1
|
Boggs TE, Gross JB. Gill morphology adapted to oxygen-limited caves in Astyanax mexicanus. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2024. [PMID: 39031584 DOI: 10.1002/jez.2840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Revised: 05/20/2024] [Accepted: 05/23/2024] [Indexed: 07/22/2024]
Abstract
Sensing and acquiring dissolved oxygen is crucial for nearly all aquatic life. This may become even more vital as dissolved oxygen concentrations continue to decline in many aquatic environments. While certain phenotypes that enable fish to live in low oxygen have been characterized, adaptations that arise following sudden, drastic reductions in dissolved oxygen are relatively unknown. Here, we assessed the blind Mexican cavefish, Astyanax mexicanus, for alterations to gill morphology that may be adaptive for life in hypoxic caves. The Astyanax system provides the unique opportunity to compare gill morphology between stereotypical "surface" adapted morphotypes and obligate cave-dwelling conspecifics. While the surface environment is well-oxygenated, cavefish must cope with significantly reduced oxygen. We began by quantifying traditional morphological gill traits including filament number and length as well as lamellar density and height in surface fish and two distinct cave populations, Pachón and Tinaja. This enabled us to estimate total lamellar height, a proxy for gill surface area. We then used immunohistochemical staining to label 5-HT-positive neuroepithelial cells (NECs), which serve as key oxygen sensors in fish. We discovered an increase in gill surface area for both cavefish populations compared to surface, which may enable a higher capacity of oxygen acquisition. Additionally, we found more NECs in Pachón cavefish compared to both surface fish and Tinaja cavefish, suggesting certain selective pressures may be cave-specific. Collectively, this work provides evidence that cavefish have adapted to low oxygen conditions via alterations to gill morphology and oxygen sensing, and informs evolutionary mechanisms of rapid adaptation to dramatic, chronic hypoxia.
Collapse
Affiliation(s)
- Tyler E Boggs
- Department of Biological Sciences, University of Cincinnati, Cincinnati, Ohio, USA
| | - Joshua B Gross
- Department of Biological Sciences, University of Cincinnati, Cincinnati, Ohio, USA
| |
Collapse
|
2
|
Leonard EM, Porteus CS, Brink D, Milsom WK. Fish gill chemosensing: knowledge gaps and inconsistencies. J Comp Physiol B 2024:10.1007/s00360-024-01553-5. [PMID: 38758303 DOI: 10.1007/s00360-024-01553-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 04/04/2024] [Indexed: 05/18/2024]
Abstract
In this review, we explore the inconsistencies in the data and gaps in our knowledge that exist in what is currently known regarding gill chemosensors which drive the cardiorespiratory reflexes in fish. Although putative serotonergic neuroepithelial cells (NEC) dominate the literature, it is clear that other neurotransmitters are involved (adrenaline, noradrenaline, acetylcholine, purines, and dopamine). And although we assume that these agents act on neurons synapsing with the NECs or in the afferent or efferent limbs of the paths between chemosensors and central integration sites, this process remains elusive and may explain current discrepancies or species differences in the literature. To date it has been impossible to link the distribution of NECs to species sensitivity to different stimuli or fish lifestyles and while the gills have been shown to be the primary sensing site for respiratory gases, the location (gills, oro-branchial cavity or elsewhere) and orientation (external/water or internal/blood sensing) of the NECs are highly variable between species of water and air breathing fish. Much of what has been described so far comes from studies of hypoxic responses in fish, however, changes in CO2, ammonia and lactate have all been shown to elicit cardio-respiratory responses and all have been suggested to arise from stimulation of gill NECs. Our view of the role of NECs is broadening as we begin to understand the polymodal nature of these cells. We begin by presenting the fundamental picture of gill chemosensing that has developed, followed by some key unanswered questions about gill chemosensing in general.
Collapse
Affiliation(s)
- Erin M Leonard
- Department of Biology, Wilfrid Laurier University, Waterloo, ON, Canada
| | - Cosima S Porteus
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, Canada.
| | - Deidre Brink
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - William K Milsom
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| |
Collapse
|
3
|
Reed M, Pan W, Musa L, Arlotta S, Mennigen JA, Jonz MG. A role for dopamine in control of the hypoxic ventilatory response via D 2 receptors in the zebrafish gill. J Comp Neurol 2024; 532:e25548. [PMID: 37837632 DOI: 10.1002/cne.25548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 09/21/2023] [Accepted: 10/03/2023] [Indexed: 10/16/2023]
Abstract
Dopamine is a neurotransmitter involved in oxygen sensing and control of reflex hyperventilation. In aquatic vertebrates, oxygen sensing occurs in the gills via chemoreceptive neuroepithelial cells (NECs), but a mechanism for dopamine in autonomic control of ventilation has not been defined. We used immunohistochemistry and confocal microscopy to map the distribution of tyrosine hydroxylase (TH), an enzyme necessary for dopamine synthesis, in the gills of zebrafish. TH was found in nerve fibers of the gill filaments and respiratory lamellae. We further identified dopamine active transporter (dat) and vesicular monoamine transporter (vmat2) expression in neurons of the gill filaments using transgenic lines. Moreover, TH- and dat-positive nerve fibers innervated NECs. In chemical screening assays, domperidone, a D2 receptor antagonist, increased ventilation frequency in zebrafish larvae in a dose-dependent manner. When larvae were confronted with acute hypoxia, the D2 agonist, quinpirole, abolished the hyperventilatory response. Quantitative polymerase chain reaction confirmed expression of drd2a and drd2b (genes encoding D2 receptors) in the gills, and their relative abundance decreased following acclimation to hypoxia for 48 h. We localized D2 receptor immunoreactivity to NECs in the efferent gill filament epithelium, and a novel cell type in the afferent filament epithelium. We provide evidence for the synthesis and storage of dopamine by sensory nerve terminals that innervate NECs. We further suggest that D2 receptors on presynaptic NECs provide a feedback mechanism that attenuates the chemoreceptor response to hypoxia. Our studies suggest that a fundamental, modulatory role for dopamine in oxygen sensing arose early in vertebrate evolution.
