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Sample records for adult zebrafish brain

  1. Isolation and Culture of Adult Zebrafish Brain-derived Neurospheres

    PubMed Central

    Lopez-Ramirez, Miguel A.; Calvo, Charles-Félix; Ristori, Emma; Thomas, Jean-Léon; Nicoli, Stefania

    2016-01-01

    The zebrafish is a highly relevant model organism for understanding the cellular and molecular mechanisms involved in neurogenesis and brain regeneration in vertebrates. However, an in-depth analysis of the molecular mechanisms underlying zebrafish adult neurogenesis has been limited due to the lack of a reliable protocol for isolating and culturing neural adult stem/progenitor cells. Here we provide a reproducible method to examine adult neurogenesis using a neurosphere assay derived from zebrafish whole brain or from the telencephalon, tectum and cerebellum regions of the adult zebrafish brain. The protocol involves, first the microdissection of zebrafish adult brain, then single cell dissociation and isolation of self-renewing multipotent neural stem/progenitor cells. The entire procedure takes eight days. Additionally, we describe how to manipulate gene expression in zebrafish neurospheres, which will be particularly useful to test the role of specific signaling pathways during adult neural stem/progenitor cell proliferation and differentiation in zebrafish. PMID:26967835

  2. Electrophysiological Recording in the Brain of Intact Adult Zebrafish

    PubMed Central

    Johnston, Lindsey; Ball, Rebecca E.; Acuff, Seth; Gaudet, John; Sornborger, Andrew; Lauderdale, James D.

    2013-01-01

    Previously, electrophysiological studies in adult zebrafish have been limited to slice preparations or to eye cup preparations and electrorentinogram recordings. This paper describes how an adult zebrafish can be immobilized, intubated, and used for in vivo electrophysiological experiments, allowing recording of neural activity. Immobilization of the adult requires a mechanism to deliver dissolved oxygen to the gills in lieu of buccal and opercular movement. With our technique, animals are immobilized and perfused with habitat water to fulfill this requirement. A craniotomy is performed under tricaine methanesulfonate (MS-222; tricaine) anesthesia to provide access to the brain. The primary electrode is then positioned within the craniotomy window to record extracellular brain activity. Through the use of a multitube perfusion system, a variety of pharmacological compounds can be administered to the adult fish and any alterations in the neural activity can be observed. The methodology not only allows for observations to be made regarding changes in neurological activity, but it also allows for comparisons to be made between larval and adult zebrafish. This gives researchers the ability to identify the alterations in neurological activity due to the introduction of various compounds at different life stages. PMID:24300281

  3. BDNF Expression in Larval and Adult Zebrafish Brain: Distribution and Cell Identification

    PubMed Central

    Cacialli, Pietro; Gueguen, Marie-Madeleine; Coumailleau, Pascal; D’Angelo, Livia; Kah, Olivier; Lucini, Carla; Pellegrini, Elisabeth

    2016-01-01

    Brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family, has emerged as an active mediator in many essential functions in the central nervous system of mammals. BDNF plays significant roles in neurogenesis, neuronal maturation and/or synaptic plasticity and is involved in cognitive functions such as learning and memory. Despite the vast literature present in mammals, studies devoted to BDNF in the brain of other animal models are scarse. Zebrafish is a teleost fish widely known for developmental genetic studies and is emerging as model for translational neuroscience research. In addition, its brain shows many sites of adult neurogenesis allowing higher regenerative properties after traumatic injuries. To add further knowledge on neurotrophic factors in vertebrate brain models, we decided to determine the distribution of bdnf mRNAs in the larval and adult zebrafish brain and to characterize the phenotype of cells expressing bdnf mRNAs by means of double staining studies. Our results showed that bdnf mRNAs were widely expressed in the brain of 7 days old larvae and throughout the whole brain of mature female and male zebrafish. In adults, bdnf mRNAs were mainly observed in the dorsal telencephalon, preoptic area, dorsal thalamus, posterior tuberculum, hypothalamus, synencephalon, optic tectum and medulla oblongata. By combining immunohistochemistry with in situ hybridization, we showed that bdnf mRNAs were never expressed by radial glial cells or proliferating cells. By contrast, bdnf transcripts were expressed in cells with neuronal phenotype in all brain regions investigated. Our results provide the first demonstration that the brain of zebrafish expresses bdnf mRNAs in neurons and open new fields of research on the role of the BDNF factor in brain mechanisms in normal and brain repairs situations. PMID:27336917

  4. Organization of the histaminergic system in adult zebrafish (Danio rerio) brain: neuron number, location, and cotransmitters.

    PubMed

    Sundvik, Maria; Panula, Pertti

    2012-12-01

    Histamine is an essential factor in the ascending arousal system (AAS) during motivated behaviors. Histamine and hypocretin/orexin (hcrt) are proposed to be responsible for different aspects of arousal and wakefulness, histamine mainly for cognitive and motivated behaviors. In this study we visualized the entire histaminergic neuron population in adult male and female zebrafish brain and quantified the histaminergic neuron numbers. There were 40-45 histaminergic neurons in both male and female zebrafish brain. Further, we identified cotransmitters of histaminergic neurons in the ventrocaudal hypothalamus, i.e., around the posterior recess (PR) in adult zebrafish. Galanin, γ-aminobutyric acid (GABA), and thyrotropin-releasing hormone (TRH) were colocalized with histamine in some but not all neurons, a result that was verified by intracerebroventricular injections of colchicine into adult zebrafish. Fibers immunoreactive (ir) for galanin, GABA, TRH, or methionine-enkephalin (mENK) were dense in the ventrocaudal hypothalamus around the histaminergic neurons. In histamine-ir fibers TRH and galanin immunoreactivities were also detected in the ventral telencephalon. All these neurotransmitters are involved in maintaining the equilibrium of the sleep-wake state. Our results are in accordance with results from rats, further supporting the use of zebrafish as a tool to study molecular mechanisms underlying complex behaviors.

  5. The chemokine receptor cxcr5 regulates the regenerative neurogenesis response in the adult zebrafish brain

    PubMed Central

    2012-01-01

    Background Unlike mammals, zebrafish exhibits extensive neural regeneration after injury in adult stages of its lifetime due to the neurogenic activity of the radial glial cells. However, the genes involved in the regenerative neurogenesis response of the zebrafish brain are largely unknown. Thus, understanding the underlying principles of this regeneration capacity of the zebrafish brain is an interesting research realm that may offer vast clinical ramifications. Results In this paper, we characterized the expression pattern of cxcr5 and analyzed the function of this gene during adult neurogenesis and regeneration of the zebrafish telencephalon. We found that cxcr5 was upregulated transiently in the RGCs and neurons, and the expression in the immune cells such as leukocytes was negligible during both adult neurogenesis and regeneration. We observed that the transgenic misexpression of cxcr5 in the ventricular cells using dominant negative and full-length variants of the gene resulted in altered proliferation and neurogenesis response of the RGCs. When we knocked down cxcr5 using antisense morpholinos and cerebroventricular microinjection, we observed outcomes similar to the overexpression of the dominant negative cxcr5 variant. Conclusions Thus, based on our results, we propose that cxcr5 imposes a proliferative permissiveness to the radial glial cells and is required for differentiation of the RGCs to neurons, highlighting novel roles of cxcr5 in the nervous system of vertebrates. We therefore suggest that cxcr5 is an important cue for ventricular cell proliferation and regenerative neurogenesis in the adult zebrafish telencephalon. Further studies on the role of cxcr5 in mediating neuronal replenishment have the potential to produce clinical ramifications in efforts for regenerative therapeutic applications for human neurological disorders or acute injuries. PMID:22824261

  6. Micromanipulation of gene expression in the adult zebrafish brain using cerebroventricular microinjection of morpholino oligonucleotides.

    PubMed

    Kizil, Caghan; Iltzsche, Anne; Kaslin, Jan; Brand, Michael

    2013-05-23

    Manipulation of gene expression in tissues is required to perform functional studies. In this paper, we demonstrate the cerebroventricular microinjection (CVMI) technique as a means to modulate gene expression in the adult zebrafish brain. By using CVMI, substances can be administered into the cerebroventricular fluid and be thoroughly distributed along the rostrocaudal axis of the brain. We particularly focus on the use of antisense morpholino oligonucleotides, which are potent tools for knocking down gene expression in vivo. In our method, when applied, morpholino molecules are taken up by the cells lining the ventricular surface. These cells include the radial glial cells, which act as neurogenic progenitors. Therefore, knocking down gene expression in the radial glial cells is of utmost importance to analyze the widespread neurogenesis response in zebrafish, and also would provide insight into how vertebrates could sustain adult neurogenesis response. Such an understanding would also help the efforts for clinical applications in human neurodegenerative disorders and central nervous system regeneration. Thus, we present the cerebroventricular microinjection method as a quick and efficient way to alter gene expression and neurogenesis response in the adult zebrafish forebrain. We also provide troubleshooting tips and other useful information on how to carry out the CVMI procedure.

  7. Methylmercury Induced Neurotoxicity and the Influence of Selenium in the Brains of Adult Zebrafish (Danio rerio).

    PubMed

    Rasinger, Josef Daniel; Lundebye, Anne-Katrine; Penglase, Samuel James; Ellingsen, Ståle; Amlund, Heidi

    2017-03-29

    The neurotoxicity of methylmercury (MeHg) is well characterised, and the ameliorating effects of selenium have been described. However, little is known about the molecular mechanisms behind this contaminant-nutrient interaction. We investigated the influence of selenium (as selenomethionine, SeMet) and MeHg on mercury accumulation and protein expression in the brain of adult zebrafish (Danio rerio). Fish were fed diets containing elevated levels of MeHg and/or SeMet in a 2 × 2 full factorial design for eight weeks. Mercury concentrations were highest in the brain tissue of MeHg-exposed fish compared to the controls, whereas lower levels of mercury were found in the brain of zebrafish fed both MeHg and SeMet compared with the fish fed MeHg alone. The expression levels of proteins associated with gap junction signalling, oxidative phosphorylation, and mitochondrial dysfunction were significantly (p < 0.05) altered in the brain of zebrafish after exposure to MeHg and SeMet alone or in combination. Analysis of upstream regulators indicated that these changes were linked to the mammalian target of rapamycin (mTOR) pathways, which were activated by MeHg and inhibited by SeMet, possibly through a reactive oxygen species mediated differential activation of RICTOR, the rapamycin-insensitive binding partner of mTOR.

  8. Expression of FoxP2 during zebrafish development and in the adult brain.

    PubMed

    Shah, Rina; Medina-Martinez, Olga; Chu, Li-Fang; Samaco, Rodney C; Jamrich, Milan

    2006-01-01

    Fox (forkhead) genes encode transcription factors that play important roles in the regulation of embryonic patterning as well as in tissue specific gene expression. Mutations in the human FOXP2 gene cause abnormal speech development. Here we report the structure and expression pattern of zebrafish FoxP2. In zebrafish, this gene is first expressed at the 20-somite stage in the presumptive telencephalon. At this stage there is a significant overlap of FoxP2 expression with the expression of the emx homeobox genes. However, in contrast to emx1, FoxP2 is not expressed in the pineal gland or in the pronephric duct. After 72 hours of development, the expression of zebrafish FoxP2 becomes more complex in the brain. The developing optic tectum becomes the major area of FoxP2 expression. In the adult brain, the highest concentrations of the FoxP2 transcript can be observed in the optic tectum. In the cerebellum, only the caudal lobes show high levels of Foxp2 expression. These regions correspond to the vestibulocerebellum of mammals. Several other regions of the brain also show high levels of Foxp2 expression.

  9. Spred-2 expression is associated with neural repair of injured adult zebrafish brain.

    PubMed

    Lim, Fei Tieng; Ogawa, Satoshi; Parhar, Ishwar S

    2016-11-01

    Sprouty-related protein-2 (Spred-2) is a negative regulator of extracellular signal-regulated kinases (ERK) pathway, which is important for cell proliferation, neuronal differentiation, plasticity and survival. Nevertheless, its general molecular characteristics such as gene expression patterns and potential role in neural repair in the brain remain unknown. Thus, this study aimed to characterise the expression of spred-2 in the zebrafish brain. Digoxigenin-in situ hybridization showed spred-2 mRNA-expressing cells were mainly seen in the proliferative zones such as the olfactory bulb, telencephalon, optic tectum, cerebellum, and the dorsal and ventral hypothalamus, and most of which were neuronal cells. To evaluate the potential role of spred-2 in neuro-regeneration, spred-2 gene expression was examined in the dorsal telencephalon followed by mechanical-lesion. Real-time PCR showed a significant reduction of spred-2 mRNA levels in the telencephalon on 1-day till 2-days post-lesion and gradually increased to normal levels as compared with intact. Furthermore, to confirm involvement of Spred-2 signalling in the cell proliferation after brain injury, double-labelling of spred-2 in-situ hybridization with immunofluorescence of BrdU and phosphorylated-ERK1/2 (p-ERK1/2), a downstream of Spred-2 was performed. Increase of BrdU and p-ERK1/2 immunoreactive cells suggest that a decrease in spred-2 after injury might associated with activation of the ERK pathway to stimulate cell proliferation in the adult zebrafish brain. The present study demonstrates the possible role of Spred-2 signalling in cell proliferative phase during the neural repair in the injured zebrafish brain.

  10. Neurodevelopment. Live imaging of adult neural stem cell behavior in the intact and injured zebrafish brain.

    PubMed

    Barbosa, Joana S; Sanchez-Gonzalez, Rosario; Di Giaimo, Rossella; Baumgart, Emily Violette; Theis, Fabian J; Götz, Magdalena; Ninkovic, Jovica

    2015-05-15

    Adult neural stem cells are the source for restoring injured brain tissue. We used repetitive imaging to follow single stem cells in the intact and injured adult zebrafish telencephalon in vivo and found that neurons are generated by both direct conversions of stem cells into postmitotic neurons and via intermediate progenitors amplifying the neuronal output. We observed an imbalance of direct conversion consuming the stem cells and asymmetric and symmetric self-renewing divisions, leading to depletion of stem cells over time. After brain injury, neuronal progenitors are recruited to the injury site. These progenitors are generated by symmetric divisions that deplete the pool of stem cells, a mode of neurogenesis absent in the intact telencephalon. Our analysis revealed changes in the behavior of stem cells underlying generation of additional neurons during regeneration.

  11. Neurochemical measurements in the zebrafish brain

    PubMed Central

    Jones, Lauren J.; McCutcheon, James E.; Young, Andrew M. J.; Norton, William H. J.

    2015-01-01

    The zebrafish is an ideal model organism for behavioral genetics and neuroscience. The high conservation of genes and neurotransmitter pathways between zebrafish and other vertebrates permits the translation of research between species. Zebrafish behavior can be studied at both larval and adult stages and recent research has begun to establish zebrafish models for human disease. Fast scan cyclic voltammetry (FSCV) is an electrochemical technique that permits the detection of neurotransmitter release and reuptake. In this study we have used in vitro FSCV to measure the release of analytes in the adult zebrafish telencephalon. We compare different stimulation methods and present a characterization of neurochemical changes in the wild-type zebrafish brain. This study represents the first FSCV recordings in zebrafish, thus paving the way for neurochemical analysis of the fish brain. PMID:26441575

  12. Electroporation of adult zebrafish.

    PubMed

    Rao, N Madhusudhana; Rambabu, K Murali; Rao, S Harinarayana

    2008-01-01

    We generated transient transgenic zebrafish by applying electrical pulses subsequent to injection of DNA into muscle tissue of 3-6-month old adult zebrafish. Electroporation parameters, such as number of pulses, voltage, and amount of plasmid DNA, were optimized and found that 6 pulses of 40 V/cm at 15 mug/fish increased the luciferase expression by 10-fold compared with those in controls. By measuring the expression of luciferase, in vivo by electroporation in adult zebrafish and in vitro using fish cell line (Xiphophorus xiphidium A2 cells), the strength of three promoters (CMV, human EF-1alpha, and Xenopus EF-1alpha) was compared. Subsequent to electroporation after injecting DNA in the mid region of zebrafish, expression of green fluorescent protein was found far away from the site of injection in the head and the tail sections. Thus, electroporation in adult zebrafish provides a rapid way of testing the behavior of gene sequences in the whole organism.

  13. Functional optoacoustic neuro-tomography of calcium fluxes in adult zebrafish brain in vivo.

    PubMed

    Deán-Ben, X Luís; Gottschalk, Sven; Sela, Gali; Shoham, Shy; Razansky, Daniel

    2017-03-01

    Genetically-encoded calcium indicators (GECIs) have revolutionized neuroimaging by enabling mapping of the activity of entire neuronal populations in vivo. Visualization of these powerful activity sensors has to date been limited to depth-restricted microscopic studies due to intense light scattering in the brain. We demonstrate, for the first time, in vivo real-time volumetric optoacoustic monitoring of calcium transients in adult transgenic zebrafish expressing the GCaMP5G calcium indicator. Fast changes in optoacoustic traces associated with GCaMP5G activity were detectable in the presence of other strongly absorbing endogenous chromophores, such as hemoglobin. The new functional optoacoustic neuroimaging method can visualize neural activity at penetration depths and spatio-temporal resolution scales not covered with the existing neuroimaging techniques.

  14. Mapping of brain lipid binding protein (Blbp) in the brain of adult zebrafish, co-expression with aromatase B and links with proliferation.

