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Maxson Jones K, Morgan JR. Lampreys and spinal cord regeneration: "a very special claim on the interest of zoologists," 1830s-present. Front Cell Dev Biol 2023; 11:1113961. [PMID: 37228651 PMCID: PMC10203415 DOI: 10.3389/fcell.2023.1113961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 04/24/2023] [Indexed: 05/27/2023] Open
Abstract
Employing history of science methods, including analyses of the scientific literature, archival documents, and interviews with scientists, this paper presents a history of lampreys in neurobiology from the 1830s to the present. We emphasize the lamprey's roles in helping to elucidate spinal cord regeneration mechanisms. Two attributes have long perpetuated studies of lampreys in neurobiology. First, they possess large neurons, including multiple classes of stereotypically located, 'identified' giant neurons in the brain, which project their large axons into the spinal cord. These giant neurons and their axonal fibers have facilitated electrophysiological recordings and imaging across biological scales, ranging from molecular to circuit-level analyses of nervous system structures and functions and including their roles in behavioral output. Second, lampreys have long been considered amongst the most basal extant vertebrates on the planet, so they have facilitated comparative studies pointing to conserved and derived characteristics of vertebrate nervous systems. These features attracted neurologists and zoologists to studies of lampreys between the 1830s and 1930s. But, the same two attributes also facilitated the rise of the lamprey in neural regeneration research after 1959, when biologists first wrote about the spontaneous, robust regeneration of some identified CNS axons in larvae after spinal cord injuries, coupled with recovery of normal swimming. Not only did large neurons promote fresh insights in the field, enabling studies incorporating multiple scales with existing and new technologies. But investigators also were able to attach a broad scope of relevance to their studies, interpreting them as suggesting conserved features of successful, and sometimes even unsuccessful, CNS regeneration. Lamprey research demonstrated that functional recovery takes place without the reformation of the original neuronal connections, for instance, by way of imperfect axonal regrowth and compensatory plasticity. Moreover, research performed in the lamprey model revealed that factors intrinsic to neurons are integral in promoting or hindering regeneration. As this work has helped illuminate why basal vertebrates accomplish CNS regeneration so well, whereas mammals do it so poorly, this history presents a case study in how biological and medical value have been, and could continue to be, gleaned from a non-traditional model organism for which molecular tools have been developed only relatively recently.
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Affiliation(s)
- Kathryn Maxson Jones
- Center for Medical Ethics and Health Policy, Baylor College of Medicine, Houston, TX, United States
- Department of History, Purdue University, West Lafayette, IN, United States
- Marine Biological Laboratory, The Eugene Bell Center for Regenerative Biology and Tissue Engineering, Woods Hole, MA, United States
| | - Jennifer R. Morgan
- Marine Biological Laboratory, The Eugene Bell Center for Regenerative Biology and Tissue Engineering, Woods Hole, MA, United States
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2
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Sobrido-Cameán D, Yáñez-Guerra LA, Deber A, Freire-Delgado M, Cacheiro-Vázquez R, Rodicio MC, Tostivint H, Anadón R, Barreiro-Iglesias A. Differential expression of somatostatin genes in the central nervous system of the sea lamprey. Brain Struct Funct 2021; 226:1031-1052. [PMID: 33532926 DOI: 10.1007/s00429-021-02224-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 01/19/2021] [Indexed: 01/29/2023]
Abstract
The identification of three somatostatin (SST) genes (SSTa, SSTb, and SSTc) in lampreys (Tostivint et al. Gen Comp Endocrinol 237:89-97 https://doi.org/10.1016/j.ygcen.2016.08.006 , 2016) prompted us to study their expression in the brain and spinal cord of the sea lamprey by in situ hybridization. These three genes were only expressed in equivalent neuronal populations in the hypothalamus. In other regions, SST transcripts showed clear differential expression. In the telencephalon, SSTc-positive cells were observed in the medial pallium, ventral part of the lateral pallium, striatum, subhippocampal lobe, and preoptic region. In the diencephalon, SSTa-positive cells were observed in the thalamus and SSTc-positive cells in the prethalamus, posterior tubercle, pretectal area, and nucleus of the medial longitudinal fascicle. In the midbrain, SSTc-positive cells were observed in the torus semicircularis, lateral reticular area, and perioculomotor tegmentum. Different SSTa- and SSTc-positive populations were observed in the isthmus. SSTc neurons were also observed in the rostral octavolateralis area and caudal rhombencephalon. In the spinal cord, SSTa was expressed in cerebrospinal-fluid-contacting (CSF-c) neurons and SSTc in non-CSF-c interneurons. Comparison with previous immunohistochemical studies using anti-SST-14 antibodies strongly suggests that SST-14-like neurons correspond with the SSTa populations. Thus, the SSTc populations were not reported previously in immunohistochemical studies. Cluster-based analyses and alignments of mature peptides suggested that SSTa is an ortholog of SST1 and that SSTb is closely related to SST2 and SST6. These results provide important new insights into the evolution of the somatostatinergic system in vertebrates.
