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González-Llera L, Santos-Durán GN, Sobrido-Cameán D, Núñez-González C, Pérez-Fernández J, Barreiro-Iglesias A. Spontaneous regeneration of cholecystokinergic reticulospinal axons after a complete spinal cord injury in sea lampreys. Comput Struct Biotechnol J 2024; 23:347-357. [PMID: 38205155 PMCID: PMC10776906 DOI: 10.1016/j.csbj.2023.12.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 12/13/2023] [Accepted: 12/14/2023] [Indexed: 01/12/2024] Open
Abstract
In contrast to humans, lampreys spontaneously recover their swimming capacity after a complete spinal cord injury (SCI). This recovery process involves the regeneration of descending axons. Spontaneous axon regeneration in lampreys has been mainly studied in giant descending neurons. However, the regeneration of neurochemically distinct descending neuronal populations with small-caliber axons, as those found in mammals, has been less studied. Cholecystokinin (CCK) is a regulatory neuropeptide found in the brain and spinal cord that modulates several processes such as satiety, or locomotion. CCK shows high evolutionary conservation and is present in all vertebrate species. Work in lampreys has shown that all CCKergic spinal cord axons originate in a single neuronal population located in the caudal rhombencephalon. Here, we investigate the spontaneous regeneration of CCKergic descending axons in larval lampreys following a complete SCI. Using anti-CCK-8 immunofluorescence, confocal microscopy and lightning adaptive deconvolution, we demonstrate the partial regeneration of CCKergic axons (81% of the number of axonal profiles seen in controls) 10 weeks after the injury. Our data also revealed a preference for regeneration of CCKergic axons in lateral spinal cord regions. Regenerated CCKergic axons exhibit colocalization with synaptic vesicle marker SV2, indicative of functional synaptic connections. We also extracted swimming dynamics in injured animals by using DeepLabCut. Interestingly, the degree of CCKergic reinnervation correlated with improved swimming performance in injured animals, suggesting a potential role in locomotor recovery. These findings open avenues for further exploration into the role of specific neuropeptidergic systems in post-SCI spinal locomotor networks.
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Affiliation(s)
- Laura González-Llera
- Department of Functional Biology, CIBUS, Faculty of Biology, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Gabriel N. Santos-Durán
- Department of Functional Biology, CIBUS, Faculty of Biology, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Daniel Sobrido-Cameán
- Department of Functional Biology, CIBUS, Faculty of Biology, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Carmen Núñez-González
- CINBIO, Neurocircuits Group, Campus Universitario Lagoas, Marcosende, Universidade de Vigo, 36310 Vigo, Spain
| | - Juan Pérez-Fernández
- CINBIO, Neurocircuits Group, Campus Universitario Lagoas, Marcosende, Universidade de Vigo, 36310 Vigo, Spain
| | - Antón Barreiro-Iglesias
- Department of Functional Biology, CIBUS, Faculty of Biology, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
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González-Llera L, Shifman MI, Barreiro-Iglesias A. Neogenin expression in ependymo-radial glia of the larval sea lamprey Petromyzon marinus spinal cord. MICROPUBLICATION BIOLOGY 2023; 2023:10.17912/micropub.biology.000810. [PMID: 37143448 PMCID: PMC10152269 DOI: 10.17912/micropub.biology.000810] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Revised: 04/05/2023] [Accepted: 04/10/2023] [Indexed: 05/06/2023]
Abstract
Neogenin is a receptor mainly known for its roles during axon pathfinding. However, neogenin is expressed in neuronal precursors of ventricular and subventricular zones of the nervous system and recent work has shown that it regulates adult neurogenesis. Here, we generated an antibody against the sea lamprey neogenin to study its expression in the larval spinal cord. Immunofluorescence experiments show that neogenin is expressed in ependymo-radial glial cells (ERGs) located in the ependymal region of the central canal of mature larval sea lampreys. Our results provide a basis for the future study of the role of neogenin in lamprey ERGs.
