1
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Raspe S, Kümmerlen K, Harzsch S. Immunolocalization of SIFamide-like neuropeptides in the adult and developing central nervous system of the amphipod Parhyale hawaiensis (Malacostraca, Peracarida, Amphipoda). ARTHROPOD STRUCTURE & DEVELOPMENT 2023; 77:101309. [PMID: 37879171 DOI: 10.1016/j.asd.2023.101309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 09/23/2023] [Accepted: 09/25/2023] [Indexed: 10/27/2023]
Abstract
Immunohistochemical analyses on the distribution of neuropeptides in the pancrustacean brain in the past have focussed mostly on representatives of the decapod ("ten-legged") pancrustaceans whereas other taxa are understudied in this respect. The current report examines the post-embryogenic and adult brain and ventral nerve cord of the amphipod pancrustacean Parhyale hawaiensis (Dana. 1853; Peracarida, Amphipoda, Hyalide), a subtropical species with a body size of 1.5 cm and a direct post-embryonic development using immunohistochemistry to label the neuropeptide SIFamide and synaptic proteins (synapsins). We found strong SIFamide-like labelling in proto-, deuto- and tritocerebrum, especially in the lamina, the lateral protocerebrum, lateral assessory lobe, the central body, olfactory lobe, medial antenna 1 neuropil and antenna 2 neuropil. Out of a total of 28 ± 5 (N = 12) SIFamide-positive neurons in the central brain of adult P. hawaiensis, we found three individually identifiable somata which were consistently present within the brain of adult and subadult animals. Additionally, the subesophageal and two adjacent thoracic ganglia were analysed in only adult animals and also showed a strong SIFamide-like immunoreactivity. We compare our findings to other pancrustaceans including hexapods and discuss them in an evolutionary context.
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Affiliation(s)
- Sophie Raspe
- University of Greifswald, Zoological Institute and Museum, Department of Cytology and Evolutionary Biology, Soldmannstrasse 23, D-17498 Greifswald, Germany
| | - Katja Kümmerlen
- University of Greifswald, Zoological Institute and Museum, Department of Cytology and Evolutionary Biology, Soldmannstrasse 23, D-17498 Greifswald, Germany
| | - Steffen Harzsch
- University of Greifswald, Zoological Institute and Museum, Department of Cytology and Evolutionary Biology, Soldmannstrasse 23, D-17498 Greifswald, Germany.
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2
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Miranda-Negrón Y, García-Arrarás JE. Radial glia and radial glia-like cells: Their role in neurogenesis and regeneration. Front Neurosci 2022; 16:1006037. [PMID: 36466166 PMCID: PMC9708897 DOI: 10.3389/fnins.2022.1006037] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 10/21/2022] [Indexed: 01/25/2024] Open
Abstract
Radial glia is a cell type traditionally associated with the developing nervous system, particularly with the formation of cortical layers in the mammalian brain. Nonetheless, some of these cells, or closely related types, called radial glia-like cells are found in adult central nervous system structures, functioning as neurogenic progenitors in normal homeostatic maintenance and in response to injury. The heterogeneity of radial glia-like cells is nowadays being probed with molecular tools, primarily by the expression of specific genes that define cell types. Similar markers have identified radial glia-like cells in the nervous system of non-vertebrate organisms. In this review, we focus on adult radial glia-like cells in neurogenic processes during homeostasis and in response to injury. We highlight our results using a non-vertebrate model system, the echinoderm Holothuria glaberrima where we have described a radial glia-like cell that plays a prominent role in the regeneration of the holothurian central nervous system.
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Affiliation(s)
| | - José E. García-Arrarás
- Department of Biology, College of Natural Sciences, University of Puerto Rico, San Juan, Puerto Rico
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3
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Benton JL, Li E, Weisbach E, Fukumura Y, Quinan VC, Chaves da Silva PG, Edwards AJ, Beltz BS. Adult neurogenesis in crayfish: Identity and regulation of neural progenitors produced by the immune system. iScience 2022; 25:103993. [PMID: 35340434 PMCID: PMC8941203 DOI: 10.1016/j.isci.2022.103993] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 12/12/2021] [Accepted: 02/24/2022] [Indexed: 11/16/2022] Open
Affiliation(s)
- Jeanne L. Benton
- Neuroscience Department, Wellesley College, Wellesley, MA 02481, USA
| | - Emmy Li
- Neuroscience Department, Wellesley College, Wellesley, MA 02481, USA
- Biomedical Sciences Graduate Program, University of California, San Francisco, CA 94158, USA
| | - Emily Weisbach
- Neuroscience Department, Wellesley College, Wellesley, MA 02481, USA
- Rhode Island Hospital, 593 Eddy Street, Providence, RI 02903, USA
| | - Yuriko Fukumura
- Neuroscience Department, Wellesley College, Wellesley, MA 02481, USA
| | | | | | - Alex J. Edwards
- Neuroscience Department, Wellesley College, Wellesley, MA 02481, USA
| | - Barbara S. Beltz
- Neuroscience Department, Wellesley College, Wellesley, MA 02481, USA
- Corresponding author
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4
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Vogt G. Cytology, function and dynamics of stem and progenitor cells in decapod crustaceans. Biol Rev Camb Philos Soc 2021; 97:817-850. [PMID: 34914163 DOI: 10.1111/brv.12824] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 11/26/2021] [Accepted: 11/30/2021] [Indexed: 12/12/2022]
Abstract
Stem cells play key roles in development, tissue homeostasis, regeneration, ageing and diseases. Comprehensive reviews on stem cells are available for the determinately growing mammals and insects and some lower invertebrates like hydra but are rare for larger, indeterminately growing invertebrates that can live for many decades. This paper reviews the cytology, function and dynamics of stem and progenitor cells in the decapod crustaceans, a species-rich and ecologically and economically important animal group that includes mainly indeterminate growers but also some determinate growers. Further advantages of decapods for stem cell research are almost 1000-fold differences in body size and longevity, the regeneration of damaged appendages and the virtual absence of age-related diseases and tumours in the indeterminately growing species. The available data demonstrate that the Decapoda possess a remarkable variety of structurally and functionally different stem cells in embryos and larvae, and in the epidermis, musculature, haematopoietic tissue, heart, brain, hepatopancreas, olfactory sense organs and gonads of adults. Some of these seem to be rather continuously active over a lifetime but others are cyclically activated and silenced in periods of days, weeks and years, depending on the specific organ and function. Stem cell proliferation is triggered by signals related to development, moulting, feeding, reproduction, injury, infection, environmental enrichment and social status. Some regulatory pathways have already been identified, including the evolutionarily conserved GATA-binding and runt-domain transcription factors, the widespread neurotransmitter serotonin, the arthropod-specific hormone 20-hydroxyecdysone and the novel astakine growth factors. Knowledge of stem cells in decapods primarily refines our picture on the development, growth and maintenance of tissues and organs in this animal group. Cultured decapod stem cells have good potential for toxicity testing and virus research with practical relevance for aquaculture. Knowledge of stem cells in decapods also broadens our understanding of the evolution of stem cells and regeneration in the animal kingdom. The stem cells of long-lived, indeterminately growing decapods may hold the key to understanding how stem and progenitor cells function into old age without adverse side effects, possibly evoking new ideas for the development of anti-ageing and anti-cancer treatments in humans.
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Affiliation(s)
- Günter Vogt
- Faculty of Biosciences, University of Heidelberg, Im Neuenheimer Feld 234, 69120 Heidelberg, Germany
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5
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Brenneis G, Schwentner M, Giribet G, Beltz BS. Insights into the genetic regulatory network underlying neurogenesis in the parthenogenetic marbled crayfish Procambarus virginalis. Dev Neurobiol 2021; 81:939-974. [PMID: 34554654 DOI: 10.1002/dneu.22852] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 07/26/2021] [Accepted: 09/20/2021] [Indexed: 11/09/2022]
Abstract
Nervous system development has been intensely studied in insects (especially Drosophila melanogaster), providing detailed insights into the genetic regulatory network governing the formation and maintenance of the neural stem cells (neuroblasts) and the differentiation of their progeny. Despite notable advances over the last two decades, neurogenesis in other arthropod groups remains by comparison less well understood, hampering finer resolution of evolutionary cell type transformations and changes in the genetic regulatory network in some branches of the arthropod tree of life. Although the neurogenic cellular machinery in malacostracan crustaceans is well described morphologically, its genetic molecular characterization is pending. To address this, we established an in situ hybridization protocol for the crayfish Procambarus virginalis and studied embryonic expression patterns of a suite of key genes, encompassing three SoxB group transcription factors, two achaete-scute homologs, a Snail family member, the differentiation determinants Prospero and Brain tumor, and the neuron marker Elav. We document cell type expression patterns with notable similarities to insects and branchiopod crustaceans, lending further support to the homology of hexapod-crustacean neuroblasts and their cell lineages. Remarkably, in the crayfish head region, cell emigration from the neuroectoderm coupled with gene expression data points to a neuroblast-independent initial phase of brain neurogenesis. Further, SoxB group expression patterns suggest an involvement of Dichaete in segmentation, in concordance with insects. Our target gene set is a promising starting point for further embryonic studies, as well as for the molecular genetic characterization of subregions and cell types in the neurogenic systems in the adult crayfish brain.
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Affiliation(s)
- Georg Brenneis
- Neuroscience Program, Wellesley College, Wellesley, Massachusetts, USA.,Zoologisches Institut und Museum, Universität Greifswald, Greifswald, Germany
| | - Martin Schwentner
- Naturhistorisches Museum Wien, Vienna, Austria.,Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts, USA
| | - Gonzalo Giribet
- Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts, USA
| | - Barbara S Beltz
- Neuroscience Program, Wellesley College, Wellesley, Massachusetts, USA
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6
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Hollmann G, da Silva PGC, Linden R, Allodi S. Cell proliferation in the central nervous system of an adult semiterrestrial crab. Cell Tissue Res 2021; 384:73-85. [PMID: 33599819 DOI: 10.1007/s00441-021-03413-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 01/01/2021] [Indexed: 10/22/2022]
Abstract
Neurogenesis occurs in adults of most organisms, both vertebrates and invertebrates. In semiterrestrial crabs of the infraorder Brachyura, the deutocerebrum, where neurogenesis occurs, processes the olfactory sensory information from the antennae. The deutocerebrum is composed of a pair of olfactory lobes associated with cell clusters 9 and 10 (Cl 9 and Cl 10), containing proliferating cells. Because the location of the neurogenic niche in brachyuran semiterrestrial crabs has not been defined, here we describe a neurogenic niche in the central olfactory system of the crab Ucides cordatus and report two types of glial cells in the deutocerebrum, based on different markers. Serotonin (5-hydroxytryptamine) labeling was used to reveal neuroanatomical aspects of the central olfactory system and the neurogenic niche. The results showed a zone of proliferating neural cells within Cl 10, which also contains III beta-tubulin (Tuj1)+ immature neurons, associated with a structure that has characteristics of the neurogenic niche. For the first time, using two glial markers, glial fibrillary acidic protein (GFAP) and glutamine synthetase (GS), we identified two types of astrocyte-like cells in different regions of the deutocerebrum. This study adds to the understanding of neurogenesis in a brachyuran semiterrestrial crustacean and encourages comparative studies between crustaceans and vertebrates, including mammals, based on shared aspects of both mechanisms of neurogenesis and regenerative potentials.
