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Gauberg J, Moreno KB, Jayaraman K, Abumeri S, Jenkins S, Salazar AM, Meharena HS, Glasgow SM. Spinal motor neuron development and metabolism are transcriptionally regulated by Nuclear Factor IA. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.26.600888. [PMID: 38979382 PMCID: PMC11230388 DOI: 10.1101/2024.06.26.600888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Neural circuits governing all motor behaviors in vertebrates rely on the proper development of motor neurons and their precise targeting of limb muscles. Transcription factors are essential for motor neuron development, regulating their specification, migration, and axonal targeting. While transcriptional regulation of the early stages of motor neuron specification is well-established, much less is known about the role of transcription factors in the later stages of maturation and terminal arborization. Defining the molecular mechanisms of these later stages is critical for elucidating how motor circuits are constructed. Here, we demonstrate that the transcription factor Nuclear Factor-IA (NFIA) is required for motor neuron positioning, axonal branching, and neuromuscular junction formation. Moreover, we find that NFIA is required for proper mitochondrial function and ATP production, providing a new and important link between transcription factors and metabolism during motor neuron development. Together, these findings underscore the critical role of NFIA in instructing the assembly of spinal circuits for movement.
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Vagnozzi AN, Moore MT, López de Boer R, Agarwal A, Zampieri N, Landmesser LT, Philippidou P. Catenin signaling controls phrenic motor neuron development and function during a narrow temporal window. Front Neural Circuits 2023; 17:1121049. [PMID: 36895798 PMCID: PMC9988953 DOI: 10.3389/fncir.2023.1121049] [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: 12/11/2022] [Accepted: 02/06/2023] [Indexed: 02/25/2023] Open
Abstract
Phrenic Motor Column (PMC) neurons are a specialized subset of motor neurons (MNs) that provide the only motor innervation to the diaphragm muscle and are therefore essential for survival. Despite their critical role, the mechanisms that control phrenic MN development and function are not well understood. Here, we show that catenin-mediated cadherin adhesive function is required for multiple aspects of phrenic MN development. Deletion of β- and γ-catenin from MN progenitors results in perinatal lethality and a severe reduction in phrenic MN bursting activity. In the absence of catenin signaling, phrenic MN topography is eroded, MN clustering is lost and phrenic axons and dendrites fail to grow appropriately. Despite the essential requirement for catenins in early phrenic MN development, they appear to be dispensable for phrenic MN maintenance, as catenin deletion from postmitotic MNs does not impact phrenic MN topography or function. Our data reveal a fundamental role for catenins in PMC development and suggest that distinct mechanisms are likely to control PMC maintenance.
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Affiliation(s)
- Alicia N. Vagnozzi
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH, United States
| | - Matthew T. Moore
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH, United States
| | - Raquel López de Boer
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH, United States
| | - Aambar Agarwal
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH, United States
| | - Niccolò Zampieri
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Lynn T. Landmesser
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH, United States
| | - Polyxeni Philippidou
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH, United States
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Catenin signaling controls phrenic motor neuron development and function during a narrow temporal window. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.18.524559. [PMID: 36711833 PMCID: PMC9882252 DOI: 10.1101/2023.01.18.524559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Phrenic Motor Column (PMC) neurons are a specialized subset of motor neurons (MNs) that provide the only motor innervation to the diaphragm muscle and are therefore essential for survival. Despite their critical role, the mechanisms that control phrenic MN development and function are not well understood. Here, we show that catenin-mediated cadherin adhesive function is required for multiple aspects of phrenic MN development. Deletion of β - and γ -catenin from MN progenitors results in perinatal lethality and a severe reduction in phrenic MN bursting activity. In the absence of catenin signaling, phrenic MN topography is eroded, MN clustering is lost and phrenic axons and dendrites fail to grow appropriately. Despite the essential requirement for catenins in early phrenic MN development, they appear to be dispensable for phrenic MN maintenance, as catenin deletion from postmitotic MNs does not impact phrenic MN topography or function. Our data reveal a fundamental role for catenins in PMC development and suggest that distinct mechanisms are likely to control PMC maintenance.