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Affiliation(s)
- Laura González-Llera
- Department of Functional Biology, CIBUS, Faculty of Biology, Universidade de Santiago de Compostela, Santiago de Compostela, Galicia, Spain
| | | | - Antón Barreiro-Iglesias
- Department of Functional Biology, CIBUS, Faculty of Biology, Universidade de Santiago de Compostela, Santiago de Compostela, Galicia, Spain
- Correspondence to: Antón Barreiro-Iglesias (
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Cortés E, Pak JS, Özkan E. Structure and evolution of neuronal wiring receptors and ligands. Dev Dyn 2023; 252:27-60. [PMID: 35727136 PMCID: PMC10084454 DOI: 10.1002/dvdy.512] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 06/13/2022] [Accepted: 06/14/2022] [Indexed: 01/04/2023] Open
Abstract
One of the fundamental properties of a neuronal circuit is the map of its connections. The cellular and developmental processes that allow for the growth of axons and dendrites, selection of synaptic targets, and formation of functional synapses use neuronal surface receptors and their interactions with other surface receptors, secreted ligands, and matrix molecules. Spatiotemporal regulation of the expression of these receptors and cues allows for specificity in the developmental pathways that wire stereotyped circuits. The families of molecules controlling axon guidance and synapse formation are generally conserved across animals, with some important exceptions, which have consequences for neuronal connectivity. Here, we summarize the distribution of such molecules across multiple taxa, with a focus on model organisms, evolutionary processes that led to the multitude of such molecules, and functional consequences for the diversification or loss of these receptors.
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Affiliation(s)
- Elena Cortés
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois, USA.,The Neuroscience Institute, University of Chicago, Chicago, Illinois, USA
| | - Joseph S Pak
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois, USA.,The Neuroscience Institute, University of Chicago, Chicago, Illinois, USA
| | - Engin Özkan
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois, USA.,The Neuroscience Institute, University of Chicago, Chicago, Illinois, USA
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Sobrido-Camean D, Barreiro-Iglesias A. Morpholino studies shed light on the signaling pathways regulating axon regeneration in lampreys. Neural Regen Res 2021; 17:1475-1477. [PMID: 34916423 PMCID: PMC8771085 DOI: 10.4103/1673-5374.330597] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Affiliation(s)
- Daniel Sobrido-Camean
- Department of Functional Biology, Faculty of Biology, CIBUS, Universidade de Santiago de Compostela, Santiago de Compostela, A Coruña, Spain
| | - Antón Barreiro-Iglesias
- Department of Functional Biology, Faculty of Biology, CIBUS, Universidade de Santiago de Compostela, Santiago de Compostela, A Coruña, Spain
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Rodemer W, Hu J, Selzer ME, Shifman MI. Heterogeneity in the regenerative abilities of central nervous system axons within species: why do some neurons regenerate better than others? Neural Regen Res 2020; 15:996-1005. [PMID: 31823869 PMCID: PMC7034288 DOI: 10.4103/1673-5374.270298] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Some neurons, especially in mammalian peripheral nervous system or in lower vertebrate or in vertebrate central nervous system (CNS) regenerate after axotomy, while most mammalian CNS neurons fail to regenerate. There is an emerging consensus that neurons have different intrinsic regenerative capabilities, which theoretically could be manipulated therapeutically to improve regeneration. Population-based comparisons between “good regenerating” and “bad regenerating” neurons in the CNS and peripheral nervous system of most vertebrates yield results that are inconclusive or difficult to interpret. At least in part, this reflects the great diversity of cells in the mammalian CNS. Using mammalian nervous system imposes several methodical limitations. First, the small sizes and large numbers of neurons in the CNS make it very difficult to distinguish regenerating neurons from non-regenerating ones. Second, the lack of identifiable neurons makes it impossible to correlate biochemical changes in a neuron with axonal damage of the same neuron, and therefore, to dissect the molecular mechanisms of regeneration on the level of single neurons. This review will survey the reported responses to axon injury and the determinants of axon regeneration, emphasizing non-mammalian model organisms, which are often under-utilized, but in which the data are especially easy to interpret.