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Affiliation(s)
- D Sobrido-Cameán
- Department of Functional Biology, Faculty of Biology, CIBUS, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, A Coruña, Spain.,Department of Zoology, University of Cambridge, Cambridge, UK
| | | | - A Deber
- Department of Functional Biology, Faculty of Biology, CIBUS, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, A Coruña, Spain
| | - M Freire-Delgado
- Department of Functional Biology, Faculty of Biology, CIBUS, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, A Coruña, Spain
| | - R Cacheiro-Vázquez
- Department of Functional Biology, Faculty of Biology, CIBUS, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, A Coruña, Spain
| | - M C Rodicio
- Department of Functional Biology, Faculty of Biology, CIBUS, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, A Coruña, Spain
| | - H Tostivint
- Molecular Physiology and Adaptation, UMR7221, CNRS and Muséum National D'Histoire Naturelle, Paris, France
| | - R Anadón
- Department of Functional Biology, Faculty of Biology, CIBUS, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, A Coruña, Spain
| | - A Barreiro-Iglesias
- Department of Functional Biology, Faculty of Biology, CIBUS, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, A Coruña, Spain.
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Becker M, Parker D. Time course of functional changes in locomotor and sensory systems after spinal cord lesions in lamprey. J Neurophysiol 2019; 121:2323-2335. [DOI: 10.1152/jn.00120.2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Changes in motor and sensory properties occur either side of spinal cord lesion sites from lower vertebrates to humans. We have previously examined these changes in the lamprey, a model system for studying recovery after spinal cord injury. These analyses were performed 8–12 wk after complete spinal cord lesions, a time when most animals have recovered good locomotor function. However, anatomical analyses have been performed at earlier and later times than this. Because there have been no functional studies at these times, in this study we have examined changes between 2 and 24+ wk after lesioning. Functional changes developed at different times in different regions of the spinal cord. Spinal cord excitability was significantly reduced above and below the lesion site less than 6 wk after lesioning but showed variable region-specific changes at later times. Excitatory synaptic inputs to motor neurons were increased above the lesion site during the recovery phase (2–8 wk after lesioning) but only increased below the lesion site once recovery had occurred (8 wk and later). These synaptic effects were associated with lesion-induced changes in connectivity between premotor excitatory interneurons. Sensory inputs were potentiated at 8 wk and later after lesioning but were markedly reduced at earlier times. There are thus time- and region-specific changes in motor and sensory properties above and below the lesion site. Although animals typically recover good locomotor function by 8 wk, there were further changes at 24+ wk. With the assumption that these changes can help to compensate for the reduced descending input to the spinal cord, effects at later times may reflect ongoing modifications as regeneration continues. NEW & NOTEWORTHY The lamprey is a model system for studying functional recovery and regeneration after spinal cord injury. We show that changes in spinal cord excitability and sensory inputs develop at different times above and below the lesion site during recovery. These changes may occur in response to the lesion-induced removal of descending inputs and may subsequently help to compensate for the reduction of the descending drive to allow locomotor recovery. Changes also continue once animals have recovered locomotor function, potentially reflecting adaptations to further regeneration at later recovery times.