    PubMed

    Diotel, Nicolas; Vaillant, Colette; Kah, Olivier; Pellegrini, Elisabeth

    2016-01-01

    Adult fish exhibit a strong neurogenic capacity due to the persistence of radial glial cells. In zebrafish, radial glial cells display well-established markers such as the estrogen-synthesizing enzyme (AroB) and the brain lipid binding protein (Blbp), which is known to strongly bind omega-3 polyunsaturated fatty acids such as docosahexaenoic acid (DHA). While Blpb is mainly described in the telencephalon of adult zebrafish, its expression in the remaining regions of the brain is poorly documented. The present study was designed to further investigate Blbp expression in the brain, its co-expression with AroB, and its link with radial glial cells proliferation in zebrafish. We generated a complete and detailed mapping of Blbp expression in the whole brain and show its complete co-expression with AroB, except in some tectal and hypothalamic regions. By performing PCNA and Blbp immunohistochemistry on cyp19a1b-GFP (AroB-GFP) fish, we also demonstrated preferential Blbp expression in proliferative radial glial cells in almost all regions studied. To our knowledge, this is the first complete and detailed mapping of Blbp-expressing cells showing strong association between Blbp and radial glial cell proliferation in the adult brain of fish. Given that zebrafish is now recognized models for studying neurogenesis and brain repair, our data provide detailed characterization of Blbp in the entire brain and open up a broad field of research investigating the role of omega-3 polyunsaturated fatty acids in neural stem cell activity in fish.

  15. Zebrafish as an emerging model for studying complex brain disorders

    PubMed Central

    Kalueff, Allan V.; Stewart, Adam Michael; Gerlai, Robert

    2014-01-01

    The zebrafish (Danio rerio) is rapidly becoming a popular model organism in pharmacogenetics and neuropharmacology. Both larval and adult zebrafish are currently used to increase our understanding of brain function, dysfunction, and their genetic and pharmacological modulation. Here we review the developing utility of zebrafish in the analysis of complex brain disorders (including, for example, depression, autism, psychoses, drug abuse and cognitive disorders), also covering zebrafish applications towards the goal of modeling major human neuropsychiatric and drug-induced syndromes. We argue that zebrafish models of complex brain disorders and drug-induced conditions have become a rapidly emerging critical field in translational neuropharmacology research. PMID:24412421

  16. A Novel Model of Traumatic Brain Injury in Adult Zebrafish Demonstrates Response to Injury and Treatment Comparable with Mammalian Models.

    PubMed

    McCutcheon, Victoria; Park, Eugene; Liu, Elaine; Sobhebidari, Pooya; Tavakkoli, Jahan; Wen, Xiao-Yan; Baker, Andrew J

    2016-12-20

    Traumatic brain injury (TBI) is a leading cause of death and morbidity in industrialized countries with considerable associated health care costs. The cost and time associated with pre-clinical development of TBI therapeutics is lengthy and expensive with a poor track record of successful translation to the clinic. The zebrafish is an emerging model organism in research with unique technical and genomic strengths in the study of disease and development. Its high degree of genetic homology and cell signaling pathways relative to mammalian species and amenability to high and medium throughput assays has potential to accelerate the rate of therapeutic drug identification. Accordingly, we developed a novel closed-head model of TBI in adult zebrafish using a targeted, pulsed, high-intensity focused ultrasound (pHIFU) to induce mechanical injury of the brain. Western blot results indicated altered microtubule and neurofilament expression as well as increased expression of cleaved caspase-3 and beta APP (β-APP; p < 0.05). We used automated behavioral tracking software to evaluate locomotor deficits 24 and 48 h post-injury. Significant behavioral impairment included decreased swim distance and velocity (p < 0.05), as well as heightened anxiety and altered group social dynamics. Responses to injury were pHIFU dose-dependent and modifiable with MK-801, MDL-28170, or temperature modulation. Together, results indicate that the zebrafish exhibits responses to injury and intervention similar to mammalian TBI pathophysiology and suggest the potential for use to rapidly evaluate therapeutic compounds with high efficiency.

  17. Regeneration of Zebrafish CNS: Adult Neurogenesis

    PubMed Central

    Ghosh, Sukla; Hui, Subhra Prakash

    2016-01-01

    Regeneration in the animal kingdom is one of the most fascinating problems that have allowed scientists to address many issues of fundamental importance in basic biology. However, we came to know that the regenerative capability may vary across different species. Among vertebrates, fish and amphibians are capable of regenerating a variety of complex organs through epimorphosis. Zebrafish is an excellent animal model, which can repair several organs like damaged retina, severed spinal cord, injured brain and heart, and amputated fins. The focus of the present paper is on spinal cord regeneration in adult zebrafish. We intend to discuss our current understanding of the cellular and molecular mechanism(s) that allows formation of proliferating progenitors and controls neurogenesis, which involve changes in epigenetic and transcription programs. Unlike mammals, zebrafish retains radial glia, a nonneuronal cell type in their adult central nervous system. Injury induced proliferation involves radial glia which proliferate, transcribe embryonic genes, and can give rise to new neurons. Recent technological development of exquisite molecular tools in zebrafish, such as cell ablation, lineage analysis, and novel and substantial microarray, together with advancement in stem cell biology, allowed us to investigate how progenitor cells contribute to the generation of appropriate structures and various underlying mechanisms like reprogramming. PMID:27382491

  18. Brain tumor - primary - adults

    MedlinePlus

    ... Vestibular schwannoma (acoustic neuroma) - adults; Meningioma - adults; Cancer - brain tumor (adults) ... Primary brain tumors include any tumor that starts in the brain. Primary brain tumors can start from brain cells, ...

  19. Regeneration of the Pancreas in Adult Zebrafish

    PubMed Central

    Moss, Jennifer B.; Koustubhan, Punita; Greenman, Melanie; Parsons, Michael J.; Walter, Ingrid; Moss, Larry G.

    2009-01-01

    OBJECTIVE Regenerating organs in diverse biological systems have provided clues to processes that can be harnessed to repair damaged tissue. Adult mammalian β-cells have a limited capacity to regenerate, resulting in diabetes and lifelong reliance on insulin. Zebrafish have been used as a model for the regeneration of many organs. We demonstrate the regeneration of adult zebrafish pancreatic β-cells. This nonmammalian model can be used to define pathways for islet-cell regeneration in humans. RESEARCH DESIGN AND METHODS Adult transgenic zebrafish were injected with a single high dose of streptozotocin or metronidazole and anesthetized at 3, 7, or 14 days or pancreatectomized. Blood glucose measurements were determined and gut sections were analyzed using specific endocrine, exocrine, and duct cell markers as well as markers for dividing cells. RESULTS Zebrafish recovered rapidly without the need for insulin injections, and normoglycemia was attained within 2 weeks. Although few proliferating cells were present in vehicles, ablation caused islet destruction and a striking increase of proliferating cells, some of which were Pdx1 positive. Dividing cells were primarily associated with affected islets and ducts but, with the exception of surgical partial pancreatectomy, were not extensively β-cells. CONCLUSIONS The ability of the zebrafish to regenerate a functional pancreas using chemical, genetic, and surgical approaches enabled us to identify patterns of cell proliferation in islets and ducts. Further study of the origin and contribution of proliferating cells in reestablishing islet function could provide strategies for treating human diseases. PMID:19491207

  20. Optimized cell transplantation using adult rag2 mutant zebrafish

    PubMed Central

    Tang, Qin; Abdelfattah, Nouran S.; Blackburn, Jessica S.; Moore, John C.; Martinez, Sarah A.; Moore, Finola E.; Lobbardi, Riadh; Tenente, Inês M.; Ignatius, Myron S.; Berman, Jason N.; Liwski, Robert S.; Houvras, Yariv; Langenau, David M.

    2014-01-01

    Cell transplantation into adult zebrafish has lagged behind mouse due to the lack of immune compromised models. Here, we have created homozygous rag2E450fs mutant zebrafish that have reduced numbers of functional T and B cells but are viable and fecund. Mutant fish engraft zebrafish muscle, blood stem cells, and cancers. rag2E450fs mutant zebrafish are the first immune compromised zebrafish model that permits robust, long-term engraftment of multiple tissues and cancer. PMID:25042784

  1. Proteomics Identification of Potential Candidates Involved in Cell Proliferation for Early Stage of Brain Regeneration in the Adult Zebrafish.

    PubMed

    Lim, Fei Tieng; Ogawa, Satoshi; Smith, A Ian; Parhar, Ishwar S

    2017-02-01

    The central nervous system (CNS) of the non-mammalian vertebrates has better neuroregenerative capability as compared with the mammalian CNS. Regeneration of habenula was observed 40 days after damage in zebrafish. During the early stage of regeneration, we found a significant increase of apoptotic cells on day-1 post-damage and of proliferative cells on day-3 post-damage. To identify the molecular factor(s) involved in the early stages of neuroregeneration, differentially expressed proteins during sham, 20- and 40-h post-habenula damage were investigated by proteomic approach by using two-dimensional differential gel electrophoresis (2D-DIGE) coupled with Matrix-Assisted Laser Desorption/Ionization-Time-of-Flight (MALDI-ToF) and tandem mass spectrometry. Protein profiles revealed 17 differentially (>1.5-fold) expressed proteins: 10 upregulated, 4 downregulated, 2 proteins were found to be downregulated at the early stage but upregulated at a later stage, and 1 protein was found to be upregulated at 2 different time points. All proteins identified can be summarized under few molecular processes involved in the early stages of neuroregeneration in zebrafish CNS: apoptosis regulation (Wnt inhibitory factor 1 [WIF1]), neuroprotection (metallothionein), cell proliferation (Spred2, ependymin, Lhx1, and Wnts), differentiation (Spred2, Lhx9, and Wnts), and morphogenesis (cytoplasmic actins and draculin). These protein profiling results suggest that drastic molecular changes occur in the neuroregenerative process during this period, which includes cell proliferation, differentiation, and protection.

  2. Manual drainage of the zebrafish embryonic brain ventricles.

    PubMed

    Chang, Jessica T; Sive, Hazel

    2012-12-16

    Cerebrospinal fluid (CSF) is a protein rich fluid contained within the brain ventricles. It is present during early vertebrate embryonic development and persists throughout life. Adult CSF is thought to cushion the brain, remove waste, and carry secreted molecules(1,2). In the adult and older embryo, the majority of CSF is made by the choroid plexus, a series of highly vascularized secretory regions located adjacent to the brain ventricles(3-5). In zebrafish, the choroid plexus is fully formed at 144 hours post fertilization (hpf)(6). Prior to this, in both zebrafish and other vertebrate embryos including mouse, a significant amount of embryonic CSF (eCSF) is present . These data and studies in chick suggest that the neuroepithelium is secretory early in development and may be the major source of eCSF prior to choroid plexus development(7). eCSF contains about three times more protein than adult CSF, suggesting that it may have an important role during development(8,9). Studies in chick and mouse demonstrate that secreted factors in the eCSF, fluid pressure, or a combination of these, are important for neurogenesis, gene expression, cell proliferation, and cell survival in the neuroepithelium(10-20). Proteomic analyses of human, rat, mouse, and chick eCSF have identified many proteins that may be necessary for CSF function. These include extracellular matrix components, apolipoproteins, osmotic pressure regulating proteins, and proteins involved in cell death and proliferation(21-24). However, the complex functions of the eCSF are largely unknown. We have developed a method for removing eCSF from zebrafish brain ventricles, thus allowing for identification of eCSF components and for analysis of the eCSF requirement during development. Although more eCSF can be collected from other vertebrate systems with larger embryos, eCSF can be collected from the earliest stages of zebrafish development, and under genetic or environmental conditions that lead to abnormal brain

  3. Embryonic exposure to 10 μg L(-1) lead results in female-specific expression changes in genes associated with nervous system development and function and Alzheimer's disease in aged adult zebrafish brain.

    PubMed

    Lee, Jinyoung; Freeman, Jennifer L

    2016-06-01

    A developmental lead (Pb) exposure has been proposed as an environmental risk factor for adult neurodegenerative diseases including Alzheimer's disease (AD). Recent animal studies showed pathological characteristics of AD in adults with a developmental Pb exposure, but additional studies are needed to investigate this phenomenon. To further assess the relationship between an embryonic Pb exposure and latent neurological alterations, the brain of adult female and male zebrafish aged 12 months that were exposed to a control treatment or 10 μg L(-1) Pb only during embryogenesis (1-72 hours after fertilization) were analyzed on a zebrafish-specific microarray platform. Gene ontology and pathway analysis revealed similarities in the top disease and functional categories in both sexes, but females had 4.3 times more genes altered than males. In addition, alterations in genes associated with nervous system development and function were more pronounced with a set of 89 genes associated with AD including amyloid precursor protein (APP), apolipoprotein (APOE), and sortlin-related receptor precursor (SORL1) observed to be changed in adult females. Our observations suggest that an embryonic exposure to Pb at levels as low as 10 μg L(-1) disturb global gene expression patterns in a sex-specific manner that could lead to neurological alterations in later life. With these findings, future studies investigating the adverse neurological outcomes of these changes in gene expression will facilitate our understanding of the impact of an embryonic 10 μg L(-1) Pb exposure on neurological disease pathogenesis and the inclusion of additional concentrations will broaden our knowledge of dose-dependent changes.

  4. Comprehensive Expression Map of Transcription Regulators in the Adult Zebrafish Telencephalon Reveals Distinct Neurogenic Niches

    PubMed Central

    Diotel, Nicolas; Rodriguez Viales, Rebecca; Armant, Olivier; März, Martin; Ferg, Marco; Rastegar, Sepand; Strähle, Uwe

    2015-01-01

    The zebrafish has become a model to study adult vertebrate neurogenesis. In particular, the adult telencephalon has been an intensely studied structure in the zebrafish brain. Differential expression of transcriptional regulators (TRs) is a key feature of development and tissue homeostasis. Here we report an expression map of 1,202 TR genes in the telencephalon of adult zebrafish. Our results are summarized in a database with search and clustering functions to identify genes expressed in particular regions of the telencephalon. We classified 562 genes into 13 distinct patterns, including genes expressed in the proliferative zone. The remaining 640 genes displayed unique and complex patterns of expression and could thus not be grouped into distinct classes. The neurogenic ventricular regions express overlapping but distinct sets of TR genes, suggesting regional differences in the neurogenic niches in the telencephalon. In summary, the small telencephalon of the zebrafish shows a remarkable complexity in TR gene expression. The adult zebrafish telencephalon has become a model to study neurogenesis. We established the expression pattern of more than 1200 transcription regulators (TR) in the adult telencephalon. The neurogenic regions express overlapping but distinct sets of TR genes suggesting regional differences in the neurogenic potential. J. Comp. Neurol. 523:1202–1221, 2015. © 2015 Wiley Periodicals, Inc. PMID:25556858

  5. Three-Dimensional Neurophenotyping of Adult Zebrafish Behavior

    PubMed Central

    Cachat, Jonathan; Stewart, Adam; Utterback, Eli; Hart, Peter; Gaikwad, Siddharth; Wong, Keith; Kyzar, Evan; Wu, Nadine; Kalueff, Allan V.

    2011-01-01

    The use of adult zebrafish (Danio rerio) in neurobehavioral research is rapidly expanding. The present large-scale study applied the newest video-tracking and data-mining technologies to further examine zebrafish anxiety-like phenotypes. Here, we generated temporal and spatial three-dimensional (3D) reconstructions of zebrafish locomotion, globally assessed behavioral profiles evoked by several anxiogenic and anxiolytic manipulations, mapped individual endpoints to 3D reconstructions, and performed cluster analysis to reconfirm behavioral correlates of high- and low-anxiety states. The application of 3D swim path reconstructions consolidates behavioral data (while increasing data density) and provides a novel way to examine and represent zebrafish behavior. It also enables rapid optimization of video tracking settings to improve quantification of automated parameters, and suggests that spatiotemporal organization of zebrafish swimming activity can be affected by various experimental manipulations in a manner predicted by their anxiolytic or anxiogenic nature. Our approach markedly enhances the power of zebrafish behavioral analyses, providing innovative framework for high-throughput 3D phenotyping of adult zebrafish behavior. PMID:21408171

  6. Radial glia and neural progenitors in the adult zebrafish central nervous system.

    PubMed

    Than-Trong, Emmanuel; Bally-Cuif, Laure

    2015-08-01

    The adult central nervous system (CNS) of the zebrafish, owing to its enrichment in constitutive neurogenic niches, is becoming an increasingly used model to address fundamental questions pertaining to adult neural stem cell (NSC) biology, adult neurogenesis and neuronal repair. Studies conducted in several CNS territories (notably the telencephalon, retina, midbrain, cerebellum and spinal cord) highlighted the presence, in these niches, of progenitor cells displaying NSC-like characters. While pointing to radial glial cells (RG) as major long-lasting, constitutively active and/or activatable progenitors in most domains, these studies also revealed a high heterogeneity in the progenitor subtypes used at the top of neurogenic hierarchies, including the persistence of neuroepithelial (NE) progenitors in some areas. Likewise, dissecting the molecular pathways underlying RG maintenance and recruitment under physiological conditions and upon repair in the zebrafish model revealed shared processes but also specific cascades triggering or sustaining reparative NSC recruitment. Together, the zebrafish adult brain reveals an extensive complexity of adult NSC niches, properties and control pathways, which extends existing understanding of adult NSC biology and gives access to novel mechanisms of efficient NSC maintenance and recruitment in an adult vertebrate brain.

