. Here, we show that the orthogonal organization already exists in retinal ganglion cell (RGC) mosaics, providing a blueprint of the organization in V1. From analysis of the RGC mosaics data in monkeys and cats, we find that the ON-OFF RGC distance and ON-OFF angle of neighboring RGCs are organized into a topographic tiling across mosaics, analogous to the orthogonal intersection of cortical tuning maps. Our model simulation shows that the ON-OFF distance and angle in RGC mosaics correspondingly initiate ocular dominance/spatial frequency tuning and orientation tuning, resulting in the orthogonal intersection of cortical tuning maps. These findings suggest that the regularly structured ON-OFF patterns mirrored from the retina initiate the uniform representation of combinations of map features over the visual space.
Collapse
Affiliation(s)
- Min Song
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea; Program of Brain and Cognitive Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Jaeson Jang
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Gwangsu Kim
- Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Se-Bum Paik
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea; Program of Brain and Cognitive Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea.
| |
Collapse
|
23
|
Liang L, Chen C. Organization, Function, and Development of the Mouse Retinogeniculate Synapse. Annu Rev Vis Sci 2020; 6:261-285. [DOI: 10.1146/annurev-vision-121219-081753] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Visual information is encoded in distinct retinal ganglion cell (RGC) types in the eye tuned to specific features of the visual space. These streams of information project to the visual thalamus, the first station of the image-forming pathway. In the mouse, this connection between RGCs and thalamocortical neurons, the retinogeniculate synapse, has become a powerful experimental model for understanding how circuits in the thalamus are constructed to process these incoming lines of information. Using modern molecular and genetic tools, recent studies have suggested a more complex circuit organization than was previously understood. In this review, we summarize the current understanding of the structural and functional organization of the retinogeniculate synapse in the mouse. We discuss a framework by which a seemingly complex circuit can effectively integrate and parse information to downstream stations of the visual pathway. Finally, we review how activity and visual experience can sculpt this exquisite connectivity.
Collapse
Affiliation(s)
- Liang Liang
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, Massachusetts 02115, USA
- Department of Neuroscience, Yale University, New Haven, Connecticut 06520, USA
| | - Chinfei Chen
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, Massachusetts 02115, USA
| |
Collapse
|
24
|
Hooks BM, Chen C. Circuitry Underlying Experience-Dependent Plasticity in the Mouse Visual System. Neuron 2020; 106:21-36. [PMID: 32272065 DOI: 10.1016/j.neuron.2020.01.031] [Citation(s) in RCA: 102] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 01/13/2020] [Accepted: 01/23/2020] [Indexed: 12/15/2022]
Abstract
Since the discovery of ocular dominance plasticity, neuroscientists have understood that changes in visual experience during a discrete developmental time, the critical period, trigger robust changes in the visual cortex. State-of-the-art tools used to probe connectivity with cell-type-specific resolution have expanded the understanding of circuit changes underlying experience-dependent plasticity. Here, we review the visual circuitry of the mouse, describing projections from retina to thalamus, between thalamus and cortex, and within cortex. We discuss how visual circuit development leads to precise connectivity and identify synaptic loci, which can be altered by activity or experience. Plasticity extends to visual features beyond ocular dominance, involving subcortical and cortical regions, and connections between cortical inhibitory interneurons. Experience-dependent plasticity contributes to the alignment of networks spanning retina to thalamus to cortex. Disruption of this plasticity may underlie aberrant sensory processing in some neurodevelopmental disorders.
Collapse
Affiliation(s)
- Bryan M Hooks
- Department of Neurobiology, University of Pittsburgh School of Medicine, W1458 BSTWR, 203 Lothrop Street, Pittsburgh, PA 15213, USA.
| | - Chinfei Chen
- Department of Neurology, F.M. Kirby Neurobiology Center, Children's Hospital, Boston, 300 Longwood Avenue, Boston, MA 02115, USA.
| |
Collapse
|
25
|
Ribic A. Stability in the Face of Change: Lifelong Experience-Dependent Plasticity in the Sensory Cortex. Front Cell Neurosci 2020; 14:76. [PMID: 32372915 PMCID: PMC7186337 DOI: 10.3389/fncel.2020.00076] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Accepted: 03/17/2020] [Indexed: 11/13/2022] Open
Abstract
Plasticity is a fundamental property of the nervous system that enables its adaptations to the ever-changing environment. Heightened plasticity typical for developing circuits facilitates their robust experience-dependent functional maturation. This plasticity wanes during adolescence to permit the stabilization of mature brain function, but abundant evidence supports that adult circuits exhibit both transient and long-term experience-induced plasticity. Cortical plasticity has been extensively studied throughout the life span in sensory systems and the main distinction between development and adulthood arising from these studies is the concept that passive exposure to relevant information is sufficient to drive robust plasticity early in life, while higher-order attentional mechanisms are necessary to drive plastic changes in adults. Recent work in the primary visual and auditory cortices began to define the circuit mechanisms that govern these processes and enable continuous adaptation to the environment, with transient circuit disinhibition emerging as a common prerequisite for both developmental and adult plasticity. Drawing from studies in visual and auditory systems, this review article summarizes recent reports on the circuit and cellular mechanisms of experience-driven plasticity in the developing and adult brains and emphasizes the similarities and differences between them. The benefits of distinct plasticity mechanisms used at different ages are discussed in the context of sensory learning, as well as their relationship to maladaptive plasticity and neurodevelopmental brain disorders. Knowledge gaps and avenues for future work are highlighted, and these will hopefully motivate future research in these areas, particularly those about the learning of complex skills during development.