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Affiliation(s)
- Matthew Becker
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - David Parker
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
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Svensson E, Apergis-Schoute J, Burnstock G, Nusbaum MP, Parker D, Schiöth HB. General Principles of Neuronal Co-transmission: Insights From Multiple Model Systems. Front Neural Circuits 2019; 12:117. [PMID: 30728768 PMCID: PMC6352749 DOI: 10.3389/fncir.2018.00117] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 12/14/2018] [Indexed: 12/22/2022] Open
Abstract
It is now accepted that neurons contain and release multiple transmitter substances. However, we still have only limited insight into the regulation and functional effects of this co-transmission. Given that there are 200 or more neurotransmitters, the chemical complexity of the nervous system is daunting. This is made more-so by the fact that their interacting effects can generate diverse non-linear and novel consequences. The relatively poor history of pharmacological approaches likely reflects the fact that manipulating a transmitter system will not necessarily mimic its roles within the normal chemical environment of the nervous system (e.g., when it acts in parallel with co-transmitters). In this article, co-transmission is discussed in a range of systems [from invertebrate and lower vertebrate models, up to the mammalian peripheral and central nervous system (CNS)] to highlight approaches used, degree of understanding, and open questions and future directions. Finally, we offer some outlines of what we consider to be the general principles of co-transmission, as well as what we think are the most pressing general aspects that need to be addressed to move forward in our understanding of co-transmission.
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Affiliation(s)
- Erik Svensson
- BMC, Department of Neuroscience, Functional Pharmacology, Uppsala University, Uppsala, Sweden
| | - John Apergis-Schoute
- Department of Neurosciences, Psychology and Behaviour, University of Leicester, Leicester, United Kingdom
| | - Geoffrey Burnstock
- Department of Pharmacology and Therapeutics, University of Melbourne, Melbourne, VIC, Australia
| | - Michael P Nusbaum
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - David Parker
- Department of Physiology, Development and Neuroscience, Faculty of Biology, University of Cambridge, Cambridge, United Kingdom
| | - Helgi B Schiöth
- BMC, Department of Neuroscience, Functional Pharmacology, Uppsala University, Uppsala, Sweden.,Institute for Translational Medicine and Biotechnology, Sechenov First Moscow State Medical University, Moscow, Russia
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Romaus-Sanjurjo D, Rodicio MC, Barreiro-Iglesias A. Gamma-aminobutyric acid (GABA) promotes recovery from spinal cord injury in lampreys: role of GABA receptors and perspective on the translation to mammals. Neural Regen Res 2019; 14:1695-1696. [PMID: 31169176 PMCID: PMC6585546 DOI: 10.4103/1673-5374.257515] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Daniel Romaus-Sanjurjo
- Department of Functional Biology, CIBUS, Faculty of Biology, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - María Celina Rodicio
- Department of Functional Biology, CIBUS, Faculty of Biology, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Antón Barreiro-Iglesias
- Department of Functional Biology, CIBUS, Faculty of Biology, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
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Sobrido-Cameán D, Rodicio MC, Barreiro-Iglesias A. Data on the effect of a muscimol treatment in caspase activation in descending neurons of lampreys after a complete spinal cord injury. Data Brief 2018; 21:2037-2041. [PMID: 30510990 PMCID: PMC6258874 DOI: 10.1016/j.dib.2018.11.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 10/31/2018] [Accepted: 11/01/2018] [Indexed: 12/26/2022] Open
Abstract
In this article, caspase activation in identifiable reticulospinal neurons of lampreys was inhibited after a complete spinal cord injury using a specific agonist of the GABAA receptor (muscimol). The data presented in this article are quantifications of fluorescent labelling of identifiable descending neurons of larval lampreys after a complete spinal cord injury using fluorochrome-labelled inhibitors of caspases (FLICA) and the corresponding statistical analysis. A single dose of muscimol decreased the intensity of FLICA labelling in giant identifiable reticulospinal neurons following spinal cord injury in lampreys.