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Vagnozzi AN, Moore MT, Lin M, Brozost EM, KC R, Agarwal A, Schwarz LA, Duan X, Zampieri N, Landmesser LT, Philippidou P. Coordinated cadherin functions sculpt respiratory motor circuit connectivity. eLife 2022; 11:e82116. [PMID: 36583530 PMCID: PMC9910829 DOI: 10.7554/elife.82116] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Accepted: 12/29/2022] [Indexed: 12/31/2022] Open
Abstract
Breathing, and the motor circuits that control it, is essential for life. At the core of respiratory circuits are Dbx1-derived interneurons, which generate the rhythm and pattern of breathing, and phrenic motor neurons (MNs), which provide the final motor output that drives diaphragm muscle contractions during inspiration. Despite their critical function, the principles that dictate how respiratory circuits assemble are unknown. Here, we show that coordinated activity of a type I cadherin (N-cadherin) and type II cadherins (Cadherin-6, -9, and -10) is required in both MNs and Dbx1-derived neurons to generate robust respiratory motor output. Both MN- and Dbx1-specific cadherin inactivation in mice during a critical developmental window results in perinatal lethality due to respiratory failure and a striking reduction in phrenic MN bursting activity. This combinatorial cadherin code is required to establish phrenic MN cell body and dendritic topography; surprisingly, however, cell body position appears to be dispensable for the targeting of phrenic MNs by descending respiratory inputs. Our findings demonstrate that type I and II cadherins function cooperatively throughout the respiratory circuit to generate a robust breathing output and reveal novel strategies that drive the assembly of motor circuits.
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Affiliation(s)
- Alicia N Vagnozzi
- Department of Neurosciences, Case Western Reserve UniversityClevelandUnited States
| | - Matthew T Moore
- Department of Neurosciences, Case Western Reserve UniversityClevelandUnited States
| | - Minshan Lin
- Department of Neurosciences, Case Western Reserve UniversityClevelandUnited States
| | - Elyse M Brozost
- Department of Neurosciences, Case Western Reserve UniversityClevelandUnited States
| | - Ritesh KC
- Department of Neurosciences, Case Western Reserve UniversityClevelandUnited States
| | - Aambar Agarwal
- Department of Neurosciences, Case Western Reserve UniversityClevelandUnited States
| | - Lindsay A Schwarz
- Department of Developmental Neurobiology, St. Jude Children's Research HospitalMemphisUnited States
| | - Xin Duan
- Department of Ophthalmology, University of California, San FranciscoSan FranciscoUnited States
| | - Niccolò Zampieri
- Max Delbrück Center for Molecular Medicine in the Helmholtz AssociationBerlinGermany
| | - Lynn T Landmesser
- Department of Neurosciences, Case Western Reserve UniversityClevelandUnited States
| | - Polyxeni Philippidou
- Department of Neurosciences, Case Western Reserve UniversityClevelandUnited States
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Gerstmann K, Jurčić N, Blasco E, Kunz S, de Almeida Sassi F, Wanaverbecq N, Zampieri N. The role of intraspinal sensory neurons in the control of quadrupedal locomotion. Curr Biol 2022; 32:2442-2453.e4. [PMID: 35512696 DOI: 10.1016/j.cub.2022.04.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 03/04/2022] [Accepted: 04/08/2022] [Indexed: 01/09/2023]
Abstract
From swimming to walking and flying, animals have evolved specific locomotor strategies to thrive in different habitats. All types of locomotion depend on the integration of motor commands and sensory information to generate precisely coordinated movements. Cerebrospinal-fluid-contacting neurons (CSF-cN) constitute a vertebrate sensory system that monitors CSF composition and flow. In fish, CSF-cN modulate swimming activity in response to changes in pH and bending of the spinal cord; however, their role in mammals remains unknown. We used mouse genetics to study their function in quadrupedal locomotion. We found that CSF-cN are directly integrated into spinal motor circuits. The perturbation of CSF-cN function does not affect general motor activity nor the generation of locomotor rhythm and pattern but results in specific defects in skilled movements. These results identify a role for mouse CSF-cN in adaptive motor control and indicate that this sensory system evolved a novel function to accommodate the biomechanical requirements of limb-based locomotion.