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Affiliation(s)
- Gabriela Hollmann
- Programa de Pós-Graduação em Ciências Biológicas - Fisiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro-UFRJ, Rio de Janeiro, RJ, 21941-590, Brazil. .,Programa de Pós-Graduação em Biologia Celular e do Desenvolvimento, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina-UFSC, João Pio Duarte Silva, 241, Florianópolis, SC, 88037-000, Brazil.
| | - Paula Grazielle Chaves da Silva
- Programa de Pós-Graduação em Ciências Biológicas - Biofísica , Instituto de Biofísica Carlos Chagas Filho Universidade Federal do Rio de Janeiro-UFRJ , 21941-590, Rio de Janeiro, Brazil
| | - Rafael Linden
- Programa de Pós-Graduação em Ciências Biológicas - Fisiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro-UFRJ, Rio de Janeiro, RJ, 21941-590, Brazil.,Programa de Pós-Graduação em Ciências Biológicas - Biofísica , Instituto de Biofísica Carlos Chagas Filho Universidade Federal do Rio de Janeiro-UFRJ , 21941-590, Rio de Janeiro, Brazil
| | - Silvana Allodi
- Programa de Pós-Graduação em Ciências Biológicas - Fisiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro-UFRJ, Rio de Janeiro, RJ, 21941-590, Brazil.,Programa de Pós-Graduação em Ciências Biológicas - Biofísica , Instituto de Biofísica Carlos Chagas Filho Universidade Federal do Rio de Janeiro-UFRJ , 21941-590, Rio de Janeiro, Brazil
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7
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Brenneis G, Beltz BS. Adult neurogenesis in crayfish: Origin, expansion, and migration of neural progenitor lineages in a pseudostratified neuroepithelium. J Comp Neurol 2019; 528:1459-1485. [PMID: 31743442 DOI: 10.1002/cne.24820] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 09/05/2019] [Accepted: 11/14/2019] [Indexed: 02/04/2023]
Abstract
Two decades after the discovery of adult-born neurons in the brains of decapod crustaceans, the deutocerebral proliferative system (DPS) producing these neural lineages has become a model of adult neurogenesis in invertebrates. Studies on crayfish have provided substantial insights into the anatomy, cellular dynamics, and regulation of the DPS. Contrary to traditional thinking, recent evidence suggests that the neurogenic niche in the crayfish DPS lacks self-renewing stem cells, its cell pool being instead sustained via integration of hemocytes generated by the innate immune system. Here, we investigated the origin, division and migration patterns of the adult-born neural progenitor (NP) lineages in detail. We show that the niche cell pool is not only replenished by hemocyte integration but also by limited numbers of symmetric cell divisions with some characteristics reminiscent of interkinetic nuclear migration. Once specified in the niche, first generation NPs act as transit-amplifying intermediate NPs that eventually exit and produce multicellular clones as they move along migratory streams toward target brain areas. Different clones may migrate simultaneously in the streams but occupy separate tracks and show spatio-temporally flexible division patterns. Based on this, we propose an extended DPS model that emphasizes structural similarities to pseudostratified neuroepithelia in other arthropods and vertebrates. This model includes hemocyte integration and intrinsic cell proliferation to synergistically counteract niche cell pool depletion during the animal's lifespan. Further, we discuss parallels to recent findings on mammalian adult neurogenesis, as both systems seem to exhibit a similar decoupling of proliferative replenishment divisions and consuming neurogenic divisions.
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Affiliation(s)
- Georg Brenneis
- Wellesley College, Neuroscience Program, Wellesley, Massachusetts, USA.,Universität Greifswald, Zoologisches Institut und Museum, AG Cytologie und Evolutionsbiologie, Greifswald, Germany
| | - Barbara S Beltz
- Wellesley College, Neuroscience Program, Wellesley, Massachusetts, USA
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8
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Di Cosmo A, Bertapelle C, Porcellini A, Polese G. Magnitude Assessment of Adult Neurogenesis in the Octopus vulgaris Brain Using a Flow Cytometry-Based Technique. Front Physiol 2018; 9:1050. [PMID: 30116204 PMCID: PMC6082961 DOI: 10.3389/fphys.2018.01050] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 07/16/2018] [Indexed: 12/11/2022] Open
Abstract
Adult neurogenesis is widespread among metazoans, it occurs in animals with a network nervous system, as cnidarians, and in animals with a complex and centralized brain, such as mammals, non-mammalian vertebrates, ecdysozoans, and a lophotrochozoan, Octopus vulgaris. Nevertheless, there are important differences among taxa, especially in the number of the regions involved and in cell proliferation rate during the life-cycle. The comparative evaluation of adult neurogenesis among different brain regions is an arduous task to achieve with only stereological techniques. However, in Octopus vulgaris we recently confirmed the presence of active proliferation in the learning-memory centers, multisensory integration centers, and the motor centers of the adult brain. Here, using a flow cytometry technique, we provide a method to quantify the active proliferation in octopus nervous system using a BrdU in vitro administration without exposing the animals to stress or painful injections usually used. This method is in line with the current animal welfare regulations regarding cephalopods, and the flow cytometry-based technique enabled us to measure adult neurogenesis more quickly and reliably than histological techniques, with the additional advantage of processing multiple samples in parallel. Flow cytometry is thus an appropriate technique for measuring and comparing adult neurogenesis in animals that are in a different physiological and/or environmental contexts. A BrdU immunoreactivity distribution, to define the neurogenic areas, and the effective penetration in vitro of the BrdU is also provided.
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Affiliation(s)
- Anna Di Cosmo
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Carla Bertapelle
- Department of Biology, University of Naples Federico II, Naples, Italy
| | | | - Gianluca Polese
- Department of Biology, University of Naples Federico II, Naples, Italy
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9
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Wittfoth C, Harzsch S. Adult neurogenesis in the central olfactory pathway of dendrobranchiate and caridean shrimps: New insights into the evolution of the deutocerebral proliferative system in reptant decapods. Dev Neurobiol 2018; 78:757-774. [PMID: 29663684 DOI: 10.1002/dneu.22596] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 04/09/2018] [Accepted: 04/09/2018] [Indexed: 11/10/2022]
Abstract
Persistent neurogenesis in the central olfactory pathway characterizes many reptant decapods such as lobsters, crayfish and crabs. In these animals, the deutocerebral proliferative system generates new neurons which integrate into the neuronal network of the first order processing neuropil of the olfactory system, the deutocerebral chemosensory lobes (also called olfactory lobes). However, differences concerning the phenotype and the mechanisms that drive adult neurogenesis were reported in crayfish versus spiny lobsters. While numerous studies have focussed on these mechanisms and regulation of adult neurogenesis, investigations about the phylogenetic distribution are missing. To contribute an evolutionary perspective on adult neurogenesis in decapods, we investigated two representatives of basally diverging lineages, the dendrobranchiate Penaeus vannamei and the caridean Crangon crangon using the thymidine analogue Bromodeoxyuridine (BrdU) as marker for the S phase of cycling cells. Compared to reptant decapods, our results suggest a simpler mechanism of neurogenesis in the adult brain of dendrobranchiate and caridean shrimps. Observed differences in the rate of proliferation and spatial dimensions are suggested to correlate with the complexity of the olfactory system. We assume that a more complex and mitotically more active proliferative system in reptant decapods evolved with the emergence of another processing neuropil, the accessory lobes. © 2018 Wiley Periodicals, Inc. Develop Neurobiol, 2018.
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Affiliation(s)
- Christin Wittfoth
- Department of Cytology and Evolutionary Biology, Ernst-Moritz-Arndt University of Greifswald, Zoological Institute & Museum, Greifswald, Germany
- Alfred Wegener Institute for Polar and Marine Research, Biologische Anstalt Helgoland, Helgoland, Germany
| | - Steffen Harzsch
- Department of Cytology and Evolutionary Biology, Ernst-Moritz-Arndt University of Greifswald, Zoological Institute & Museum, Greifswald, Germany
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10
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Beltz BS, Benton JL. From Blood to Brain: Adult-Born Neurons in the Crayfish Brain Are the Progeny of Cells Generated by the Immune System. Front Neurosci 2017; 11:662. [PMID: 29270102 PMCID: PMC5725445 DOI: 10.3389/fnins.2017.00662] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 11/13/2017] [Indexed: 11/23/2022] Open
Abstract
New neurons continue to be born and integrated into the brains of adult decapod crustaceans. Evidence in crayfish indicates that the 1st-generation neural precursors that generate these adult-born neurons originate in the immune system and travel to the neurogenic niche via the circulatory system. These precursors are attracted to the niche, become integrated amongst niche cells, and undergo mitosis within a few days; both daughters of this division migrate away from the niche toward the brain clusters where they will divide again and differentiate into neurons. In the crustacean brain, the rate of neuronal production is highly sensitive to serotonin (5-hydroxytryptamine, 5-HT) levels. These effects are lineage-dependent, as serotonin's influence is limited to late 2nd-generation neural precursors and their progeny. Experiments indicate that serotonin regulates adult neurogenesis in the crustacean brain by multiple mechanisms: via direct effects of serotonin released from brain neurons into the hemolymph or by local release onto target cells, or by indirect influences via a serotonin-mediated release of agents from other regions, such as hormones from the sinus gland and cytokines from hematopoietic tissues. Evidence in crayfish also indicates that serotonin mediates the attraction of neural precursors generated by the immune system to the neurogenic niche. Thus, studies in the crustacean brain have revealed multiple roles for this monoamine in adult neurogenesis, and identified several pathways by which serotonin influences the generation of new neurons.
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Affiliation(s)
- Barbara S Beltz
- Neuroscience Program, Wellesley College, Wellesley, MA, United States
| | - Jeanne L Benton
- Neuroscience Program, Wellesley College, Wellesley, MA, United States
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11
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Abstract
During brain development, highly complex and interconnected neural circuits are established. This intricate wiring needs to be robust to faithfully perform adult brain function throughout life, but at the same time offer room for plasticity to integrate new information. In the mammalian brain, adult-born neurons are produced in restricted niches harboring neural stem cells. In the fruit fly Drosophila, low-level adult neurogenesis arising from a dispersed population of neural progenitors has recently been detected in the optic lobes. Strikingly, these normally quiescent neural stem cells proliferate upon brain injury and produce new neurons for brain regeneration. Here, we review adult neurogenesis in crustaceans and insects and highlight that neurogenesis in the visual system is prominent in arthropods, but its role and underlying mechanisms are unclear. Moreover, we discuss how the study of damage-responsive progenitor cells in Drosophila may help to understand robust regenerative neurogenesis and open new avenues to enhance brain repair after injury or stroke in humans.