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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
| | - 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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7
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Neural Cotransmission in Spinal Circuits Governing Locomotion. Trends Neurosci 2018; 41:540-550. [DOI: 10.1016/j.tins.2018.04.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 04/06/2018] [Accepted: 04/17/2018] [Indexed: 01/08/2023]
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GABA promotes survival and axonal regeneration in identifiable descending neurons after spinal cord injury in larval lampreys. Cell Death Dis 2018; 9:663. [PMID: 29950557 PMCID: PMC6021415 DOI: 10.1038/s41419-018-0704-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 04/24/2018] [Accepted: 05/14/2018] [Indexed: 12/25/2022]
Abstract
The poor regenerative capacity of descending neurons is one of the main causes of the lack of recovery after spinal cord injury (SCI). Thus, it is of crucial importance to find ways to promote axonal regeneration. In addition, the prevention of retrograde degeneration leading to the atrophy/death of descending neurons is an obvious prerequisite to activate axonal regeneration. Lampreys show an amazing regenerative capacity after SCI. Recent histological work in lampreys suggested that GABA, which is massively released after a SCI, could promote the survival of descending neurons. Here, we aimed to study if GABA, acting through GABAB receptors, promotes the survival and axonal regeneration of descending neurons of larval sea lampreys after a complete SCI. First, we used in situ hybridization to confirm that identifiable descending neurons of late-stage larvae express the gabab1 subunit of the GABAB receptor. We also observed an acute increase in the expression of this subunit in descending neurons after SCI, which further supported the possible role of GABA and GABAB receptors in promoting the survival and regeneration of these neurons. So, we performed gain and loss of function experiments to confirm this hypothesis. Treatments with GABA and baclofen (GABAB agonist) significantly reduced caspase activation in descending neurons 2 weeks after a complete SCI. Long-term treatments with GABOB (a GABA analogue) and baclofen significantly promoted axonal regeneration of descending neurons after SCI. These data indicate that GABAergic signalling through GABAB receptors promotes the survival and regeneration of descending neurons after SCI. Finally, we used morpholinos against the gabab1 subunit to knockdown the expression of the GABAB receptor in descending neurons. Long-term morpholino treatments caused a significant inhibition of axonal regeneration. This shows that endogenous GABA promotes axonal regeneration after a complete SCI in lampreys by activating GABAB receptors.
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9
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Romaus-Sanjurjo D, Valle-Maroto SM, Barreiro-Iglesias A, Fernández-López B, Rodicio MC. Anatomical recovery of the GABAergic system after a complete spinal cord injury in lampreys. Neuropharmacology 2018; 131:389-402. [PMID: 29317225 DOI: 10.1016/j.neuropharm.2018.01.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 12/26/2017] [Accepted: 01/04/2018] [Indexed: 12/16/2022]
Abstract
Lampreys recover locomotion spontaneously several weeks after a complete spinal cord injury. Dysfunction of the GABAergic system following SCI has been reported in mammalian models. So, it is of great interest to understand how the GABAergic system of lampreys adapts to the post-injury situation and how this relates to spontaneous recovery. The spinal cord of lampreys contains 3 populations of GABAergic neurons and most of the GABAergic innervation of the spinal cord comes from these local cells. GABAB receptors are expressed in the spinal cord of lampreys and they play important roles in the control of locomotion. The aims of the present study were to quantify: 1) the changes in the number of GABAergic neurons and innervation of the spinal cord and 2) the changes in the expression of the gabab receptor subunits b1 and b2 in the spinal cord of the sea lamprey after SCI. We performed complete spinal cord transections at the level of the fifth gill of mature larval lampreys and GABA immunohistochemistry or gabab in situ hybridization experiments. Animals were analysed up to 10 weeks post-lesion (wpl), when behavioural analyses showed that they recovered normal appearing locomotion (stage 6 in the Ayer's scale of locomotor recovery). We observed a significant decrease in the number of GABA-ir cells and fibres 1 h after lesion both rostral and caudal to the lesion site. GABA-ir cell numbers and innervation were recovered to control levels 1 to 2 wpl. At 1, 4 and 10 wpl the expression of gabab1 and gabab2 transcripts was significantly decreased in the spinal cord compared to control un-lesioned animals. This is the first study reporting the quantitative long-term changes in the number of GABAergic cells and fibres and in the expression of gabab receptors in the spinal cord of any vertebrate following a traumatic SCI. Our results show that in lampreys there is a full recovery of the GABAergic neurons and a decrease in the expression of gabab receptors when functional recovery is achieved.