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Affiliation(s)
- Katrin Gerstmann
- Max Delbrück Center for Molecular Medicine, Robert-Rössle-Str. 10, 13125 Berlin, Germany
| | - Nina Jurčić
- Institut de Neurosciences de la Timone, Aix-Marseille Université (AMU) & CNRS, UMR7289, Timone Campus, 27 Boulevard Jean Moulin, 13005 Marseille, France
| | - Edith Blasco
- Institut de Neurosciences de la Timone, Aix-Marseille Université (AMU) & CNRS, UMR7289, Timone Campus, 27 Boulevard Jean Moulin, 13005 Marseille, France
| | - Severine Kunz
- Technology Platform for Electron Microscopy, Max Delbrück Center for Molecular Medicine, Robert-Rössle-Str. 10, 13125 Berlin, Germany
| | | | - Nicolas Wanaverbecq
- Institut de Neurosciences de la Timone, Aix-Marseille Université (AMU) & CNRS, UMR7289, Timone Campus, 27 Boulevard Jean Moulin, 13005 Marseille, France
| | - Niccolò Zampieri
- Max Delbrück Center for Molecular Medicine, Robert-Rössle-Str. 10, 13125 Berlin, Germany.
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Rabies anterograde monosynaptic tracing allows identification of postsynaptic circuits receiving distinct somatosensory input. Neuroscience 2022; 491:75-86. [DOI: 10.1016/j.neuroscience.2022.03.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 03/08/2022] [Accepted: 03/09/2022] [Indexed: 01/13/2023]
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Quantitative lineage analysis identifies a hepato-pancreato-biliary progenitor niche. Nature 2021; 597:87-91. [PMID: 34433966 DOI: 10.1038/s41586-021-03844-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 07/21/2021] [Indexed: 02/07/2023]
Abstract
Studies based on single cells have revealed vast cellular heterogeneity in stem cell and progenitor compartments, suggesting continuous differentiation trajectories with intermixing of cells at various states of lineage commitment and notable degrees of plasticity during organogenesis1-5. The hepato-pancreato-biliary organ system relies on a small endoderm progenitor compartment that gives rise to a variety of different adult tissues, including the liver, pancreas, gall bladder and extra-hepatic bile ducts6,7. Experimental manipulation of various developmental signals in the mouse embryo has underscored important cellular plasticity in this embryonic territory6. This is reflected in the existence of human genetic syndromes as well as congenital malformations featuring multi-organ phenotypes in liver, pancreas and gall bladder6. Nevertheless, the precise lineage hierarchy and succession of events leading to the segregation of an endoderm progenitor compartment into hepatic, biliary and pancreatic structures have not yet been established. Here we combine computational modelling approaches with genetic lineage tracing to accurately reconstruct the hepato-pancreato-biliary lineage tree. We show that a multipotent progenitor subpopulation persists in the pancreato-biliary organ rudiment, contributing cells not only to the pancreas and gall bladder but also to the liver. Moreover, using single-cell RNA sequencing and functional experiments we define a specialized niche that supports this subpopulation in a multipotent state for an extended time during development. Together these findings indicate sustained plasticity underlying hepato-pancreato-biliary development that might also explain the rapid expansion of the liver while attenuating pancreato-biliary growth.
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Skarlatou S, Hérent C, Toscano E, Mendes CS, Bouvier J, Zampieri N. Afadin Signaling at the Spinal Neuroepithelium Regulates Central Canal Formation and Gait Selection. Cell Rep 2021; 31:107741. [PMID: 32521266 DOI: 10.1016/j.celrep.2020.107741] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 04/03/2020] [Accepted: 05/15/2020] [Indexed: 11/28/2022] Open
Abstract
Afadin, a scaffold protein controlling the activity of the nectin family of cell adhesion molecules, regulates important morphogenetic processes during development. In the central nervous system, afadin has critical roles in neuronal migration, axonal elongation, and synapse formation. Here we examine the role of afadin in development of spinal motor circuits. Afadin elimination in motor neuron progenitors results in striking locomotor behavior: left-right limb alternation is substituted by synchronous activation, characteristic of bound gait. We find that afadin function at the neuroepithelium is required for structural organization of the spinal midline and central canal morphogenesis. Perturbation of afadin results in formation of two central canals, aberrant contralateral wiring of different classes of spinal premotor interneurons, and loss of left-right limb alternation, highlighting important developmental principles controlling the assembly of spinal motor circuits.