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12
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Beltz BS, Brenneis G, Benton JL. Adult Neurogenesis: Lessons from Crayfish and the Elephant in the Room. BRAIN, BEHAVIOR AND EVOLUTION 2016; 87:146-155. [DOI: 10.1159/000447084] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The 1st-generation neural precursors in the crustacean brain are functionally analogous to neural stem cells in mammals. Their slow cycling, migration of their progeny, and differentiation of their descendants into neurons over several weeks are features of the neural precursor lineage in crayfish that also characterize adult neurogenesis in mammals. However, the 1st-generation precursors in crayfish do not self-renew, contrasting with conventional wisdom that proposes the long-term self-renewal of adult neural stem cells. Nevertheless, the crayfish neurogenic niche, which contains a total of 200-300 cells, is never exhausted and neurons continue to be produced in the brain throughout the animal's life. The pool of neural precursors in the niche therefore cannot be a closed system, and must be replenished from an extrinsic source. Our in vitro and in vivo data show that cells originating in the innate immune system (but not other cell types) are attracted to and incorporated into the neurogenic niche, and that they express a niche-specific marker, glutamine synthetase. Further, labeled hemocytes that undergo adoptive transfer to recipient crayfish generate cells in neuronal clusters in the olfactory pathway of the adult brain. These hemocyte descendants express appropriate neurotransmitters and project to target areas typical of neurons in these regions. These studies indicate that under natural conditions, the immune system provides neural precursors supporting adult neurogenesis in the crayfish brain, challenging the canonical view that ectodermal tissues generating the embryonic nervous system are the sole source of neurons in the adult brain. However, these are not the first studies that directly implicate the immune system as a source of neural precursor cells. Several types of data in mammals, including adoptive transfers of bone marrow or stem cells as well as the presence of fetal microchimerism, suggest that there must be a population of cells that are able to access the brain and generate new neurons in these species.
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13
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Harzsch S, von Bohlen und Halbach O. A possible role for the immune system in adult neurogenesis: new insights from an invertebrate model. ZOOLOGY 2016; 119:153-157. [DOI: 10.1016/j.zool.2015.11.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 11/30/2015] [Indexed: 10/22/2022]
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14
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Rodríguez-Muñoz MDLP, Escamilla-Chimal EG. Glial fibrillary acidic protein (GFAP) shows circadian oscillations in crayfishProcambarus clarkiiputative pacemakers. Chronobiol Int 2015; 32:1135-44. [DOI: 10.3109/07420528.2015.1071385] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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15
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Beltz BS, Cockey EL, Li J, Platto JF, Ramos KA, Benton JL. Adult neural stem cells: Long-term self-renewal, replenishment by the immune system, or both? Bioessays 2015; 37:495-501. [PMID: 25761245 DOI: 10.1002/bies.201400198] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The current model of adult neurogenesis in mammals suggests that adult-born neurons are generated by stem cells that undergo long-term self-renewal, and that a lifetime supply of stem cells resides in the brain. In contrast, it has recently been demonstrated that adult-born neurons in crayfish are generated by precursors originating in the immune system. This is particularly interesting because studies done many years ago suggest that a similar mechanism might exist in rodents and humans, with bone marrow providing stem cells that can generate neurons. However, the relevance of these findings for natural mechanisms underlying adult neurogenesis in mammals is not clear, because of uncertainties at many levels. We argue here that the recent findings in crayfish send a strong signal to re-examine existing data from rodents and humans, and to design new experiments that will directly test the contributions of the immune system to adult neurogenesis in mammals.
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16
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Kornthong N, Cummins SF, Chotwiwatthanakun C, Khornchatri K, Engsusophon A, Hanna PJ, Sobhon P. Identification of genes associated with reproduction in the Mud Crab (Scylla olivacea) and their differential expression following serotonin stimulation. PLoS One 2014; 9:e115867. [PMID: 25542017 PMCID: PMC4277393 DOI: 10.1371/journal.pone.0115867] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 11/27/2014] [Indexed: 11/18/2022] Open
Abstract
The central nervous system (CNS) is often intimately involved in reproduction control and is therefore a target organ for transcriptomic investigations to identify reproduction-associated genes. In this study, 454 transcriptome sequencing was performed on pooled brain and ventral nerve cord of the female mud crab (Scylla olivacea) following serotonin injection (5 µg/g BW). A total of 197,468 sequence reads was obtained with an average length of 828 bp. Approximately 38.7% of 2,183 isotigs matched with significant similarity (E value < 1e−4) to sequences within the Genbank non-redundant (nr) database, with most significant matches being to crustacean and insect sequences. Approximately 32 putative neuropeptide genes were identified from nonmatching blast sequences. In addition, we identified full-length transcripts for crustacean reproductive-related genes, namely farnesoic acid o-methyltransferase (FAMeT), estrogen sulfotransferase (ESULT) and prostaglandin F synthase (PGFS). Following serotonin injection, which would normally initiate reproductive processes, we found up-regulation of FAMeT, ESULT and PGFS expression in the female CNS and ovary. Our data here provides an invaluable new resource for understanding the molecular role of the CNS on reproduction in S. olivacea.
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Affiliation(s)
- Napamanee Kornthong
- Chulabhorn International College of Medicine, Thammasat University, Pathumthani, 12121, Thailand
- Department of Anatomy, Faculty of Science, Mahidol University, Rama VI Road, Ratchathewi, Bangkok, 10400, Thailand
| | - Scott F. Cummins
- Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Maroochydore, Queensland, 4558, Australia
- * E-mail: (SFC); (PS)
| | - Charoonroj Chotwiwatthanakun
- Department of Anatomy, Faculty of Science, Mahidol University, Rama VI Road, Ratchathewi, Bangkok, 10400, Thailand
- Mahidol University, Nakhonsawan Campus, Nakhonsawan, 60130, Thailand
| | - Kanjana Khornchatri
- Department of Anatomy, Faculty of Science, Mahidol University, Rama VI Road, Ratchathewi, Bangkok, 10400, Thailand
| | - Attakorn Engsusophon
- Department of Anatomy, Faculty of Science, Mahidol University, Rama VI Road, Ratchathewi, Bangkok, 10400, Thailand
| | - Peter J. Hanna
- Department of Anatomy, Faculty of Science, Mahidol University, Rama VI Road, Ratchathewi, Bangkok, 10400, Thailand
- Pro Vice-Chancellor's Office, Faculty of Science, Engineering and Built Environment, Deakin University, Locked Bag 20000, Geelong, Victoria, 3220, Australia
| | - Prasert Sobhon
- Department of Anatomy, Faculty of Science, Mahidol University, Rama VI Road, Ratchathewi, Bangkok, 10400, Thailand
- * E-mail: (SFC); (PS)
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Benton JL, Kery R, Li J, Noonin C, Söderhäll I, Beltz BS. Cells from the immune system generate adult-born neurons in crayfish. Dev Cell 2014; 30:322-33. [PMID: 25117683 DOI: 10.1016/j.devcel.2014.06.016] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2012] [Revised: 04/08/2014] [Accepted: 06/19/2014] [Indexed: 10/24/2022]
Abstract
Neurogenesis is an ongoing process in the brains of adult decapod crustaceans. However, the first-generation precursors that produce adult-born neurons, which reside in a neurogenic niche, are not self-renewing in crayfish and must be replenished. The source of these neuronal precursors is unknown. Here, we report that adult-born neurons in crayfish can be derived from hemocytes. Following adoptive transfer of 5-ethynyl-2'-deoxyuridine (EdU)-labeled hemocytes, labeled cells populate the neurogenic niche containing the first-generation neuronal precursors. Seven weeks after adoptive transfer, EdU-labeled cells are located in brain clusters 9 and 10 (where adult-born neurons differentiate) and express appropriate neurotransmitters. Moreover, the number of cells composing the neurogenic niche in crayfish is tightly correlated with total hemocyte counts (THCs) and can be manipulated by raising or lowering THC. These studies identify hemocytes as a source of adult-born neurons in crayfish and demonstrate that the immune system is a key contributor to adult neurogenesis.
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Affiliation(s)
- Jeanne L Benton
- Neuroscience Program, Wellesley College, Wellesley, MA 02481, USA
| | - Rachel Kery
- Neuroscience Program, Wellesley College, Wellesley, MA 02481, USA
| | - Jingjing Li
- Neuroscience Program, Wellesley College, Wellesley, MA 02481, USA
| | - Chadanat Noonin
- Department of Comparative Physiology, Uppsala University, SE-752 36 Uppsala, Sweden
| | - Irene Söderhäll
- Department of Comparative Physiology, Uppsala University, SE-752 36 Uppsala, Sweden.
| | - Barbara S Beltz
- Neuroscience Program, Wellesley College, Wellesley, MA 02481, USA.
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Vascular endothelial growth factor-like and its receptor in a crustacean optic ganglia: A role in neuronal differentiation? Biochem Biophys Res Commun 2014; 447:299-303. [DOI: 10.1016/j.bbrc.2014.03.137] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Accepted: 03/27/2014] [Indexed: 11/21/2022]
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Brenneis G, Scholtz G. The 'ventral organs' of Pycnogonida (Arthropoda) are neurogenic niches of late embryonic and post-embryonic nervous system development. PLoS One 2014; 9:e95435. [PMID: 24736377 PMCID: PMC3988247 DOI: 10.1371/journal.pone.0095435] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Accepted: 03/27/2014] [Indexed: 11/19/2022] Open
Abstract
Early neurogenesis in arthropods has been in the focus of numerous studies, its cellular basis, spatio-temporal dynamics and underlying genetic network being by now comparably well characterized for representatives of chelicerates, myriapods, hexapods and crustaceans. By contrast, neurogenesis during late embryonic and/or post-embryonic development has received less attention, especially in myriapods and chelicerates. Here, we apply (i) immunolabeling, (ii) histology and (iii) scanning electron microscopy to study post-embryonic ventral nerve cord development in Pseudopallene sp., a representative of the sea spiders (Pycnogonida), the presumable sister group of the remaining chelicerates. During early post-embryonic development, large neural stem cells give rise to additional ganglion cell material in segmentally paired invaginations in the ventral ectoderm. These ectodermal cell regions - traditionally designated as 'ventral organs' - detach from the surface into the interior and persist as apical cell clusters on the ventral ganglion side. Each cluster is a post-embryonic neurogenic niche that features a tiny central cavity and initially still houses larger neural stem cells. The cluster stays connected to the underlying ganglionic somata cortex via an anterior and a posterior cell stream. Cell proliferation remains restricted to the cluster and streams, and migration of newly produced cells along the streams seems to account for increasing ganglion cell numbers in the cortex. The pycnogonid cluster-stream-systems show striking similarities to the life-long neurogenic system of decapod crustaceans, and due to their close vicinity to glomerulus-like neuropils, we consider their possible involvement in post-embryonic (perhaps even adult) replenishment of olfactory neurons - as in decapods. An instance of a potentially similar post-embryonic/adult neurogenic system in the arthropod outgroup Onychophora is discussed. Additionally, we document two transient posterior ganglia in the ventral nerve cord of Pseudopallene sp. and evaluate this finding in light of the often discussed reduction of a segmented 'opisthosoma' during pycnogonid evolution.