  7. Whole-brain activity mapping onto a zebrafish brain atlas.

    PubMed

    Randlett, Owen; Wee, Caroline L; Naumann, Eva A; Nnaemeka, Onyeka; Schoppik, David; Fitzgerald, James E; Portugues, Ruben; Lacoste, Alix M B; Riegler, Clemens; Engert, Florian; Schier, Alexander F

    2015-11-01

    In order to localize the neural circuits involved in generating behaviors, it is necessary to assign activity onto anatomical maps of the nervous system. Using brain registration across hundreds of larval zebrafish, we have built an expandable open-source atlas containing molecular labels and definitions of anatomical regions, the Z-Brain. Using this platform and immunohistochemical detection of phosphorylated extracellular signal–regulated kinase (ERK) as a readout of neural activity, we have developed a system to create and contextualize whole-brain maps of stimulus- and behavior-dependent neural activity. This mitogen-activated protein kinase (MAP)-mapping assay is technically simple, and data analysis is completely automated. Because MAP-mapping is performed on freely swimming fish, it is applicable to studies of nearly any stimulus or behavior. Here we demonstrate our high-throughput approach using pharmacological, visual and noxious stimuli, as well as hunting and feeding. The resultant maps outline hundreds of areas associated with behaviors.

  8. Whole-body and multispectral photoacoustic imaging of adult zebrafish

    NASA Astrophysics Data System (ADS)

    Huang, Na; Xi, Lei

    2016-10-01

    Zebrafish is a top vertebrate model to study developmental biology and genetics, and it is becoming increasingly popular for studying human diseases due to its high genome similarity to that of humans and the optical transparency in embryonic stages. However, it becomes difficult for pure optical imaging techniques to volumetric visualize the internal organs and structures of wild-type zebrafish in juvenile and adult stages with excellent resolution and penetration depth. Even with the establishment of mutant lines which remain transparent over the life cycle, it is still a challenge for pure optical imaging modalities to image the whole body of adult zebrafish with micro-scale resolution. However, the method called photoacoustic imaging that combines all the advantages of the optical imaging and ultrasonic imaging provides a new way to image the whole body of the zebrafish. In this work, we developed a non-invasive photoacoustic imaging system with optimized near-infrared illumination and cylindrical scanning to image the zebrafish. The lateral and axial resolution yield to 80 μm and 600 μm, respectively. Multispectral strategy with wavelengths from 690 nm to 930 nm was employed to image various organs inside the zebrafish. From the reconstructed images, most major organs and structures inside the body can be precisely imaged. Quantitative and statistical analysis of absorption for organs under illumination with different wavelengths were carried out.

  9. Subdivisions of the adult zebrafish pallium based on molecular marker analysis

    PubMed Central

    Ganz, Julia; Kroehne, Volker; Freudenreich, Dorian; Machate, Anja; Geffarth, Michaela; Braasch, Ingo; Kaslin, Jan; Brand, Michael

    2015-01-01

    Background: The telencephalon shows a remarkable structural diversity among vertebrates. In particular, the everted telencephalon of ray-finned fishes has a markedly different morphology compared to the evaginated telencephalon of all other vertebrates. This difference in development has hampered the comparison between different areas of the pallium of ray-finned fishes and the pallial nuclei of all other vertebrates. Various models of homology between pallial subdivisions in ray-finned fishes and the pallial nuclei in tetrapods have been proposed based on connectional, neurochemical, gene expression and functional data. However, no consensus has been reached so far. In recent years, the analysis of conserved developmental marker genes has assisted the identification of homologies for different parts of the telencephalon among several tetrapod species. Results: We have investigated the gene expression pattern of conserved marker genes in the adult zebrafish ( Danio rerio) pallium to identify pallial subdivisions and their homology to pallial nuclei in tetrapods. Combinatorial expression analysis of ascl1a, eomesa, emx1, emx2, emx3, and Prox1 identifies four main divisions in the adult zebrafish pallium. Within these subdivisions, we propose that Dm is homologous to the pallial amygdala in tetrapods and that the dorsal subdivision of Dl is homologous to part of the hippocampal formation in mouse. We have complemented this analysis be examining the gene expression of emx1, emx2 and emx3 in the zebrafish larval brain. Conclusions: Based on our gene expression data, we propose a new model of subdivisions in the adult zebrafish pallium and their putative homologies to pallial nuclei in tetrapods. Pallial nuclei control sensory, motor, and cognitive functions, like memory, learning and emotion. The identification of pallial subdivisions in the adult zebrafish and their homologies to pallial nuclei in tetrapods will contribute to the use of the zebrafish system as a model

  10. Trim69 regulates zebrafish brain development by ap-1 pathway

    PubMed Central

    Han, Ruiqin; Wang, Renxian; Zhao, Qing; Han, Yongqing; Zong, Shudong; Miao, Shiying; Song, Wei; Wang, Linfang

    2016-01-01

    Proteins belonging to the TRIM family have been implicated in a variety of cellular processes such as apoptosis, differentiation, neurogenesis, muscular physiology and innate immune responses. Trim69, previously identified as a novel gene cloned from a human testis cDNA library, has a homologous gene in zebrafish and this study focused on investigating the function of trim69 in zebrafish neurogenesis. Trim69 was found to be expressed in zebrafish embryo brain at the early stages. Knockdown of trim69 led to deformed brain development, obvious signs of apoptosis present in the head, and decreased expression of neuronal differentiation and stem cell markers. This phenotype was rescued upon co-injection of human mRNA together along with the trim69 knockdown. Results of this study also showed an interaction between TRIM69 and c-Jun in human cells, and upon TRIM69 knock down c-Jun expression subsequently increased, whereas the over-expression of TRIM69 led to the down-regulation of c-Jun. Additionally, knockdown both c-Jun and trim69 can rescue the deformed brain, evident cellular apoptosis in the head and decreased expression of neuronal differentiation and stem cell markers. Overall, our results support a role for trim69 in the development of the zebrafish brain through ap-1 pathway. PMID:27050765

  11. Characterization of multiciliated ependymal cells that emerge in the neurogenic niche of the aged zebrafish brain.

    PubMed

    Ogino, Takashi; Sawada, Masato; Takase, Hiroshi; Nakai, Chiemi; Herranz-Pérez, Vicente; Cebrián-Silla, Arantxa; Kaneko, Naoko; García-Verdugo, José Manuel; Sawamoto, Kazunobu

    2016-10-15

    In mammals, ventricular walls of the developing brain maintain a neurogenic niche, in which radial glial cells act as neural stem cells (NSCs) and generate new neurons in the embryo. In the adult brain, the neurogenic niche is maintained in the ventricular-subventricular zone (V-SVZ) of the lateral wall of lateral ventricles and the hippocampal dentate gyrus. In the neonatal V-SVZ, radial glial cells transform into astrocytic postnatal NSCs and multiciliated ependymal cells. On the other hand, in zebrafish, radial glial cells continue to cover the surface of the adult telencephalic ventricle and maintain a higher neurogenic potential in the adult brain. However, the cell composition of the neurogenic niche of the aged zebrafish brain has not been investigated. Here we show that multiciliated ependymal cells emerge in the neurogenic niche of the aged zebrafish telencephalon. These multiciliated cells appear predominantly in the dorsal part of the ventral telencephalic ventricular zone, which also contains clusters of migrating new neurons. Scanning electron microscopy and live imaging analyses indicated that these multiple cilia beat coordinately and generate constant fluid flow within the ventral telencephalic ventricle. Analysis of the cell composition by transmission electron microscopy revealed that the neurogenic niche in the aged zebrafish contains different types of cells, with ultrastructures similar to those of ependymal cells, transit-amplifying cells, and migrating new neurons in postnatal mice. These data suggest that the transformation capacity of radial glial cells is conserved but that its timing is different between fish and mice. J. Comp. Neurol. 524:2982-2992, 2016. © 2016 Wiley Periodicals, Inc.

  12. Zebrafish adult-derived hypothalamic neurospheres generate gonadotropin-releasing hormone (GnRH) neurons

    PubMed Central

    Cortés-Campos, Christian; Letelier, Joaquín; Ceriani, Ricardo; Whitlock, Kathleen E.

    2015-01-01

    ABSTRACT Gonadotropin-releasing hormone (GnRH) is a hypothalamic decapeptide essential for fertility in vertebrates. Human male patients lacking GnRH and treated with hormone therapy can remain fertile after cessation of treatment suggesting that new GnRH neurons can be generated during adult life. We used zebrafish to investigate the neurogenic potential of the adult hypothalamus. Previously we have characterized the development of GnRH cells in the zebrafish linking genetic pathways to the differentiation of neuromodulatory and endocrine GnRH cells in specific regions of the brain. Here, we developed a new method to obtain neural progenitors from the adult hypothalamus in vitro. Using this system, we show that neurospheres derived from the adult hypothalamus can be maintained in culture and subsequently differentiate glia and neurons. Importantly, the adult derived progenitors differentiate into neurons containing GnRH and the number of cells is increased through exposure to either testosterone or GnRH, hormones used in therapeutic treatment in humans. Finally, we show in vivo that a neurogenic niche in the hypothalamus contains GnRH positive neurons. Thus, we demonstrated for the first time that neurospheres can be derived from the hypothalamus of the adult zebrafish and that these neural progenitors are capable of producing GnRH containing neurons. PMID:26209533

  13. Unpredictable Chronic Stress Alters Adenosine Metabolism in Zebrafish Brain.

    PubMed

    Zimmermann, F F; Altenhofen, S; Kist, L W; Leite, C E; Bogo, M R; Cognato, G P; Bonan, C D

    2016-05-01

    Stress is considered a risk factor for several human disorders. Despite the broad knowledge of stress responses in mammals, data on the relationship between unpredictable chronic stress (UCS) and its effects on purinergic signaling are limited. ATP hydrolysis by ectonucleotidases is an important source of adenosine, and adenosine deaminase (ADA) contributes to the control of the nucleoside concentrations. Considering that some stress models could affect signaling systems, the objective of this study was to investigate whether UCS alters ectonucleotidase and ADA pathway in zebrafish brain. Additionally, we analyzed ATP metabolism as well as ada1, ada2.1, ada2.2, adaL, and adaasi gene expression in zebrafish brain. Our results have demonstrated that UCS did not alter ectonucleotidase and soluble ADA activities. However, ecto-ADA activity was significantly decreased (26.8%) in brain membranes of animals exposed to UCS when compared to the control group. Quantitative reverse transcription PCR (RT-PCR) analysis did not show significant changes on ADA gene expression after the UCS exposure. The brain ATP metabolism showed a marked increase in adenosine levels (ADO) in animals exposed to UCS. These data suggest an increase on extracellular adenosine levels in zebrafish brain. Since this nucleoside has neuromodulatory and anxiolytic effects, changes in adenosine levels could play a role in counteracting the stress, which could be related to a compensatory mechanism in order to restore the homeostasis.

  14. F-Spondin/spon1b Expression Patterns in Developing and Adult Zebrafish

    PubMed Central

    Akle, Veronica; Guelin, Emmanuel; Yu, Lili; Brassard-Giordano, Helena; Slack, Barbara E.; Zhdanova, Irina V.

    2012-01-01

    F-spondin, an extracellular matrix protein, is an important player in embryonic morphogenesis and CNS development, but its presence and role later in life remains largely unknown. We generated a transgenic zebrafish in which GFP is expressed under the control of the F-spondin (spon1b) promoter, and used it in combination with complementary techniques to undertake a detailed characterization of the expression patterns of F-spondin in developing and adult brain and periphery. We found that F-spondin is often associated with structures forming long neuronal tracts, including retinal ganglion cells, the olfactory bulb, the habenula, and the nucleus of the medial longitudinal fasciculus (nMLF). F-spondin expression coincides with zones of adult neurogenesis and is abundant in CSF-contacting secretory neurons, especially those in the hypothalamus. Use of this new transgenic model also revealed F-spondin expression patterns in the peripheral CNS, notably in enteric neurons, and in peripheral tissues involved in active patterning or proliferation in adults, including the endoskeleton of zebrafish fins and the continuously regenerating pharyngeal teeth. Moreover, patterning of the regenerating caudal fin following fin amputation in adult zebrafish was associated with F-spondin expression in the blastema, a proliferative region critical for tissue reconstitution. Together, these findings suggest major roles for F-spondin in the CNS and periphery of the developing and adult vertebrate. PMID:22768035

  15. Absence of rapid eye movements during sleep in adult zebrafish.

    PubMed

    Árnason, B B; Þorsteinsson, H; Karlsson, K Æ

    2015-09-15

    Sleep is not a uniform phenomenon, but is organized in alternating, fundamentally different states, rapid eye movement sleep and non-rapid eye movement sleep. Zebrafish (Danio rerio) have recently emerged as an excellent model for sleep research. Zebrafish are well characterized in terms of development, neurobiology and genetics. Moreover, there are many experimental tools not easily applied in mammalian models that can be readily applied to zebrafish, making them a valuable additional animal model for sleep research. Sleep in zebrafish is defined behaviorally and exhibits the hallmarks of mammalian sleep (e.g. sleep homeostasis and pressure). To our knowledge no attempts have been made to discern if sleep in zebrafish entails alternations of REM-NREM sleep cycles which are critical for further development of the model. In the current experiment we quantify two key REM sleep components, rapid eye movements and respiratory rates, across sleep-wake cycles. We find no sleep-related rapid eye movements. During sleep respiratory rates, however, are reduced and become less regular, further establishing that the behavioral definition used truly captures a change in the fish's physiology. We thus fail to find evidence for REM-NREM sleep cycles in zebrafish but demonstrate a physiological change that occurs concomitantly with the previously defined behavioral state of sleep. We do not rule out that other phasic REM components (e.g. atonia, cardiac arrhythmias, myoclonic twitches or desynchronized EEG) are coherently expressed during sleep but we conclude that adult zebrafish do not have REM-sleep-related rapid eye movements.

  16. Atlas of Cellular Dynamics during Zebrafish Adult Kidney Regeneration

    PubMed Central

    McCampbell, Kristen K.; Springer, Kristin N.; Wingert, Rebecca A.

    2015-01-01

    The zebrafish is a useful animal model to study the signaling pathways that orchestrate kidney regeneration, as its renal nephrons are simple, yet they maintain the biological complexity inherent to that of higher vertebrate organisms including mammals. Recent studies have suggested that administration of the aminoglycoside antibiotic gentamicin in zebrafish mimics human acute kidney injury (AKI) through the induction of nephron damage, but the timing and details of critical phenotypic events associated with the regeneration process, particularly in existing nephrons, have not been characterized. Here, we mapped the temporal progression of cellular and molecular changes that occur during renal epithelial regeneration of the proximal tubule in the adult zebrafish using a platform of histological and expression analysis techniques. This work establishes the timing of renal cell death after gentamicin injury, identifies proliferative compartments within the kidney, and documents gene expression changes associated with the regenerative response of proliferating cells. These data provide an important descriptive atlas that documents the series of events that ensue after damage in the zebrafish kidney, thus availing a valuable resource for the scientific community that can facilitate the implementation of zebrafish research to delineate the mechanisms that control renal regeneration. PMID:26089919

  17. Wnt/β-catenin signaling promotes regeneration after adult zebrafish spinal cord injury.

    PubMed

    Strand, Nicholas S; Hoi, Kimberly K; Phan, Tien M T; Ray, Catherine A; Berndt, Jason D; Moon, Randall T

    2016-09-02

    Unlike mammals, zebrafish can regenerate their injured spinal cord and regain control of caudal tissues. It was recently shown that Wnt/β-catenin signaling is necessary for spinal cord regeneration in the larval zebrafish. However, the molecular mechanisms of regeneration may or may not be conserved between larval and adult zebrafish. To test this, we assessed the role of Wnt/β-catenin signaling after spinal cord injury in the adult zebrafish. We show that Wnt/β-catenin signaling is increased after spinal cord injury in the adult zebrafish. Moreover, overexpression of Dkk1b inhibited Wnt/β-catenin signaling in the regenerating spinal cord of adult zebrafish. Dkk1b overexpression also inhibited locomotor recovery, axon regeneration, and glial bridge formation in the injured spinal cord. Thus, our data illustrate a conserved role for Wnt/β-catenin signaling in adult and larval zebrafish spinal cord regeneration.

  18. Analysis of Extracellular Nucleotide Metabolism in Adult Zebrafish After Embryological Exposure to Valproic Acid.

    PubMed

    Zimmermann, Fernanda Francine; Gaspary, Karina Vidarte; Siebel, Anna Maria; Leite, Carlos Eduardo; Kist, Luiza Wilges; Bogo, Mauricio Reis; Bonan, Carla Denise

    2016-05-17

    Autism is a neurodevelopmental disorder characterized by symptoms related to stereotyped movements, deficits in social interaction, impaired communication, anxiety, hyperactivity, and the presence of restricted interests. Evidence indicates an important role of extracellular ATP and adenosine as signaling molecules in autism. ATP hydrolysis by ectonucleotidases is an important source of adenosine, and adenosine deaminase (ADA) contributes to the control of the nucleoside concentrations. Considering zebrafish is an animal model that may contribute towards to understanding the mechanisms that underlie social behavior, we investigated the purinergic signaling in a model of embryological exposure to valproic acid (VPA) that induces social interaction deficit in adult zebrafish. We demonstrated embryological exposure to VPA did not change ATP and ADP hydrolysis in zebrafish at 120 dpf, and the cytosolic (soluble) ADA activity was not altered. However, we observed an increase of AMP hydrolysis (12.5 %) whereas the ecto-ADA activity was decreased (19.2 %) in adult zebrafish submitted to embryological exposure to VPA. Quantitative reverse transcription PCR (RT-PCR) analysis showed changes on ntpd8, ADA 2.1, and A2a1 mRNA transcript levels. Brain ATP metabolism showed a rapid catabolism of ATP and ADP, whereas the extracellular metabolism of AMP and adenosine (ADO) occurred slowly. We demonstrated that embryological exposure to VPA altered biochemical and molecular parameters related to purinergic system in adult zebrafish. These findings indicate that the enzyme activities involved in the control of ATP and adenosine levels may be involved in the pathophysiological mechanisms of diseases related to the impairment of social interaction, such as autism.