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Affiliation(s)
- D Romaus-Sanjurjo
- Department of Functional Biology, CIBUS, Faculty of Biology, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - S M Valle-Maroto
- Department of Functional Biology, CIBUS, Faculty of Biology, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - A Barreiro-Iglesias
- Department of Functional Biology, CIBUS, Faculty of Biology, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - B Fernández-López
- Department of Functional Biology, CIBUS, Faculty of Biology, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - M C Rodicio
- Department of Functional Biology, CIBUS, Faculty of Biology, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
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Parker D. The Lesioned Spinal Cord Is a "New" Spinal Cord: Evidence from Functional Changes after Spinal Injury in Lamprey. Front Neural Circuits 2017; 11:84. [PMID: 29163065 PMCID: PMC5681538 DOI: 10.3389/fncir.2017.00084] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 10/16/2017] [Indexed: 01/13/2023] Open
Abstract
Finding a treatment for spinal cord injury (SCI) focuses on reconnecting the spinal cord by promoting regeneration across the lesion site. However, while regeneration is necessary for recovery, on its own it may not be sufficient. This presumably reflects the requirement for regenerated inputs to interact appropriately with the spinal cord, making sub-lesion network properties an additional influence on recovery. This review summarizes work we have done in the lamprey, a model system for SCI research. We have compared locomotor behavior (swimming) and the properties of descending inputs, locomotor networks, and sensory inputs in unlesioned animals and animals that have received complete spinal cord lesions. In the majority (∼90%) of animals swimming parameters after lesioning recovered to match those in unlesioned animals. Synaptic inputs from individual regenerated axons also matched the properties in unlesioned animals, although this was associated with changes in release parameters. This suggests against any compensation at these synapses for the reduced descending drive that will occur given that regeneration is always incomplete. Compensation instead seems to occur through diverse changes in cellular and synaptic properties in locomotor networks and proprioceptive systems below, but also above, the lesion site. Recovery of locomotor performance is thus not simply the reconnection of the two sides of the spinal cord, but reflects a distributed and varied range of spinal cord changes. While locomotor network changes are insufficient on their own for recovery, they may facilitate locomotor outputs by compensating for the reduction in descending drive. Potentiated sensory feedback may in turn be a necessary adaptation that monitors and adjusts the output from the “new” locomotor network. Rather than a single aspect, changes in different components of the motor system and their interactions may be needed after SCI. If these are general features, and where comparisons with mammalian systems can be made effects seem to be conserved, improving functional recovery in higher vertebrates will require interventions that generate the optimal spinal cord conditions conducive to recovery. The analyses needed to identify these conditions are difficult in the mammalian spinal cord, but lower vertebrate systems should help to identify the principles of the optimal spinal cord response to injury.