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Affiliation(s)
- William Rodemer
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), the Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Jianli Hu
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), the Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Michael E Selzer
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation); Department of Neurology, the Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Michael I Shifman
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), the Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
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Sobrido-Cameán D, Robledo D, Sánchez L, Rodicio MC, Barreiro-Iglesias A. Serotonin inhibits axonal regeneration of identifiable descending neurons after a complete spinal cord injury in lampreys. Dis Model Mech 2019; 12:dmm.037085. [PMID: 30709851 PMCID: PMC6398502 DOI: 10.1242/dmm.037085] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 01/22/2019] [Indexed: 02/06/2023] Open
Abstract
Classical neurotransmitters are mainly known for their roles as neuromodulators, but they also play important roles in the control of developmental and regenerative processes. Here, we used the lamprey model of spinal cord injury to study the effect of serotonin in axon regeneration at the level of individually identifiable descending neurons. Pharmacological and genetic manipulations after a complete spinal cord injury showed that endogenous serotonin inhibits axonal regeneration in identifiable descending neurons through the activation of serotonin 1A receptors and a subsequent decrease in cyclic adenosine monophosphate (cAMP) levels. RNA sequencing revealed that changes in the expression of genes that control axonal guidance could be a key factor determining the serotonin effects during regeneration. This study provides new targets of interest for research in non-regenerating mammalian models of traumatic central nervous system injuries and extends the known roles of serotonin signalling during neuronal regeneration.
This article has an associated First Person interview with the first author of the paper. Summary: Pharmacological and genetic manipulations show that endogenous serotonin inhibits axonal regeneration of individually identifiable descending neurons of lampreys after a complete spinal cord injury.
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Affiliation(s)
- Daniel Sobrido-Cameán
- Department of Functional Biology, CIBUS, Faculty of Biology, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Diego Robledo
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Midlothian EH25 9RG, UK
| | - Laura Sánchez
- Department of Genetics, University of Santiago de Compostela, Campus de Lugo, 27002 Lugo, Spain
| | - María Celina Rodicio
- Department of Functional Biology, CIBUS, Faculty of Biology, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Antón Barreiro-Iglesias
- Department of Functional Biology, CIBUS, Faculty of Biology, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
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Chen J, Laramore C, Shifman MI. The expression of chemorepulsive guidance receptors and the regenerative abilities of spinal-projecting neurons after spinal cord injury. Neuroscience 2016; 341:95-111. [PMID: 27890825 DOI: 10.1016/j.neuroscience.2016.11.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 11/14/2016] [Accepted: 11/16/2016] [Indexed: 12/31/2022]
Abstract
Spinal cord injury (SCI) in mammals leads to permanent loss of function because axons do not regenerate in the central nervous system (CNS). To date, treatments based on neutralizing inhibitory environmental cues, such as the myelin-associated growth inhibitors and chondroitin sulfate proteoglycans, or on adding neurotrophic factors, have had limited success in enhancing regeneration. Published studies suggested that multiple axon guidance cues (repulsive guidance molecule (RGM) family, semaphorins, ephrins, and netrins) persist in adult animals, and that their expression is upregulated after CNS injury. Moreover, many adult CNS neurons continue to express axon guidance receptors. We used the advantages of the lamprey CNS to test the hypotheses that the regenerative abilities of spinal-projecting neurons depend upon their expression of chemorepulsive guidance receptors. After complete spinal transection, lampreys recover behaviorally, and injured axons grow selectively in their correct paths. However, the large identified reticulospinal (RS) neurons in the lamprey brain are heterogeneous in their regenerative abilities - some are high regeneration capacity neurons (probability of axon regeneration >50%), others are low regeneration capacity neurons (<30%). Here we report that the RGM receptor Neogenin is expressed preferentially in the low regeneration capacity RS neurons that regenerate poorly, and that downregulation of Neogenin by morpholino antisense oligonucleotides enhances regeneration of RS axons after SCI. Moreover, lamprey CNS neurons co-express multiple guidance receptors (Neogenin, UNC5 and PlexinA), suggesting that the regenerative abilities of spinal-projecting neurons might reflect the summed influences of the chemorepulsive guidance receptors that they express.
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Affiliation(s)
- Jie Chen
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), USA
| | - Cindy Laramore
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), USA
| | - Michael I Shifman
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), USA; Department of Neuroscience, Temple University School of Medicine, 3500 North Broad Street, Philadelphia, PA 19140, USA.