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Affiliation(s)
- Georg Brenneis
- Humboldt-Universität zu Berlin, Institut für Biologie/Vergleichende Zoologie, Berlin, Germany
| | - Gerhard Scholtz
- Humboldt-Universität zu Berlin, Institut für Biologie/Vergleichende Zoologie, Berlin, Germany
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20
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Kim YF, Sandeman DC, Benton JL, Beltz BS. Birth, survival and differentiation of neurons in an adult crustacean brain. Dev Neurobiol 2013; 74:602-15. [PMID: 24339155 DOI: 10.1002/dneu.22156] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 11/22/2013] [Accepted: 11/24/2013] [Indexed: 02/06/2023]
Abstract
Life-long neurogenesis is a characteristic feature of many vertebrate and invertebrate species. In decapod crustaceans, new neurons are added throughout life to two cell clusters containing local (cluster 9) and projection (cluster 10) interneurons in the olfactory pathway. Adult-born neurons in clusters 9 and 10 in crayfish have the anatomical properties and chemistry of mature neurons by 6 months after birth. Here we use 5-bromo-2'-deoxyuridine (BrdU) incorporation to pulse label mitotically active cells in these cell clusters, followed by a survival time of up to 8 months, during which crayfish (Cherax destructor) were sacrificed at intervals and the numbers of BrdU-labeled cells quantified. We find a decrease in the numbers of BrdU-labeled cells in cell cluster 10 between the first and second weeks following BrdU exposure, suggesting a period of cell death shortly after proliferation. Additional delayed cell divisions in both cell clusters are indicated by increases in labeled cells long after the BrdU clearing time. The differentiation time of these cells into neurons was defined by detection of the first immunoreactivity for the transmitter SIFamide in cluster 10 BrdU-labeled cells, which begins at 4 weeks after BrdU labeling; the numbers of SIFamide-labeled cells continues to increase over the following month. Experiments testing whether proliferation and survival of Cluster 10 cells are influenced by locomotor activity provided no evidence of a correlation between activity levels and cell proliferation, but suggest a strong influence of locomotor activity on cell survival.
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Affiliation(s)
- Youngmi Faith Kim
- Neuroscience Program, Wellesley College, Wellesley, Massachusetts, 02481
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21
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Chaves da Silva PG, Benton JL, Sandeman DC, Beltz BS. Adult Neurogenesis in the Crayfish Brain: The Hematopoietic Anterior Proliferation Center Has Direct Access to the Brain and Stem Cell Niche. Stem Cells Dev 2013. [DOI: 10.1089/scd.2012.0583] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Paula Grazielle Chaves da Silva
- Neuroscience Program, Wellesley College, Wellesley, Massachusetts
- Programa de Pós-Graduação em Ciências Morfológicas, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Jeanne L. Benton
- Neuroscience Program, Wellesley College, Wellesley, Massachusetts
| | | | - Barbara S. Beltz
- Neuroscience Program, Wellesley College, Wellesley, Massachusetts
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22
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First-generation neuronal precursors in the crayfish brain are not self-renewing. Int J Dev Neurosci 2012; 31:657-66. [PMID: 23219763 DOI: 10.1016/j.ijdevneu.2012.11.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Revised: 11/17/2012] [Accepted: 11/23/2012] [Indexed: 12/13/2022] Open
Abstract
Adult-born neurons in crayfish (Procambarus clarkii) are the progeny of 1st-generation precursor cells (functionally analogous to neuronal stem cells in vertebrates) that are located in a neurogenic niche on the ventral surface of the brain. The daughters of these precursor cells migrate along the processes of bipolar niche cells to proliferation zones in the cell clusters where the somata of the olfactory interneurons reside. Here they divide again, producing offspring that differentiate into olfactory local and projection neurons. The features of this neuronal assembly line, and the fact that it continues to function when the brain is isolated and perfused or maintained in organotypic culture, provide opportunities unavailable in other organisms to explore the sequence of cellular and molecular events leading to the production of new neurons in adult brains. Further, we have determined that the 1st-generation precursor cells are not a self-renewing population, and that the niche is, nevertheless, not depleted as the animals grow and age. We conclude, therefore, that the niche is not a closed system and that there must be an extrinsic source of neuronal stem cells. Based on in vitro studies demonstrating that cells extracted from the hemolymph are attracted to the niche, as well as the intimate relationship between the niche and vasculature, we hypothesize that the hematopoietic system is a likely source of these cells.
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23
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Alteration of c-Fos mRNA in the accessory lobe of crayfish is associated with a conditioned-cocaine induced reward. Neurosci Res 2012; 72:243-56. [DOI: 10.1016/j.neures.2011.11.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2011] [Revised: 11/04/2011] [Accepted: 11/28/2011] [Indexed: 02/02/2023]
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24
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Barker JM, Boonstra R, Wojtowicz JM. From pattern to purpose: how comparative studies contribute to understanding the function of adult neurogenesis. Eur J Neurosci 2012; 34:963-77. [PMID: 21929628 DOI: 10.1111/j.1460-9568.2011.07823.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The study of adult neurogenesis has had an explosion of fruitful growth. Yet numerous uncertainties and challenges persist. Our review begins with a survey of species that show evidence of adult neurogenesis. We then discuss how neurogenesis varies across brain regions and point out that regional specializations can indicate functional adaptations. Lifespan and aging are key life-history traits. Whereas 'adult neurogenesis' is the common term in the literature, it does not reflect the reality of neurogenesis being primarily a 'juvenile' phenomenon. We discuss the sharp decline with age as a universal trait of neurogenesis with inevitable functional consequences. Finally, the main body of the review focuses on the function of neurogenesis in birds and mammals. Selected examples illustrate how our understanding of avian and mammalian neurogenesis can complement each other. It is clear that although the two phyla have some common features, the function of adult neurogenesis may not be similar between them and filling the gaps will help us understand neurogenesis as an evolutionarily conserved trait to meet particular ecological pressures.
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Affiliation(s)
- Jennifer M Barker
- GIGA Neurosciences, University of Liège, 1 avenue de l'Hôpital, B-4000 Liège, Belgium.
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25
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Beltz BS, Zhang Y, Benton JL, Sandeman DC. Adult neurogenesis in the decapod crustacean brain: a hematopoietic connection? Eur J Neurosci 2012; 34:870-83. [PMID: 21929622 DOI: 10.1111/j.1460-9568.2011.07802.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
New neurons are produced and integrated into circuits in the adult brains of many organisms, including crustaceans. In some crustacean species, the first-generation neuronal precursors reside in a niche exhibiting characteristics analogous to mammalian neurogenic niches. However, unlike mammalian niches where several generations of neuronal precursors co-exist, the lineage of precursor cells in crayfish is spatially separated allowing the influence of environmental and endogenous regulators on specific generations in the neuronal precursor lineage to be defined. Experiments also demonstrate that the first-generation neuronal precursors in the crayfish Procambarus clarkii are not self-renewing. A source external to the neurogenic niche must therefore provide cells that replenish the first-generation precursor pool, because although these cells divide and produce a continuous efflux of second-generation cells from the niche, the population of first-generation niche precursors is not diminished with growth and aging. In vitro studies show that cells extracted from the hemolymph, but not other tissues, are attracted to and incorporated into the neurogenic niche, a phenomenon that appears to involve serotonergic mechanisms. We propose that, in crayfish, the hematopoietic system may be a source of cells that replenish the niche cell pool. These and other studies reviewed here establish decapod crustaceans as model systems in which the processes underlying adult neurogenesis, such as stem cell origins and transformation, can be readily explored. Studies in diverse species where adult neurogenesis occurs will result in a broader understanding of fundamental mechanisms and how evolutionary processes may have shaped the vertebrate/mammalian condition.
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Affiliation(s)
- Barbara S Beltz
- Neuroscience Program, Wellesley College, 106 Central Street, Wellesley, MA 02481, USA.
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26
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Sintoni S, Benton JL, Beltz BS, Hansson BS, Harzsch S. Neurogenesis in the central olfactory pathway of adult decapod crustaceans: development of the neurogenic niche in the brains of procambarid crayfish. Neural Dev 2012; 7:1. [PMID: 22225949 PMCID: PMC3266201 DOI: 10.1186/1749-8104-7-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Accepted: 01/06/2012] [Indexed: 12/13/2022] Open
Abstract
Background In the decapod crustacean brain, neurogenesis persists throughout the animal's life. After embryogenesis, the central olfactory pathway integrates newborn olfactory local and projection interneurons that replace old neurons or expand the existing population. In crayfish, these neurons are the descendants of precursor cells residing in a neurogenic niche. In this paper, the development of the niche was documented by monitoring proliferating cells with S-phase-specific markers combined with immunohistochemical, dye-injection and pulse-chase experiments. Results Between the end of embryogenesis and throughout the first post-embryonic stage (POI), a defined transverse band of mitotically active cells (which we will term 'the deutocerebral proliferative system' (DPS) appears. Just prior to hatching and in parallel with the formation of the DPS, the anlagen of the niche appears, closely associated with the vasculature. When the hatchling molts to the second post-embryonic stage (POII), the DPS differentiates into the lateral (LPZ) and medial (MPZ) proliferative zones. The LPZ and MPZ are characterized by a high number of mitotically active cells from the beginning of post-embryonic life; in contrast, the developing niche contains only very few dividing cells, a characteristic that persists in the adult organism. Conclusions Our data suggest that the LPZ and MPZ are largely responsible for the production of new neurons in the early post-embryonic stages, and that the neurogenic niche in the beginning plays a subordinate role. However, as the neuroblasts in the proliferation zones disappear during early post-embryonic life, the neuronal precursors in the niche gradually become the dominant and only mechanism for the generation of new neurons in the adult brain.
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Affiliation(s)
- Silvia Sintoni
- Max Planck Institute for Chemical Ecology, Department of Evolutionary Neuroethology, Hans-Knöll-Straße 8, D-07745 Jena, Germany
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27
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Schmidt M, Derby CD. Cytoarchitecture and ultrastructure of neural stem cell niches and neurogenic complexes maintaining adult neurogenesis in the olfactory midbrain of spiny lobsters, Panulirus argus. J Comp Neurol 2011; 519:2283-319. [PMID: 21523781 DOI: 10.1002/cne.22657] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
New interneurons are continuously generated in small proliferation zones within neuronal somata clusters in the olfactory deutocerebrum of adult decapod crustaceans. Each proliferation zone is connected to a clump of cells containing one neural stem cell (i.e., adult neuroblast), thus forming a "neurogenic complex." Here we provide a detailed analysis of the cytoarchitecture of neurogenic complexes in adult spiny lobsters, Panulirus argus, based on transmission electron microscopy and labeling with cell-type-selective markers. The clump of cells is composed of unique bipolar clump-forming cells that collectively completely envelop the adult neuroblast and are themselves ensheathed by a layer of processes of multipolar cell body glia. An arteriole is attached to the clump of cells, but dye perfusion experiments show that hemolymph has no access to the interior of the clump of cells. Thus, the clump of cells fulfills morphological criteria of a protective stem cell niche, with clump-forming cells constituting the adult neuroblast's microenvironment together with the cell body glia processes separating it from other tissue components. Bromodeoxyuridine pulse-chase experiments with short survival times suggest that adult neuroblasts are not quiescent but rather cycle actively during daytime. We propose a cell lineage model in which an asymmetrically dividing adult neuroblast repopulates the pool of neuronal progenitor cells in the associated proliferation zone. In conclusion, as in mammalian brains, adult neurogenesis in crustacean brains is fueled by neural stem cells that are maintained by stem cell niches that preserve elements of the embryonic microenvironment and contain glial and vascular elements.