Collapse
Affiliation(s)
- Maddison Reed
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Wen Pan
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Lina Musa
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Stefania Arlotta
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Jan A Mennigen
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Michael G Jonz
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
- Brain and Mind Research Institute, University of Ottawa, Ottawa, Ontario, Canada
| |
Collapse
|
4
|
Ekman DR, Evich MG, Mosley JD, Doering JA, Fay KA, Ankley GT, Collette TW. Expanding non-invasive approaches for fish-health monitoring: A survey of the epidermal mucous metabolomes of phylogenetically diverse freshwater fish species. JOURNAL OF FISH BIOLOGY 2023; 103:1178-1189. [PMID: 37492948 PMCID: PMC10735230 DOI: 10.1111/jfb.15512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 07/10/2023] [Accepted: 07/24/2023] [Indexed: 07/27/2023]
Abstract
There is a pressing need for more-holistic approaches to fisheries assessments along with growing demand to reduce the health impacts of sample collections. Metabolomic tools enable the use of sample matrices that can be collected with minimal impact on the organism (e.g., blood, urine, and mucus) and provide high-throughput, untargeted biochemical information without the requirement of a sequenced genome. These qualities make metabolomics ideal for monitoring a wide range of fish species, particularly those under protected status. In the current study, we surveyed the relative abundances of 120 endogenous metabolites in epidermal mucus across eight freshwater fish species belonging to seven phylogenetic orders. Principal component analysis was used to provide an overview of the data set, revealing strong interspecies relationships in the epidermal mucous metabolome. Normalized relative abundances of individual endogenous metabolites were then used to identify commonalities across multiple species, as well as those metabolites that showed notable species specificity. For example, taurine was measured in high relative abundance in the epidermal mucus of common carp (Cyprinus carpio), northern pike (Esox lucius), golden shiner (Notemigonus crysoleucas), rainbow trout (Oncorhynchus mykiss), and rainbow smelt (Osmerus mordax), whereas γ-amino butyric acid (GABA) exhibited a uniquely high relative abundance in flathead catfish (Pylodictis olivaris). Finally, hierarchical cluster analysis was used to evaluate species relatedness as characterized by both the epidermal mucous metabolome (phenotype) and genetic phylogeny (genotype). This comparison revealed species for which relatedness in the epidermal mucous metabolome composition closely aligns with phylogenetic relatedness (e.g., N. crysoleucas and C. carpio), as well as species for which these two measures are not well aligned (e.g., P. olivaris and Polyodon spathula). These, and other findings reported here, highlight novel areas for future research with fish, including development of epidermal mucous-based markers for non-invasive health monitoring, sex determination, and hypoxia tolerance.
Collapse
Affiliation(s)
- Drew R Ekman
- U.S. Environmental Protection Agency, Center for Environmental Measurement and Modeling, Athens, Georgia, USA
| | - Marina G Evich
- U.S. Environmental Protection Agency, Center for Environmental Measurement and Modeling, Athens, Georgia, USA
| | - Jonathan D Mosley
- U.S. Environmental Protection Agency, Center for Environmental Measurement and Modeling, Athens, Georgia, USA
| | - Jon A Doering
- Louisiana State University, Department of Environmental Sciences, Baton Rouge, Louisiana, USA
- U.S. Environmental Protection Agency, National Research Council, Duluth, Minnesota, USA
| | - Kellie A Fay
- U.S. Environmental Protection Agency, Office of Chemical Safety and Pollution Prevention, Washington, DC, USA
| | - Gerald T Ankley
- U.S. Environmental Protection Agency, Center for Computational Toxicology and Exposure, Duluth, Minnesota, USA
| | - Timothy W Collette
- U.S. Environmental Protection Agency, Center for Environmental Measurement and Modeling, Athens, Georgia, USA
| |
Collapse
|
5
|
Lauriano ER, Capillo G, Icardo JM, Fernandes JMO, Kiron V, Kuciel M, Zuwala K, Guerrera MC, Aragona M, Germana' A, Zaccone G. Neuroepithelial cells (NECs) and mucous cells express a variety of neurotransmitters and neurotransmitter receptors in the gill and respiratory air-sac of the catfish Heteropneustes fossilis (Siluriformes, Heteropneustidae): a possible role in local immune defence. ZOOLOGY 2021; 148:125958. [PMID: 34399394 DOI: 10.1016/j.zool.2021.125958] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 07/20/2021] [Accepted: 07/22/2021] [Indexed: 11/19/2022]
Abstract
Heteropneustes fossilis is an air-breathing teleost inhabiting environments with very poor O2 conditions, and so it has evolved to cope with hypoxia. In the gills and respiratory air-sac, the sites for O2 sensing and the response to hypoxia rely on the expression of acetylcholine (Ach) acting via its nicotinic receptor (nAChR). This study examined the expression patterns of neuronal markers and some compounds in the NECs of the gills and respiratory air sac having an immunomodulatory function in mammalian lungs. Mucous cells, epithelial cells and neuroepithelial cells (NECs) were immunopositive to a variety of both neuronal markers (VAChT, nAChR, GABA-B-R1 receptor, GAD679) and the antimicrobial peptide piscidin, an evolutionary conserved humoral component of the mucosal immune system in fish. We speculate that Ach release via nAChR from mucous cells may be modulated by GABA production in the NECs and it is required for the induction of mucus production in both normoxic and hypoxic conditions. The presence of piscidin in mucous cells may act in synergy with the autocrine/paracrine signals of Ach and GABA binding to GABA B R1B receptor that may play a local immunomodulatory function in the mucous epithelia of the gills and the respiratory air sac. The potential role of the NECs in the immunobiological behaviour of the gill/air-sac is at moment a matter of speculation. The extent to which the NECs as such may participate is elusive at this stage and waits investigation.