Collapse
Affiliation(s)
- Adema Ribic
- Department of Psychology, College and Graduate School of Arts and Sciences, University of Virginia, Charlottesville, VA, United States
| |
Collapse
|
26
|
Lešták J, Fůs M. Neuroprotection in glaucoma-electrophysiology. Exp Ther Med 2020; 19:2401-2405. [PMID: 32256717 PMCID: PMC7086198 DOI: 10.3892/etm.2020.8509] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 11/06/2019] [Indexed: 11/15/2022] Open
Abstract
Hypertensive glaucoma is defined as a group of diseases with progressive loss of the neuroretinal margin of the optic disc that causes characteristic degenerative optic neuropathy. The present study provided an updated summary of the physiology and pathology of neurotransmission in the visual path, with the focus on glaucoma. The results of positron emission tomography, functional magnetic resonance imaging and mainly electrophysiological methods demonstrated pathogenesis of nerve cell damage in the visual pathway. Based on these conclusions, neuroprotection in glaucoma was proposed. This consists mainly of the reduction of the intraocular pressure. It is followed by a decrease of glutamate in the synaptic cleft and blockade of its binding to the NMDA receptors. The supply of energy substrates to altered nerve cells is also indispensable. Therapy should be systemic due to impairment of the complete visual path.
Collapse
Affiliation(s)
- Ján Lešták
- Eye Clinic, JL Faculty of Biomedical Engineering CTU in Prague, 158 00 Prague 5, Czech Republic
- CTU in Prague, Faculty of Biomedical Engineering, 272 01 Kladno 2, Czech Republic
| | - Martin Fůs
- Eye Clinic, JL Faculty of Biomedical Engineering CTU in Prague, 158 00 Prague 5, Czech Republic
- CTU in Prague, Faculty of Biomedical Engineering, 272 01 Kladno 2, Czech Republic
| |
Collapse
|
27
|
Huh CYL, Abdelaal K, Salinas KJ, Gu D, Zeitoun J, Figueroa Velez DX, Peach JP, Fowlkes CC, Gandhi SP. Long-term Monocular Deprivation during Juvenile Critical Period Disrupts Binocular Integration in Mouse Visual Thalamus. J Neurosci 2020; 40:585-604. [PMID: 31767678 PMCID: PMC6961993 DOI: 10.1523/jneurosci.1626-19.2019] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 11/06/2019] [Accepted: 11/20/2019] [Indexed: 02/08/2023] Open
Abstract
Study of the neural deficits caused by mismatched binocular vision in early childhood has predominantly focused on circuits in the primary visual cortex (V1). Recent evidence has revealed that neurons in mouse dorsolateral geniculate nucleus (dLGN) can undergo rapid ocular dominance plasticity following monocular deprivation (MD). It remains unclear, however, whether the long-lasting deficits attributed to MD during the critical period originate in the thalamus. Using in vivo two-photon Ca2+ imaging of dLGN afferents in superficial layers of V1 in female and male mice, we demonstrate that 14 d MD during the critical period leads to a chronic loss of binocular dLGN inputs while sparing response strength and spatial acuity. Importantly, MD leads to profoundly mismatched visual tuning properties in remaining binocular dLGN afferents. Furthermore, MD impairs binocular modulation, reducing facilitation of responses of both binocular and monocular dLGN inputs during binocular viewing. As predicted by our findings in thalamic inputs, Ca2+ imaging from V1 neurons revealed spared spatial acuity but impaired binocularity in L4 neurons. V1 L2/3 neurons in contrast displayed deficits in both binocularity and spatial acuity. Our data demonstrate that critical-period MD produces long-lasting disruptions in binocular integration beginning in early binocular circuits in dLGN, whereas spatial acuity deficits first arise from circuits further downstream in V1. Our findings indicate that the development of normal binocular vision and spatial acuity depend upon experience-dependent refinement of distinct stages in the mammalian visual system.SIGNIFICANCE STATEMENT Abnormal binocular vision and reduced acuity are hallmarks of amblyopia, a disorder that affects 2%-5% of the population. It is widely thought that the neural deficits underlying amblyopia begin in the circuits of primary visual cortex. Using in vivo two-photon calcium imaging of thalamocortical axons in mice, we show that depriving one eye of input during a critical period in development chronically impairs binocular integration in thalamic inputs to primary visual cortex. In contrast, visual acuity is spared in thalamic inputs. These findings shed new light on the role for developmental mechanisms in the thalamus in establishing binocular vision and may have critical implications for amblyopia.