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Affiliation(s)
- David Parker
- Department of Physiology, Neuroscience and Development, University of Cambridge, Cambridge, United Kingdom
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11
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Romaus-Sanjurjo D, Fernández-López B, Sobrido-Cameán D, Barreiro-Iglesias A, Rodicio MC. Cloning of the GABA B Receptor Subunits B1 and B2 and their Expression in the Central Nervous System of the Adult Sea Lamprey. Front Neuroanat 2016; 10:118. [PMID: 28008311 PMCID: PMC5143684 DOI: 10.3389/fnana.2016.00118] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 11/22/2016] [Indexed: 11/25/2022] Open
Abstract
In vertebrates, γ-aminobutyric acid (GABA) is the main inhibitory transmitter in the central nervous system (CNS) acting through ionotropic (GABAA) and metabotropic (GABAB) receptors. The GABAB receptor produces a slow inhibition since it activates second messenger systems through the binding and activation of guanine nucleotide-binding proteins [G-protein-coupled receptors (GPCRs)]. Lampreys are a key reference to understand molecular evolution in vertebrates. The importance of the GABAB receptor for the modulation of the circuits controlling locomotion and other behaviors has been shown in pharmacological/physiological studies in lampreys. However, there is no data about the sequence of the GABAB subunits or their expression in the CNS of lampreys. Our aim was to identify the sea lamprey GABAB1 and GABAB2 transcripts and study their expression in the CNS of adults. We cloned two partial sequences corresponding to the GABAB1 and GABAB2 cDNAs of the sea lamprey as confirmed by sequence analysis and comparison with known GABAB sequences of other vertebrates. In phylogenetic analyses, the sea lamprey GABAB sequences clustered together with GABABs sequences of vertebrates and emerged as an outgroup to all gnathostome sequences. We observed a broad and overlapping expression of both transcripts in the entire CNS. Expression was mainly observed in neuronal somas of the periventricular regions including the identified reticulospinal cells. No expression was observed in identifiable fibers. Comparison of our results with those reported in other vertebrates indicates that a broad and overlapping expression of the GABAB subunits in the CNS is a conserved character shared by agnathans and gnathostomes.
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Affiliation(s)
- Daniel Romaus-Sanjurjo
- Department of Functional Biology, CIBUS, Faculty of Biology, Universidade de Santiago de Compostela Santiago de Compostela, Spain
| | - Blanca Fernández-López
- Department of Functional Biology, CIBUS, Faculty of Biology, Universidade de Santiago de Compostela Santiago de Compostela, Spain
| | - Daniel Sobrido-Cameán
- Department of Functional Biology, CIBUS, Faculty of Biology, Universidade de Santiago de Compostela Santiago de Compostela, Spain
| | - Antón Barreiro-Iglesias
- Department of Functional Biology, CIBUS, Faculty of Biology, Universidade de Santiago de Compostela Santiago de Compostela, Spain
| | - María Celina Rodicio
- Department of Functional Biology, CIBUS, Faculty of Biology, Universidade de Santiago de Compostela Santiago de Compostela, Spain
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Chen S, Yang G, Zhu Y, Liu Z, Wang W, Wei J, Li K, Wu J, Chen Z, Li Y, Mu S, OuYang L, Lei W. A Comparative Study of Three Interneuron Types in the Rat Spinal Cord. PLoS One 2016; 11:e0162969. [PMID: 27658248 PMCID: PMC5033377 DOI: 10.1371/journal.pone.0162969] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Accepted: 08/31/2016] [Indexed: 12/19/2022] Open
Abstract
Interneurons are involved in the physiological function and the pathomechanism of the spinal cord. Present study aimed to examine and compare the characteristics of Cr+, Calb+ and Parv+ interneurons in morphology and distribution by using immunhistochemical and Western blot techniques. Results showed that 1) Cr-Calb presented a higher co-existence rate than that of Cr-Parv, and both of them were higher in the ventral horn than in the dosal horn; 2) Cr+, Calb+ and Parv+ neurons distributing zonally in the superficial dosal horn were small-sized. Parv+ neuronswere the largest, and Cr+ and Calb+ neurons were higher density among them. In the deep dorsal horn, Parv+ neurons were mainly located in nucleus thoracicus and the remaining scatteredly distributed. Cr+ neuronal size was the largest, and Calb+ neurons were the least among three interneuron types; 3) Cr+, Calb+ and Parv+ neurons of ventral horns displayed polygonal, round and fusiform, and Cr+ and Parv+ neurons were mainly distributed in the deep layer, but Calb+ neurons mainly in the superficial layer. Cr+ neurons were the largest, and distributed more in ventral horns than in dorsal horns; 4) in the dorsal horn of lumbar cords, Calb protein levels was the highest, but Parv protein level in ventral horns was the highest among the three protein types. Present results suggested that the morphological characteristics of three interneuron types imply their physiological function and pathomechanism relevance.