Collapse
Affiliation(s)
- Eugenia Rita Lauriano
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale F. Stagno d'Alcontres 31, 98166, Messina, Italy
| | - Gioele Capillo
- Department of Veterinary Sciences, University of Messina, Polo Universitario dell'Annunziata, 98168, Messina, Italy; Institute of Marine Biological Resources and Biotechnology - National Research Council (IRBIM, CNR), Spianata S. Raineri, 86, 98122, Messina, Italy.
| | - Jose Manuel Icardo
- Department of Anatomy and Cell Biology, Poligono de Cazona, Faculty of Medicine, University of Cantabria, Santander, 39011, Spain
| | | | - Viswanath Kiron
- Faculty of Biosciences and Aquaculture, Nord University, 8049, Bodo, Norway
| | - Michal Kuciel
- Poison Information Centre, Department of Toxicology and Environmental Disease, Faculty of Medicine, Jagellonian University, Kopernika 15, 30501, Cracow, Poland
| | - Krystyna Zuwala
- Department of Comparative Anatomy, Faculty of Biology, Institute of Zoology and Biomedical Research, Jagiellonian University, Cracow, 30387, Poland
| | - Maria Cristina Guerrera
- Department of Veterinary Sciences, University of Messina, Polo Universitario dell'Annunziata, 98168, Messina, Italy
| | - Marialuisa Aragona
- Department of Veterinary Sciences, University of Messina, Polo Universitario dell'Annunziata, 98168, Messina, Italy
| | - Antonino Germana'
- Department of Veterinary Sciences, University of Messina, Polo Universitario dell'Annunziata, 98168, Messina, Italy
| | - Giacomo Zaccone
- Department of Veterinary Sciences, University of Messina, Polo Universitario dell'Annunziata, 98168, Messina, Italy
| |
Collapse
|
6
|
Capillo G, Zaccone G, Cupello C, Fernandes JMO, Viswanath K, Kuciel M, Zuwala K, Guerrera MC, Aragona M, Icardo JM, Lauriano ER. Expression of acetylcholine, its contribution to regulation of immune function and O 2 sensing and phylogenetic interpretations of the African butterfly fish Pantodon buchholzi (Osteoglossiformes, Pantodontidae). FISH & SHELLFISH IMMUNOLOGY 2021; 111:189-200. [PMID: 33588082 DOI: 10.1016/j.fsi.2021.02.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 02/02/2021] [Accepted: 02/08/2021] [Indexed: 06/12/2023]
Abstract
Acetylcholine (Ach) is the main neurotransmitter in the neuronal cholinergic system and also works as a signaling molecule in non-neuronal cells and tissues. The diversity of signaling pathways mediated by Ach provides a basis for understanding the biology of the cholinergic epithelial cells and immune cells in the gill of the species studied. NECs in the gill were not found surprisingly, but specialized cells showing the morphological, histochemical and ultrastructural characteristics of eosinophils were located in the gill filaments and respiratory lamellae. Much remains unknown about the interaction between the nerves and eosinophils that modulate both the release of acetylcholine and its nicotinic and muscarinic receptors including the role of acetylcholine in the mechanisms of O2 chemosensing. In this study we report for the first time the expression of Ach in the pavement cells of the gill lamellae in fish, the mast cells associated with eosinophils and nerve interaction for both immune cell types, in the gill of the extant butterfly fish Pantodon buchholzi. Multiple roles have been hypothesized for Ach and alpha nAChR in the gills. Among these there are the possible involvement of the pavement cells of the gill lamellae as O2 chemosensitive cells, the interaction of Ach positive mast cells with eosinophils and interaction of eosinophils with nerve terminals. This could be related to the use of the vesicular acetylcholine transporter (VAChT) and the alpha 2 subunit of the acetylcholine nicotinic receptor (alpha 2 nAChR). These data demonstrate the presence of Ach multiple sites of neuronal and non-neuronal release and reception within the gill and its ancestral signaling that arose during the evolutionary history of this conservative fish species.
Collapse
Affiliation(s)
- Gioele Capillo
- Department of Veterinary Sciences, University of Messina, Polo Universitario Dell'Annunziata, I-98168, Messina, Italy
| | - Giacomo Zaccone
- Department of Veterinary Sciences, University of Messina, Polo Universitario Dell'Annunziata, I-98168, Messina, Italy.