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Affiliation(s)
- Manfred Schmidt
- Neuroscience Institute and Department of Biology, Georgia State University, Atlanta, Georgia 30302-5030, USA.
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28
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Benton JL, Zhang Y, Kirkhart CR, Sandeman DC, Beltz BS. Primary neuronal precursors in adult crayfish brain: replenishment from a non-neuronal source. BMC Neurosci 2011; 12:53. [PMID: 21635768 PMCID: PMC3127996 DOI: 10.1186/1471-2202-12-53] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Accepted: 06/02/2011] [Indexed: 12/12/2022] Open
Abstract
Background Adult neurogenesis, the production and integration of new neurons into circuits in the brains of adult animals, is a common feature of a variety of organisms, ranging from insects and crustaceans to birds and mammals. In the mammalian brain the 1st-generation neuronal precursors, the astrocytic stem cells, reside in neurogenic niches and are reported to undergo self-renewing divisions, thereby providing a source of new neurons throughout an animal's life. In contrast, our work shows that the 1st-generation neuronal precursors in the crayfish (Procambarus clarkii) brain, which also have glial properties and lie in a neurogenic niche resembling that of vertebrates, undergo geometrically symmetrical divisions and both daughters appear to migrate away from the niche. However, in spite of this continuous efflux of cells, the number of neuronal precursors in the crayfish niche continues to expand as the animals grow and age. Based on these observations we have hypothesized that (1) the neuronal stem cells in the crayfish brain are not self-renewing, and (2) a source external to the neurogenic niche must provide cells that replenish the stem cell pool. Results In the present study, we tested the first hypothesis using sequential double nucleoside labeling to track the fate of 1st- and 2nd-generation neuronal precursors, as well as testing the size of the labeled stem cell pool following increasing incubation times in 5-bromo-2'-deoxyuridine (BrdU). Our results indicate that the 1st-generation precursor cells in the crayfish brain, which are functionally analogous to neural stem cells in vertebrates, are not a self-renewing population. In addition, these studies establish the cycle time of these cells. In vitro studies examining the second hypothesis show that Cell Tracker™ Green-labeled cells extracted from the hemolymph, but not other tissues, are attracted to and incorporated into the neurogenic niche, a phenomenon that appears to involve serotonergic mechanisms. Conclusions These results challenge our current understanding of self-renewal capacity as a defining characteristic of all adult neuronal stem cells. In addition, we suggest that in crayfish, the hematopoietic system may be a source of cells that replenish the niche stem cell pool.
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Affiliation(s)
- Jeanne L Benton
- Neuroscience Program, Wellesley College, 106 Central Street, Wellesley, MA 02481, USA
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29
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Christie AE. Crustacean neuroendocrine systems and their signaling agents. Cell Tissue Res 2011; 345:41-67. [PMID: 21597913 DOI: 10.1007/s00441-011-1183-9] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Accepted: 04/20/2011] [Indexed: 11/24/2022]
Abstract
Decapod crustaceans have long served as important models for the study of neuroendocrine signaling. For example, the process of neurosecretion was first formally demonstrated by using a member of this order. In this review, the major decapod neuroendocrine organs are described, as are their phylogenetic conservation and neurochemistry. In addition, recent advances in crustacean neurohormone discovery and tissue mapping are discussed, as are several recent advances in our understanding of hormonal control in this group of animals.
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Affiliation(s)
- Andrew E Christie
- Neuroscience Program, John W. and Jean C. Boylan Center for Cellular and Molecular Physiology, Mount Desert Island Biological Laboratory, Old Bar Harbor Road, Salisbury Cove, ME 04672, USA.
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Ayub N, Benton JL, Zhang Y, Beltz BS. Environmental enrichment influences neuronal stem cells in the adult crayfish brain. Dev Neurobiol 2011; 71:351-61. [PMID: 21485010 PMCID: PMC3143225 DOI: 10.1002/dneu.20864] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
New neurons are incorporated throughout life into the brains of many vertebrate and non-vertebrate species. This process of adult neurogenesis is regulated by a variety of external and endogenous factors, including environmental enrichment, which increases the production of neurons in juvenile mice and crayfish. The primary goal of the present study was to exploit the spatial separation of the neuronal precursor cell lineage in crayfish to determine which generation(s) of precursors is altered by environmental conditions. Further, in crayfish, an intimate relationship between the 1st generation neuronal precursors (stem cells) and cells circulating in the hemolymph has been proposed (Zhang et al., 2009 ). Therefore, a second goal was to assess whether environmental enrichment alters the numbers or types of cells circulating in the hemolymph. We find that neurogenesis in the brains of sexually differentiated procambarid crayfish is enhanced by environmental enrichment as previously demonstrated by Sandeman and Sandeman (2000) in young, sexually undifferentiated Cherax destructor . We also show that environmental enrichment increases the cell cycle rate of neuronal stem cells. While there was no effect of environment on the overall numbers of cells circulating in the hemolymph, enrichment resulted in increased expression of glutamine synthetase, a marker of the neuronal stem cells, in a small percentage of circulating cells; there was little or no expression of this enzyme in hemolymph cells extracted from deprived animals. Thus, environmental enrichment influences the rate of neuronal stem cell division in adult crayfish, as well as the composition of cells circulating in the hemolymph.
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Affiliation(s)
- Neishay Ayub
- Neuroscience Program, Wellesley College, Wellesley, MA 02481
| | | | - Yi Zhang
- Neuroscience Program, Wellesley College, Wellesley, MA 02481
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Sandeman DC, Bazin F, Beltz BS. Adult neurogenesis: examples from the decapod crustaceans and comparisons with mammals. ARTHROPOD STRUCTURE & DEVELOPMENT 2011; 40:258-75. [PMID: 21396485 PMCID: PMC3117910 DOI: 10.1016/j.asd.2011.03.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Revised: 02/28/2011] [Accepted: 03/01/2011] [Indexed: 05/30/2023]
Abstract
Defining evolutionary origins is a means of understanding an organism's position within the integrated web of living beings, and not only to trace characteristics back in time, but also to project forward in an attempt to reveal relationships with more recently evolved forms. Both the vertebrates and arthropods possess condensed nervous systems, but this is dorsal in the vertebrates and ventral in the arthropods. Also, whereas the nervous system in the vertebrates develops from a neural tube in the embryo, that of the arthropods comes from an ectodermal plate. Despite these apparently fundamental differences, it is now generally accepted that life-long neurogenesis, the generation of functionally integrated neurons from progenitor cells, is a common feature of the adult brains of a variety of organisms, ranging from insects and crustaceans to birds and mammals. Among decapod crustaceans, there is evidence for adult neurogenesis in basal species of the Dendrobranchiata, as well as in more recent terrestrial, marine and fresh-water species. The widespread nature of this phenomenon in decapod species may relate to the importance of the adult-born neurons, although their functional contribution is not yet known. The many similarities between the systems generating neurons in the adult brains of decapod crustaceans and mammals, reviewed in this paper, suggest that adult neurogenesis is governed by common ancestral mechanisms that have been retained in a phylogenetically broad group of species.
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Affiliation(s)
| | - Francois Bazin
- Laboratoire de Biologie Animale et du Laboratoire Maritime, Université de Caen, Normandy, France
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Zhang Y, Benton JL, Beltz BS. 5-HT receptors mediate lineage-dependent effects of serotonin on adult neurogenesis in Procambarus clarkii. Neural Dev 2011; 6:2. [PMID: 21205292 PMCID: PMC3022547 DOI: 10.1186/1749-8104-6-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Accepted: 01/04/2011] [Indexed: 01/23/2023] Open
Abstract
Background Serotonin (5-HT) is a potent regulator of adult neurogenesis in the crustacean brain, as in the vertebrate brain. However, there are relatively few data regarding the mechanisms of serotonin's action and which precursor cells are targeted. Therefore, we exploited the spatial separation of the neuronal precursor lineage that generates adult-born neurons in the crayfish (Procambarus clarkii) brain to determine which generation(s) is influenced by serotonin, and to identify and localize serotonin receptor subtypes underlying these effects. Results RT-PCR shows that mRNAs of serotonin receptors homologous to mammalian subtypes 1A and 2B are expressed in P. clarkii brain (referred to here as 5-HT1α and 5-HT2β). In situ hybridization with antisense riboprobes reveals strong expression of these mRNAs in several brain regions, including cell clusters 9 and 10 where adult-born neurons reside. Antibodies generated against the crustacean forms of these receptors do not bind to the primary neuronal precursors (stem cells) in the neurogenic niche or their daughters as they migrate, but do label these second-generation precursors as they approach the proliferation zones of cell clusters 9 and 10. Like serotonin, administration of the P. clarkii 5-HT1α-specific agonist quipazine maleate salt (QMS) increases the number of bromodeoxyuridine (BrdU)-labeled cells in cluster 10; the P. clarkii 5-HT2β-specific antagonist methiothepin mesylate salt (MMS) suppresses neurogenesis in this region. However, serotonin, QMS and MMS do not alter the rate of BrdU incorporation into niche precursors or their migratory daughters. Conclusion Our results demonstrate that the influences of serotonin on adult neurogenesis in the crayfish brain are confined to the late second-generation precursors and their descendants. Further, the distribution of 5-HT1α and 5-HT2β mRNAs and proteins indicate that these serotonergic effects are exerted directly on specific generations of neuronal precursors. Taken together, these results suggest that the influence of serotonin on adult neurogenesis in the crustacean brain is lineage dependent, and that 5-HT1α and 5-HT2β receptors underlie these effects.