Collapse
Affiliation(s)
| | | | | | - Diyue Gu
- Donald Bren School of Information & Computer Sciences
| | | | | | - John P Peach
- Whiting School of Engineering, Johns Hopkins University, Baltimore, Maryland 21218
| | | | - Sunil P Gandhi
- Department of Neurobiology and Behavior,
- Center for Neurobiology of Learning and Memory, University of California, Irvine, California 92697, and
| |
Collapse
|
28
|
The metabotropic glutamate receptor subtype 1 regulates development and maintenance of lemniscal synaptic connectivity in the somatosensory thalamus. PLoS One 2019; 14:e0226820. [PMID: 31881077 PMCID: PMC6934304 DOI: 10.1371/journal.pone.0226820] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 12/05/2019] [Indexed: 11/19/2022] Open
Abstract
The metabotropic glutamate receptor subtype 1 (mGluR1) is a major subtype of group I mGluRs, which contributes to the development and plasticity of synapses in the brain. In the sensory thalamus, the thalamocortical neuron receives sensory afferents and massive feedback input from corticothalamic (CT) fibers. Notably, mGluR1 is more concentrated in CT synapses in the sensory thalamus. In the visual thalamus, mGluR1 maintains mature afferent synaptic connectivity. However, it is unknown whether mGluR1 contributes to strengthening of immature synapses or weakening of excess synapses during development and whether mGluR1 at CT synapses heterosynaptically regulates the development or refinement of afferent synapses. Here we investigated the effects of knocking out the gene encoding mGluR1 or pharmacologically blocking cortical activity on the development and maintenance of lemniscal synapses, i.e., the somatosensory afferent synapses, in the ventral posteromedial somatosensory thalamus. mGluR1-knockout (KO) mice exhibited delayed developmental strengthening as well as incomplete elimination and remodeling after maturation of lemniscal synapses. Similar to the phenotypes exhibited by mGluR1-KO mice, pharmacological blockade of somatosensory cortical activity from P12 or P21 for 1 week in wild-type mice perturbed elimination or maintenance of lemniscal synapses, respectively. The same manipulation in mGluR1-KO mice failed to induce additional abnormalities in lemniscal synaptic connectivity. These results suggest that activation of mGluR1, driven by CT input, regulates multiple stages of the development of lemniscal synapses, including strengthening, refinement, and maintenance in the somatosensory thalamus.
Collapse
|
29
|
Gribizis A, Ge X, Daigle TL, Ackman JB, Zeng H, Lee D, Crair MC. Visual Cortex Gains Independence from Peripheral Drive before Eye Opening. Neuron 2019; 104:711-723.e3. [PMID: 31561919 DOI: 10.1016/j.neuron.2019.08.015] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 07/15/2019] [Accepted: 08/08/2019] [Indexed: 10/26/2022]
Abstract
Visual spatial perception in the mammalian brain occurs through two parallel pathways: one reaches the primary visual cortex (V1) through the thalamus and another the superior colliculus (SC) via direct projections from the retina. The origin, development, and relative function of these two evolutionarily distinct pathways remain obscure. We examined the early functional development of both pathways by simultaneously imaging pre- and post-synaptic spontaneous neuronal activity. We observed that the quality of retinal activity transfer to the thalamus and superior colliculus does not change across the first two postnatal weeks. However, beginning in the second postnatal week, retinal activity does not drive V1 as strongly as earlier wave activity, suggesting that intrinsic cortical activity competes with signals from the sensory periphery as the cortex matures. Together, these findings bring new insight into the function of the SC and V1 and the role of peripheral activity in driving both circuits across development.
Collapse
Affiliation(s)
- Alexandra Gribizis
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Xinxin Ge
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Tanya L Daigle
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | - James B Ackman
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - Hongkui Zeng
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | - Daeyeol Lee
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Michael C Crair
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA.
| |
Collapse
|
30
|
Abstract
In this article, we review the anatomical inputs and outputs to the mouse primary visual cortex, area V1. Our survey of data from the Allen Institute Mouse Connectivity project indicates that mouse V1 is highly interconnected with both cortical and subcortical brain areas. This pattern of innervation allows for computations that depend on the state of the animal and on behavioral goals, which contrasts with simple feedforward, hierarchical models of visual processing. Thus, to have an accurate description of the function of V1 during mouse behavior, its involvement with the rest of the brain circuitry has to be considered. Finally, it remains an open question whether the primary visual cortex of higher mammals displays the same degree of sensorimotor integration in the early visual system.
Collapse
Affiliation(s)
- Emmanouil Froudarakis
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030, USA;
- Center for Neuroscience and Artificial Intelligence, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Paul G Fahey
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030, USA;
- Center for Neuroscience and Artificial Intelligence, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Jacob Reimer
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030, USA;
- Center for Neuroscience and Artificial Intelligence, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Stelios M Smirnakis
- Department of Neurology, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA
- Jamaica Plain VA Medical Center, Boston, Massachusetts 02130, USA
| | - Edward J Tehovnik
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030, USA;
- Center for Neuroscience and Artificial Intelligence, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Andreas S Tolias
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030, USA;
- Center for Neuroscience and Artificial Intelligence, Baylor College of Medicine, Houston, Texas 77030, USA
- Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, USA
| |
Collapse
|
31
|
Abstract
Functional neural circuits of mature animals are shaped during postnatal development by eliminating early-formed redundant synapses and strengthening of necessary connections. In the nervous system of newborn animals, redundant synapses are only transient features of the circuit. During subsequent postnatal development, some synapses are strengthened whereas other redundant connections are weakened and eventually eliminated. In this review, we introduce recent studies on the mechanisms of developmental remodeling of climbing fiber-to-Purkinje cell synapses in the cerebellum and synapses from the retina to neurons in the dorsal lateral geniculate nucleus of the visual thalamus (retinogeniculate synapses). These are the two representative models of developmental synapse remodeling in the brain and they share basic principles, including dependency on neural activity. However, recent studies have disclosed that, in several respects, the two models use different molecules and strategies to establish mature synaptic connectivity. We describe similarities and differences between the two models and discuss remaining issues to be tackled in the future in order to understand the general schemes of developmental synapse remodeling.