| | - Camila Cupello
- Departamento de Zoologia, Instituto de Biologia-IBRAG, Universidade de Estado Do Rio de Janeiro, Rua Sao Francisco Xavier, 524, 20550-900, Rio de Janeiro, Brazil
| | | | - Kiron Viswanath
- Faculty of Biosciences and Aquaculture, Nord University, 8026, Bodø, Norway
| | - Michal Kuciel
- Poison Information Centre, Department of Toxicology and Environmental Disease, Faculty of Medicine, Jagiellonian University, Kopernika 15, 30-501, Cracow, Poland
| | - Krystyna Zuwala
- Department of Comparative Anatomy, Faculty of Biology, Institute of Zoology and Biomedical Research, Jagellonian University, Cracow, Poland
| | - Maria Cristina Guerrera
- Department of Veterinary Sciences, University of Messina, Polo Universitario Dell'Annunziata, I-98168, Messina, Italy
| | - Marialuisa Aragona
- Department of Veterinary Sciences, University of Messina, Polo Universitario Dell'Annunziata, I-98168, Messina, Italy
| | - Jose Manuel Icardo
- Department of Anatomy and Cell Biology, Poligono de Cazona, Faculty of Medicine, University of Cantabria, Santander, Spain
| | - Eugenia Rita Lauriano
- Department of Chemical, Biological, Pharmaceutical, and Environmental Sciences, University of Messina, Messina, Italy
| |
Collapse
|
7
|
Disruption of tph1 genes demonstrates the importance of serotonin in regulating ventilation in larval zebrafish (Danio rerio). Respir Physiol Neurobiol 2020; 285:103594. [PMID: 33271304 DOI: 10.1016/j.resp.2020.103594] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/13/2020] [Accepted: 11/23/2020] [Indexed: 01/22/2023]
Abstract
Serotonergic neuroepithelial cells (NECs) in larval zebrafish are believed to be O2 chemoreceptors. Serotonin (5-HT) within these NECs has been implicated as a neurotransmitter mediating the hypoxic ventilatory response (HVR). Here, we use knockout approaches to discern the role of 5-HT in regulating the HVR by targeting the rate limiting enzyme for 5-HT synthesis, tryptophan hydroxylase (Tph). Using transgenic lines, we determined that Tph1a is expressed in skin and pharyngeal arch NECs, as well as in pharyngeal arch Merkel-like cells (MLCs), whereas Tph1b is expressed predominately in MLCs. Knocking out the two tph1 paralogs resulted in similar changes in detectable serotonergic cell density between the two mutants, yet their responses to hypoxia (35 mmHg) were different. Larvae lacking Tph1a (tph1a-/- mutants) displayed a higher ventilation rate when exposed to hypoxia compared to wild-types, whereas tph1b-/- mutants exhibited a lower ventilation rate suggesting that 5-HT located in locations other than NECs, may play a dominant role in regulating the HVR.
Collapse
|
8
|
Zaccone G, Cupello C, Capillo G, Kuciel M, Nascimento ALR, Gopesh A, Germanà GP, Spanò N, Guerrera MC, Aragona M, Crupi R, Icardo JM, Lauriano ER. Expression of Acetylcholine- and G protein coupled Muscarinic receptor in the Neuroepithelial cells (NECs) of the obligated air-breathing fish, Arapaima gigas (Arapaimatidae: Teleostei). ZOOLOGY 2020; 139:125755. [PMID: 32088527 DOI: 10.1016/j.zool.2020.125755] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 01/28/2020] [Accepted: 01/30/2020] [Indexed: 01/18/2023]
Abstract
The air-breathing specialization has evolved idependently in vertebrates, as many different organs can perfom gas exchange. The largest obligate air-breathing fish from South America Arapaima gigas breathe air using its gas bladder, and its dependence on air breathing increases during its growth. During its development, gill morphology shows a dramatic change, remodeling with a gradual reduction of gill lamellae during the transition from water breathing to air breathing . It has been suggested that in this species the gills remain the main site of O2 and CO2 sensing. Consistent with this, we demonstrate for the first time the occurrence of the neuroepithelial cells (NECs) in the glottis, and in the gill filament epithelia and their distal halves. These cells contain a broader spectrum of neurotransmitters (5-HT, acetylcholine, nNOS), G-protein subunits and the muscarininic receptors that are coupled to G proteins (G-protein coupled receptors). We report also for the first time the presence of G alpha proteins coupled with muscarinic receptors on the NECs, that are thought as receptors that initiate the cardiorespiratory reflexes in aquatic vertebrates. Based on the specific orientation in the epithelia and their closest vicinity to efferent vasculatures, the gill and glottal NECs of A. gigas could be regarded as potential O2 and CO2 sensing receptors. However, future studies are needed to ascertain the neurophysiological characterization of these cells.
Collapse
Affiliation(s)
- Giacomo Zaccone
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Polo Universitario dell'Annunziata, I-98168 Messina, Italy
| | - Camila Cupello
- Departamento de Zoologia, Instituto de Biologia, Universidade do Estado do Rio de Janeiro, Rua São Francisco Xavier, 524, 20550-900, Rio de Janeiro, Brazil
| | - Gioele Capillo
- Department of Veterinary Sciences, University of Messina, Viale dell'Annunziata, I-98168 Messina, Italy.
| | - Michal Kuciel
- Poison Information Centre, Department of Toxicology and Environmental Disease, Faculty of Medicine, Jagellonian University, Kpernika 15, 30-501 Krakòw, Poland
| | - Ana L R Nascimento
- Departamento de Histologia e Embriologia, Instituto de Biologia, Universidade do Estado do Rio de Janeiro, Avenida 28 de Setembro, 87, 20551-030, Rio de Janeiro, Brazil
| | - Anita Gopesh
- Department of Zoology, University of Allahabad, Allahabad 211002, U.P., India
| | - Germana Patrizia Germanà
- Department of Veterinary Sciences, University of Messina, Viale dell'Annunziata, I-98168 Messina, Italy
| | - Nunziacarla Spanò
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Polo Universitario dell'Annunziata, I-98168 Messina, Italy
| | - Maria Cristina Guerrera
- Department of Veterinary Sciences, University of Messina, Viale dell'Annunziata, I-98168 Messina, Italy
| | - Marialuisa Aragona
- Department of Veterinary Sciences, University of Messina, Viale dell'Annunziata, I-98168 Messina, Italy
| | - Rosalia Crupi
- Department of Veterinary Sciences, University of Messina, Viale dell'Annunziata, I-98168 Messina, Italy
| | - Jose Manuel Icardo
- Department of Anatomy and Cell Biology, Poligono de Cazona, Faculty of Medicine, University of Cantabria, Santander, Spain
| | - Eugenia Rita Lauriano
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale F. Stagno d'Alcontres 31, I-98166 Messina, Italy
| |
Collapse
|
9
|
Abstract
Respiratory chemoreceptors in vertebrates are specialized cells that detect chemical changes in the environment or arterial blood supply and initiate autonomic responses, such as hyperventilation or changes in heart rate, to improve O2 uptake and delivery to tissues. These chemoreceptors are sensitive to changes in O2, CO2 and/or H+. In fish and mammals, respiratory chemoreceptors may be additionally sensitive to ammonia, hypoglycemia, and numerous other stimuli. Thus, chemoreceptors that affect respiration respond to different types of stimuli (or modalities) and are considered to be "polymodal". This review discusses the polymodal nature of respiratory chemoreceptors in vertebrates with a particular emphasis on chemoreceptors of the carotid body and pulmonary epithelium in mammals, and on neuroepithelial cells in water- and air-breathing fish. A major goal will be to examine the evidence for putative polymodal chemoreceptors in fish within the context of studies on mammalian models, for which polymodal chemoreceptors are well described, in order to improve our understanding of the evolution of polymodal chemoreceptors in vertebrates, and to aid in future studies that aim to identify putative receptors in air- and water-breathing fish.