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Affiliation(s)
- Yi Zhang
- Neuroscience Program, Wellesley College, Wellesley, MA 02481, USA
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Effects of seasonality and moult cycle on the proliferation of nerve cells and on the labelling of ecdysone receptors in an estuarine crab. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2010; 197:293-300. [PMID: 21140155 DOI: 10.1007/s00359-010-0611-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2010] [Revised: 11/04/2010] [Accepted: 11/05/2010] [Indexed: 10/18/2022]
Abstract
Decapod crustaceans show proliferation of the nerve cells in the olfactory lobe throughout their lives. However, the regulation of this process is still poorly understood, since it may vary with endogenous and exogenous factors. The objective of the present investigation was to quantify the proliferation of nerve cells and number of nerve cells with ecdysone receptors in the clusters of the central olfactory system in Neohelice granulata, according to moult stages and in different seasons (summer and winter). Three injections of bromodeoxyuridine (BrdU) were administered to the crabs. Brains were sectioned by microtome and fixed on slides for immunohistochemistry with anti-BrdU and anti-EcR antibodies. The proliferation of nerve cells was higher in winter than in summer, probably because in winter the crabs do not breed and the premoult and postmoult periods are longer. Crabs in postmoult exhibited more BrdU-labelled cells than crabs in premoult or intermoult in winter, because of a greater number of mitoses related to an increase in body size and addition of olfactory receptor neurons. The number of EcR-labelled cells was higher in premoult than in postmoult or intermoult in winter. The proliferation of nerve cells is regulated seasonally and according to moult stages.
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Christie AE, Stemmler EA, Dickinson PS. Crustacean neuropeptides. Cell Mol Life Sci 2010; 67:4135-69. [PMID: 20725764 PMCID: PMC11115526 DOI: 10.1007/s00018-010-0482-8] [Citation(s) in RCA: 167] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2010] [Revised: 07/09/2010] [Accepted: 07/28/2010] [Indexed: 10/19/2022]
Abstract
Crustaceans have long been used for peptide research. For example, the process of neurosecretion was first formally demonstrated in the crustacean X-organ-sinus gland system, and the first fully characterized invertebrate neuropeptide was from a shrimp. Moreover, the crustacean stomatogastric and cardiac nervous systems have long served as models for understanding the general principles governing neural circuit functioning, including modulation by peptides. Here, we review the basic biology of crustacean neuropeptides, discuss methodologies currently driving their discovery, provide an overview of the known families, and summarize recent data on their control of physiology and behavior.
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Affiliation(s)
- Andrew E Christie
- Program in Neuroscience, John W. and Jean C. Boylan Center for Cellular and Molecular Physiology, Mount Desert Island Biological Laboratory, Old Bar Harbor Road, P.O. Box 35, Salisbury Cove, ME 04672, USA.
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Krieger J, Sandeman RE, Sandeman DC, Hansson BS, Harzsch S. Brain architecture of the largest living land arthropod, the Giant Robber Crab Birgus latro (Crustacea, Anomura, Coenobitidae): evidence for a prominent central olfactory pathway? Front Zool 2010; 7:25. [PMID: 20831795 PMCID: PMC2945339 DOI: 10.1186/1742-9994-7-25] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2010] [Accepted: 09/10/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Several lineages within the Crustacea conquered land independently during evolution, thereby requiring physiological adaptations for a semi-terrestrial or even a fully terrestrial lifestyle. Birgus latro Linnaeus, 1767, the giant robber crab or coconut crab (Anomura, Coenobitidae), is the largest land-living arthropod and inhabits Indo-Pacific islands such as Christmas Island. B. latro has served as a model in numerous studies of physiological aspects related to the conquest of land by crustaceans. From an olfactory point of view, a transition from sea to land means that molecules need to be detected in gas phase instead of in water solution. Previous studies have provided physiological evidence that terrestrial hermit crabs (Coenobitidae) such as B. latro have a sensitive and well differentiated sense of smell. Here we analyze the brain, in particular the olfactory processing areas of B. latro, by morphological analysis followed by 3 D reconstruction and immunocytochemical studies of synaptic proteins and a neuropeptide. RESULTS The primary and secondary olfactory centers dominate the brain of B. latro and together account for ca. 40% of the neuropil volume in its brain. The paired olfactory neuropils are tripartite and composed of more than 1,000 columnar olfactory glomeruli, which are radially arranged around the periphery of the olfactory neuropils. The glomeruli are innervated ca. 90,000 local interneurons and ca. 160,000 projection neurons per side. The secondary olfactory centers, the paired hemiellipsoid neuropils, are targeted by the axons of these olfactory projection neurons. The projection neuron axonal branches make contact to ca. 250.000 interneurons (per side) associated with the hemiellipsoid neuropils. The hemiellipsoid body neuropil is organized into parallel neuropil lamellae, a design that is quite unusual for decapod crustaceans. The architecture of the optic neuropils and areas associated with antenna two suggest that B. latro has visual and mechanosensory skills that are comparable to those of marine Crustacea. CONCLUSIONS In parallel to previous behavioral findings that B. latro has aerial olfaction, our results indicate that their central olfactory pathway is indeed most prominent. Similar findings from the closely related terrestrial hermit crab Coenobita clypeatus suggest that in Coenobitidae, olfaction is a major sensory modality processed by the brain, and that for these animals, exploring the olfactory landscape is vital for survival in their terrestrial habitat. Future studies on terrestrial members of other crustacean taxa such as Isopoda, Amphipoda, Astacida, and Brachyura will shed light on how frequently the establishment of an aerial sense of olfaction evolved in Crustacea during the transition from sea to land. Amounting to ca. 1,000,000, the numbers of interneurons that analyse the olfactory input in B. latro brains surpasses that in other terrestrial arthropods, as e.g. the honeybee Apis mellifera or the moth Manduca sexta, by two orders of magnitude suggesting that B. latro in fact is a land-living arthropod that has devoted a substantial amount of nervous tissue to the sense of smell.
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Affiliation(s)
- Jakob Krieger
- Institute of Zoology, Department of Cytology and Evolution, University of Greifswald, Johann-Sebastian-Bach-Straße 11/12, D-17487 Greifswald, Germany
| | - Renate E Sandeman
- Justus-Liebig-Universität Gießen, Fachbereich 06 Psychologie und Sportwissenschaft, Abteilung für Entwicklungspsychologie, Otto-Behaghel-Strasse 10F, D-35394 Giessen, Germany
| | - David C Sandeman
- Wellesley College, 106 Central Street, Wellesley College, Department of Biological Sciences, Wellesley, MA 02481-8203, USA
| | - Bill S Hansson
- Max Planck Institute for Chemical Ecology, Department of Evolutionary Neuroethology, Beutenberg Campus, Hans-Knöll-Str. 8, D-07745 Jena, Germany
| | - Steffen Harzsch
- Institute of Zoology, Department of Cytology and Evolution, University of Greifswald, Johann-Sebastian-Bach-Straße 11/12, D-17487 Greifswald, Germany.,Max Planck Institute for Chemical Ecology, Department of Evolutionary Neuroethology, Beutenberg Campus, Hans-Knöll-Str. 8, D-07745 Jena, Germany
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Helluy S, Thomas F. Parasitic manipulation and neuroinflammation: Evidence from the system Microphallus papillorobustus (Trematoda) - Gammarus (Crustacea). Parasit Vectors 2010; 3:38. [PMID: 20398322 PMCID: PMC2874546 DOI: 10.1186/1756-3305-3-38] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2010] [Accepted: 04/15/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Neuropathological consequences of neuroinflammatory processes have been implicated in a wide range of diseases affecting the central nervous system (CNS). Glial cells, the resident immune cells of the CNS, respond to tissue injury by releasing proinflammatory cytokines and free radicals such as nitric oxide. We explored the possibility that neuroimmune responses are involved in parasitic manipulation of host behavior in a trematode-crustacean association. The cerebral larva of the flatworm Microphallus papillorobustus alters responses to environmental stimuli - and thus reflex pathways - in the crustacean Gammarus insensibilis, in a way that enhances predation of the crustacean by birds, definitive hosts of the parasite. RESULTS Immunocytochemical experiments followed by confocal microscopy were performed to study the distribution of glutamine synthetase, a glial cell marker, and nitric oxide synthase in the brain of gammarids. Astrocyte-like glia and their processes were abundant at the surface of the parasites while levels of nitric oxide synthase were elevated at the host-parasite interface in the brain of gammarids harboring mature cerebral larvae and demonstrating altered behavior. CONCLUSION Taken together these results lend support to the neuroinflammation hypothesis whereby a chronic CNS specific immune response induced by the parasite plays a role in the disruption of neuromodulation, neuronal integrity, and behavior in infected hosts.
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Affiliation(s)
- Simone Helluy
- Department of Biological Sciences, Wellesley College, Wellesley, MA 02481, USA.
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Vázquez-Acevedo N, Rivera NM, Torres-González AM, Rullan-Matheu Y, Ruíz-Rodríguez EA, Sosa MA. GYRKPPFNGSIFamide (Gly-SIFamide) modulates aggression in the freshwater prawn Macrobrachium rosenbergii. THE BIOLOGICAL BULLETIN 2009; 217:313-26. [PMID: 20040755 PMCID: PMC2892311 DOI: 10.1086/bblv217n3p313] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The freshwater prawn Macrobrachium rosenbergii is a tropical crustacean with characteristics similar to those of lobsters and crayfish. Adult males develop through three morphological types-small (SC), yellow (YC), and blue claws (BC)-with each representing a level in the dominance hierarchy of a group, BC males being the most dominant. We are interested in understanding the role played by neuropeptides in the mechanisms underlying aggressive behavior and the establishment of dominance hierarchies in this type of prawn. SIFamides are a family of arthropod peptides recently identified in the central nervous system of insects and crustaceans, where it has been linked to olfaction, sexual behavior, and gut endocrine functions. One of the six SIFamide isoforms, GYRKPPFNGSIFamide (Gly-SIFamide), is highly conserved among decapod crustaceans such as crabs and crayfish. We wanted to determine whether Gly-SIFamide plays a role in modulating aggression and dominant behavior in the prawn. To do this, we performed behavioral experiments in which interactions between BC/YC pairs were recorded and quantified before and after injecting Gly-SIFamide directly into the circulating hemolymph of the living animal. Behavioral data showed that aggression among interacting BC/YC prawns was enhanced by injection of Gly-SIFamide, suggesting that this neuropeptide does have a modulatory role for this type of behavior in the prawn.
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Affiliation(s)
- Nietzell Vázquez-Acevedo
- Department of Anatomy and Neurobiology, School of Medicine, Medical Sciences Campus, University of Puerto Rico, PO Box 365067, San Juan, Puerto Rico 00936-5067
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Ghosal K, Gupta M, Killian KA. Agonistic behavior enhances adult neurogenesis in male Acheta domesticus crickets. ACTA ACUST UNITED AC 2009; 212:2045-56. [PMID: 19525431 DOI: 10.1242/jeb.026682] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We examined the effect of agonistic behavior on cell proliferation and neurogenesis in the central nervous system (CNS) of adult male Acheta domesticus crickets. We combined 5-bromo,2'deoxyuridine (BrdU)-labeling of dividing cells with immunocytochemical detection of the neuronal marker horseradish peroxidase to examine the proliferation of progenitor cells and the survival of newborn neurons. In crickets, the mushroom bodies of the brain contain clusters of proliferative cells that divide and generate new neurons in adulthood. Pairs of male crickets were allowed to fight and establish social rank and were then injected with BrdU. Proliferation of mushroom body neurogenic cluster cells was unaffected by agonistic interactions; 24 h after a fight, the number of BrdU positive cells in fought and un-fought males did not significantly differ. However, agonistic interactions did influence cell survival. Two weeks after an agonistic interaction, fought males had more newborn neurons than males that did not fight. There was also a rank-specific effect because dominant males had significantly more new neurons than subordinates. We also report for the first time that neurogenesis in adult crickets can occur in other regions of the brain and in other CNS ganglia, including the terminal abdominal ganglion (TAG). Agonistic interactions enhanced the proliferation of these distributed precursor cells but did not increase the survival of the newborn neurons generated by these cells.