Collapse
Affiliation(s)
- Masanobu Kano
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan.,International Research Center for Neurointelligence (WPI-IRCN), The University of Tokyo Institutes for Advanced Study (UTIAS), The University of Tokyo, Tokyo, 113-0033, Japan
| | - Takaki Watanabe
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan.,International Research Center for Neurointelligence (WPI-IRCN), The University of Tokyo Institutes for Advanced Study (UTIAS), The University of Tokyo, Tokyo, 113-0033, Japan
| |
Collapse
|
32
|
Picard N, Fagiolini M. MeCP2: an epigenetic regulator of critical periods. Curr Opin Neurobiol 2019; 59:95-101. [PMID: 31163286 DOI: 10.1016/j.conb.2019.04.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 04/10/2019] [Indexed: 01/30/2023]
Abstract
Complex adult behaviors arise from the integration of sequential and often overlapping critical periods (CPs) early in life and adolescence. These processes rely on a subtle interplay between the set of genes inherited from the parents, the surrounding environment and epigenetic regulation. Methyl-CpG-binding protein 2 (MeCP2) has been shown to recognize epigenetic states and regulate gene expression by reading methylated DNA. Here, we will review the recent findings revealing the role of MeCP2 during postnatal CPs of development using mouse models of Rett (RTT) syndrome.
Collapse
Affiliation(s)
- Nathalie Picard
- FM Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States.
| | - Michela Fagiolini
- FM Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States; International Research Center for Neurointelligence, University of Tokyo Institutes for Advanced Study, Tokyo, 113-0033, Japan.
| |
Collapse
|
33
|
Adams W, Graham JN, Han X, Riecke H. Top-down inputs drive neuronal network rewiring and context-enhanced sensory processing in olfaction. PLoS Comput Biol 2019; 15:e1006611. [PMID: 30668563 PMCID: PMC6358160 DOI: 10.1371/journal.pcbi.1006611] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Revised: 02/01/2019] [Accepted: 10/29/2018] [Indexed: 11/18/2022] Open
Abstract
Much of the computational power of the mammalian brain arises from its extensive top-down projections. To enable neuron-specific information processing these projections have to be precisely targeted. How such a specific connectivity emerges and what functions it supports is still poorly understood. We addressed these questions in silico in the context of the profound structural plasticity of the olfactory system. At the core of this plasticity are the granule cells of the olfactory bulb, which integrate bottom-up sensory inputs and top-down inputs delivered by vast top-down projections from cortical and other brain areas. We developed a biophysically supported computational model for the rewiring of the top-down projections and the intra-bulbar network via adult neurogenesis. The model captures various previous physiological and behavioral observations and makes specific predictions for the cortico-bulbar network connectivity that is learned by odor exposure and environmental contexts. Specifically, it predicts that-after learning-the granule-cell receptive fields with respect to sensory and with respect to cortical inputs are highly correlated. This enables cortical cells that respond to a learned odor to enact disynaptic inhibitory control specifically of bulbar principal cells that respond to that odor. For this the reciprocal nature of the granule cell synapses with the principal cells is essential. Functionally, the model predicts context-enhanced stimulus discrimination in cluttered environments ('olfactory cocktail parties') and the ability of the system to adapt to its tasks by rapidly switching between different odor-processing modes. These predictions are experimentally testable. At the same time they provide guidance for future experiments aimed at unraveling the cortico-bulbar connectivity.
Collapse
Affiliation(s)
- Wayne Adams
- Engineering Sciences and Applied Mathematics, Northwestern University, Evanston, IL, USA
| | - James N. Graham
- Engineering Sciences and Applied Mathematics, Northwestern University, Evanston, IL, USA
| | - Xuchen Han
- Mathematics, Northwestern University, Evanston, IL, USA
| | - Hermann Riecke
- Engineering Sciences and Applied Mathematics, Northwestern University, Evanston, IL, USA
| |
Collapse
|
34
|
Crandall SR, Patrick SL, Cruikshank SJ, Connors BW. Infrabarrels Are Layer 6 Circuit Modules in the Barrel Cortex that Link Long-Range Inputs and Outputs. Cell Rep 2018; 21:3065-3078. [PMID: 29241536 DOI: 10.1016/j.celrep.2017.11.049] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Revised: 10/11/2017] [Accepted: 11/14/2017] [Indexed: 10/18/2022] Open
Abstract
The rodent somatosensory cortex includes well-defined examples of cortical columns-the barrel columns-that extend throughout the cortical depth and are defined by discrete clusters of neurons in layer 4 (L4) called barrels. Using the cell-type-specific Ntsr1-Cre mouse line, we found that L6 contains infrabarrels, readily identifiable units that align with the L4 barrels. Corticothalamic (CT) neurons and their local axons cluster within the infrabarrels, whereas corticocortical (CC) neurons are densest between infrabarrels. Optogenetic experiments showed that CC cells received robust input from somatosensory thalamic nuclei, whereas CT cells received much weaker thalamic inputs. We also found that CT neurons are intrinsically less excitable, revealing that both synaptic and intrinsic mechanisms contribute to the low firing rates of CT neurons often reported in vivo. In summary, infrabarrels are discrete cortical circuit modules containing two partially separated excitatory networks that link long-distance thalamic inputs with specific outputs.