Collapse
|
10
|
Zaccone G, Lauriano ER, Capillo G, Kuciel M. Air- breathing in fish: Air- breathing organs and control of respiration: Nerves and neurotransmitters in the air-breathing organs and the skin. Acta Histochem 2018; 120:630-641. [PMID: 30266194 DOI: 10.1016/j.acthis.2018.08.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In fishes, exploitation of aerial gas exchange has evolved independently many times, involving a variety of air-breathing organs. Indeed, air-breathing occurs in at least 49 known families of fish (Graham, 1997). Many amphibious vertebrates, at some stage of their development are actually trimodal breathers that use various combinations of respiratory surfaces to breath both water (skin and/or gill) and air (skin and/or lung). The present review examines the evolutionary implications of air-breathing organs in fishes and the morphology of the peripheral receptors and the neurotransmitter content of the cells involved in the control of air-breathing. Control of breathing, whether gill ventilation or air-breathing, is influenced by feedback from peripheral and/or central nervous system receptors that respond to changes in PO2, PCO2 and/or pH. Although the specific chemoreceptors mediating the respiratory reflexes have not been conclusively identified, studies in water-breathing teleosts have implicated the neuroepithelial cells (NECs) existing in gill tissues as the O2 sensitive chemoreceptors that initiate the cardiorespiratory reflexes in aquatic vertebrates. Some of the air-breathing fishes, such as Protopterus, Polypterus and Amia have been shown to have NECs in the gills and/or lungs, although the role of these receptors and their innervation in the control of breathing is not known. NECs have been also reported in the specialized respiratory epithelia of accessory respiratory organs (ARO's) of some catfish species and in the gill and skin of the mudskipper Periophthalmodon schlosseri. Unlike teleosts matching an O2-oriented ventilation to ambient O2 levels, lungfishes have central and peripheral H+/CO2 receptors that control the acid-base status of the blood.
Collapse
Affiliation(s)
- Giacomo Zaccone
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, 98168, Messina, Italy.
| | - Eugenia Rita Lauriano
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale F. Stagno d'Alcontres 31, 98166, Messina, Italy.
| | - Gioele Capillo
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale F. Stagno d'Alcontres 31, 98166, Messina, Italy
| | - Michał Kuciel
- Poison Information Centre, Department of Toxicology and Environmental Disease, Faculty of Medicine, Jagiellonian University, Kopernika 15, 30-501 Kraków, Poland.
| |
Collapse
|
11
|
Zaccone G, Lauriano ER, Kuciel M, Capillo G, Pergolizzi S, Alesci A, Ishimatsu A, Ip YK, Icardo JM. Identification and distribution of neuronal nitric oxide synthase and neurochemical markers in the neuroepithelial cells of the gill and the skin in the giant mudskipper, Periophthalmodon schlosseri. ZOOLOGY 2017; 125:41-52. [PMID: 28830730 DOI: 10.1016/j.zool.2017.08.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 08/02/2017] [Accepted: 08/02/2017] [Indexed: 12/12/2022]
Abstract
Mudskippers are amphibious fishes living in mudflats and mangroves. These fishes hold air in their large buccopharyngeal-opercular cavities where respiratory gas exchange takes place via the gills and higher vascularized epithelium lining the cavities and also the skin epidermis. Although aerial ventilation response to changes in ambient gas concentration has been studied in mudskippers, the localization and distribution of respiratory chemoreceptors, their neurochemical coding and function as well as physiological evidence for the gill or skin as site for O2 and CO2 sensing are currently not known. In the present study we assessed the distribution of serotonin, acetylcholine, catecholamines and nitric oxide in the neuroepithelial cells (NECs) of the mudskipper gill and skin epithelium using immunohistochemistry and confocal microscopy. Colocalization studies showed that 5-HT is coexpressed with nNOS, Na+/K+-ATPase, TH and VAChT; nNOS is coexpressed with Na+/K+-ATPase and TH in the skin. In the gill 5-HT is coexpressed with nNOS and VAhHT and nNOS is coexpressed with Na+/K+-ATPase and TH. Acetylcholine is also expressed in chain and proximal neurons projecting to the efferent filament artery and branchial smooth muscle. The serotonergic cells c labeled with VAChT, nNOS and TH, thus indicating the presence of NEC populations and the possibility that these neurotransmitters (other than serotonin) may act as primary transmitters in the hypoxic reflex in fish gills. Immunolabeling with TH antibodies revealed that NECs in the gill and the skin are innervated by catecholaminergic nerves, thus suggesting that these cells are involved in a central control of branchial functions through their relationships with the sympathetic branchial nervous system. The Na+/K+-ATPase in mitochondria-rich cells (MRCs), which are most concentrated in the gill lamellar epithelium, is colabeled with nNOS and associated with TH nerve terminals. TH-immunopositive fine varicosities were also associated with the numerous capillaries in the skin surface and the layers of the swollen cells. Based on the often hypercapnic and hypoxic habitat of the mudskippers, these fishes may represent an attractive model for pursuing studies on O2 and CO2 sensing due to the air-breathing that increases the importance of acid/base regulation and the O2-related drive including the function of gasotransmitters such as nitric oxide that has an inhibitory (regulatory) function in ionoregulation.