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Affiliation(s)
- Si Chen
- Department of Anatomy, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Guangqi Yang
- Department of Radiology, the First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Yaxi Zhu
- Department of Anatomy, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Zongwei Liu
- Department of Anatomy, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Weiping Wang
- Department of Anatomy, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Jiayou Wei
- Department of Anatomy, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Keyi Li
- Department of Anatomy, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Jiajia Wu
- Department of Anatomy, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Zhi Chen
- Department of Anatomy, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Youlan Li
- Department of Anatomy, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Shuhua Mu
- School of Medicine, Shenzhen University, Shenzhen, Guangdong, China
| | - Lisi OuYang
- Department of Anatomy, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Wanlong Lei
- Department of Anatomy, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
- * E-mail: ,
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Full anatomical recovery of the dopaminergic system after a complete spinal cord injury in lampreys. Neural Plast 2015; 2015:350750. [PMID: 25861481 PMCID: PMC4378702 DOI: 10.1155/2015/350750] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2014] [Revised: 02/18/2015] [Accepted: 03/02/2015] [Indexed: 12/11/2022] Open
Abstract
Following a spinal injury, lampreys at first are paralyzed below the level of transection. However, they recover locomotion after several weeks, and this is accompanied by the regeneration of descending axons from the brain and the production of new neurons in the spinal cord. Here, we aimed to analyse the changes in the dopaminergic system of the sea lamprey after a complete spinal transection by studying the changes in dopaminergic cell numbers and dopaminergic innervation in the spinal cord. Changes in the expression of the D2 receptor were also studied. We report the full anatomical regeneration of the dopaminergic system after an initial decrease in the number of dopaminergic cells and fibres. Numbers of dopaminergic cells were recovered rostrally and caudally to the site of injury. Quantification of dopaminergic profiles revealed the full recovery of the dopaminergic innervation of the spinal cord rostral and caudal to the site of injury. Interestingly, no changes in the expression of the D2 receptor were observed at time points in which a reduced dopaminergic innervation of the spinal cord was observed. Our observations reveal that in lampreys a spinal cord injury is followed by the full anatomical recovery of the dopaminergic system.
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14
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Mao LF, Wang LD, Zhang HW, Liu JH, Du XJ, Peng ZH. Functional dyspepsia and brain-gut peptides. Shijie Huaren Xiaohua Zazhi 2015; 23:570-576. [DOI: 10.11569/wcjd.v23.i4.570] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Functional dyspepsia (FD) is a frequently occurring gastrointestinal disorder, but its etiology and pathogenesis are still unclear because it is associated with multiple factors. As a typically physical and psychological disease, the role of psychological factors in the pathogenesis of FD involves the brain-gut axis, mainly abnormal stimulation processing by the central nervous system and abnormal levels of brain-gut peptides. Brain-gut peptides are the molecular basis of the action of the brain-gut axis, and the brain-gut axis affects the occurrence of FD by regulating the levels of brain-gut peptides. So far, 15 brain-gut peptides associated with FD have been found, which are predominantly expressed in the hypothalamus, medulla oblongata, spinal cord and gastrointestinal mucosa. The aim of this study is to clarify the relationship between brain-gut peptide levels and the occurrence of FD based on brain-gut peptide in terms of their secretion and mechanisms of action.