Collapse
Affiliation(s)
- Shane R Crandall
- Department of Neuroscience, Division of Biology and Medicine, Brown University, Providence, RI 02912, USA.
| | - Saundra L Patrick
- Department of Neuroscience, Division of Biology and Medicine, Brown University, Providence, RI 02912, USA
| | - Scott J Cruikshank
- Department of Neuroscience, Division of Biology and Medicine, Brown University, Providence, RI 02912, USA
| | - Barry W Connors
- Department of Neuroscience, Division of Biology and Medicine, Brown University, Providence, RI 02912, USA
| |
Collapse
|
35
|
Guido W. Development, form, and function of the mouse visual thalamus. J Neurophysiol 2018; 120:211-225. [PMID: 29641300 PMCID: PMC6093956 DOI: 10.1152/jn.00651.2017] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 04/04/2018] [Accepted: 04/04/2018] [Indexed: 12/16/2022] Open
Abstract
The dorsal lateral geniculate nucleus (dLGN) of the thalamus is the exclusive relay of retinal information en route to the visual cortex. Although much of our understanding about dLGN comes from studies done in higher mammals, such as the cat and primate, the mouse as a model organism has moved to the forefront as a tractable experimental platform to examine cell type-specific relations. This review highlights our current knowledge about the development, structure, and function of the mouse dLGN.
Collapse
Affiliation(s)
- William Guido
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine , Louisville, Kentucky
| |
Collapse
|
36
|
Refinement of Spatial Receptive Fields in the Developing Mouse Lateral Geniculate Nucleus Is Coordinated with Excitatory and Inhibitory Remodeling. J Neurosci 2018; 38:4531-4542. [PMID: 29661964 DOI: 10.1523/jneurosci.2857-17.2018] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 04/03/2018] [Accepted: 04/10/2018] [Indexed: 11/21/2022] Open
Abstract
Receptive field properties of individual visual neurons are dictated by the precise patterns of synaptic connections they receive, including the arrangement of inputs in visual space and features such as polarity (On vs Off). The inputs from the retina to the lateral geniculate nucleus (LGN) in the mouse undergo significant refinement during development. However, it is unknown how this refinement corresponds to the establishment of functional visual response properties. Here we conducted in vivo and in vitro recordings in the mouse LGN, beginning just after natural eye opening, to determine how receptive fields develop as excitatory and feedforward inhibitory retinal afferents refine. Experiments used both male and female subjects. For in vivo assessment of receptive fields, we performed multisite extracellular recordings in awake mice. Spatial receptive fields at eye-opening were >2 times larger than in adulthood, and decreased in size over the subsequent week. This topographic refinement was accompanied by other spatial changes, such as a decrease in spot size preference and an increase in surround suppression. Notably, the degree of specificity in terms of On/Off and sustained/transient responses appeared to be established already at eye opening and did not change. We performed in vitro recordings of the synaptic responses evoked by optic tract stimulation across the same time period. These recordings revealed a pairing of decreased excitatory and increased feedforward inhibitory convergence, providing a potential mechanism to explain the spatial receptive field refinement.SIGNIFICANCE STATEMENT The development of precise patterns of retinogeniculate connectivity has been a powerful model system for understanding the mechanisms underlying the activity-dependent refinement of sensory systems. Here we link the maturation of spatial receptive field properties in the lateral geniculate nucleus (LGN) to the remodeling of retinal and inhibitory feedforward convergence onto LGN neurons. These findings should thus provide a starting point for testing the cell type-specific plasticity mechanisms that lead to refinement of different excitatory and inhibitory inputs, and for determining the effect of these mechanisms on the establishment of mature receptive fields in the LGN.