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Barreiro-Iglesias A, Zhang G, Selzer ME, Shifman MI. Complete spinal cord injury and brain dissection protocol for subsequent wholemount in situ hybridization in larval sea lamprey. J Vis Exp 2014:e51494. [PMID: 25350040 DOI: 10.3791/51494] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
After a complete spinal cord injury, sea lampreys at first are paralyzed below the level of transection. However, they recover locomotion after several weeks, and this is accompanied by short distance regeneration (a few mm) of propriospinal axons and spinal-projecting axons from the brainstem. Among the 36 large identifiable spinal-projecting neurons, some are good regenerators and others are bad regenerators. These neurons can most easily be identified in wholemount CNS preparations. In order to understand the neuron-intrinsic mechanisms that favor or inhibit axon regeneration after injury in the vertebrates CNS, we determine differences in gene expression between the good and bad regenerators, and how expression is influenced by spinal cord transection. This paper illustrates the techniques for housing larval and recently transformed adult sea lampreys in fresh water tanks, producing complete spinal cord transections under microscopic vision, and preparing brain and spinal cord wholemounts for in situ hybridization. Briefly, animals are kept at 16°C and anesthetized in 1% Benzocaine in lamprey Ringer. The spinal cord is transected with iridectomy scissors via a dorsal approach and the animal is allowed to recover in fresh water tanks at 23 °C. For in situ hybridization, animals are reanesthetized and the brain and cord removed via a dorsal approach.
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Affiliation(s)
| | - Guixin Zhang
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), Temple University School of Medicine
| | - Michael E Selzer
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), Temple University School of Medicine; Department of Neurology, Temple University School of Medicine
| | - Michael I Shifman
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), Temple University School of Medicine
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Hume JB, Bean CW, Adams CE. Morphological abnormalities in a population of Lampetra planeri, with a short review of petromyzontid teratologies. JOURNAL OF FISH BIOLOGY 2014; 84:1614-1619. [PMID: 24773546 DOI: 10.1111/jfb.12369] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 02/03/2014] [Indexed: 06/03/2023]
Abstract
Reported here are several deviations (n = 15; 1·96%) from typical morphology in a large sample (n = 767) of European brook lamprey Lampetra planeri from a single population in the Loch Lomond catchment; this includes one specimen bearing a true anal fin. A brief review of petromyzontid teratology is provided.
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Affiliation(s)
- J B Hume
- Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, U.K
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Use of fluorochrome-labeled inhibitors of caspases to detect neuronal apoptosis in the whole-mounted lamprey brain after spinal cord injury. Enzyme Res 2012; 2012:835731. [PMID: 22829997 PMCID: PMC3399409 DOI: 10.1155/2012/835731] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Accepted: 06/16/2012] [Indexed: 11/17/2022] Open
Abstract
Apoptosis is a major feature in neural development and important in traumatic diseases. The presence of active caspases is a widely accepted marker of apoptosis. We report here the development of a method to study neuronal apoptotic death in whole-mounted brain preparations using fluorochrome-labeled inhibitors of caspases (FLICA). As a model we used axotomy-induced retrograde neuronal death in the CNS of larval sea lampreys. Once inside the cell, the FLICA reagents bind covalently to active caspases causing apoptotic cells to fluoresce, whereas nonapoptotic cells remain unstained. The fluorescent probe, the poly caspase inhibitor FAM-VAD-FMK, was applied to whole-mounted brain preparations of larval sea lampreys 2 weeks after a complete spinal cord (SC) transection. Specific labeling occurred only in identifiable spinal-projecting neurons of the brainstem previously shown to undergo apoptotic neuronal death at later times after SC transection. These neurons also exhibited intense labeling 2 weeks after a complete SC transection when a specific caspase-8 inhibitor (FAM-LETD-FMK) served as the probe. In this study we show that FLICA reagents can be used to detect specific activated caspases in identified neurons of the whole-mounted lamprey brain. Our results suggest that axotomy may cause neuronal apoptosis by activation of the extrinsic apoptotic pathway.
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