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Affiliation(s)
- Sophie Skarlatou
- Cluster of Excellence NeuroCure, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany; Max Delbrück Center for Molecular Medicine, Robert-Rössle-Str. 10, 13125 Berlin, Germany
| | - Coralie Hérent
- Paris-Saclay Institute of Neuroscience, UMR 9197 CNRS & Université Paris-Saclay, Avenue de La Terrasse, 91190 Gif sur Yvette, France
| | - Elisa Toscano
- Max Delbrück Center for Molecular Medicine, Robert-Rössle-Str. 10, 13125 Berlin, Germany
| | - César S Mendes
- CEDOC, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, 1169-056 Lisboa, Portugal
| | - Julien Bouvier
- Paris-Saclay Institute of Neuroscience, UMR 9197 CNRS & Université Paris-Saclay, Avenue de La Terrasse, 91190 Gif sur Yvette, France
| | - Niccolò Zampieri
- Cluster of Excellence NeuroCure, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany; Max Delbrück Center for Molecular Medicine, Robert-Rössle-Str. 10, 13125 Berlin, Germany.
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9
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Hiesinger PR. Brain wiring with composite instructions. Bioessays 2020; 43:e2000166. [PMID: 33145823 DOI: 10.1002/bies.202000166] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 09/27/2020] [Accepted: 09/29/2020] [Indexed: 11/12/2022]
Abstract
The quest for molecular mechanisms that guide axons or specify synaptic contacts has largely focused on molecules that intuitively relate to the idea of an "instruction." By contrast, "permissive" factors are traditionally considered background machinery without contribution to the information content of a molecularly executed instruction. In this essay, I recast this dichotomy as a continuum from permissive to instructive actions of single factors that provide relative contributions to a necessarily collaborative effort. Individual molecules or other factors do not constitute absolute instructions by themselves; they provide necessary context for each other, thereby creating a composite that defines the overall instruction. The idea of composite instructions leads to two main conclusions: first, a composite of many seemingly permissive factors can define a specific instruction even in the absence of a single dominant contributor; second, individual factors are not necessarily related intuitively to the overall instruction or phenotypic outcome.
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Affiliation(s)
- P Robin Hiesinger
- Division of Neurobiology, Institute for Biology, Freie Universität Berlin, Berlin, Germany
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Knüfer A, Diana G, Walsh GS, Clarke JD, Guthrie S. Cadherins regulate nuclear topography and function of developing ocular motor circuitry. eLife 2020; 9:56725. [PMID: 33001027 PMCID: PMC7599068 DOI: 10.7554/elife.56725] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Accepted: 09/30/2020] [Indexed: 12/30/2022] Open
Abstract
In the vertebrate central nervous system, groups of functionally related neurons, including cranial motor neurons of the brainstem, are frequently organised as nuclei. The molecular mechanisms governing the emergence of nuclear topography and circuit function are poorly understood. Here we investigate the role of cadherin-mediated adhesion in the development of zebrafish ocular motor (sub)nuclei. We find that developing ocular motor (sub)nuclei differentially express classical cadherins. Perturbing cadherin function in these neurons results in distinct defects in neuronal positioning, including scattering of dorsal cells and defective contralateral migration of ventral subnuclei. In addition, we show that cadherin-mediated interactions between adjacent subnuclei are critical for subnucleus position. We also find that disrupting cadherin adhesivity in dorsal oculomotor neurons impairs the larval optokinetic reflex, suggesting that neuronal clustering is important for co-ordinating circuit function. Our findings reveal that cadherins regulate distinct aspects of cranial motor neuron positioning and establish subnuclear topography and motor function.