Collapse
|
37
|
Single-cell transcriptomics of the developing lateral geniculate nucleus reveals insights into circuit assembly and refinement. Proc Natl Acad Sci U S A 2018; 115:E1051-E1060. [PMID: 29343640 PMCID: PMC5798372 DOI: 10.1073/pnas.1717871115] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Neurons and nonneuronal cells in the developing brain dynamically regulate gene expression as neural connectivity is established. However, the specific gene programs activated in distinct cell populations during the assembly and refinement of many intact neuronal circuits have not been thoroughly characterized. In this study, we take advantage of recent advances in transcriptomic profiling techniques to characterize gene expression in the postnatal developing lateral geniculate nucleus (LGN) at single-cell resolution. Our data reveal that genes involved in brain development are dynamically regulated in all major cell types of the LGN, suggesting that the establishment of neural connectivity depends upon functional collaboration between multiple neuronal and nonneuronal cell types in this brain region. Coordinated changes in gene expression underlie the early patterning and cell-type specification of the central nervous system. However, much less is known about how such changes contribute to later stages of circuit assembly and refinement. In this study, we employ single-cell RNA sequencing to develop a detailed, whole-transcriptome resource of gene expression across four time points in the developing dorsal lateral geniculate nucleus (LGN), a visual structure in the brain that undergoes a well-characterized program of postnatal circuit development. This approach identifies markers defining the major LGN cell types, including excitatory relay neurons, oligodendrocytes, astrocytes, microglia, and endothelial cells. Most cell types exhibit significant transcriptional changes across development, dynamically expressing genes involved in distinct processes including retinotopic mapping, synaptogenesis, myelination, and synaptic refinement. Our data suggest that genes associated with synapse and circuit development are expressed in a larger proportion of nonneuronal cell types than previously appreciated. Furthermore, we used this single-cell expression atlas to identify the Prkcd-Cre mouse line as a tool for selective manipulation of relay neurons during a late stage of sensory-driven synaptic refinement. This transcriptomic resource provides a cellular map of gene expression across several cell types of the LGN, and offers insight into the molecular mechanisms of circuit development in the postnatal brain.
Collapse
|
38
|
Guerguiev J, Lillicrap TP, Richards BA. Towards deep learning with segregated dendrites. eLife 2017; 6. [PMID: 29205151 PMCID: PMC5716677 DOI: 10.7554/elife.22901] [Citation(s) in RCA: 159] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 10/22/2017] [Indexed: 01/24/2023] Open
Abstract
Deep learning has led to significant advances in artificial intelligence, in part, by adopting strategies motivated by neurophysiology. However, it is unclear whether deep learning could occur in the real brain. Here, we show that a deep learning algorithm that utilizes multi-compartment neurons might help us to understand how the neocortex optimizes cost functions. Like neocortical pyramidal neurons, neurons in our model receive sensory information and higher-order feedback in electrotonically segregated compartments. Thanks to this segregation, neurons in different layers of the network can coordinate synaptic weight updates. As a result, the network learns to categorize images better than a single layer network. Furthermore, we show that our algorithm takes advantage of multilayer architectures to identify useful higher-order representations—the hallmark of deep learning. This work demonstrates that deep learning can be achieved using segregated dendritic compartments, which may help to explain the morphology of neocortical pyramidal neurons. Artificial intelligence has made major progress in recent years thanks to a technique known as deep learning, which works by mimicking the human brain. When computers employ deep learning, they learn by using networks made up of many layers of simulated neurons. Deep learning has opened the door to computers with human – or even super-human – levels of skill in recognizing images, processing speech and controlling vehicles. But many neuroscientists are skeptical about whether the brain itself performs deep learning. The patterns of activity that occur in computer networks during deep learning resemble those seen in human brains. But some features of deep learning seem incompatible with how the brain works. Moreover, neurons in artificial networks are much simpler than our own neurons. For instance, in the region of the brain responsible for thinking and planning, most neurons have complex tree-like shapes. Each cell has ‘roots’ deep inside the brain and ‘branches’ close to the surface. By contrast, simulated neurons have a uniform structure. To find out whether networks made up of more realistic simulated neurons could be used to make deep learning more biologically realistic, Guerguiev et al. designed artificial neurons with two compartments, similar to the ‘roots’ and ‘branches’. The network learned to recognize hand-written digits more easily when it had many layers than when it had only a few. This shows that artificial neurons more like those in the brain can enable deep learning. It even suggests that our own neurons may have evolved their shape to support this process. If confirmed, the link between neuronal shape and deep learning could help us develop better brain-computer interfaces. These allow people to use their brain activity to control devices such as artificial limbs. Despite advances in computing, we are still superior to computers when it comes to learning. Understanding how our own brains show deep learning could thus help us develop better, more human-like artificial intelligence in the future.
Collapse
Affiliation(s)
- Jordan Guerguiev
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, Canada
| | | | - Blake A Richards
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, Canada.,Learning in Machines and Brains Program, Canadian Institute for Advanced Research, Toronto, Canada
| |
Collapse
|
39
|
Abstract
The corticogeniculate circuit is an evolutionarily conserved pathway linking the primary visual cortex with the visual thalamus in the feedback direction. While the corticogeniculate circuit is anatomically robust, the impact of corticogeniculate feedback on the visual response properties of visual thalamic neurons is subtle. Accordingly, discovering the function of corticogeniculate feedback in vision has been a particularly challenging task. In this review, the morphology, organization, physiology, and function of corticogeniculate feedback is compared across mammals commonly studied in visual neuroscience: primates, carnivores, rabbits, and rodents. Common structural and organizational motifs are present across species, including the organization of corticogeniculate feedback into parallel processing streams in highly visual mammals.