  19. G-protein-coupled estrogen receptor 1 is involved in brain development during zebrafish (Danio rerio) embryogenesis

    SciTech Connect

    Shi, Yanan; Liu, Xiaochun; Zhu, Pei; Li, Jianzhen; Sham, Kathy W.Y.; Cheng, Shuk Han; Li, Shuisheng; Zhang, Yong; Cheng, Christopher H.K.; Lin, Haoran

    2013-05-24

    Highlights: •The Gper expression was detected in the developing brain of zebrafish. •Gper morpholino knockdown induced apoptosis of brain cells. •Gper morpholino knockdown reduced expression in neuron markers. •Zebrafish Gper may be involved in neuronal development. -- Abstract: G-protein-coupled estrogen receptor 1 (Gper, formerly known as GPR30) is found to be a trophic and protective factor in mediating action of estrogen in adult brain, while its role in developing brain remains to be elucidated. Here we present the expression pattern of Gper and its functions during embryogenesis in zebrafish. Both the mRNA and protein of Gper were detected throughout embryogenesis. Whole mount in situ hybridization (WISH) revealed a wide distribution of gper mRNAs in various regions of the developing brain. Gper knockdown by specific morpholinos resulted in growth retardation in embryos and morphological defects in the developing brain. In addition, induced apoptosis, decreased proliferation of the brain cells and maldevelopment of sensory and motor neurons were also found in the morphants. Our results provide novel insights into Gper functions in the developing brain, revealing that Gper can maintain the survival of the brain cells, and formation and/or differentiation of the sensory and motor neurons.

  20. Whole-body multispectral photoacoustic imaging of adult zebrafish

    PubMed Central

    Huang, Na; Guo, Heng; Qi, Weizhi; Zhang, Zhiwei; Rong, Jian; Yuan, Zhen; Ge, Wei; Jiang, Huabei; Xi, Lei

    2016-01-01

    The zebrafish, an ideal vertebrate for studying developmental biology and genetics, is increasingly being used to understand human diseases, due to its high similarity to the human genome and its optical transparency during embryonic stages. Once the zebrafish has fully developed, especially wild-type breeds, conventional optical imaging techniques have difficulty in imaging the internal organs and structures with sufficient resolution and penetration depth. Even with established mutant lines that remain transparent throughout their life cycle, it is still challenging for purely optical imaging modalities to visualize the organs of juvenile and adult zebrafish at a micro-scale spatial resolution. In this work, we developed a non-invasive three-dimensional photoacoustic imaging platform with an optimized illumination pattern and a cylindrical-scanning-based data collection system to image entire zebrafish with micro-scale resolutions of 80 μm and 600 μm in the lateral and axial directions, respectively. In addition, we employed a multispectral strategy that utilized excitation wavelengths from 690 nm to 930 nm to statistically quantify the relative optical absorption spectrum of major organs. PMID:27699119

  1. Development and specification of cerebellar stem and progenitor cells in zebrafish: from embryo to adult

    PubMed Central

    2013-01-01

    Background Teleost fish display widespread post-embryonic neurogenesis originating from many different proliferative niches that are distributed along the brain axis. During the development of the central nervous system (CNS) different cell types are produced in a strict temporal order from increasingly committed progenitors. However, it is not known whether diverse neural stem and progenitor cell types with restricted potential or stem cells with broad potential are maintained in the teleost fish brain. Results To study the diversity and output of neural stem and progenitor cell populations in the zebrafish brain the cerebellum was used as a model brain region, because of its well-known architecture and development. Transgenic zebrafish lines, in vivo imaging and molecular markers were used to follow and quantify how the proliferative activity and output of cerebellar progenitor populations progress. This analysis revealed that the proliferative activity and progenitor marker expression declines in juvenile zebrafish before they reach sexual maturity. Furthermore, this correlated with the diminished repertoire of cell types produced in the adult. The stem and progenitor cells derived from the upper rhombic lip were maintained into adulthood and they actively produced granule cells. Ventricular zone derived progenitor cells were largely quiescent in the adult cerebellum and produced a very limited number of glia and inhibitory inter-neurons. No Purkinje or Eurydendroid cells were produced in fish older than 3 months. This suggests that cerebellar cell types are produced in a strict temporal order from distinct pools of increasingly committed stem and progenitor cells. Conclusions Our results in the zebrafish cerebellum show that neural stem and progenitor cell types are specified and they produce distinct cell lineages and sub-types of brain cells. We propose that only specific subtypes of brain cells are continuously produced throughout life in the teleost fish

  2. A Simple Method for Immunohistochemical Staining of Zebrafish Brain Sections for c-fos Protein Expression.

    PubMed

    Chatterjee, Diptendu; Tran, Steven; Shams, Soaleha; Gerlai, Robert

    2015-12-01

    Immediate early genes (IEGs) are transcription factors whose own transcription is initiated rapidly, for example, in the brain in response to environmental stimuli. c-fos is an IEG often used as a marker of neuronal activation. c-fos mRNA expression has started to be quantified and localized in the zebrafish brain following environmental manipulations but analysis of the expression of c-fos protein in the zebrafish brain has rarely been attempted. Here, we describe an immunofluorescence staining method for quantifying c-fos protein expression in different regions of the zebrafish brain. In addition, we expose zebrafish to caffeine, a positive control for c-fos activation in the brain. To confirm cell nucleus specific binding of the c-fos antibody, we counterstained brain sections with the nuclear fluorescent stain DAPI. Furthermore, we describe a method for reducing background autofluorescence often observed in zebrafish brain tissue. Our analysis showed that exposure to caffeine increased the number of c-fos protein-positive cells in specific zebrafish brain regions detected by the immunofluorescence method. Our results demonstrate the feasibility of immunofluorescence-based methods in the analysis of neuronal activation in the zebrafish brain, and reinforce the utility of the zebrafish in behavioral neuroscience research.

  3. Social modulation of brain monoamine levels in zebrafish.

    PubMed

    Teles, Magda C; Dahlbom, S Josefin; Winberg, Svante; Oliveira, Rui F

    2013-09-15

    In social species animals tend to adjust their social behaviour according to the available social information in the group, in order to optimize and improve their one social status. This changing environment requires for rapid and transient behavioural changes that relies primarily on biochemical switching of existing neural networks. Monoamines and neuropeptides are the two major candidates to mediate these changes in brain states underlying socially behavioural flexibility. In the current study we used zebrafish (Danio rerio) males to study the effects of acute social interactions on rapid regional changes in brain levels of monoamines (serotonin and dopamine). A behavioural paradigm under which male zebrafish consistently express fighting behaviour was used to investigate the effects of different social experiences: winning the interaction, losing the interaction, or fighting an unsolved interaction (mirror image). We found that serotonergic activity is significantly higher in the telencephalon of winners and in the optic tectum of losers, and no significant changes were observed in mirror fighters suggesting that serotonergic activity is differentially regulated in different brain regions by social interactions. Dopaminergic activity it was also significantly higher in the telencephalon of winners which may be representative of social reward. Together our data suggests that acute social interactions elicit rapid and differential changes in serotonergic and dopaminergic activity across different brain regions.

  4. In vivo cell tracking and quantification method in adult zebrafish

    NASA Astrophysics Data System (ADS)

    Zhang, Li; Alt, Clemens; Li, Pulin; White, Richard M.; Zon, Leonard I.; Wei, Xunbin; Lin, Charles P.

    2012-03-01

    Zebrafish have become a powerful vertebrate model organism for drug discovery, cancer and stem cell research. A recently developed transparent adult zebrafish using double pigmentation mutant, called casper, provide unparalleled imaging power in in vivo longitudinal analysis of biological processes at an anatomic resolution not readily achievable in murine or other systems. In this paper we introduce an optical method for simultaneous visualization and cell quantification, which combines the laser scanning confocal microscopy (LSCM) and the in vivo flow cytometry (IVFC). The system is designed specifically for non-invasive tracking of both stationary and circulating cells in adult zebrafish casper, under physiological conditions in the same fish over time. The confocal imaging part in this system serves the dual purposes of imaging fish tissue microstructure and a 3D navigation tool to locate a suitable vessel for circulating cell counting. The multi-color, multi-channel instrument allows the detection of multiple cell populations or different tissues or organs simultaneously. We demonstrate initial testing of this novel instrument by imaging vasculature and tracking circulating cells in CD41: GFP/Gata1: DsRed transgenic casper fish whose thrombocytes/erythrocytes express the green and red fluorescent proteins. Circulating fluorescent cell incidents were recorded and counted repeatedly over time and in different types of vessels. Great application opportunities in cancer and stem cell researches are discussed.

  5. Fgf regulates dedifferentiation during skeletal muscle regeneration in adult zebrafish.

    PubMed

    Saera-Vila, Alfonso; Kish, Phillip E; Kahana, Alon

    2016-09-01

    Fibroblast growth factors (Fgfs) regulate critical biological processes such as embryonic development, tissue homeostasis, wound healing, and tissue regeneration. In zebrafish, Fgf signaling plays an important role in the regeneration of the spinal cord, liver, heart, fin, and photoreceptors, although its exact mechanism of action is not fully understood. Utilizing an adult zebrafish extraocular muscle (EOM) regeneration model, we demonstrate that blocking Fgf receptor function using either a chemical inhibitor (SU5402) or a dominant-negative transgenic construct (dnFGFR1a:EGFP) impairs muscle regeneration. Adult zebrafish EOMs regenerate through a myocyte dedifferentiation process, which involves a muscle-to-mesenchyme transition and cell cycle reentry by differentiated myocytes. Blocking Fgf signaling reduced cell proliferation and active caspase 3 levels in the regenerating muscle with no detectable levels of apoptosis, supporting the hypothesis that Fgf signaling is involved in the early steps of dedifferentiation. Fgf signaling in regenerating myocytes involves the MAPK/ERK pathway: inhibition of MEK activity with U0126 mimicked the phenotype of the Fgf receptor inhibition on both muscle regeneration and cell proliferation, and activated ERK (p-ERK) was detected in injured muscles by immunofluorescence and western blot. Interestingly, following injury, ERK2 expression is specifically induced and activated by phosphorylation, suggesting a key role in muscle regeneration. We conclude that the critical early steps of myocyte dedifferentiation in EOM regeneration are dependent on Fgf signaling.

  6. Characterization of Proliferating Neural Progenitors after Spinal Cord Injury in Adult Zebrafish

    PubMed Central

    Hui, Subhra Prakash; Nag, Tapas Chandra; Ghosh, Sukla

    2015-01-01

    Zebrafish can repair their injured brain and spinal cord after injury unlike adult mammalian central nervous system. Any injury to zebrafish spinal cord would lead to increased proliferation and neurogenesis. There are presences of proliferating progenitors from which both neuronal and glial loss can be reversed by appropriately generating new neurons and glia. We have demonstrated the presence of multiple progenitors, which are different types of proliferating populations like Sox2+ neural progenitor, A2B5+ astrocyte/ glial progenitor, NG2+ oligodendrocyte progenitor, radial glia and Schwann cell like progenitor. We analyzed the expression levels of two common markers of dedifferentiation like msx-b and vimentin during regeneration along with some of the pluripotency associated factors to explore the possible role of these two processes. Among the several key factors related to pluripotency, pou5f1 and sox2 are upregulated during regeneration and associated with activation of neural progenitor cells. Uncovering the molecular mechanism for endogenous regeneration of adult zebrafish spinal cord would give us more clues on important targets for future therapeutic approach in mammalian spinal cord repair and regeneration. PMID:26630262

  7. Preconditioning boosts regenerative programmes in the adult zebrafish heart

    PubMed Central

    de Preux Charles, Anne-Sophie; Bise, Thomas; Baier, Felix; Sallin, Pauline; Jaźwińska, Anna

    2016-01-01

    During preconditioning, exposure to a non-lethal harmful stimulus triggers a body-wide increase of survival and pro-regenerative programmes that enable the organism to better withstand the deleterious effects of subsequent injuries. This phenomenon has first been described in the mammalian heart, where it leads to a reduction of infarct size and limits the dysfunction of the injured organ. Despite its important clinical outcome, the actual mechanisms underlying preconditioning-induced cardioprotection remain unclear. Here, we describe two independent models of cardiac preconditioning in the adult zebrafish. As noxious stimuli, we used either a thoracotomy procedure or an induction of sterile inflammation by intraperitoneal injection of immunogenic particles. Similar to mammalian preconditioning, the zebrafish heart displayed increased expression of cardioprotective genes in response to these stimuli. As zebrafish cardiomyocytes have an endogenous proliferative capacity, preconditioning further elevated the re-entry into the cell cycle in the intact heart. This enhanced cycling activity led to a long-term modification of the myocardium architecture. Importantly, the protected phenotype brought beneficial effects for heart regeneration within one week after cryoinjury, such as a more effective cell-cycle reentry, enhanced reactivation of embryonic gene expression at the injury border, and improved cell survival shortly after injury. This study reveals that exposure to antecedent stimuli induces adaptive responses that render the fish more efficient in the activation of the regenerative programmes following heart damage. Our results open a new field of research by providing the adult zebrafish as a model system to study remote cardiac preconditioning. PMID:27440423

  8. Distinct expression patterns of syndecans in the embryonic zebrafish brain.

    PubMed

    Hofmeister, Wolfgang; Devine, Christine A; Key, Brian

    2013-01-01

    Axon pathfinding in the neuroepithelium of embryonic brain is dependent on a variety of short and long range guidance cues. Heparan sulfate proteoglycans such as syndecans act as modulators of these cues and their importance in neural development is highlighted by their phylogenetic conservation. In Drosophilia, a single syndecan is present on the surface of axon growth cones and is required for chemorepulsive signalling during midline crossing. Understanding the role of syndecans in the vertebrate nervous system is challenging given that there are four homologous genes, syndecans 1-4. We show here that syndecans 2-4 are expressed in the zebrafish embryonic brain during the major period of axon growth. These genes show differing expression patterns in the brain which provides putative insights into their functional specificity.

  9. Gene expression changes in female zebrafish (Danio rerio) brain in response to acute exposure to methylmercury

    USGS Publications Warehouse

    Richter, Catherine A.; Garcia-Reyero, Natàlia; Martyniuk, Chris; Knoebl, Iris; Pope, Marie; Wright-Osment, Maureen K.; Denslow, Nancy D.; Tillitt, Donald E.

    2011-01-01

    Methylmercury (MeHg) is a potent neurotoxicant and endocrine disruptor that accumulates in aquatic systems. Previous studies have shown suppression of hormone levels in both male and female fish, suggesting effects on gonadotropin regulation in the brain. The gene expression profile in adult female zebrafish whole brain induced by acute (96 h) MeHg exposure was investigated. Fish were exposed by injection to 0 or 0.5(mu or u)g MeHg/g. Gene expression changes in the brain were examined using a 22,000-feature zebrafish microarray. At a significance level of pbrain. Future studies will compare the gene expression profile induced in response to MeHg with that induced by other toxicants and will investigate responsive genes as potential biomarkers of MeHg exposure.

  10. GENE EXPRESSION CHANGES IN FEMALE ZEBRAFISH (DANIO RERIO) BRAIN IN RESPONSE TO ACUTE EXPOSURE TO METHYLMERCURY

    PubMed Central

    Richter, Catherine A.; Garcia-Reyero, Natàlia; Martyniuk, Chris; Knoebl, Iris; Pope, Marie; Wright-Osment, Maureen K.; Denslow, Nancy D.; Tillitt, Donald E.

    2010-01-01

    Methylmercury (MeHg) is a potent neurotoxicant and endocrine disruptor that accumulates in aquatic systems. Previous studies have shown suppression of hormone levels in both male and female fish, suggesting effects on gonadotropin regulation in the brain. The gene expression profile in adult female zebrafish whole brain induced by acute (96 hr) MeHg exposure was investigated. Fish were exposed by injection to 0 or 0.5 μg MeHg/g. Gene expression changes in the brain were examined using a 22,000 feature zebrafish microarray. At a significance level of p<0.01, 79 genes were up-regulated and 76 genes were down-regulated in response to MeHg exposure. Individual genes exhibiting altered expression in response to MeHg exposure implicate effects on glutathione metabolism in the mechanism of MeHg neurotoxicity. Gene ontology (GO) terms significantly enriched among altered genes included protein folding, cell redox homeostasis, and steroid biosynthetic process. The most affected biological functions were related to the nervous system development and function, as well as lipid metabolism and molecular transport. These results support the involvement of oxidative stress and effects on protein structure in the mechanism of action of MeHg in the female brain. Future studies will compare the gene expression profile induced in response to MeHg with that induced by other toxicants and investigate responsive genes as potential biomarkers of MeHg exposure. PMID:21082716

  11. Brain and gonadal aromatase as potential targets of endocrine disrupting chemicals in a model species, the zebrafish (Danio rerio).

    PubMed

    Hinfray, N; Palluel, O; Turies, C; Cousin, C; Porcher, J M; Brion, F

    2006-08-01

    Many chemicals in the aquatic environment are able to adversely affect in vitro brain and ovarian aromatase expression/activity. However, it remains to be determined if these substances elicit in vivo effect in fish. With the view to further understanding possible effects of endocrine disrupting chemicals (EDCs) on aromatase function, we first developed methods to measure brain and ovarian aromatase expression/activity in a model species, the zebrafish, and assessed the effect of estradiol (E2) and androstatrienedione (ATD), a steroidal aromatase inhibitor. We showed that CYP19b gene was predominantly expressed in the brain whereas in the ovary CYP19a mRNA level was predominant. Moreover, aromatase activities (AA) were higher in brain than in ovary. In adult zebrafish, E2 treatment had no effect on aromatase expression/activity in brain, whereas at larval stage, E2 strongly triggered CYP19b expression. In the ovaries, E2 led to a complete inhibition of both CYP19a expression and AA. Exposure to ATD led to a total inhibition of both brain and ovarian AA but had no effect on CYP19 transcripts abundance. Together, these results provide relevant knowledge concerning the characterization of aromatase in the zebrafish, and reinforce the idea that brain and ovarian aromatase are promising markers of EDCs in fish and deserve further in vivo studies.