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Affiliation(s)
- Athene Knüfer
- Centre for Developmental Neurobiology, King's College London, London, United Kingdom
| | - Giovanni Diana
- Centre for Developmental Neurobiology, King's College London, London, United Kingdom
| | - Gregory S Walsh
- Department of Biology, Virginia Commonwealth University, Richmond, United States
| | - Jonathan Dw Clarke
- Centre for Developmental Neurobiology, King's College London, London, United Kingdom
| | - Sarah Guthrie
- School of Life Sciences, University of Sussex, Brighton, United Kingdom
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Balaskas N, Ng D, Zampieri N. The Positional Logic of Sensory-Motor Reflex Circuit Assembly. Neuroscience 2020; 450:142-150. [PMID: 32387250 DOI: 10.1016/j.neuroscience.2020.04.038] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Revised: 04/11/2020] [Accepted: 04/22/2020] [Indexed: 12/18/2022]
Abstract
Throughout his scientific career, Tom Jessell pioneered the spinal cord as a model system to study the molecular programs of neural specification, axon guidance, and connection specificity. His contributions to these fields and more broadly to that of developmental neuroscience will continue to inspire and define many generations of researchers. It is challenging to capture all of Tom's findings in one essay, and therefore, here we wish to briefly highlight his contributions to the problem of connection specificity, with a focus on the spinal sensory-motor reflex circuit. In particular, emphasis will be placed on discoveries from his laboratory that revealed a significant role of positional strategies in establishing selective sensory-motor connections. This work introduced novel principles of neuronal connectivity that may apply to how precise circuit wiring occurs throughout the nervous system.
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Affiliation(s)
- Nikolaos Balaskas
- The Mortimer B. Zuckerman Mind, Brain, and Behavior Institute, Department of Neuroscience, Columbia University, New York, NY 10027, USA.
| | - David Ng
- The Mortimer B. Zuckerman Mind, Brain, and Behavior Institute, Columbia University, New York, NY 10027, USA.
| | - Niccolò Zampieri
- Max-Delbrück-Center for Molecular Medicine Berlin-Buch, Robert-Rössle-Str. 10, 13125 Berlin, Germany.
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Agi E, Kulkarni A, Hiesinger PR. Neuronal strategies for meeting the right partner during brain wiring. Curr Opin Neurobiol 2020; 63:1-8. [PMID: 32036252 DOI: 10.1016/j.conb.2020.01.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 01/04/2020] [Indexed: 02/07/2023]
Abstract
Two neurons can only form a synapse if their axonal and dendritic projections meet at the same time and place. While spatiotemporal proximity is necessary for synapse formation, it remains unclear to what extent the underlying positional strategies are sufficient to ensure synapse formation between the right partners. Many neurons readily form synapses with wrong partners if they find themselves at the wrong place or time. Minimally, restricting spatiotemporal proximity can prevent incorrect synapses. Maximally, restricting encounters in time and space could be sufficient to ensure correct partnerships between neurons that can form synapses promiscuously. In this review we explore recent findings on positional strategies during developmental growth that contribute to precise outcomes in brain wiring.
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The Temporal Neurogenesis Patterning of Spinal p3-V3 Interneurons into Divergent Subpopulation Assemblies. J Neurosci 2019; 40:1440-1452. [PMID: 31826942 DOI: 10.1523/jneurosci.1518-19.2019] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 12/01/2019] [Accepted: 12/06/2019] [Indexed: 11/21/2022] Open
Abstract
Neuronal diversity provides the spinal cord with the functional flexibility required to perform complex motor tasks. Spinal neurons arise during early embryonic development with the establishment of spatially and molecularly discrete progenitor domains that give rise to distinct, but highly heterogeneous, postmitotic interneuron (IN) populations. Our previous studies have shown that Sim1-expressing V3 INs, originating from the p3 progenitor domain, are anatomically and physiologically divergent. However, the developmental logic guiding V3 subpopulation diversity remains elusive. In specific cases of other IN classes, neurogenesis timing can play a role in determining the ultimate fates and unique characteristics of distinctive subpopulations. To examine whether neurogenesis timing contributes to V3 diversity, we systematically investigated the temporal neurogenesis profiles of V3 INs in the mouse spinal cord. Our work uncovered that V3 INs were organized into either early-born [embryonic day 9.5 (E9.5) to E10.5] or late-born (E11.5-E12.5) neurogenic waves. Early-born V3 INs displayed both ascending and descending commissural projections and clustered into subgroups across dorsoventral spinal laminae. In contrast, late-born V3 INs became fate-restricted to ventral laminae and displayed mostly descending and local commissural projections and uniform membrane properties. Furthermore, we found that the postmitotic transcription factor, Sim1, although expressed in all V3 INs, exclusively regulated the dorsal clustering and electrophysiological diversification of early-born, but not late-born, V3 INs, which indicates that neurogenesis timing may enable newborn V3 INs to interact with different postmitotic differentiation pathways. Thus, our work demonstrates neurogenesis timing as a developmental mechanism underlying the postmitotic differentiation of V3 INs into distinct subpopulation assemblies.SIGNIFICANCE STATEMENT Interneuron (IN) diversity empowers the spinal cord with the computation flexibility required to perform appropriate sensorimotor control. As such, uncovering the developmental logic guiding spinal IN diversity is fundamental to understanding the development of movement. In our current work, through a focus on the cardinal spinal V3 IN population, we investigated the role of neurogenesis timing on IN diversity. We uncovered that V3 INs are organized into early-born [embryonic day 9.5 (E9.5) to E10.5] or late-born (E11.5-E12.5) neurogenic waves, where late-born V3 INs display increasingly restricted subpopulation fates. Next, to better understand the consequences of V3 neurogenesis timing, we investigated the time-dependent functions of the Sim1 transcription factor, which is expressed in postmitotic V3 INs. Interestingly, Sim1 exclusively regulated the diversification of early-born, but not late-born, V3 INs. Thus, our current work indicates neurogenesis timing can modulate the functions of early postmitotic transcription factors and, thus, subpopulation fate specifications.