Collapse
Affiliation(s)
- J Michael Hasse
- Program in Experimental and Molecular Medicine at Dartmouth, Hanover, New Hampshire
- Ernest J. Del Monte Institute for Neuroscience, University of Rochester School of Medicine, Rochester, New York
| | - Farran Briggs
- Program in Experimental and Molecular Medicine at Dartmouth, Hanover, New Hampshire
- Ernest J. Del Monte Institute for Neuroscience, University of Rochester School of Medicine, Rochester, New York
- Neuroscience, University of Rochester School of Medicine, Rochester, New York
- Center for Visual Science, University of Rochester, Rochester, New York
| |
Collapse
|
40
|
Litvina EY, Chen C. Functional Convergence at the Retinogeniculate Synapse. Neuron 2017; 96:330-338.e5. [PMID: 29024658 DOI: 10.1016/j.neuron.2017.09.037] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 09/01/2017] [Accepted: 09/22/2017] [Indexed: 01/03/2023]
Abstract
Precise connectivity between retinal ganglion cells (RGCs) and thalamocortical (TC) relay neurons is thought to be essential for the transmission of visual information. Consistent with this view, electrophysiological measurements have previously estimated that 1-3 RGCs converge onto a mouse geniculate TC neuron. Recent advances in connectomics and rabies tracing have yielded much higher estimates of retinogeniculate convergence, although not all identified contacts may be functional. Here we use optogenetics and a computational simulation to determine the number of functionally relevant retinogeniculate inputs onto TC neurons in mice. We find an average of ten RGCs converging onto a mature TC neuron, in contrast to >30 inputs before developmental refinement. However, only 30% of retinogeniculate inputs exceed the threshold for dominating postsynaptic activity. These results signify a greater role for the thalamus in visual processing and provide a functional perspective of anatomical connectivity data.
Collapse
Affiliation(s)
- Elizabeth Y Litvina
- Department of Neurology, F.M. Kirby Neurobiology Center, Children's Hospital, Boston, 300 Longwood Avenue, Boston, MA 02115, USA; Program in Neuroscience, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Chinfei Chen
- Department of Neurology, F.M. Kirby Neurobiology Center, Children's Hospital, Boston, 300 Longwood Avenue, Boston, MA 02115, USA; Program in Neuroscience, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA.
| |
Collapse
|
41
|
Sommeijer JP, Ahmadlou M, Saiepour MH, Seignette K, Min R, Heimel JA, Levelt CN. Thalamic inhibition regulates critical-period plasticity in visual cortex and thalamus. Nat Neurosci 2017; 20:1715-1721. [DOI: 10.1038/s41593-017-0002-3] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2017] [Accepted: 08/23/2017] [Indexed: 11/09/2022]
|
42
|
Narushima M. Comparison of the role of metabotropic glutamate receptor subtype 1 in developmental refinement of neuronal connectivity between the cerebellum and the sensory thalamus. Neurosci Res 2017; 129:24-31. [PMID: 28711710 DOI: 10.1016/j.neures.2017.06.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 06/15/2017] [Accepted: 06/15/2017] [Indexed: 11/30/2022]
Abstract
Developmental refinement of neuronal connectivity is crucial for proper brain function. In the early phase of development, input fibers arrive at their target areas guided by specific molecular cues and form abundant immature synapses. Then, functionally important synapses are preserved and strengthened by neural activity while unnecessary synapses are eliminated. Afferent synapses in the sensory thalamus, such as from retina to lateral geniculate nucleus, and climbing fiber (CF)-Purkinje cell (PC) synapses in the cerebellum are valuable models for studying this developmental refinement of synaptic connectivity because only a limited number of input fibers innervate a given postsynaptic thalamocortical (TC) neuron or PC. The metabotropic glutamate receptor subtype 1 (mGluR1) is required for the refinement of both afferent-TC neuron and CF-PC synapses. However, mGluR1 functions differently at these synapses. While mGluR1 is critical for elimination of surplus CF-PC synapses in the cerebellum, retinogeniculate synapses require mGluR1 for maintenance of mature connectivity.
Collapse
Affiliation(s)
- Madoka Narushima
- Department of Physiology (I), School of Medicine, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan.
| |
Collapse
|
43
|
Thompson AD, Chen C. The importance of constructive feedback: Implications of top-down regulation in the development of neural circuits. NEUROGENESIS 2017; 4:e1287553. [PMID: 28331874 DOI: 10.1080/23262133.2017.1287553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 01/22/2017] [Indexed: 10/20/2022]
Abstract
Neural circuits in sensory pathways develop through a general strategy of overproduction of synapses followed by activity-driven pruning to fine-tune connectivity for optimal function. The early visual pathway, consisting of the retina → visual thalamus → primary visual cortex, has served for decades as a powerful model system for probing the mechanisms and logic of this process. In addition to these feedforward projections, the early visual pathway also includes a substantial feedback component in the form of corticothalamic projections from the deepest layer of primary visual cortex. The role of this feedback in visual processing has been studied extensively in mature animals, yet historically, its role in development has received comparatively little attention. Recent technological advances allowing for selective manipulation of neural activity in development led to the uncovering of a role for feedback in guiding the refinement of the forward projection from retina to visual thalamus. Here we discuss the implications of feedback exerting influence on the development of sensory pathways. We propose several possible advantages to constructing neural circuits with top-down regulation, and discuss the potential significance of this finding for certain neurologic disorders.