  12. Molecular psychiatry of zebrafish

    PubMed Central

    Stewart, Adam Michael; Ullmann, Jeremy F.P.; Norton, William H.J.; Brennan, Caroline H.; Parker, Matthew O.; Gerlai, Robert; Kalueff, Allan V.

    2014-01-01

    Due to their well-characterized neural development and high genetic homology to mammals, zebrafish (Danio rerio) have emerged as a powerful model organism in the field of biological psychiatry. Here, we discuss the molecular psychiatry of zebrafish, and its implications for translational neuroscience research and modeling CNS disorders. In particular, we outline recent genetic and technological developments allowing for in-vivo examinations, high-throughput screening and whole-brain analyses in larval and adult zebrafish. We also summarize the application of these molecular techniques to the understanding of neuropsychiatric disease, outlining the potential of zebrafish for modeling complex brain disorders, including attention-deficit/hyperactivity disorder (ADHD), aggression, post-traumatic stress and substance abuse. Critically evaluating the advantages and limitations of larval and adult fish tests, we suggest that zebrafish models become a rapidly emerging new field in modern biological psychiatry research. PMID:25349164

  13. Photopic and scotopic spatiotemporal tuning of adult zebrafish vision

    PubMed Central

    Hollbach, Nadine; Tappeiner, Christoph; Jazwinska, Anna; Enzmann, Volker; Tschopp, Markus

    2015-01-01

    Sensitivity to spatial and temporal patterns is a fundamental aspect of vision. Herein, we investigated this sensitivity in adult zebrafish for a wide range of spatial (0.014 to 0.511 cycles/degree [c/d]) and temporal frequencies (0.025 to 6 cycles/s) to better understand their visual system. Measurements were performed at photopic (1.8 log cd m−2) and scotopic (−4.5 log cd m−2) light levels to assess the optokinetic response (OKR). The resulting spatiotemporal contrast sensitivity (CS) functions revealed that the OKR of zebrafish is tuned to spatial frequency and speed but not to temporal frequencies. Thereby, optimal test parameters for CS measurements were identified. At photopic light levels, a spatial frequency of 0.116 ± 0.01 c/d (mean ± SD) and a grating speed of 8.42 ± 2.15 degrees/second (d/s) was ideal; at scotopic light levels, these values were 0.110 ± 0.02 c/d and 5.45 ± 1.31 d/s, respectively. This study allows to better characterize zebrafish mutants with altered vision and to distinguish between defects of rod and cone photoreceptors as measurements were performed under different light conditions. PMID:25788878

  14. Effects of piracetam on behavior and memory in adult zebrafish.

    PubMed

    Grossman, Leah; Stewart, Adam; Gaikwad, Siddharth; Utterback, Eli; Wu, Nadine; Dileo, John; Frank, Kevin; Hart, Peter; Howard, Harry; Kalueff, Allan V

    2011-04-25

    Piracetam, a derivative of γ-aminobutyric acid, exerts memory-enhancing and mild anxiolytic effects in human and rodent studies. To examine the drug's behavioral profile further, we assessed its effects on behavioral and endocrine (cortisol) responses of adult zebrafish (Danio rerio)--a novel model species rapidly gaining popularity in neurobehavioral research. Overall, acute piracetam did not affect zebrafish novel tank and light-dark box behavior at mild doses (25-400mg/L), but produced nonspecific behavioral inhibition at 700mg/L. No effects on cortisol levels or inter-/intra-session habituation in the novel tank test were observed for acute or chronic mild non-sedative dose of 200mg/L. In contrast, fish exposed to chronic piracetam at this dose performed significantly better in the cued learning plus-maze test. This observation parallels clinical and rodent literature on the behavioral profile of piracetam, supporting the utility of zebrafish paradigms for testing nootropic agents.

  15. Myocyte Dedifferentiation Drives Extraocular Muscle Regeneration in Adult Zebrafish

    PubMed Central

    Saera-Vila, Alfonso; Kasprick, Daniel S.; Junttila, Tyler L.; Grzegorski, Steven J.; Louie, Ke'ale W.; Chiari, Estelle F.; Kish, Phillip E.; Kahana, Alon

    2015-01-01

    Purpose The purpose of this study was to characterize the injury response of extraocular muscles (EOMs) in adult zebrafish. Methods Adult zebrafish underwent lateral rectus (LR) muscle myectomy surgery to remove 50% of the muscle, followed by molecular and cellular characterization of the tissue response to the injury. Results Following myectomy, the LR muscle regenerated an anatomically correct and functional muscle within 7 to 10 days post injury (DPI). Following injury, the residual muscle stump was replaced by a mesenchymal cell population that lost cell polarity and expressed mesenchymal markers. Next, a robust proliferative burst repopulated the area of the regenerating muscle. Regenerating cells expressed myod, identifying them as myoblasts. However, both immunofluorescence and electron microscopy failed to identify classic Pax7-positive satellite cells in control or injured EOMs. Instead, some proliferating nuclei were noted to express mef2c at the very earliest point in the proliferative burst, suggesting myonuclear reprogramming and dedifferentiation. Bromodeoxyuridine (BrdU) labeling of regenerating cells followed by a second myectomy without repeat labeling resulted in a twice-regenerated muscle broadly populated by BrdU-labeled nuclei with minimal apparent dilution of the BrdU signal. A double-pulse experiment using BrdU and 5-ethynyl-2′-deoxyuridine (EdU) identified double-labeled nuclei, confirming the shared progenitor lineage. Rapid regeneration occurred despite a cell cycle length of 19.1 hours, whereas 72% of the regenerating muscle nuclei entered the cell cycle by 48 hours post injury (HPI). Dextran lineage tracing revealed that residual myocytes were responsible for muscle regeneration. Conclusions EOM regeneration in adult zebrafish occurs by dedifferentiation of residual myocytes involving a muscle-to-mesenchyme transition. A mechanistic understanding of myocyte reprogramming may facilitate novel approaches to the development of molecular

  16. Brain-wide neuronal dynamics during motor adaptation in zebrafish.

    PubMed

    Ahrens, Misha B; Li, Jennifer M; Orger, Michael B; Robson, Drew N; Schier, Alexander F; Engert, Florian; Portugues, Ruben

    2012-05-09

    A fundamental question in neuroscience is how entire neural circuits generate behaviour and adapt it to changes in sensory feedback. Here we use two-photon calcium imaging to record the activity of large populations of neurons at the cellular level, throughout the brain of larval zebrafish expressing a genetically encoded calcium sensor, while the paralysed animals interact fictively with a virtual environment and rapidly adapt their motor output to changes in visual feedback. We decompose the network dynamics involved in adaptive locomotion into four types of neuronal response properties, and provide anatomical maps of the corresponding sites. A subset of these signals occurred during behavioural adjustments and are candidates for the functional elements that drive motor learning. Lesions to the inferior olive indicate a specific functional role for olivocerebellar circuitry in adaptive locomotion. This study enables the analysis of brain-wide dynamics at single-cell resolution during behaviour.

  17. MicroRNAs regulate brain morphogenesis in zebrafish.

    PubMed

    Giraldez, Antonio J; Cinalli, Ryan M; Glasner, Margaret E; Enright, Anton J; Thomson, J Michael; Baskerville, Scott; Hammond, Scott M; Bartel, David P; Schier, Alexander F

    2005-05-06

    MicroRNAs (miRNAs) are small RNAs that regulate gene expression posttranscriptionally. To block all miRNA formation in zebrafish, we generated maternal-zygotic dicer (MZdicer) mutants that disrupt the Dicer ribonuclease III and double-stranded RNA-binding domains. Mutant embryos do not process precursor miRNAs into mature miRNAs, but injection of preprocessed miRNAs restores gene silencing, indicating that the disrupted domains are dispensable for later steps in silencing. MZdicer mutants undergo axis formation and differentiate multiple cell types but display abnormal morphogenesis during gastrulation, brain formation, somitogenesis, and heart development. Injection of miR-430 miRNAs rescues the brain defects in MZdicer mutants, revealing essential roles for miRNAs during morphogenesis.

  18. Brain-wide neuronal dynamics during motor adaptation in zebrafish

    PubMed Central

    Ahrens, Misha B; Li, Jennifer M; Orger, Michael B; Robson, Drew N; Schier, Alexander F; Engert, Florian; Portugues, Ruben

    2013-01-01

    A fundamental question in neuroscience is how entire neural circuits generate behavior and adapt it to changes in sensory feedback. Here we use two-photon calcium imaging to record activity of large populations of neurons at the cellular level throughout the brain of larval zebrafish expressing a genetically-encoded calcium sensor, while the paralyzed animals interact fictively with a virtual environment and rapidly adapt their motor output to changes in visual feedback. We decompose the network dynamics involved in adaptive locomotion into four types of neural response properties, and provide anatomical maps of the corresponding sites. A subset of these signals occurred during behavioral adjustments and are candidates for the functional elements that drive motor learning. Lesions to the inferior olive indicate a specific functional role for olivocerebellar circuitry in adaptive locomotion. This study enables the analysis of brain-wide dynamics at single-cell resolution during behavior. PMID:22622571

  19. Regulation of Müller Glial Dependent Neuronal Regeneration in the Damaged Adult Zebrafish Retina

    PubMed Central

    Gorsuch, Ryne A.; Hyde, David R.

    2013-01-01

    This article examines our current knowledge underlying the mechanisms involved in neuronal regeneration in the adult zebrafish retina. Zebrafish, which has the capacity to regenerate a wide variety of tissues and organs (including the fins, kidney, heart, brain, and spinal cord), has become the premier model system to study retinal regeneration due to the robustness and speed of the response and the variety of genetic tools that can be applied to study this question. It is now well documented that retinal damage induces the resident Müller glia to dedifferentiate and reenter the cell cycle to produce neuronal progenitor cells that continue to proliferate, migrate to the damaged retinal layer and differentiate into the missing neuronal cell types. Increasing our understanding of how these cellular events are regulated and occur in response to neuronal damage may provide critical information that can be applied to stimulating a regeneration response in the mammalian retina. In this review, we will focus on the genes/proteins that regulate zebrafish retinal regeneration and will attempt to critically evaluate how these factors may interact to correctly orchestrate the definitive cellular events that occur during regeneration. PMID:23880528

  20. Regulation of Müller glial dependent neuronal regeneration in the damaged adult zebrafish retina.

    PubMed

    Gorsuch, Ryne A; Hyde, David R

    2014-06-01

    This article examines our current knowledge underlying the mechanisms involved in neuronal regeneration in the adult zebrafish retina. Zebrafish, which has the capacity to regenerate a wide variety of tissues and organs (including the fins, kidney, heart, brain, and spinal cord), has become the premier model system to study retinal regeneration due to the robustness and speed of the response and the variety of genetic tools that can be applied to study this question. It is now well documented that retinal damage induces the resident Müller glia to dedifferentiate and reenter the cell cycle to produce neuronal progenitor cells that continue to proliferate, migrate to the damaged retinal layer and differentiate into the missing neuronal cell types. Increasing our understanding of how these cellular events are regulated and occur in response to neuronal damage may provide critical information that can be applied to stimulating a regeneration response in the mammalian retina. In this review, we will focus on the genes/proteins that regulate zebrafish retinal regeneration and will attempt to critically evaluate how these factors may interact to correctly orchestrate the definitive cellular events that occur during regeneration.

  1. Enantio-alteration of gene transcription associated with bioconcentration in adult zebrafish (Danio rerio) exposed to chiral PCB149

    PubMed Central

    Chai, Tingting; Cui, Feng; Mu, Pengqian; Yang, Yang; Xu, Nana; Yin, Zhiqiang; Jia, Qi; Yang, Shuming; Qiu, Jing; Wang, Chengju

    2016-01-01

    Enantioselective enrichment of chiral PCB149 (2,2’,3,4’,5’,6-hexachlorobiphenyl) was analysed in adult zebrafish (Danio rerio) exposed to the racemate, (−)-PCB149, and (+)-PCB149. Greater enrichment of (−)-PCB149 compared to (+) PCB149 was observed following 0.5 ng/L exposure; however, as the exposure time and concentration increased, racemic enrichment was observed in adult fish exposed to the racemate. No biotransformation between the two isomers was observed in fish exposed to single enantiomers. When zebrafish were exposed to different forms of chiral PCB149, enantioselective expression of genes associated with polychlorinated biphenyls (PCBs) was observed in brain and liver tissues and enantioselective correlations between bioconcentration and target gene expression levels were observed in brain and liver tissues. The strong positive correlations between expression levels of target genes (alox5a and alox12) and PCB149 bioconcentration suggest that prolonged exposure to the racemate of chiral PCB149 may result in inflammation-associated diseases. Prolonged exposure to (−)-PCB149 may also affect metabolic pathways such as dehydrogenation and methylation in the brain tissues of adult zebrafish. Hepatic expression levels of genes related to the antioxidant system were significantly negatively correlated with bioconcentration following exposure to (+)-PCB149. PMID:26786282

  2. Enantio-alteration of gene transcription associated with bioconcentration in adult zebrafish (Danio rerio) exposed to chiral PCB149

    NASA Astrophysics Data System (ADS)

    Chai, Tingting; Cui, Feng; Mu, Pengqian; Yang, Yang; Xu, Nana; Yin, Zhiqiang; Jia, Qi; Yang, Shuming; Qiu, Jing; Wang, Chengju

    2016-01-01

    Enantioselective enrichment of chiral PCB149 (2,2’,3,4’,5’,6-hexachlorobiphenyl) was analysed in adult zebrafish (Danio rerio) exposed to the racemate, (‑)-PCB149, and (+)-PCB149. Greater enrichment of (‑)-PCB149 compared to (+) PCB149 was observed following 0.5 ng/L exposure; however, as the exposure time and concentration increased, racemic enrichment was observed in adult fish exposed to the racemate. No biotransformation between the two isomers was observed in fish exposed to single enantiomers. When zebrafish were exposed to different forms of chiral PCB149, enantioselective expression of genes associated with polychlorinated biphenyls (PCBs) was observed in brain and liver tissues and enantioselective correlations between bioconcentration and target gene expression levels were observed in brain and liver tissues. The strong positive correlations between expression levels of target genes (alox5a and alox12) and PCB149 bioconcentration suggest that prolonged exposure to the racemate of chiral PCB149 may result in inflammation-associated diseases. Prolonged exposure to (‑)-PCB149 may also affect metabolic pathways such as dehydrogenation and methylation in the brain tissues of adult zebrafish. Hepatic expression levels of genes related to the antioxidant system were significantly negatively correlated with bioconcentration following exposure to (+)-PCB149.

  3. Early dioxin exposure causes toxic effects in adult zebrafish.

    PubMed

    Baker, Tracie R; Peterson, Richard E; Heideman, Warren

    2013-09-01

    The acute effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure have been well documented in many vertebrate species. However, less is known about the consequences in adulthood from sublethal exposure during development. To address this, we exposed zebrafish to sublethal levels of TCDD (1h; 50 pg/ml), either in early embryogenesis (day 0) or during sexual determination (3 and 7 weeks), and assessed the effects later in adulthood. We found that exposure during embryogenesis produced few effects on the adults themselves but did affect the offspring of these fish: Malformations and increased mortality were observed in the subsequent generation. Zebrafish exposed during sexual development showed defects in the cranial and axial skeleton as adults. This was most clearly manifested as scoliosis caused by malformation of individual vertebrae. These fish also showed defects in reproduction, producing fewer eggs with lower fertilization success. Both males and females were affected, with males contributing to the decrease in egg release from the females and exposed females contributing to fertilization failure. TCDD exposure at 3 and 7 weeks produced feminization of the population. Surprisingly, part of this was due to the appearance of fish with clearly female bodies, yet carrying testes in place of ovaries. Our results show that exposures that produce little if any impact during development can cause severe consequences during adulthood and present a model for studying this process.

  4. Developmental origins of neurotransmitter and transcriptome alterations in adult female zebrafish exposed to atrazine during embryogenesis.

    PubMed

    Wirbisky, Sara E; Weber, Gregory J; Sepúlveda, Maria S; Xiao, Changhe; Cannon, Jason R; Freeman, Jennifer L

    2015-07-03

    Atrazine is an herbicide applied to agricultural crops and is indicated to be an endocrine disruptor. Atrazine is frequently found to contaminate potable water supplies above the maximum contaminant level of 3μg/L as defined by the U.S. Environmental Protection Agency. The developmental origin of adult disease hypothesis suggests that toxicant exposure during development can increase the risk of certain diseases during adulthood. However, the molecular mechanisms underlying disease progression are still unknown. In this study, zebrafish embryos were exposed to 0, 0.3, 3, or 30μg/L atrazine throughout embryogenesis. Larvae were then allowed to mature under normal laboratory conditions with no further chemical treatment until 7 days post fertilization (dpf) or adulthood and neurotransmitter analysis completed. No significant alterations in neurotransmitter levels was observed at 7dpf or in adult males, but a significant decrease in 5-hydroxyindoleacetic acid (5-HIAA) and serotonin turnover was seen in adult female brain tissue. Transcriptomic analysis was completed on adult female brain tissue to identify molecular pathways underlying the observed neurological alterations. Altered expression of 1928, 89, and 435 genes in the females exposed to 0.3, 3, or 30μg/L atrazine during embryogenesis were identified, respectively. There was a high level of overlap between the biological processes and molecular pathways in which the altered genes were associated. Moreover, a subset of genes was down regulated throughout the serotonergic pathway. These results provide support of the developmental origins of neurological alterations observed in adult female zebrafish exposed to atrazine during embryogenesis.