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Chaimowicz C, Ruffault PL, Chéret C, Woehler A, Zampieri N, Fortin G, Garratt AN, Birchmeier C. Teashirt 1 (Tshz1) is essential for the development, survival and function of hypoglossal and phrenic motor neurons in mouse. Development 2019; 146:dev.174045. [PMID: 31427287 PMCID: PMC6765129 DOI: 10.1242/dev.174045] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 08/09/2019] [Indexed: 11/20/2022]
Abstract
Feeding and breathing are essential motor functions and rely on the activity of hypoglossal and phrenic motor neurons that innervate the tongue and diaphragm, respectively. Little is known about the genetic programs that control the development of these neuronal subtypes. The transcription factor Tshz1 is strongly and persistently expressed in developing hypoglossal and phrenic motor neurons. We used conditional mutation of Tshz1 in the progenitor zone of motor neurons (Tshz1MN Δ) to show that Tshz1 is essential for survival and function of hypoglossal and phrenic motor neurons. Hypoglossal and phrenic motor neurons are born in correct numbers, but many die between embryonic day 13.5 and 14.5 in Tshz1MN Δ mutant mice. In addition, innervation and electrophysiological properties of phrenic and hypoglossal motor neurons are altered. Severe feeding and breathing problems accompany this developmental deficit. Although motor neuron survival can be rescued by elimination of the pro-apoptotic factor Bax, innervation, feeding and breathing defects persist in Bax-/-; Tshz1MN Δ mutants. We conclude that Tshz1 is an essential transcription factor for the development and physiological function of phrenic and hypoglossal motor neurons.
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Affiliation(s)
- Charlotte Chaimowicz
- Developmental Biology/Signal Transduction, Max Delbrück Center for Molecular Medicine (MDC) in the Helmholtz Society, 13125 Berlin, Germany
| | - Pierre-Louis Ruffault
- Developmental Biology/Signal Transduction, Max Delbrück Center for Molecular Medicine (MDC) in the Helmholtz Society, 13125 Berlin, Germany
| | - Cyril Chéret
- Developmental Biology/Signal Transduction, Max Delbrück Center for Molecular Medicine (MDC) in the Helmholtz Society, 13125 Berlin, Germany
| | - Andrew Woehler
- Systems Biology Imaging, Max Delbrück Center for Molecular Medicine (MDC) in the Helmholtz Society, 13125 Berlin, Germany
| | - Niccolò Zampieri
- Development and Function of Neural Circuits, Max Delbrück Center for Molecular Medicine (MDC) in the Helmholtz Society, 13125 Berlin, Germany
| | - Gilles Fortin
- UMR9197, CNRS/Université Paris-Sud, Paris-Saclay Institute of Neuroscience, 1 Avenue de la Terrasse, 91190 Gif-sur-Yvette, France
| | - Alistair N Garratt
- Institute of Cell Biology and Neurobiology, Charité-Universitätsmedizin Berlin, Virchowweg 6, 10117 Berlin, Germany
| | - Carmen Birchmeier
- Developmental Biology/Signal Transduction, Max Delbrück Center for Molecular Medicine (MDC) in the Helmholtz Society, 13125 Berlin, Germany
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15
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Dewolf AH, Ivanenko YP, Zelik KE, Lacquaniti F, Willems PA. Differential activation of lumbar and sacral motor pools during walking at different speeds and slopes. J Neurophysiol 2019; 122:872-887. [PMID: 31291150 DOI: 10.1152/jn.00167.2019] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Organization of spinal motor output has become of interest for investigating differential activation of lumbar and sacral motor pools during locomotor tasks. Motor pools are associated with functional grouping of motoneurons of the lower limb muscles. Here we examined how the spatiotemporal organization of lumbar and sacral motor pool activity during walking is orchestrated with slope of terrain and speed of progression. Ten subjects walked on an instrumented treadmill at different slopes and imposed speeds. Kinetics, kinematics, and electromyography of 16 lower limb muscles were recorded. The spinal locomotor output was assessed by decomposing the coordinated muscle activation profiles into a small set of common factors and