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15
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Becker MI, Parker D. Changes in functional properties and 5-HT modulation above and below a spinal transection in lamprey. Front Neural Circuits 2015; 8:148. [PMID: 25653594 PMCID: PMC4299445 DOI: 10.3389/fncir.2014.00148] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Accepted: 12/08/2014] [Indexed: 12/22/2022] Open
Abstract
In addition to the disruption of neural function below spinal cord injuries (SCI), there also can be changes in neuronal properties above and below the lesion site. The relevance of these changes is generally unclear, but they must be understood if we are to provide rational interventions. Pharmacological approaches to improving locomotor function have been studied extensively, but it is still unclear what constitutes an optimal approach. Here, we have used the lamprey to compare the modulatory effects of 5-HT and lesion-induced changes in cellular and synaptic properties in unlesioned and lesioned animals. While analyses typically focus on the sub-lesion spinal cord, we have also examined effects above the lesion to see if there are changes here that could potentially contribute to the functional recovery. Cellular and synaptic properties differed in unlesioned and lesioned spinal cords and above and below the lesion site. The cellular and synaptic modulatory effects of 5-HT also differed in lesioned and unlesioned animals, again in region-specific ways above and below the lesion site. A role for 5-HT in promoting recovery was suggested by the potential for improvement in locomotor activity when 5-HT was applied to poorly recovered animals, and by the consistent failure of animals to recover when they were incubated in PCPA to deplete 5-HT. However, PCPA did not affect swimming in animals that had already recovered, suggesting a difference in 5-HT effects after lesioning. These results show changes in 5-HT modulation and cellular and synaptic properties after recovery from a spinal cord transection. Importantly, effects are not confined to the sub-lesion spinal cord but also occur above the lesion site. This suggests that the changes may not simply reflect compensatory responses to the loss of descending inputs, but reflect the need for co-ordinated changes above and below the lesion site. The changes in modulatory effects should be considered in pharmacological approaches to functional recovery, as assumptions based on effects in the unlesioned spinal cord may not be justified.
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Affiliation(s)
- Matthew I Becker
- Department of Physiology, Development and Neuroscience, University of Cambridge Cambridge, UK
| | - David Parker
- Department of Physiology, Development and Neuroscience, University of Cambridge Cambridge, UK
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16
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Fernández-López B, Valle-Maroto SM, Barreiro-Iglesias A, Rodicio MC. Neuronal release and successful astrocyte uptake of aminoacidergic neurotransmitters after spinal cord injury in lampreys. Glia 2014; 62:1254-69. [PMID: 24733772 DOI: 10.1002/glia.22678] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 03/13/2014] [Accepted: 04/03/2014] [Indexed: 12/27/2022]
Abstract
In contrast to mammals, the spinal cord of lampreys spontaneously recovers from a complete spinal cord injury (SCI). Understanding the differences between lampreys and mammals in their response to SCI could provide valuable information to propose new therapies. Unique properties of the astrocytes of lampreys probably contribute to the success of spinal cord regeneration. The main aim of our study was to investigate, in the sea lamprey, the release of aminoacidergic neurotransmitters and the subsequent astrocyte uptake of these neurotransmitters during the first week following a complete SCI by detecting glutamate, GABA, glycine, Hu and cytokeratin immunoreactivities. This is the first time that aminoacidergic neurotransmitter release from neurons and the subsequent astrocytic response after SCI are analysed by immunocytochemistry in any vertebrate. Spinal injury caused the immediate loss of glutamate, GABA and glycine immunoreactivities in neurons close to the lesion site (except for the cerebrospinal fluid-contacting GABA cells). Only after SCI, astrocytes showed glutamate, GABA and glycine immunoreactivity. Treatment with an inhibitor of glutamate transporters (DL-TBOA) showed that neuronal glutamate was actively transported into astrocytes after SCI. Moreover, after SCI, a massive accumulation of inhibitory neurotransmitters around some reticulospinal axons was observed. Presence of GABA accumulation significantly correlated with a higher survival ability of these neurons. Our data show that, in contrast to mammals, astrocytes of lampreys have a high capacity to actively uptake glutamate after SCI. GABA may play a protective role that could explain the higher regenerative and survival ability of specific descending neurons of lampreys.
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Affiliation(s)
- Blanca Fernández-López
- Department of Cell Biology and Ecology, CIBUS, University of Santiago de Compostela, 15782, Santiago de Compostela, Spain
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