  5. Developmental origins of neurotransmitter and transcriptome alterations in adult female zebrafish exposed to atrazine during embryogenesis

    PubMed Central

    Wirbisky, Sara E.; Weber, Gregory J.; Sepúlveda, Maria S.; Xiao, Changhe; Cannon, Jason R.; Freeman, Jennifer L.

    2015-01-01

    Atrazine is an herbicide applied to agricultural crops and is indicated to be an endocrine disruptor. Atrazine is frequently found to contaminate potable water supplies above the maximum contaminant level of 3 µg/L as defined by the U. S. Environmental Protection Agency. The developmental origin of adult disease hypothesis suggests that toxicant exposure during development can increase the risk of certain diseases during adulthood. However, the molecular mechanisms underlying disease progression are still unknown. In this study, zebrafish embryos were exposed to 0, 0.3, 3, or 30 µg/L atrazine throughout embryogenesis. Larvae were then allowed to mature under normal laboratory conditions with no further chemical treatment until 7 days post fertilization (dpf) or adulthood and neurotransmitter analysis completed. No significant alterations in neurotransmitter levels was observed at 7 dpf or in adult males, but a significant decrease in 5-Hydroxyindoleacetic acid (5-HIAA) and serotonin turnover was seen in adult female brain tissue. Transcriptomic analysis was completed on adult female brain tissue to identify molecular pathways underlying the observed neurological alterations. Altered expression of 1853, 84, and 419 genes in the females exposed to 0.3, 3, or 30 µg/L atrazine during embryogenesis were identified, respectively. There was a high level of overlap between the biological processes and molecular pathways in which the altered genes were associated. Moreover, a subset of genes was down regulated throughout the serotonergic pathway. These results provide support of the developmental origins of neurological alterations observed in adult female zebrafish exposed to atrazine during embryogenesis. PMID:25929836

  6. Long-term exposure to paraquat alters behavioral parameters and dopamine levels in adult zebrafish (Danio rerio).

    PubMed

    Bortolotto, Josiane W; Cognato, Giana P; Christoff, Raissa R; Roesler, Laura N; Leite, Carlos E; Kist, Luiza W; Bogo, Mauricio R; Vianna, Monica R; Bonan, Carla D

    2014-04-01

    Chronic exposure to paraquat (Pq), a toxic herbicide, can result in Parkinsonian symptoms. This study evaluated the effect of the systemic administration of Pq on locomotion, learning and memory, social interaction, tyrosine hydroxylase (TH) expression, dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC) levels, and dopamine transporter (DAT) gene expression in zebrafish. Adult zebrafish received an i.p. injection of either 10 mg/kg (Pq10) or 20 mg/kg (Pq20) of Pq every 3 days for a total of six injections. Locomotion and distance traveled decreased at 24 h after each injection in both treatment doses. In addition, both Pq10- and Pq20-treated animals exhibited differential effects on the absolute turn angle. Nonmotor behaviors were also evaluated, and no changes were observed in anxiety-related behaviors or social interactions in Pq-treated zebrafish. However, Pq-treated animals demonstrated impaired acquisition and consolidation of spatial memory in the Y-maze task. Interestingly, dopamine levels increased while DOPAC levels decreased in the zebrafish brain after both treatments. However, DAT expression decreased in the Pq10-treated group, and there was no change in the Pq20-treated group. The amount of TH protein showed no significant difference in the treated group. Our study establishes a new model to study Parkinson-associated symptoms in zebrafish that have been chronically treated with Pq.

  7. In vivo metabolism of organophosphate flame retardants and distribution of their main metabolites in adult zebrafish.

    PubMed

    Wang, Guowei; Chen, Hanyan; Du, Zhongkun; Li, Jianhua; Wang, Zunyao; Gao, Shixiang

    2017-07-15

    Understanding the metabolism of chemicals as well as the distribution and depuration of their main metabolites in tissues are essential for evaluating their fate and potential toxicity in vivo. Herein, we investigated the metabolism of six typical organophosphate (OP) flame retardants (tripropyl phosphate (TPRP), tri-n-butyl phosphate (TNBP), tris(2-butoxyethyl) phosphate (TBOEP), tris(2-chloroethyl) phosphate (TCEP), tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) and tri-p-cresyl phosphate (p-TCP)) in adult zebrafish in laboratory at three levels (0, 1/150 LC50 (environmentally relevant level), and 1/30 LC50 per OP analog). Twenty main metabolites were detected in the liver of OPs-exposed zebrafish using high resolution mass spectrometry (Q-TOF). The reaction pathways involving scission of the ester bond (hydrolysis), cleavage of the ether bond, oxidative hydroxylation, dechlorination, and coupling with glucuronic acid were proposed, and were further confirmed by the frontier electron density and point charge calculations. Tissue distribution of the twenty metabolites revealed that liver and intestine with the highest levels of metabolites were the most active organs for OPs biotransformation among the studied tissues of intestine, liver, roe, brain, muscle, and gill, which showed the importance of hepatobiliary system (liver-bile-intestine) in the metabolism and excretion of OPs in zebrafish. Fast depuration of metabolites from tissues indicated that the formed metabolites might be not persistent in fish, and easily released into water. This study provides comprehensive information on the metabolism of OPs in the tissue of zebrafish, which might give some hints for the exploration of their toxic mechanism in aquatic life.

  8. Deep brain photoreceptors control light seeking behavior in zebrafish larvae

    PubMed Central

    Fernandes, António M.; Fero, Kandice; Arrenberg, Aristides B.; Bergeron, Sadie A.; Driever, Wolfgang; Burgess, Harold A.

    2012-01-01

    Summary Most vertebrates process visual information using elaborately structured photosensory tissues including the eyes and pineal. However there is strong evidence that other tissues can detect and respond to photic stimuli [1, 2, 3]. Many reports suggest that photosensitive elements exist within the brain itself and influence physiology and behavior, however a long standing puzzle has been the identity of the neurons and photoreceptor molecules involved [4, 5]. We tested whether light cues influence behavior in zebrafish larvae through deep brain photosensors. We found that larvae lacking eyes and pineal perform a simple light-seeking behavior triggered by loss of illumination (`dark photokinesis'). Neuroanatomical considerations prompted us to test orthopedia (otpa) deficient fish which showed a profound reduction in dark photokinesis. Using targeted genetic ablations, we narrowed the photosensitive region to neurons in the preoptic area. Neurons in this region express several photoreceptive molecules, but expression of the melanopsin opn4a is selectively lost in otpa mutants, suggesting that opn4a mediates dark photokinesis. Our findings shed light on the identity and function of deep brain photoreceptors and suggest that otpa specifies an ancient population of sensory neurons that mediate behavioral responses to light. PMID:23000151

  9. Manganese(II) chloride alters behavioral and neurochemical parameters in larvae and adult zebrafish.

    PubMed

    Altenhofen, Stefani; Wiprich, Melissa Talita; Nery, Laura Roesler; Leite, Carlos Eduardo; Vianna, Monica Ryff Moreira Roca; Bonan, Carla Denise

    2017-01-01

    Manganese (Mn) is an essential metal for organisms, but high levels can cause serious neurological damage. The aim of this study was to evaluate the effects of MnCl2 exposure on cognition and exploratory behavior in adult and larval zebrafish and correlate these findings with brain accumulation of Mn, overall brain tyrosine hydroxylase (TH) levels, dopamine (DA) levels, 3,4-dihydroxyphenylacetic acid (DOPAC) levels and cell death markers in the nervous system. Adults exposed to MnCl2 for 4days (0.5, 1.0 and 1.5mM) and larvae exposed for 5days (0.1, 0.25 and 0.5mM) displayed decreased exploratory behaviors, such as distance traveled and absolute body turn angle, in addition to reduced movement time and an increased number of immobile episodes in larvae. Adults exposed to MnCl2 for 4days showed impaired aversive long-term memory in the inhibitory avoidance task. The overall brain TH levels were elevated in adults and larvae evaluated at 5 and 7 days post-fertilization (dpf). Interestingly, the protein level of this enzyme was decreased in larval animals at 10dpf. Furthermore, DOPAC levels were increased in adult animals exposed to MnCl2. Protein analysis showed increased apoptotic markers in both the larvae and adult nervous system. The results demonstrated that prolonged exposure to MnCl2 leads to locomotor deficits that may be associated with damage caused by this metal in the CNS, particularly in the dopaminergic system.

  10. Zebrafish brain mapping--standardized spaces, length scales, and the power of N and n.

    PubMed

    Hunter, Paul R; Hendry, Aenea C; Lowe, Andrew S

    2015-06-01

    Mapping anatomical and functional parameters of the zebrafish brain is moving apace. Research communities undertaking such studies are becoming ever larger and more diverse. The unique features, tools, and technologies associated with zebrafish are propelling them as the 21st century model organism for brain mapping. Uniquely positioned as a vertebrate model system, the zebrafish enables imaging of anatomy and function at different length scales from intraneuronal compartments to sparsely distributed whole brain patterns. With a variety of diverse and established statistical modeling and analytic methods available from the wider brain mapping communities, the richness of zebrafish neuroimaging data is being realized. The statistical power of population observations (N) within and across many samples (n) projected onto a standardized space will provide vast databases for data-driven biological approaches. This article reviews key brain mapping initiatives at different levels of scale that highlight the potential of zebrafish brain mapping. By way of introduction to the next wave of brain mappers, an accessible introduction to the key concepts and caveats associated with neuroimaging are outlined and discussed.

  11. Satellite-like cells contribute to pax7-dependent skeletal muscle repair in adult zebrafish.

    PubMed

    Berberoglu, Michael A; Gallagher, Thomas L; Morrow, Zachary T; Talbot, Jared C; Hromowyk, Kimberly J; Tenente, Inês M; Langenau, David M; Amacher, Sharon L

    2017-04-15

    Satellite cells, also known as muscle stem cells, are responsible for skeletal muscle growth and repair in mammals. Pax7 and Pax3 transcription factors are established satellite cell markers required for muscle development and regeneration, and there is great interest in identifying additional factors that regulate satellite cell proliferation, differentiation, and/or skeletal muscle regeneration. Due to the powerful regenerative capacity of many zebrafish tissues, even in adults, we are exploring the regenerative potential of adult zebrafish skeletal muscle. Here, we show that adult zebrafish skeletal muscle contains cells similar to mammalian satellite cells. Adult zebrafish satellite-like cells have dense heterochromatin, express Pax7 and Pax3, proliferate in response to injury, and show peak myogenic responses 4-5 days post-injury (dpi). Furthermore, using a pax7a-driven GFP reporter, we present evidence implicating satellite-like cells as a possible source of new muscle. In lieu of central nucleation, which distinguishes regenerating myofibers in mammals, we describe several characteristics that robustly identify newly-forming myofibers from surrounding fibers in injured adult zebrafish muscle. These characteristics include partially overlapping expression in satellite-like cells and regenerating myofibers of two RNA-binding proteins Rbfox2 and Rbfoxl1, known to regulate embryonic muscle development and function. Finally, by analyzing pax7a; pax7b double mutant zebrafish, we show that Pax7 is required for adult skeletal muscle repair, as it is in the mouse.

  12. Accumulation and effects of the UV-filter octocrylene in adult and embryonic zebrafish (Danio rerio).

    PubMed

    Blüthgen, Nancy; Meili, Nicole; Chew, Geraldine; Odermatt, Alex; Fent, Karl

    2014-04-01

    Wide application of the UV-filter octocrylene (OC) in cosmetics leads to contamination of the aquatic environment, but effects of OC remain unclear. Here we determine bioaccumulation and molecular effects of OC. Adult male zebrafish were exposed to 22, 209 and 383 μg/L and embryos to 69, 293 and 925 μg/L OC. OC accumulated in fish up to 17 μg/g. Calculated BCF varied between 41 and 136. Microarray analysis in brain and liver following exposure to 383 μg/L OC revealed alteration of 628 and 136 transcripts, respectively. Most prominent GO processes included developmental processes, organ development, hematopoiesis, formation of blood vessels, blood circulation, fat cell differentiation and metabolism. Validation by RT-qPCR in brain and liver of adult fish and embryos included a series of genes. Blood levels of 11-ketotestosterone were not altered. The transcriptomics data suggest that OC mainly affects transcription of genes related to developmental processes in the brain and liver as well as metabolic processes in the liver.

  13. Embryonic alcohol exposure promotes long-term effects on cerebral glutamate transport of adult zebrafish.

    PubMed

    Baggio, Suelen; Mussulini, Ben Hur; de Oliveira, Diogo Losch; Zenki, Kamila Cagliari; Santos da Silva, Emerson; Rico, Eduardo Pacheco

    2017-01-01

    Ethanol is a widely consumed substance throughout the world. During development it can substantially damage the human fetus, whereas the developing brain is particularly vulnerable. The brain damage induced by prenatal alcohol exposure may lead to a variety of long-lasting behavioral and neurochemical problems. However, there are no data concerning the effects of developmental ethanol exposure on the glutamatergic system, where extracellular glutamate acts as signaling molecule. Here we investigated the effect of ethanol exposure for 2h (concentrations of 0.0%, 0.1%, 0.25%, 0.50%, and 1.00%) in embryos at 24h post-fertilization (hpf) by measuring the functionality of glutamate transporters in the brain of adult (4 months) zebrafish. However, ethanol 0.1%, 0.25% and 0.50% decreased transport of glutamate to 81.96%, 60.65% and 45.91% respectively, when compared with the control group. Interestingly, 1.00% was able to inhibit the transport activity to 68.85%. In response to the embryonic alcohol exposure, we found impairment in the function of cerebral glutamate transport in adult fish, contributing to long-term alteration in the homeostasis glutamatergic signaling.

  14. Robust regeneration of adult zebrafish lateral line hair cells reflects continued precursor pool maintenance

    PubMed Central

    Cruz, Ivan A.; Kappedal, Ryan; Mackenzie, Scott M.; Hailey, Dale W.; Hoffman, Trevor L.; Schilling, Thomas F.; Raible, David W.

    2015-01-01

    We have examined lateral line hair cell and support cell maintenance in adult zebrafish when growth is largely complete. We demonstrate that adult zebrafish not only replenish hair cells after a single instance of hair cell damage, but also maintain hair cells and support cells after multiple rounds of damage and regeneration. We find that hair cells undergo continuous turnover in adult zebrafish in the absence of damage. We identify mitotically-distinct support cell populations and show that hair cells regenerate from underlying support cells in a region-specific manner. Our results demonstrate that there are two distinct support cell populations in the lateral line, which may help explain why zebrafish hair cell regeneration is extremely robust, retained throughout life, and potentially unlimited in regenerative capacity. PMID:25869855

  15. Base-resolution DNA methylation landscape of zebrafish brain and liver.

    PubMed

    Chatterjee, Aniruddha; Stockwell, Peter A; Horsfield, Julia A; Morison, Ian M; Nakagawa, Shinichi

    2014-12-01

    Zebrafish (Danio rerio) is a vertebrate model organism that is widely used for studying a plethora of biological questions, including developmental processes, effects of external cues on phenotype, and human disease modeling. DNA methylation is an important epigenetic mechanism that contributes to gene regulation, and is prevalent in all vertebrates. Reduced representation bisulfite sequencing (RRBS) is a cost-effective technique to generate genome-wide DNA methylation maps and has been used in mammalian genomes (e.g., human, mouse and rat) but not in zebrafish. High-resolution DNA methylation data in zebrafish are limited: increased availability of such data will enable us to model and better understand the roles, causes and consequences of changes in DNA methylation. Here we present five high-resolution DNA methylation maps for wild-type zebrafish brain (two pooled male and two pooled female methylomes) and liver. These data were generated using the RRBS technique (includes 1.43 million CpG sites of zebrafish genome) on the Illumina HiSeq platform. Alignment to the reference genome was performed using the Zv9 genome assembly. To our knowledge, these datasets are the only RRBS datasets and base-resolution DNA methylation data available at this time for zebrafish brain and liver. These datasets could serve as a resource for future studies to document the functional role of DNA methylation in zebrafish. In addition, these datasets could be used as controls while performing analysis on treated samples.

  16. Sex differences in DNA methylation and expression in zebrafish brain: a test of an extended 'male sex drive' hypothesis.

    PubMed

    Chatterjee, Aniruddha; Lagisz, Malgorzata; Rodger, Euan J; Zhen, Li; Stockwell, Peter A; Duncan, Elizabeth J; Horsfield, Julia A; Jeyakani, Justin; Mathavan, Sinnakaruppan; Ozaki, Yuichi; Nakagawa, Shinichi

    2016-09-30

    The sex drive hypothesis predicts that stronger selection on male traits has resulted in masculinization of the genome. Here we test whether such masculinizing effects can be detected at the level of the transcriptome and methylome in the adult zebrafish brain. Although methylation is globally similar, we identified 914 specific differentially methylated CpGs (DMCs) between males and females (435 were hypermethylated and 479 were hypomethylated in males compared to females). These DMCs were prevalent in gene body, intergenic regions and CpG island shores. We also discovered 15 distinct CpG clusters with striking sex-specific DNA methylation differences. In contrast, at transcriptome level, more female-biased genes than male-biased genes were expressed, giving little support for the male sex drive hypothesis. Our study provides genome-wide methylome and transcriptome assessment and sheds light on sex-specific epigenetic patterns and in zebrafish for the first time.