Collapse
Affiliation(s)
- Giacomo Zaccone
- Department of Biomedical and Dental Sciences and Department of Morphofunctional Imaging, University of Messina, Polo Universitario dell'Annunziata, 98168 Messina, Italy.
| | - Eugenia Rita Lauriano
- Department of Environmental Sciences, Territorial, Food and Health Security (S.A.S.T.A.S.), University of Messina, Viale Stagno d'Alcontres 31, 98166 Messina, Italy
| | - Michał Kuciel
- Poison Information Centre, Department of Toxicology and Environmental Disease, Jagiellonian University Medical Collage, Kopernika 15, 31-501 Krakow, Poland.
| | - Gioele Capillo
- Department of Environmental Sciences, Territorial, Food and Health Security (S.A.S.T.A.S.), University of Messina, Viale Stagno d'Alcontres 31, 98166 Messina, Italy
| | - Simona Pergolizzi
- Department of Environmental Sciences, Territorial, Food and Health Security (S.A.S.T.A.S.), University of Messina, Viale Stagno d'Alcontres 31, 98166 Messina, Italy
| | - Alessio Alesci
- Department of Environmental Sciences, Territorial, Food and Health Security (S.A.S.T.A.S.), University of Messina, Viale Stagno d'Alcontres 31, 98166 Messina, Italy
| | - Atsushi Ishimatsu
- Institute for East China Sea Research, Nagasaki University, 1551-7 Tairamachi, Nagasaki 851-2213, Japan
| | - Yuen Kwong Ip
- Department of Biological Science, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore
| | - Jose M Icardo
- Department of Anatomy and Cell Biology, Polígono de Cazoña, University of Cantabria, 39011 Santander, Spain
| |
Collapse
|
12
|
Hockman D, Burns AJ, Schlosser G, Gates KP, Jevans B, Mongera A, Fisher S, Unlu G, Knapik EW, Kaufman CK, Mosimann C, Zon LI, Lancman JJ, Dong PDS, Lickert H, Tucker AS, Baker CVH. Evolution of the hypoxia-sensitive cells involved in amniote respiratory reflexes. eLife 2017; 6:e21231. [PMID: 28387645 PMCID: PMC5438250 DOI: 10.7554/elife.21231] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Accepted: 04/07/2017] [Indexed: 01/01/2023] Open
Abstract
The evolutionary origins of the hypoxia-sensitive cells that trigger amniote respiratory reflexes - carotid body glomus cells, and 'pulmonary neuroendocrine cells' (PNECs) - are obscure. Homology has been proposed between glomus cells, which are neural crest-derived, and the hypoxia-sensitive 'neuroepithelial cells' (NECs) of fish gills, whose embryonic origin is unknown. NECs have also been likened to PNECs, which differentiate in situ within lung airway epithelia. Using genetic lineage-tracing and neural crest-deficient mutants in zebrafish, and physical fate-mapping in frog and lamprey, we find that NECs are not neural crest-derived, but endoderm-derived, like PNECs, whose endodermal origin we confirm. We discover neural crest-derived catecholaminergic cells associated with zebrafish pharyngeal arch blood vessels, and propose a new model for amniote hypoxia-sensitive cell evolution: endoderm-derived NECs were retained as PNECs, while the carotid body evolved via the aggregation of neural crest-derived catecholaminergic (chromaffin) cells already associated with blood vessels in anamniote pharyngeal arches.