Collapse
Affiliation(s)
- Andrew D Thompson
- Department of Neurology, F.M. Kirby Neurobiology Center, Children's Hospital Boston , Boston, MA, USA
| | - Chinfei Chen
- Department of Neurology, F.M. Kirby Neurobiology Center, Children's Hospital Boston, Boston, MA, USA; Program in Neuroscience, Harvard Medical School, Boston, MA, USA
| |
Collapse
|
44
|
Thompson A, Gribizis A, Chen C, Crair MC. Activity-dependent development of visual receptive fields. Curr Opin Neurobiol 2017; 42:136-143. [PMID: 28088066 DOI: 10.1016/j.conb.2016.12.007] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 12/16/2016] [Accepted: 12/19/2016] [Indexed: 11/17/2022]
Abstract
It is widely appreciated that neuronal activity contributes to the development of brain representations of the external world. In the visual system, in particular, it is well known that activity cooperates with molecular cues to establish the topographic organization of visual maps on a macroscopic scale [1,2] (Huberman et al., 2008; Cang and Feldheim, 2013), mapping axons in a retinotopic and eye-specific manner. In recent years, significant progress has been made in elucidating the role of activity in driving the finer-scale circuit refinement that shapes the receptive fields of individual cells. In this review, we focus on these recent breakthroughs-primarily in mice, but also in other mammals where noted.
Collapse
Affiliation(s)
- Andrew Thompson
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Alexandra Gribizis
- Department of Neuroscience, Kavli Institute for Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Chinfei Chen
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA.
| | - Michael C Crair
- Department of Neuroscience, Kavli Institute for Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA.
| |
Collapse
|
45
|
Abstract
The thalamocortical (TC) relay neuron of the dorsoLateral Geniculate Nucleus (dLGN) has borne its imprecise label for many decades in spite of strong evidence that its role in visual processing transcends the implied simplicity of the term "relay". The retinogeniculate synapse is the site of communication between a retinal ganglion cell and a TC neuron of the dLGN. Activation of retinal fibers in the optic tract causes reliable, rapid, and robust postsynaptic potentials that drive postsynaptics spikes in a TC neuron. Cortical and subcortical modulatory systems have been known for decades to regulate retinogeniculate transmission. The dynamic properties that the retinogeniculate synapse itself exhibits during and after developmental refinement further enrich the role of the dLGN in the transmission of the retinal signal. Here we consider the structural and functional substrates for retinogeniculate synaptic transmission and plasticity, and reflect on how the complexity of the retinogeniculate synapse imparts a novel dynamic and influential capacity to subcortical processing of visual information.
Collapse
Affiliation(s)
- Elizabeth Y Litvina
- Department of Neurology,F.M. Kirby Neurobiology Center,Children's Hospital, Boston,Boston,Massachusetts 02115
| | - Chinfei Chen
- Department of Neurology,F.M. Kirby Neurobiology Center,Children's Hospital, Boston,Boston,Massachusetts 02115
| |
Collapse
|
46
|
Monavarfeshani A, Sabbagh U, Fox MA. Not a one-trick pony: Diverse connectivity and functions of the rodent lateral geniculate complex. Vis Neurosci 2017; 34:E012. [PMID: 28965517 PMCID: PMC5755970 DOI: 10.1017/s0952523817000098] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Often mislabeled as a simple relay of sensory information, the thalamus is a complicated structure with diverse functions. This diversity is exemplified by roles visual thalamus plays in processing and transmitting light-derived stimuli. Such light-derived signals are transmitted to the thalamus by retinal ganglion cells (RGCs), the sole projection neurons of the retina. Axons from RGCs innervate more than ten distinct nuclei within thalamus, including those of the lateral geniculate complex. Nuclei within the lateral geniculate complex of nocturnal rodents, which include the dorsal lateral geniculate nucleus (dLGN), ventral lateral geniculate nucleus (vLGN), and intergeniculate leaflet (IGL), are each densely innervated by retinal projections, yet, exhibit distinct cytoarchitecture and connectivity. These features suggest that each nucleus within this complex plays a unique role in processing and transmitting light-derived signals. Here, we review the diverse cytoarchitecture and connectivity of these nuclei in nocturnal rodents, in an effort to highlight roles for dLGN in vision and for vLGN and IGL in visuomotor, vestibular, ocular, and circadian function.
Collapse
Affiliation(s)
- Aboozar Monavarfeshani
- Developmental and Translational Neurobiology Center,Virginia Tech Carilion Research Institute,Roanoke,Virginia
| | - Ubadah Sabbagh
- Developmental and Translational Neurobiology Center,Virginia Tech Carilion Research Institute,Roanoke,Virginia
| | - Michael A Fox
- Developmental and Translational Neurobiology Center,Virginia Tech Carilion Research Institute,Roanoke,Virginia
| |
Collapse
|
47
|
Bray N. Neural development: Sight development. Nat Rev Neurosci 2016; 17:603. [PMID: 27640978 DOI: 10.1038/nrn.2016.129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|