  17. High-throughput imaging of adult fluorescent zebrafish with an LED fluorescence macroscope

    PubMed Central

    Blackburn, Jessica S; Liu, Sali; Raimondi, Aubrey R; Ignatius, Myron S; Salthouse, Christopher D; Langenau, David M

    2011-01-01

    Zebrafish are a useful vertebrate model for the study of development, behavior, disease and cancer. A major advantage of zebrafish is that large numbers of animals can be economically used for experimentation; however, high-throughput methods for imaging live adult zebrafish had not been developed. Here, we describe protocols for building a light-emitting diode (LED) fluorescence macroscope and for using it to simultaneously image up to 30 adult animals that transgenically express a fluorescent protein, are transplanted with fluorescently labeled tumor cells or are tagged with fluorescent elastomers. These protocols show that the LED fluorescence macroscope is capable of distinguishing five fluorescent proteins and can image unanesthetized swimming adult zebrafish in multiple fluorescent channels simultaneously. The macroscope can be built and used for imaging within 1 day, whereas creating fluorescently labeled adult zebrafish requires 1 hour to several months, depending on the method chosen. The LED fluorescence macroscope provides a low-cost, high-throughput method to rapidly screen adult fluorescent zebrafish and it will be useful for imaging transgenic animals, screening for tumor engraftment, and tagging individual fish for long-term analysis. PMID:21293462

  18. Normal and Malignant Muscle Cell Transplantation into Immune Compromised Adult Zebrafish

    PubMed Central

    Moore, John C.; Langenau, David M.

    2014-01-01

    Zebrafish have become a powerful tool for assessing development, regeneration, and cancer. More recently, allograft cell transplantation protocols have been developed that permit engraftment of normal and malignant cells into irradiated, syngeneic, and immune compromised adult zebrafish. These models when coupled with optimized cell transplantation protocols allow for the rapid assessment of stem cell function, regeneration following injury, and cancer. Here, we present a method for cell transplantation of zebrafish adult skeletal muscle and embryonal rhabdomyosarcoma (ERMS), a pediatric sarcoma that shares features with embryonic muscle, into immune compromised adult rag2E450fs homozygous mutant zebrafish. Importantly, these animals lack T cells and have reduced B cell function, facilitating engraftment of a wide range of tissues from unrelated donor animals. Our optimized protocols show that fluorescently labeled muscle cell preparations from α-actin-RFP transgenic zebrafish engraft robustly when implanted into the dorsal musculature of rag2 homozygous mutant fish. We also demonstrate engraftment of fluorescent-transgenic ERMS where fluorescence is confined to cells based on differentiation status. Specifically, ERMS were created in AB-strain myf5-GFP; mylpfa-mCherry double transgenic animals and tumors injected into the peritoneum of adult immune compromised fish. The utility of these protocols extends to engraftment of a wide range of normal and malignant donor cells that can be implanted into dorsal musculature or peritoneum of adult zebrafish. PMID:25591079

  19. Functional diversity of excitatory commissural interneurons in adult zebrafish

    PubMed Central

    Björnfors, E Rebecka; El Manira, Abdeljabbar

    2016-01-01

    Flexibility in the bilateral coordination of muscle contraction underpins variable locomotor movements or gaits. While the locomotor rhythm is generated by ipsilateral excitatory interneurons, less is known about the commissural excitatory interneurons. Here we examined how the activity of the V0v interneurons – an important commissural neuronal class – varies with the locomotor speed in adult zebrafish. Although V0v interneurons are molecularly homogenous, their activity pattern during locomotion is not uniform. They consist of two distinct types dependent on whether they display rhythmicity or not during locomotion. The rhythmic V0v interneurons were further subdivided into three sub-classes engaged sequentially, first at slow then intermediate and finally fast locomotor speeds. Their order of recruitment is defined by scaling their synaptic current with their input resistance. Thus we uncover, in an adult vertebrate, a novel organizational principle for a key class of commissural interneurons and their recruitment pattern as a function of locomotor speed. DOI: http://dx.doi.org/10.7554/eLife.18579.001 PMID:27559611

  20. Husbandry stress exacerbates mycobacterial infections in adult zebrafish, Danio rerio (Hamilton)

    USGS Publications Warehouse

    Ramsay, J.M.; Watral, V.; Schreck, C.B.; Kent, M.L.

    2009-01-01

    Mycobacteria are significant pathogens of laboratory zebrafish, Danio rerio (Hamilton). Stress is often implicated in clinical disease and morbidity associated with mycobacterial infections but has yet to be examined with zebrafish. The aim of this study was to examine the effects of husbandry stressors on zebrafish infected with mycobacteria. Adult zebrafish were exposed to Mycobacterium marinum or Mycobacterium chelonae, two species that have been associated with disease in zebrafish. Infected fish and controls were then subjected to chronic crowding and handling stressors and examined over an 8-week period. Whole-body cortisol was significantly elevated in stressed fish compared to non-stressed fish. Fish infected with M. marinum ATCC 927 and subjected to husbandry stressors had 14% cumulative mortality while no mortality occurred among infected fish not subjected to husbandry stressors. Stressed fish, infected with M. chelonae H1E2 from zebrafish, were 15-fold more likely to be infected than non-stressed fish at week 8 post-injection. Sub-acute, diffuse infections were more common among stressed fish infected with M. marinum or M. chelonae than non-stressed fish. This is the first study to demonstrate an effect of stress and elevated cortisol on the morbidity, prevalence, clinical disease and histological presentation associated with mycobacterial infections in zebrafish. Minimizing husbandry stress may be effective at reducing the severity of outbreaks of clinical mycobacteriosis in zebrafish facilities. ?? 2009 Blackwell Publishing Ltd.

  1. Copper at low levels impairs memory of adult zebrafish (Danio rerio) and affects swimming performance of larvae.

    PubMed

    Acosta, Daiane da Silva; Danielle, Naissa Maria; Altenhofen, Stefani; Luzardo, Milene Dornelles; Costa, Patrícia Gomes; Bianchini, Adalto; Bonan, Carla Denise; da Silva, Rosane Souza; Dafre, Alcir Luiz

    2016-01-01

    Metal contamination at low levels is an important issue because it usually produces health and environmental effects, either positive or deleterious. Contamination of surface waters with copper (Cu) is a worldwide event, usually originated by mining, agricultural, industrial, commercial, and residential activities. Water quality criteria for Cu are variable among countries but allowed limits are generally in the μg/L range, which can disrupt several functions in the early life-stages of fish species. Behavioral and biochemical alterations after Cu exposure have also been described at concentrations close to the allowed limits. Aiming to search for the effects of Cu in the range of the allowed limits, larvae and adult zebrafish (Danio rerio) were exposed to different concentrations of dissolved Cu (nominally: 0, 5, 9, 20 and 60μg/L; measured: 0.4, 5.7, 7.2 16.6 and 42.3μg/L, respectively) for 96h. Larvae swimming and body length, and adult behavior and biochemical biomarkers (activity of glutathione-related enzymes in gills, muscle, and brain) were assessed after Cu exposure. Several effects were observed in fish exposed to 9μg/L nominal Cu, including increased larvae swimming distance and velocity, abolishment of adult inhibitory avoidance memory, and decreased glutathione S-transferase (GST) activity in gills of adult fish. At the highest Cu concentration tested (nominally: 60μg/L), body length of larvae, spatial memory of adults, and gill GST activity were decreased. Social behavior (aggressiveness and conspecific interaction), and glutathione reductase (GR) activity were not affected in adult zebrafish. Exposure to Cu, at concentrations close to the water quality criteria for this metal in fresh water, was able to alter larvae swimming performance and to induce detrimental effects on the behavior of adult zebrafish, thus indicating the need for further studies to reevaluate the currently allowed limits for Cu in fresh water.

  2. Fluorescence-Activated Cell Sorting (FACS) Protocol for Podocyte Isolation in Adult Zebrafish.

    PubMed

    Bates, Thomas J D; Naumann, Uta; Englert, Christoph

    2016-01-01

    Zebrafish is becoming a very important model for studying human diseases. The conserved structure of the nephrons in the kidney allows the user to answer questions relating to study human kidney disorders. Wt1a-expressing podocytes are the most important cells within the glomeruli of adult zebrafish. In order to understand the molecular characteristics of these cells, within damage models, we have established a method for isolating them.

  3. Whole Adult Organism Transcriptional Profiling of Acute Metal Exposures in Male Zebrafish

    DTIC Science & Technology

    2014-03-10

    adult organism transcriptional profiling of acute metal exposures in male Zebrafish Naissan Hussainzada1, John A Lewis2, Christine E Baer4, Danielle L...fish were pulverized under liquid nitrogen using a SPEX 6750 freezer mill (SPEX Sample Prep, Metuchen, NJ). Total RNA was isolated from the pulverized...advantages and current limitations. Toxicol Pathol 2003, 31(Suppl):62–87. 3. Carvan MJ III, Dalton TP, Stuart GW, Nebert DW: Transgenic zebrafish as

  4. Long-term drug administration in the adult zebrafish using oral gavage for cancer preclinical studies

    PubMed Central

    Dang, Michelle; Henderson, Rachel E.; Garraway, Levi A.

    2016-01-01

    ABSTRACT Zebrafish are a major model for chemical genetics, and most studies use embryos when investigating small molecules that cause interesting phenotypes or that can rescue disease models. Limited studies have dosed adults with small molecules by means of water-borne exposure or injection techniques. Challenges in the form of drug delivery-related trauma and anesthesia-related toxicity have excluded the adult zebrafish from long-term drug efficacy studies. Here, we introduce a novel anesthetic combination of MS-222 and isoflurane to an oral gavage technique for a non-toxic, non-invasive and long-term drug administration platform. As a proof of principle, we established drug efficacy of the FDA-approved BRAFV600E inhibitor, Vemurafenib, in adult zebrafish harboring BRAFV600E melanoma tumors. In the model, adult casper zebrafish intraperitoneally transplanted with a zebrafish melanoma cell line (ZMEL1) and exposed to daily sub-lethal dosing at 100 mg/kg of Vemurafenib for 2 weeks via oral gavage resulted in an average 65% decrease in tumor burden and a 15% mortality rate. In contrast, Vemurafenib-resistant ZMEL1 cell lines, generated in culture from low-dose drug exposure for 4 months, did not respond to the oral gavage treatment regimen. Similarly, this drug treatment regimen can be applied for treatment of primary melanoma tumors in the zebrafish. Taken together, we developed an effective long-term drug treatment system that will allow the adult zebrafish to be used to identify more effective anti-melanoma combination therapies and opens up possibilities for treating adult models of other diseases. PMID:27482819

  5. Analysis of Nephron Composition and Function in the Adult Zebrafish Kidney

    PubMed Central

    McCampbell, Kristen K.; Springer, Kristin N.; Wingert, Rebecca A.

    2014-01-01

    The zebrafish model has emerged as a relevant system to study kidney development, regeneration and disease. Both the embryonic and adult zebrafish kidneys are composed of functional units known as nephrons, which are highly conserved with other vertebrates, including mammals. Research in zebrafish has recently demonstrated that two distinctive phenomena transpire after adult nephrons incur damage: first, there is robust regeneration within existing nephrons that replaces the destroyed tubule epithelial cells; second, entirely new nephrons are produced from renal progenitors in a process known as neonephrogenesis. In contrast, humans and other mammals seem to have only a limited ability for nephron epithelial regeneration. To date, the mechanisms responsible for these kidney regeneration phenomena remain poorly understood. Since adult zebrafish kidneys undergo both nephron epithelial regeneration and neonephrogenesis, they provide an outstanding experimental paradigm to study these events. Further, there is a wide range of genetic and pharmacological tools available in the zebrafish model that can be used to delineate the cellular and molecular mechanisms that regulate renal regeneration. One essential aspect of such research is the evaluation of nephron structure and function. This protocol describes a set of labeling techniques that can be used to gauge renal composition and test nephron functionality in the adult zebrafish kidney. Thus, these methods are widely applicable to the future phenotypic characterization of adult zebrafish kidney injury paradigms, which include but are not limited to, nephrotoxicant exposure regimes or genetic methods of targeted cell death such as the nitroreductase mediated cell ablation technique. Further, these methods could be used to study genetic perturbations in adult kidney formation and could also be applied to assess renal status during chronic disease modeling. PMID:25145398

  6. Knockdown of monocarboxylate transporter 8 (mct8) disturbs brain development and locomotion in zebrafish.

    PubMed

    de Vrieze, Erik; van de Wiel, Sandra M W; Zethof, Jan; Flik, Gert; Klaren, Peter H M; Arjona, Francisco J

    2014-06-01

    Allan-Herndon-Dudley syndrome (AHDS) is an inherited disorder of brain development characterized by severe psychomotor retardation. This X-linked disease is caused by mutations in the monocarboxylate transporter 8 (MCT8), an important thyroid hormone transporter in brain neurons. MCT8-knockout mice lack the 2 major neurological symptoms of AHDS, namely locomotor problems and cognitive impairment. The pathological mechanism explaining the symptoms is still obscure, and no cure for this condition is known. The development of an animal model that carries MCT8-related neurological symptoms is warranted. We have employed morpholino-based gene knockdown to create zebrafish deficient for mct8. Knockdown of mct8 results in specific symptoms in the thyroid axis and brain. The mct8-morphants showed impaired locomotor behavior and brain development. More specifically, we observed maldevelopment of the cerebellum and mid-hindbrain boundary and apoptotic clusters in the zebrafish brain. The mRNA expression of zebrafish orthologs of mammalian TSH, thyroid hormone transporters, and deiodinases was altered in mct8 morphants. In particular, deiodinase type 3 gene expression was consistently up-regulated in zebrafish mct8 morphants. The thyroid hormone metabolite tetrac, but not T3, partly ameliorated the affected phenotype and locomotion disability of morphant larvae. Our results show that mct8 knockdown in zebrafish larvae results in disturbances in the thyroid axis, brain, and locomotion behavior, which is congruent with the clinical aspect of impaired locomotion and cognition in patients with AHDS. Taken together, the zebrafish is a suitable animal model for the study of the pathophysiology of AHDS.

  7. Early life stage and genetic toxicity of stannous chloride on zebrafish embryos and adults: toxic effects of tin on zebrafish.

    PubMed

    Şişman, Turgay

    2011-06-01

    Humans are exposed to stannous chloride (SnCl(2)), known as tin chloride, present in packaged food, soft drinks, biocides, dentifrices, etc. Health effects in children exposed to tin and tin compounds have not been investigated yet. Therefore, we evaluated the possible teratogenic effects and genotoxic of SnCl(2) in zebrafish (Danio rerio) adults and their embryos. In the embryo-larval study, SnCl(2) showed embryo toxicity and developmental delay after exposure to the various concentrations of 10-250 μM for 120 h. Teratogenic effects including morphological malformations of the embryos and larvae were observed. The embryos exposed to 100 μM displayed tail deformation at 28 hpf and the larvae exposed to 50 μM showed reduced body growth, smaller head and eyes, bent trunk, mild pericardial edema, and smaller caudal fin at 96 hpf. The results of the teratological study show that SnCl(2) induced a significant decrease in the number of living embryos and larvae. Regarding the chromosome analysis, SnCl(2) induced a dose-dependent increase in the micronucleus (MN) frequency in peripheral erythrocytes of adult zebrafish. In blood cells, the 25 μM dose of SnCl(2) caused a nonsignificant increase in the total chromosomal aberrations, but the high doses significantly increased the total number of chromosomal aberrations compared with the control groups. Overall, the results clearly indicate that SnCl(2) is teratogenic and genotoxic to zebrafish.

  8. Impaired brain StAR and HSP70 gene expression in zebrafish exposed to Methyl-Parathion based insecticide.

    PubMed

    da Rosa, João Gabriel Santos; Koakoski, Gessi; Piato, Angelo L; Bogo, Maurício Reis; Bonan, Carla Denise; Barcellos, Leonardo José Gil

    2016-01-01

    Fish production ponds and natural water body areas located in close proximity to agricultural fields receive water with variable amounts of agrochemicals, and consequently, compounds that produce adverse effects may reach nontarget organisms. The aim of this study was to investigate whether waterborne methyl-parathion-based insecticide (MPBI) affected gene expression patterns of brain glucocorticoid receptor (GR), steroidogenic acute regulatory protein (StAR), and heat shock protein 70 (hsp70) in adult zebrafish (Danio rerio) exposed to this chemical for 96 h. Treated fish exposed to MPBI-contaminated water showed an inhibition of brain StAR and hsp70 gene expression. Data demonstrated that MPBI produced a decrease brain StAR and hsp70 gene expression.

  9. Adaptation-induced modification of motion selectivity tuning in visual tectal neurons of adult zebrafish

    PubMed Central

    Lucks, Valerie; Kurtz, Rafael; Engelmann, Jacob

    2015-01-01

    In the developing brain, training-induced emergence of direction selectivity and plasticity of orientation tuning appear to be widespread phenomena. These are found in the visual pathway across different classes of vertebrates. Moreover, short-term plasticity of orientation tuning in the adult brain has been demonstrated in several species of mammals. However, it is unclear whether neuronal orientation and direction selectivity in nonmammalian species remains modifiable through short-term plasticity in the fully developed brain. To address this question, we analyzed motion tuning of neurons in the optic tectum of adult zebrafish by calcium imaging. In total, orientation and direction selectivity was enhanced by adaptation, responses of previously orientation-selective neurons were sharpened, and even adaptation-induced emergence of selectivity in previously nonselective neurons was observed in some cases. The different observed effects are mainly based on the relative distance between the previously preferred and the adaptation direction. In those neurons in which a shift of the preferred orientation or direction was induced by adaptation, repulsive shifts (i.e., away from the adapter) were more prevalent than attractive shifts. A further novel finding for visually induced adaptation that emerged from our study was that repulsive and attractive shifts can occur within one brain area, even with uniform stimuli. The type of shift being induced also depends on the difference between the adapting and the initially preferred stimulus direction. Our data indicate that, even within the fully developed optic tectum, short-term plasticity might have an important role in adjusting neuronal tuning functions to current stimulus conditions. PMID:26378206

  10. Early embryonic ethanol exposure impairs shoaling and the dopaminergic and serotoninergic systems in adult zebrafish.