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Affiliation(s)
- Kaushik Ghosal
- Department of Zoology and Center for Neuroscience, Miami University, Oxford, OH 45056, USA
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Sandeman DC, Benton JL, Beltz BS. An identified serotonergic neuron regulates adult neurogenesis in the crustacean brain. Dev Neurobiol 2009; 69:530-45. [PMID: 19373861 DOI: 10.1002/dneu.20722] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
New neurons are born and integrated into functional circuits in the brains of many adult organisms. In virtually all of these systems, serotonin is a potent regulator of neuronal proliferation. Specific neural pathways underlying these serotonergic influences have not, however, been identified and manipulated. The goal of this study was to test whether adult neurogenesis in the crustacean brain is influenced by electrical activity in the serotonergic dorsal giant neurons (DGNs) innervating the primary olfactory processing areas, the olfactory lobes, and higher order centers, the accessory lobes. Adult-born neurons occur in two interneuronal cell clusters that are part of the olfactory pathway. This study demonstrates that neurogenesis also continues in these areas in a dissected, perfused brain preparation, although the rate of neuronal production is lower than in brains from intact same-sized animals. Inclusion of 10(-9) M serotonin in the perfusate delivered to the dissected brain preparation restores the rate of neurogenesis to in vivo levels. Although subthreshold stimulation of the DGN does not significantly alter the rate of neurogenesis, electrical activation of a single DGN results in significant increases in neurogenesis in Cluster 10 on the same side of the brain, when compared with levels on the contralateral, unstimulated side. Measurements of serotonin levels in the perfusate using high-performance liquid chromatography established that serotonin levels are elevated about 10-fold during DGN stimulation, confirming that serotonin is released during DGN activity. This is the first identified neural pathway through which adult neurogenesis has been directly manipulated.
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Affiliation(s)
- D C Sandeman
- Neuroscience Program, Wellesley College, Wellesley, Massachusetts 02481, USA
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Zhang Y, Allodi S, Sandeman DC, Beltz BS. Adult neurogenesis in the crayfish brain: proliferation, migration, and possible origin of precursor cells. Dev Neurobiol 2009; 69:415-36. [PMID: 19294644 DOI: 10.1002/dneu.20717] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The birth of new neurons and their incorporation into functional circuits in the adult brain is a characteristic of many vertebrate and invertebrate organisms, including decapod crustaceans. Precursor cells maintaining life-long proliferation in the brains of crayfish (Procambarus clarkii, Cherax destructor) and clawed lobsters (Homarus americanus) reside within a specialized niche on the ventral surface of the brain; their daughters migrate to two proliferation zones along a stream formed by processes of the niche precursors. Here they divide again, finally producing interneurons in the olfactory pathway. The present studies in P. clarkii explore (1) differential proliferative activity among the niche precursor cells with growth and aging, (2) morphological characteristics of cells in the niche and migratory streams, and (3) aspects of the cell cycle in this lineage. Morphologically symmetrical divisions of neuronal precursor cells were observed in the niche near where the migratory streams emerge, as well as in the streams and proliferation zones. The nuclei of migrating cells elongate and undergo shape changes consistent with nucleokinetic movement. LIS1, a highly conserved dynein-binding protein, is expressed in cells in the migratory stream and neurogenic niche, implicating this protein in the translocation of crustacean brain neuronal precursor cells. Symmetrical divisions of the niche precursors and migration of both daughters raised the question of how the niche precursor pool is replenished. We present here preliminary evidence for an association between vascular cells and the niche precursors, which may relate to the life-long growth and maintenance of the crustacean neurogenic niche.
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Affiliation(s)
- Yi Zhang
- Neurobiology Program, Wellesley College, Wellesley, MA 02481, USA
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Song CK, Johnstone LM, Edwards DH, Derby CD, Schmidt M. Cellular basis of neurogenesis in the brain of crayfish, Procambarus clarkii: Neurogenic complex in the olfactory midbrain from hatchlings to adults. ARTHROPOD STRUCTURE & DEVELOPMENT 2009; 38:339-360. [PMID: 19185059 DOI: 10.1016/j.asd.2008.12.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2008] [Revised: 11/14/2008] [Accepted: 12/30/2008] [Indexed: 05/27/2023]
Abstract
Neurogenesis in the central olfactory pathway of decapod crustaceans persists throughout life. Here we describe the structural basis of neurogenesis within the olfactory deutocerebrum of the crayfish Procambarus clarkii from hatchlings to adults. Using a proliferation marker and immunostaining, we found that throughout development each hemibrain contains a neurogenic complex consisting of five parts: two proliferation zones, each within the neuronal soma clusters containing local or projection interneurons, a tail of proliferating cells extending from each proliferation zone, and an elongated clump of cells where the two tails meet. The clump of cells comprises two subdivisions joined at a nucleus-free central area. Each subdivision consists of a dense group of clump cells with small, spindle-shaped nuclei and is connected to one of the proliferation zones by a strand of fibrous material encompassing the tail of proliferating cells extending from it. We identify one proliferating cell with a large nucleus in each subdivision as a putative neuroblast. Its daughter cells migrate through the strands to the associated proliferation zones, but in the strand leading to the soma cluster of local interneurons this is masked by local proliferation. We conclude that neurogenesis in the olfactory deutocerebrum of juvenile and adult P. clarkii is based on a few neuroblasts that are associated with unique clumps of cells likely representing stem cell niches.
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Affiliation(s)
- Cha-Kyong Song
- Neuroscience Institute and Department of Biology, Georgia State University, P.O. Box 5030, Atlanta, GA 30302-5030, USA
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Verleyen P, Huybrechts J, Schoofs L. SIFamide illustrates the rapid evolution in Arthropod neuropeptide research. Gen Comp Endocrinol 2009; 162:27-35. [PMID: 19014945 DOI: 10.1016/j.ygcen.2008.10.020] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2008] [Revised: 09/28/2008] [Accepted: 10/09/2008] [Indexed: 11/27/2022]
Abstract
This review is focussed on SIFamide. This neuropeptide was discovered as a result of an extensive purification process, typical for 20th century physiology, of an extract of 350,000 flesh flies. Our knowledge of SIFamide greatly expanded since the first publication in 1996. Describing the minor and major findings on this peptide is our lead to summarise a number of innovations that recently became common in research on Arthropods. Mass spectrometry, nanoLC, whole mount immunocytochemistry, genome sequencing, deorphanizing receptors and functional gene knock downs are aspects that dramatically improved and changed peptide research. Some of the techniques mentioned in this review were of course applied before 1996, but they were not widespread. Although the focus of the review is on insects we incorporated the data of SIFamide in Crustaceans as well. SIFamide illustrates that crustaceans and insects might have more in common than was previously anticipated. Today, six isoforms of SIFamide are discovered in many crustaceans, several insects and a tick. The sequence of SIFamide is extremely conserved among these species. Deorphanizing its receptor in Drosophila, learned that both the ligand and receptor are impressively conserved, pointing at a crucial function. Immunohistochemistry and mass spectrometry data reveal that SIFamide is present in the crustacean brain and gut, but restricted to four neurons in the insect pars intercerebralis. The immunoreactive patterns in the brain refer to a neuromodulatory role in combining visual, tactile and olfactory input. Eventually, targeted cell ablation and RNAi revealed that SIFamide modulates sexual behaviour in fruit flies.
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Affiliation(s)
- Peter Verleyen
- K.U. Leuven, Zoological Institute, Research Group of Functional Genomics and Proteomics, Naamsestraat 59, B-3000 Leuven, Belgium.
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von Trotha JW, Egger B, Brand AH. Cell proliferation in the Drosophila adult brain revealed by clonal analysis and bromodeoxyuridine labelling. Neural Dev 2009; 4:9. [PMID: 19254370 PMCID: PMC2662830 DOI: 10.1186/1749-8104-4-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2008] [Accepted: 03/02/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The production of new neurons during adulthood and their subsequent integration into a mature central nervous system have been shown to occur in all vertebrate species examined to date. However, the situation in insects is less clear and, in particular, it has been reported that there is no proliferation in the Drosophila adult brain. RESULTS We report here, using clonal analysis and 5'-bromo-2'-deoxyuridine (BrdU) labelling, that cell proliferation does occur in the Drosophila adult brain. The majority of clones cluster on the ventrolateral side of the antennal lobes, as do the BrdU-positive cells. Of the BrdU-labelled cells, 86% express the glial gene reversed polarity (repo), and 14% are repo negative. CONCLUSION We have observed cell proliferation in the Drosophila adult brain. The dividing cells may be adult stem cells, generating glial and/or non-glial cell types.
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Affiliation(s)
- Jakob W von Trotha
- The Wellcome Trust/Cancer Research UK Gurdon Institute, Department of Physiology, Development and Neuroscience, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN, UK.
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Benton JL, Goergen EM, Rogan SC, Beltz BS. Hormonal and synaptic influences of serotonin on adult neurogenesis. Gen Comp Endocrinol 2008; 158:183-90. [PMID: 18692503 PMCID: PMC3081605 DOI: 10.1016/j.ygcen.2008.07.016] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2008] [Accepted: 07/16/2008] [Indexed: 12/13/2022]
Abstract
New neurons are incorporated into the adult brains of a variety of organisms, from humans and higher vertebrates, to non-vertebrates such as crustaceans. In virtually all of these systems serotonergic pathways appear to provide important regulatory influences over the machinery producing the new neurons. We have developed an in vitro preparation where adult neurogenesis can be maintained under highly controlled conditions, and are using this to test the influence of hormones on the production of neurons in the crustacean (Homarus americanus) brain. Serotonin levels have been manipulated in this in vitro preparation, and the resulting effects on the rate of neurogenesis have been documented. In addition we have compared in vitro influences of serotonin with results acquired from in vivo exposure of whole animals to serotonin. These experiments suggest that there are multiple mechanisms and pathways by which serotonin may regulate neurogenesis in the crustacean brain: (1) serotonin is effective in regulating neurogenesis at levels as low as 10(-10)M, suggesting that circulating serotonin may have hormonal influences on neuronal precursor cells residing in a vascular niche or the proliferation zones; (2) contrasting effects of serotonin on neurogenesis (up- vs. down-regulation) at high concentrations (10(-4)M), dependent upon whether eyestalk tissue is present or absent, indicate that serotonin elicits the release of substances from the sinus glands that are capable of suppressing neurogenesis; (3) previously demonstrated (Beltz, B.S., Benton, J.L., Sullivan, J.M., 2001. Transient uptake of serotonin by newborn olfactory projection neurons. Proc. Natl. Acad. Sci. USA 98, 12730-12735) serotonergic fibers from the dorsal giant neuron project directly into the proliferation zone in Cluster 10, suggest synaptic or local influences on neurogenesis in the proliferation zones where the final cell divisions and neuronal differentiation occur. Serotonin therefore regulates neurogenesis by multiple pathways, and the specific mode of influence is concentration-dependent.