by mapping them onto the rostrocaudal location of the motoneuron pools. Our results show that lumbar and sacral motor pool activity depend on slope and speed. Compared with level walking, sacral motor pools decrease their activity at negative slopes and increase at positive slopes, whereas lumbar motor pools increase their engagement when both positive and negative slope increase. These findings are consistent with a differential involvement of the lumbar and the sacral motor pools in relation to changes in positive and negative center of body mass mechanical power production due to slope and speed.NEW & NOTEWORTHY In this study, the spatiotemporal maps of motoneuron activity in the spinal cord were assessed during walking at different slopes and speeds. We found differential involvement of lumbar and sacral motor pools in relation to changes in positive and negative center of body mass power production due to slope and speed. The results are consistent with recent findings about the specialization of neuronal networks located at different segments of the spinal cord for performing specific locomotor tasks.
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Affiliation(s)
- A H Dewolf
- Laboratory of Biomechanics and Physiology of Locomotion, Institute of NeuroScience, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Y P Ivanenko
- Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, Rome, Italy
| | - K E Zelik
- Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, Rome, Italy.,Department of Mechanical Engineering, Vanderbilt University, Nashville, Tennessee.,Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee.,Department of Physical Medicine and Rehabilitation, Vanderbilt University, Nashville, Tennessee
| | - F Lacquaniti
- Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, Rome, Italy.,Department of Systems Medicine and Center of Space Biomedicine, University of Rome Tor Vergata, Rome, Italy
| | - P A Willems
- Laboratory of Biomechanics and Physiology of Locomotion, Institute of NeuroScience, Université catholique de Louvain, Louvain-la-Neuve, Belgium
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Dewitz C, Duan X, Zampieri N. Organization of motor pools depends on the combined function of N-cadherin and type II cadherins. Development 2019; 146:dev.180422. [PMID: 31235635 DOI: 10.1242/dev.180422] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 06/17/2019] [Indexed: 12/16/2022]
Abstract
Type I and type II classical cadherins constitute a family of cell adhesion molecules expressed in complex combinatorial profiles in the nervous system, suggesting that a cadherin code implements specific adhesive recognition events that control the development of neural circuits. In the spinal cord, classical cadherins define at a molecular level the positional organization of motor neuron subtypes into discrete nuclear structures termed motor pools. However, the roles and contributions of different members of the family in defining motor neuron spatial organization are not yet clear. By combining mouse genetics with quantitative positional analysis, we found that motor neuron organization into pools depends on type II cadherins. Type II cadherin function, however, does not strictly reflect the predictions arising from binding specificities at a molecular level, but instead relies on N-cadherin, a type I cadherin whose elimination is required to reveal type II contributions.
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Affiliation(s)
- Carola Dewitz
- Cluster of Excellence NeuroCure, Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany.,Max Delbrück Center for Molecular Medicine Berlin-Buch, Robert-Rössle-Str. 10, 13125 Berlin, Germany
| | - Xin Duan
- Departments of Ophthalmology and Physiology, Weill Institute for Neurosciences, University of California San Francisco, 1550 4th Street, San Francisco, CA 94143-2811, USA
| | - Niccolò Zampieri
- Cluster of Excellence NeuroCure, Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany .,Max Delbrück Center for Molecular Medicine Berlin-Buch, Robert-Rössle-Str. 10, 13125 Berlin, Germany
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