Collapse
Affiliation(s)
- Dorit Hockman
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
- Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town, South Africa
| | - Alan J Burns
- Stem Cells and Regenerative Medicine, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
- Department of Clinical Genetics, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Gerhard Schlosser
- School of Natural Sciences, National University of Ireland, Galway, Ireland
| | - Keith P Gates
- Human Genetics Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, United States
| | - Benjamin Jevans
- Stem Cells and Regenerative Medicine, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
| | - Alessandro Mongera
- Department of Genetics, Max-Planck Institut für Entwicklungsbiologie, Tübingen, Germany
| | - Shannon Fisher
- Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, United States
| | - Gokhan Unlu
- Division of Genetic Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, United States
| | - Ela W Knapik
- Division of Genetic Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, United States
| | - Charles K Kaufman
- Children’s Hospital Boston, Howard Hughes Medical Institute, Harvard Medical School, Boston, United States
| | - Christian Mosimann
- Children’s Hospital Boston, Howard Hughes Medical Institute, Harvard Medical School, Boston, United States
| | - Leonard I Zon
- Children’s Hospital Boston, Howard Hughes Medical Institute, Harvard Medical School, Boston, United States
| | - Joseph J Lancman
- Human Genetics Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, United States
| | - P Duc S Dong
- Human Genetics Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, United States
| | - Heiko Lickert
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, Neuherberg, Germany
| | - Abigail S Tucker
- Department of Craniofacial Development and Stem Cell Biology, King’s College London, London, United Kingdom
| | - Clare V H Baker
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| |
Collapse
|
13
|
Zachar PC, Pan W, Jonz MG. Distribution and morphology of cholinergic cells in the branchial epithelium of zebrafish (Danio rerio). Cell Tissue Res 2016; 367:169-179. [DOI: 10.1007/s00441-016-2531-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 10/25/2016] [Indexed: 10/20/2022]
|
14
|
Zhang DL, Liu SY, Zhang J, Zhang JK, Hu CX, Liu YD. Respiratory toxicity of cyanobacterial aphantoxins from Aphanizomenon flos-aquae DC-1 in the zebrafish gill. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2016; 176:106-115. [PMID: 27130970 DOI: 10.1016/j.aquatox.2016.04.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Revised: 04/12/2016] [Accepted: 04/13/2016] [Indexed: 06/05/2023]
Abstract
Aphantoxins from Aphanizomenon flos-aquae are frequently identified in eutrophic waterbodies worldwide. These toxins severely endanger environmental safety and human health due to the production of paralytic shellfish poisons (PSPs). Although the molecular mechanisms of aphantoxin neurotoxicity have been studied, many questions remain to be resolved such as in vivo alterations in branchial histology and neurotransmitter inactivation induced by these neurotoxins. Aphantoxins extracted from a naturally isolated strain of A. flos-aquae DC-1 were determined by high performance liquid chromatography. The basic components of the isolated aphantoxins identified were gonyautoxin 1 (GTX1), gonyautoxin 5 (GTX5), and neosaxitoxin (neoSTX), which comprised 34.04, 21.28, and 12.77% of the total, respectively. Zebrafish (Danio rerio) was administrated 5.3 or 7.61mg STX equivalents (eq)/kg (low and high doses, respectively) of the A. flos-aquae DC-1 aphantoxins by intraperitoneal injection. Histological alterations and changes in neurotransmitter inactivation in the gills of zebrafish were investigated for 24h following exposure. Aphantoxin exposure significantly increased the activities of gill alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and resulted in histological alterations in the gills during the first 12h of exposure, indicating the induction of functional and structural damage. Gill acetylcholinesterase (AChE) and monoamine oxidase (MAO) activities were inhibited significantly, suggesting an alteration of neurotransmitter inactivation in zebrafish gills. The observed alterations in gill structure and function followed a time- and dose-dependent pattern. The results demonstrate that aphantoxins or PSPs lead to structural damage and altered function in the gills of zebrafish, including changes in histological structure and increases in the activities of AST and ALT. The inhibition of the activities of AChE and MAO suggest that aphantoxins or PSPs could induce respiratory toxicity in the zebrafish gill. Furthermore, these parameters may be used as bioindicators for investigating aphantoxin exposure and cyanobacterial blooms in nature.
Collapse
Affiliation(s)
- De Lu Zhang
- Department of Lifescience and Biotechnology, College of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, PR China.
| | - Si Yi Liu
- Department of Lifescience and Biotechnology, College of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, PR China
| | - Jing Zhang
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China
| | - Jian Kun Zhang
- Department of Lifescience and Biotechnology, College of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, PR China
| | - Chun Xiang Hu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, PR China.
| | - Yong Ding Liu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, PR China
| |
Collapse
|
15
|
The sensing of respiratory gases in fish: Mechanisms and signalling pathways. Respir Physiol Neurobiol 2016; 224:71-9. [DOI: 10.1016/j.resp.2015.06.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 06/16/2015] [Accepted: 06/17/2015] [Indexed: 12/29/2022]
|
16
|
An emerging role for gasotransmitters in the control of breathing and ionic regulation in fish. J Comp Physiol B 2015; 186:145-59. [DOI: 10.1007/s00360-015-0949-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 11/04/2015] [Accepted: 11/25/2015] [Indexed: 10/22/2022]
|
17
|
Jonz MG, Zachar PC, Da Fonte DF, Mierzwa AS. Peripheral chemoreceptors in fish: A brief history and a look ahead. Comp Biochem Physiol A Mol Integr Physiol 2015; 186:27-38. [DOI: 10.1016/j.cbpa.2014.09.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 09/03/2014] [Accepted: 09/03/2014] [Indexed: 11/24/2022]
|
18
|
Dzal YA, Jenkin SEM, Lague SL, Reichert MN, York JM, Pamenter ME. Oxygen in demand: How oxygen has shaped vertebrate physiology. Comp Biochem Physiol A Mol Integr Physiol 2015; 186:4-26. [PMID: 25698654 DOI: 10.1016/j.cbpa.2014.10.029] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2014] [Revised: 10/07/2014] [Accepted: 10/10/2014] [Indexed: 10/24/2022]
Abstract
In response to varying environmental and physiological challenges, vertebrates have evolved complex and often overlapping systems. These systems detect changes in environmental oxygen availability and respond by increasing oxygen supply to the tissues and/or by decreasing oxygen demand at the cellular level. This suite of responses is termed the oxygen transport cascade and is comprised of several components. These components include 1) chemosensory detectors that sense changes in oxygen, carbon dioxide, and pH in the blood, and initiate changes in 2) ventilation and 3) cardiac work, thereby altering the rate of oxygen delivery to, and carbon dioxide clearance from, the tissues. In addition, changes in 4) cellular and systemic metabolism alters tissue-level metabolic demand. Thus the need for oxygen can be managed locally when increasing oxygen supply is not sufficient or possible. Together, these mechanisms provide a spectrum of responses that facilitate the maintenance of systemic oxygen homeostasis in the face of environmental hypoxia or physiological oxygen depletion (i.e. due to exercise or disease). Bill Milsom has dedicated his career to the study of these responses across phylogenies, repeatedly demonstrating the power of applying the comparative approach to physiological questions. The focus of this review is to discuss the anatomy, signalling pathways, and mechanics of each step of the oxygen transport cascade from the perspective of a Milsomite. That is, by taking into account the developmental, physiological, and evolutionary components of questions related to oxygen transport. We also highlight examples of some of the remarkable species that have captured Bill's attention through their unique adaptations in multiple components of the oxygen transport cascade, which allow them to achieve astounding physiological feats. Bill's research examining the oxygen transport cascade has provided important insight and leadership to the study of the diverse suite of adaptations that maintain cellular oxygen content across vertebrate taxa, which underscores the value of the comparative approach to the study of physiological systems.