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Affiliation(s)
- J L Benton
- Neuroscience Program, Wellesley College, 106 Central Street, Wellesley, MA 02421, USA
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Benton JL, Sandeman DC, Beltz BS. Nitric oxide in the crustacean brain: regulation of neurogenesis and morphogenesis in the developing olfactory pathway. Dev Dyn 2008; 236:3047-60. [PMID: 17948307 DOI: 10.1002/dvdy.21340] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Nitric oxide (NO) plays major roles during development and in adult organisms. We examined the temporal and spatial patterns of nitric oxide synthase (NOS) appearance in the embryonic lobster brain to localize sources of NO activity; potential NO targets were identified by defining the distribution of NO-induced cGMP. Staining patterns are compared with NOS and cyclic 3,5 guanosine monophosphate (cGMP) distribution in adult lobster brains. Manipulation of NO levels influences olfactory glomerular formation and stabilization, as well as levels of neurogenesis among the olfactory projection neurons. In the first 2 days following ablation of the lateral antennular flagella in juvenile lobsters, a wave of increased NOS immunoreactivity and a reduction in neurogenesis occur. These studies implicate nitric oxide as a developmental architect and also support a role for this molecule in the neural response to injury in the olfactory pathway.
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Affiliation(s)
- J L Benton
- Neuroscience Program, Wellesley College, Wellesley, Massachusetts 02481, USA.
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Song CK, Johnstone LM, Schmidt M, Derby CD, Edwards DH. Social domination increases neuronal survival in the brain of juvenile crayfish Procambarus clarkii. ACTA ACUST UNITED AC 2007; 210:1311-24. [PMID: 17401115 DOI: 10.1242/jeb.02758] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Olfactory cues are among the sensory inputs that crayfish use in establishing dominance hierarchies. Throughout their lives, new neurons are continuously added into brain cell clusters 9 and 10, which contain somata of olfactory local and projection interneurons, respectively. Using markers for DNA synthesis (bromodeoxyuridine) and mitosis (phospho-histone-3), we tested juvenile crayfish (Procambarus clarkii) to examine effects of pairwise social experience on proliferation and survival of cells in these brain regions. Proliferating and mitotic cells appeared within restricted neurogenic areas in both clusters and in ;tails' extending from them. These tails, embedded in tubulin-positive strands, are linked by a patch of cells. Neither cell proliferation nor mitotic activity was affected by social dominance. Cell survival of neuronal precursors was affected by dominance: compared to dominants, subordinates had fewer newborn cells surviving in cluster 9 after 14 days of social experience. Social experience also affected body growth rate, but the effect of social experience on neurogenesis remained when differences in body growth rate were statistically controlled. We conclude that social domination enhances survival of new olfactory interneuronal precursors compared to social subordination but not compared to social isolation.
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Affiliation(s)
- Cha-Kyong Song
- Department of Biology, Program in Brains and Behavior, and Center for Behavioral Neuroscience, Georgia State University, Atlanta, GA 30302-4010, USA.
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Polanska MA, Yasuda A, Harzsch S. Immunolocalisation of crustacean-SIFamide in the median brain and eyestalk neuropils of the marbled crayfish. Cell Tissue Res 2007; 330:331-44. [PMID: 17828557 DOI: 10.1007/s00441-007-0473-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2007] [Accepted: 07/11/2007] [Indexed: 11/29/2022]
Abstract
Crustacean-SIFamide (GYRKPPFNGSIFamide) is a novel neuropeptide that was recently isolated from crayfish nervous tissue. We mapped the localisation of this peptide in the median brain and eyestalk neuropils of the marbled crayfish (Marmorkrebs), a parthenogenetic crustacean. Our experiments showed that crustacean-SIFamide is strongly expressed in all major compartments of the crayfish brain, including all three optic neuropils, the lateral protocerebrum with the hemiellipsoid body, and the medial protocerebrum with the central complex. These findings imply a role of this peptide in visual processing already at the level of the lamina but also at the level of the deeper relay stations. Immunolabelling is particularly strong in the accessory lobes and the deutocerebral olfactory lobes that receive a chemosensory input from the first antennae. Most cells of the olfactory globular tract, a projection neuron pathway that links deuto- and protocerebrum, are labelled. This pathway plays a central role in conveying tactile and olfactory stimuli to the lateral protocerebrum, where this input converges with optic information. Weak labelling is also present in the tritocerebrum that is associated with the mechanosensory second antennae. Taken together, we suggest an important role of crustacean-SIFamidergic neurons in processing high-order, multimodal input in the crayfish brain.
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Affiliation(s)
- M A Polanska
- Institute of Infectious Diseases, Medical University of Warsaw, Warsaw, 02-106, Poland.
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Schmidt M. Identification of putative neuroblasts at the base of adult neurogenesis in the olfactory midbrain of the spiny lobster, Panulirus argus. J Comp Neurol 2007; 503:64-84. [PMID: 17480012 DOI: 10.1002/cne.21366] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Continuous neurogenesis persists during adulthood in the olfactory midbrain of decapod crustaceans, including spiny lobsters, Panulirus argus. This encompasses generation of projection and local interneurons, whose somata are in the lateral soma cluster (LC) and medial soma cluster (MC), respectively. Both neuronal types originate from immediate precursors labeled by a single injection of BrdU and located in a small proliferation zone within each cluster. The aim of this study was to identify neuroblasts as a source of the dividing cells by multiple injections of BrdU over 2 days. All animals receiving multiple injections had one or a few 'extra' BrdU-positive nuclei near the proliferation zones, and these nuclei were significantly larger than nuclei of neurons or BrdU-positive cells in the proliferation zones. Since the defining morphological feature of neuroblasts in preadult neurogenesis in arthropods is being larger than their progeny, these large extra BrdU-positive nuclei represent "putative adult neuroblasts." Multiple BrdU-injections revealed a clump of small cells enclosing the putative adult neuroblasts in LC and MC, and these cells shared morphological characteristics with newly identified putative glial cells in the soma clusters and perivascular cells in the walls of arterioles. These results on P. argus suggest that adult neurogenesis is based on one adult neuroblast per soma cluster, adult neurogenesis appears to be a continuation of embryonic and larval neurogenesis, and the newly identified clumps of cells surrounding the putative adult neuroblasts might provide them with specific microenvironments necessary for their unusual lifelong proliferative and self-renewal capacity.
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Affiliation(s)
- Manfred Schmidt
- Department of Biology, Georgia State University, Atlanta, GA 30303, USA.
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Sullivan JM, Sandeman DC, Benton JL, Beltz BS. Adult neurogenesis and cell cycle regulation in the crustacean olfactory pathway: from glial precursors to differentiated neurons. J Mol Histol 2007; 38:527-42. [PMID: 17624620 PMCID: PMC2725433 DOI: 10.1007/s10735-007-9112-7] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2007] [Accepted: 06/01/2007] [Indexed: 12/11/2022]
Abstract
Adult neurogenesis is a characteristic feature of the olfactory pathways of decapod crustaceans. In crayfish and clawed lobsters, adult-born neurons are the progeny of precursor cells with glial characteristics located in a neurogenic niche on the ventral surface of the brain. The daughters of these precursor cells migrate during S and G(2 )stages of the cell cycle along glial fibers to lateral (cluster 10) and medial (cluster 9) proliferation zones. Here, they divide (M phase) producing offspring that differentiate into olfactory interneurons. The complete lineage of cells producing neurons in these animals, therefore, is arranged along the migratory stream according to cell cycle stage. We have exploited this model to examine the influence of environmental and endogenous factors on adult neurogenesis. We find that increased levels of serotonin upregulate neuronal production, as does maintaining animals in an enriched (versus deprived) environment or augmenting their diet with omega-3 fatty acids; increased levels of nitric oxide, on the other hand, decrease the rate of neurogenesis. The features of the neurogenic niche and migratory streams, and the fact that these continue to function in vitro, provide opportunities unavailable in other organisms to explore the sequence of cellular and molecular events leading to the production of new neurons in adult brains.
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Schmidt M. The olfactory pathway of decapod crustaceans--an invertebrate model for life-long neurogenesis. Chem Senses 2007; 32:365-84. [PMID: 17404151 DOI: 10.1093/chemse/bjm008] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The first part of this review includes a short description of the cellular and morphological organization of the olfactory pathway of decapod crustaceans, followed by an overview of adult neurogenesis in this pathway focusing on the olfactory lobe (OL), the first synaptic relay in the brain. Adult neurogenesis in the central olfactory pathway has the following characteristics. 1) It is present in all the diverse species of decapod crustaceans so far studied. 2) In all these species, projection neurons (PNs), which have multiglomerular dendritic arborizations, are generated. 3) Neurons are generated by one round of symmetrical cell divisions of a small population of immediate precursor cells that are located in small proliferation zones at the inner margin of the respective soma clusters. 4) The immediate precursor cells in each soma cluster appear to be generated by repeated cell divisions of one or few neuronal stem cells that are located outside of the proliferation zone. 5) These neuronal stem cells are enclosed in a highly structured clump of small glial-like cells, which likely establishes a specific microenvironment and thus can be regarded as a stem cell niche. 6) Diverse internal and external factors, such as presence of olfactory afferents, age, season of the year, and living under constant and deprived conditions modulate the generation and/or survival of new neurons. In the second part of this review, I address the question why in decapod crustaceans adult neurogenesis persists in the visual and olfactory pathways of the brain but is lacking in all other mechanosensory-chemosensory pathways. Due to the indeterminate growth of most adult decapod crustaceans, new sensory neurons of all modalities (olfaction and chemo-, mechano-, and photoreception) are continuously added during adulthood and provide an ever-increasing sensory input to all primary sensory neuropils of the central nervous system. From these facts, I conclude that adult neurogenesis in the brain cannot simply be a mechanism to accommodate increasing sensory input and propose instead that it is causally linked to the specific "topographic logic" of information processing implemented in the sensory neuropils serving different modalities. For the presumptive odotopic type of information processing in the OL, new multiglomerular PNs allow interconnection of novel combinations of spatially unrelated input channels (glomeruli), whose simultaneous activation by specific odorants is the basis of odor coding. Thus, adult neurogenesis could provide a unique way to increase the resolution of odorant quality coding and allow adaptation of the olfactory system of these long-lived animals to ever-changing odor environments.
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Affiliation(s)
- Manfred Schmidt
- Department of Biology, Georgia State University, PO Box 4010, Atlanta, GA 30303, USA.
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