Collapse
Affiliation(s)
- Yvonne A Dzal
- Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Sarah E M Jenkin
- Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Sabine L Lague
- Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Michelle N Reichert
- Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Julia M York
- Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Matthew E Pamenter
- Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
| |
Collapse
|
19
|
Porteus CS, Wright PA, Milsom WK. Characterisation of putative oxygen chemoreceptors in bowfin (Amia calva). J Exp Biol 2014; 217:1269-77. [DOI: 10.1242/jeb.098467] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Serotonin containing neuroepithelial cells (NECs) are putative oxygen sensing cells found in different locations within the gills of fish. In this study we wished to determine the effect of sustained internal (blood) hypoxaemia versus external (aquatic) hypoxia on the size and density of NECs in the first gill arch of bowfin (Amia calva), a facultative air breather. We identified five different populations of serotonergic NECs in this species (Types I–V) based on location, presence of synaptic vesicles (SV) that stain for the antibody SV2, innervation and labelling with the neural crest marker HNK-1. Cell Types I–III were innervated, and these cells, which participate in central O2 chemoreflexes, were studied further. Although there was no change in the density of any cell type in bowfin after exposure to sustained hypoxia (6.0 kPa for 7 days) without access to air, all three of these cell types increased in size. In contrast, only Type II and III cells increased in size in bowfin exposed to sustained hypoxia with access to air. These data support the suggestion that NECs are putative oxygen-sensing cells, that they occur in several locations, and that Type I cells monitor only hypoxaemia, whereas both other cell types monitor hypoxia and hypoxaemia.
Collapse
Affiliation(s)
- Cosima S. Porteus
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
| | - Patricia A. Wright
- Department of Integrative Biology, University of Guelph, Guelph, ON, Canada, N1G 2W1
| | - William K. Milsom
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
| |
Collapse
|
20
|
Shakarchi K, Zachar PC, Jonz MG. Serotonergic and cholinergic elements of the hypoxic ventilatory response in developing zebrafish. ACTA ACUST UNITED AC 2012; 216:869-80. [PMID: 23155078 DOI: 10.1242/jeb.079657] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The chemosensory roles of gill neuroepithelial cells (NECs) in mediating the hyperventilatory response to hypoxia are not clearly defined in fish. While serotonin (5-HT) is the predominant neurotransmitter in O(2)-sensitive gill NECs, acetylcholine (ACh) plays a more prominent role in O(2) sensing in terrestrial vertebrates. The present study characterized the developmental chronology of potential serotonergic and cholinergic chemosensory pathways of the gill in the model vertebrate, the zebrafish (Danio rerio). In immunolabelled whole gills from larvae, serotonergic NECs were observed in epithelia of the gill filaments and gill arches, while non-serotonergic NECs were found primarily in the gill arches. Acclimation of developing zebrafish to hypoxia (P(O2)=75 mmHg) reduced the number of serotonergic NECs observed at 7 days post-fertilization (d.p.f.), and this effect was absent at 10 d.p.f. In vivo administration of 5-HT mimicked hypoxia by increasing ventilation frequency (f(V)) in early stage (7-10 d.p.f.) and late stage larvae (14-21 d.p.f.), while ACh increased f(V) only in late stage larvae. In time course experiments, application of ketanserin inhibited the hyperventilatory response to acute hypoxia (P(O2)=25 mmHg) at 10 d.p.f., while hexamethonium did not have this effect until 12 d.p.f. Cells immunoreactive for the vesicular acetylcholine transporter (VAChT) began to appear in the gill filaments by 14 d.p.f. Characterization in adult gills revealed that VAChT-positive cells were a separate population of neurosecretory cells of the gill filaments. These studies suggest that serotonergic and cholinergic pathways in the zebrafish gill develop at different times and contribute to the hyperventilatory response to hypoxia.
Collapse
Affiliation(s)
- Kamila Shakarchi
- Department of Biology, University of Ottawa, Ottawa, ON, Canada K1N 6N5
| | | | | |
Collapse
|
21
|
Porteus CS, Brink DL, Milsom WK. Neurotransmitter profiles in fish gills: putative gill oxygen chemoreceptors. Respir Physiol Neurobiol 2012; 184:316-25. [PMID: 22728948 DOI: 10.1016/j.resp.2012.06.019] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 06/12/2012] [Accepted: 06/15/2012] [Indexed: 12/14/2022]
Abstract
In fish, cells containing serotonin, ACh, catecholamines, NO, H(2)S, leu-5-enkephalin, met-5-enkephalin and neuropeptide Y are found in the gill filaments and lamellae. Serotonin containing neuroepithelial cells (NECs) located along the filament are most abundant and are the only group found in all fish studied to date. The presence of NECs in other locations or containing other transmitters is species specific and it is rare that any one NEC contains more than one neurochemical. The gills are innervated by both extrinsic and intrinsic nerves and they can be cholinergic, serotonergic or contain both transmitters. Some NECs are presumed to be involved in paracrine regulation of gill blood flow, while others part of the reflex pathways involved in cardiorespiratory control. There is both direct and indirect evidence to indicate that the chemosensing cells involved in these latter reflexes sit in locations where some monitor O(2) levels in water, blood or both, yet the anatomical data do not show such clear distinctions.
Collapse
Affiliation(s)
- Cosima S Porteus
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4.
| | | | | |
Collapse
|