    PubMed

    Buske, Christine; Gerlai, Robert

    2011-01-01

    Fetal alcohol syndrome (FAS) is a devastating disorder accompanied by numerous morphological and behavioral abnormalities. Human FAS has been modeled in laboratory animals including the zebrafish. Recently, embryonic exposure to low doses of ethanol has been shown to impair behavior without any gross morphological alterations in zebrafish. The exposed zebrafish showed reduced responses to animated conspecific images. The effect of embryonic ethanol exposure, however, has not been investigated in a real shoal and the potential mechanisms underlying the behavioral impairment are also unknown. Here we show that a 2h long immersion in 0.25% and 0.50% (vol/vol) alcohol at 24h post fertilization significantly increases the distance among members of freely swimming groups of zebrafish when measured at 70 days post fertilization. We also show that this impaired behavior is accompanied by reduced levels of dopamine, DOPAC, serotonin and 5HIAA as quantified by HPLC from whole brain extracts. Our results demonstrate that even very low concentrations of alcohol applied for a short period of time during the development of zebrafish can impair behavior and brain function. We argue that the observed behavioral impairment is not likely to be due to altered performance capabilities, e.g. motor function or perception, but possibly to social behavior itself. We also argue that our neurochemical data represent the first step towards understanding the mechanisms of this abnormality in zebrafish, which may lead to better modeling of, and ultimately perhaps better therapies for human FAS.

  11. Inhibition of phosphorylated tyrosine hydroxylase attenuates ethanol-induced hyperactivity in adult zebrafish (Danio rerio)

    PubMed Central

    Nowicki, Magda; Tran, Steven; Chatterjee, Diptendu; Gerlai, Robert

    2015-01-01

    Zebrafish have been successfully employed in the study of the behavioural and biological effects of ethanol. Like in mammals, low to moderate doses of ethanol induce motor hyperactivity in zebrafish, an effect that has been attributed to the activation of the dopaminergic system. Acute ethanol exposure increases dopamine (DA) in the zebrafish brain, and it has been suggested that tyrosine hydroxylase, the rate-limiting enzyme of DA synthesis, may be activated in response to ethanol via phosphorylation. The current study employed tetrahydropapaveroline (THP), a selective inhibitor of phosphorylated tyrosine hydroxylase, for the first time, in zebrafish. We treated zebrafish with a THP dose that did not alter baseline motor responses to examine whether it can attenuate or abolish the effects of acute exposure to alcohol (ethanol) on motor activity, on levels of DA, and on levels of dopamine’s metabolite 3,4-dihydroxyphenylacetic acid (DOPAC). We found that 60-minute exposure to 1% alcohol induced motor hyperactivity and an increase in brain DA. Both of these effects were attenuated by pre-treatment with THP. However, no differences in DOPAC levels were found among the treatment groups. These findings suggest that tyrosine hydroxylase is activated via phosphorylation to increase DA synthesis during alcohol exposure in zebrafish, and this partially mediates alcohol’s locomotor stimulant effects. Future studies will investigate other potential candidates in the molecular pathway to further decipher the neurobiological mechanism that underlies the stimulatory properties of this popular psychoactive drug. PMID:26366782

  12. Inhibition of phosphorylated tyrosine hydroxylase attenuates ethanol-induced hyperactivity in adult zebrafish (Danio rerio).

    PubMed

    Nowicki, Magda; Tran, Steven; Chatterjee, Diptendu; Gerlai, Robert

    2015-11-01

    Zebrafish have been successfully employed in the study of the behavioural and biological effects of ethanol. Like in mammals, low to moderate doses of ethanol induce motor hyperactivity in zebrafish, an effect that has been attributed to the activation of the dopaminergic system. Acute ethanol exposure increases dopamine (DA) in the zebrafish brain, and it has been suggested that tyrosine hydroxylase, the rate-limiting enzyme of DA synthesis, may be activated in response to ethanol via phosphorylation. The current study employed tetrahydropapaveroline (THP), a selective inhibitor of phosphorylated tyrosine hydroxylase, for the first time, in zebrafish. We treated zebrafish with a THP dose that did not alter baseline motor responses to examine whether it can attenuate or abolish the effects of acute exposure to alcohol (ethanol) on motor activity, on levels of DA, and on levels of dopamine's metabolite 3,4-dihydroxyphenylacetic acid (DOPAC). We found that 60-minute exposure to 1% alcohol induced motor hyperactivity and an increase in brain DA. Both of these effects were attenuated by pre-treatment with THP. However, no differences in DOPAC levels were found among the treatment groups. These findings suggest that tyrosine hydroxylase is activated via phosphorylation to increase DA synthesis during alcohol exposure in zebrafish, and this partially mediates alcohol's locomotor stimulant effects. Future studies will investigate other potential candidates in the molecular pathway to further decipher the neurobiological mechanism that underlies the stimulatory properties of this popular psychoactive drug.

  13. Calpain 2 Is Required for the Invasion of Glioblastoma Cells in the Zebrafish Brain Microenvironment

    PubMed Central

    Lal, Sangeet; La Du, Jane; Tanguay, Robert L.; Greenwood, Jeffrey A.

    2012-01-01

    Glioblastoma is an aggressive primary brain tumor with a 5-year survival rate of less than 5%. The ability of glioblastoma cells to invade surrounding brain tissue presents the primary challenge for the success of focal therapeutic approaches. We previously reported that the calcium-activated protease calpain 2 is critical for glioblastoma cell invasion in vitro. Here, we show that expression of calpain 2 is required for the dispersal of glioblastoma cells in a living brain microenvironment. Knockdown of calpain 2 resulted in a 2.9-fold decrease in the invasion of human glioblastoma cells in zebrafish brain. Control cells diffusely migrated up to 450 μm from the site of injection, whereas knockdown cells remained confined in clusters. The invasion study was repeated in organotypic mouse brain tissues, and calpain 2 knockdown cells demonstrated a 2.3-fold lower area of dispersal compared with control cells. In zebrafish brain, glioblastoma cells appeared to migrate in part along the blood vessels of the host. Furthermore, angiogenesis was detected in 27% of zebrafish injected with control cells, whereas only 12.5% of fish receiving knockdown cells showed the formation of new vessels, suggesting a role for calpain 2 in tumor cell angiogenesis. Consistent with the progression of glioblastoma in humans, transplanted tumor cells were not observed to metastasize outside the brain of zebrafish. This study demonstrates that calpain 2 expression is required for the dispersal of glioblastoma cells within the dynamic microenvironment of the brain, identifying zebrafish as a valuable orthotopic system for studying glioblastoma cell invasion. PMID:22183788

  14. Normal anatomy and histology of the adult zebrafish.

    PubMed

    Menke, Aswin L; Spitsbergen, Jan M; Wolterbeek, Andre P M; Woutersen, Ruud A

    2011-08-01

    The zebrafish has been shown to be an excellent vertebrate model for studying the roles of specific genes and signaling pathways. The sequencing of its genome and the relative ease with which gene modifications can be performed have led to the creation of numerous human disease models that can be used for testing the potential and the toxicity of new pharmaceutical compounds. Many pharmaceutical companies already use the zebrafish for prescreening purposes. So far, the focus has been on ecotoxicity and the effects on embryonic development, but there is a trend to expand the use of the zebrafish with acute, subchronic, and chronic toxicity studies that are currently still carried out with the more conventional test animals such as rodents. However, before we can fully realize the potential of the zebrafish as an animal model for understanding human development, disease, and toxicology, we must first greatly advance our knowledge of normal zebrafish physiology, anatomy, and histology. To further this knowledge, we describe, in the present article, location and histology of the major zebrafish organ systems with a brief description of their function.

  15. The utility of zebrafish to study the mechanisms by which ethanol affects social behavior and anxiety during early brain development.

    PubMed

    Parker, Matthew O; Annan, Leonette V; Kanellopoulos, Alexandros H; Brock, Alistair J; Combe, Fraser J; Baiamonte, Matteo; Teh, Muy-Teck; Brennan, Caroline H

    2014-12-03

    Exposure to moderate levels of ethanol during brain development has a number of effects on social behavior but the molecular mechanisms that mediate this are not well understood. Gaining a better understanding of these factors may help to develop therapeutic interventions in the future. Zebrafish offer a potentially useful model in this regard. Here, we introduce a zebrafish model of moderate prenatal ethanol exposure. Embryos were exposed to 20mM ethanol for seven days (48hpf-9dpf) and tested as adults for individual social behavior and shoaling. We also tested their basal anxiety with the novel tank diving test. We found that the ethanol-exposed fish displayed reductions in social approach and shoaling, and an increase in anxiety in the novel tank test. These behavioral differences corresponded to differences in hrt1aa, slc6a4 and oxtr expression. Namely, acute ethanol caused a spike in oxtr and ht1aa mRNA expression, which was followed by down-regulation at 7dpf, and an up-regulation in slc6a4 at 72hpf. This study confirms the utility of zebrafish as a model system for studying the molecular basis of developmental ethanol exposure. Furthermore, it proposes a putative developmental mechanism characterized by ethanol-induced OT inhibition leading to suppression of 5-HT and up-regulation of 5-HT1A, which leads, in turn, to possible homeostatic up-regulation of 5-HTT at 72hpf and subsequent imbalance of the 5-HT system.

  16. Rhodopsin expression in the zebrafish pineal gland from larval to adult stage.

    PubMed

    Magnoli, Domenico; Zichichi, Rosalia; Laurà, Rosaria; Guerrera, Maria Cristina; Campo, Salvatore; de Carlos, Felix; Suárez, Alberto Álvarez; Abbate, Francesco; Ciriaco, Emilia; Vega, Jose Antonio; Germanà, Antonino

    2012-03-09

    The zebrafish pineal gland plays an important role in different physiological functions including the regulation of the circadian clock. In the fish pineal gland the pinealocytes are made up of different segments: outer segment, inner segment and basal pole. Particularly, in the outer segment the rhodopsin participates in the external environment light reception that represents the first biochemical step in the melatonin production. It is well known that the rhodopsin in the adult zebrafish is well expressed in the pineal gland but both the expression and the cellular localization of this protein during development remain still unclear. In this study using qRT-PCR, sequencing and immunohistochemistry the expression as well as the protein localization of the rhodopsin in the zebrafish from larval (10 dpf) to adult stage (90 dpf) were demonstrated. The rhodopsin mRNA expression presents a peak of expression at 10 dpf, a further reduction to 50 dpf before increasing again in the adult stage. Moreover, the cellular localization of the rhodopsin-like protein was always localized in the pinealocyte at all ages examined. Our results demonstrated the involvement of the rhodopsin in the zebrafish pineal gland physiology particularly in the light capture during the zebrafish lifespan.

  17. Limb Regeneration is Impaired in an Adult Zebrafish Model of Diabetes Mellitus

    PubMed Central

    Olsen, Ansgar S.; Sarras, Michael P.; Intine, Robert V.

    2010-01-01

    The zebrafish (Danio Rerio) is an established model organism for the study of developmental processes, human disease and tissue regeneration. We report that limb regeneration is severely impaired in our newly developed adult zebrafish model of type I diabetes. Intraperitoneal streptozocin injection of adult, wild type zebrafish results in a sustained hyperglycemic state as determined by elevated fasting blood glucose values and increased glycation of serum protein. Serum insulin levels are also decreased and pancreas immunohistochemisty revealed a lesser amount of insulin signal in hyperglycemic fish. Additionally, the diabetic complications of retinal thinning and glomerular basement membrane thickening (early signs of retinopathy and nephropathy) resulting from the hyperglycemic state were evident in streptozocin injected fish at three weeks. Most significantly, limb regeneration, following caudal fin amputation, is severely impaired in diabetic zebrafish. Nonspecific toxic effects outside the pancreas were not found to contribute to impaired limb regeneration. This experimental system using adult zebrafish facilitates a broad spectrum of genetic and molecular approaches to study regeneration in the diabetic background. PMID:20840523

  18. Estrogenic Effects of Several BPA Analogs in the Developing Zebrafish Brain

    PubMed Central

    Cano-Nicolau, Joel; Vaillant, Colette; Pellegrini, Elisabeth; Charlier, Thierry D.; Kah, Olivier; Coumailleau, Pascal

    2016-01-01

    Important set of studies have demonstrated the endocrine disrupting activity of Bisphenol A (BPA). The present work aimed at defining estrogenic-like activity of several BPA structural analogs, including BPS, BPF, BPAF, and BPAP, on 4- or 7-day post-fertilization (dpf) zebrafish larva as an in vivo model. We measured the induction level of the estrogen-sensitive marker cyp19a1b gene (Aromatase B), expressed in the brain, using three different in situ/in vivo strategies: (1) Quantification of cyp19a1b transcripts using RT-qPCR in wild type 7-dpf larva brains exposed to bisphenols; (2) Detection and distribution of cyp19a1b transcripts using in situ hybridization on 7-dpf brain sections (hypothalamus); and (3) Quantification of the cyp19a1b promoter activity in live cyp19a1b-GFP transgenic zebrafish (EASZY assay) at 4-dpf larval stage. These three different experimental approaches demonstrated that BPS, BPF, or BPAF exposure, similarly to BPA, significantly activates the expression of the estrogenic marker in the brain of developing zebrafish. In vitro experiments using both reporter gene assay in a glial cell context and competitive ligand binding assays strongly suggested that up-regulation of cyp19a1b is largely mediated by the zebrafish estrogen nuclear receptor alpha (zfERα). Importantly, and in contrast to other tested bisphenol A analogs, the bisphenol AP (BPAP) did not show estrogenic activity in our model. PMID:27047331

  19. The photoreceptive cells of the pineal gland in adult zebrafish (Danio rerio).

    PubMed

    Laurà, Rosaria; Magnoli, Domenico; Zichichi, Rosalia; Guerrera, Maria Cristina; De Carlos, Felix; Suárez, Alberto Álvarez; Abbate, Francesco; Ciriaco, Emilia; Vega, Jose Antonio; Germanà, Antonino

    2012-03-01

    The zebrafish pineal gland plays a fundamental role in the regulation of the circadian rhythm through the melatonin secretion. The pinealocytes, also called photoreceptive cells, are considered the morphofunctional unit of pineal gland. In literature, the anatomical features, the cellular characteristics, and the pinealocytes morphology of zebrafish pineal gland have not been previously described in detail. Therefore, this study was undertaken to analyze the structure and ultrastructure, as well as the immunohistochemical profile of the zebrafish pineal gland with particular reference to the pinealocytes. Here, we demonstrated, using RT-PCR, immunohistochemistry and transmission electron microscopy, the expression of the mRNA for rhodopsin in the pineal gland of zebrafish, as well as its cellular localization exclusively in the pinealocytes of adult zebrafish. Moreover, the ultrastructural observations demonstrated that the pinealocytes were constituted by an outer segment with numerous lamellar membranes, an inner segment with many mitochondria, and a basal pole with the synapses. Our results taken together demonstrated a central role of zebrafish pinealocytes in the control of pineal gland functions.

  20. Reducing the noise in behavioral assays: sex and age in adult zebrafish locomotion.

    PubMed

    Philpott, Catelyn; Donack, Corey J; Cousin, Margot A; Pierret, Chris

    2012-12-01

    Many assays are used in animal model systems to measure specific human disease-related behaviors. The use of both adult and larval zebrafish as a behavioral model is gaining popularity. As this work progresses and potentially translates into new treatments, we must do our best to improve the sensitivity of these assays by reducing confounding factors. Scientists who use the mouse model system have demonstrated that sex and age can influence a number of behaviors. As a community, they have moved to report the age and sex of all animals used in their studies. Zebrafish work does not yet carry the same mandate. In this study, we evaluated sex and age differences in locomotion behavior. We found that age was a significant factor in locomotion, as was sex within a given age group. In short, as zebrafish age, they appear to show less base level locomotion. With regard to sex, younger (10 months) zebrafish showed more locomotion in males, while older zebrafish (22 months) showed more movement in females. These findings have led us to suggest that those using the zebrafish for behavioral studies control for age and sex within their experimental design and report these descriptors in their methods.

  1. Zebrafish locomotor capacity and brain acetylcholinesterase activity is altered by Aphanizomenon flos-aquae DC-1 aphantoxins.

    PubMed

    Zhang, De Lu; Hu, Chun Xiang; Li, Dun Hai; Liu, Yong Ding

    2013-08-15

    Aphanizomenon flos-aquae (A. flos-aquae) is a source of neurotoxins known as aphantoxins or paralytic shellfish poisons (PSPs) that present a major threat to the environment and to human health. Generally, altered neurological function is reflected in behavior. Although the molecular mechanism of action of PSPs is well known, its neurobehavioral effects on adult zebrafish and its relationship with altered neurological functions are poorly understood. Aphantoxins purified from a natural isolate of A. flos-aquae DC-1 were analyzed by HPLC. The major analogs found in the toxins were the gonyautoxins 1 and 5 (GTX1 and GTX5; 34.04% and 21.28%, respectively) and the neosaxitoxin (neoSTX, 12.77%). Zebrafish (Danio rerio) were intraperitoneally injected with 5.3 and 7.61 μg STXeq/kg (low and high dose, respectively) of A. flos-aquae DC-1 aphantoxins. The swimming activity was investigated by observation combined with video at 6 timepoints from 1 to 24 h post-exposure. Both aphantoxin doses were associated with delayed touch responses, reduced head-tail locomotory abilities, inflexible turning of head, and a tailward-shifted center of gravity. The normal S-pattern (or undulating) locomotor trajectory was replaced by a mechanical motor pattern of swinging the head after wagging the tail. Finally, these fish principally distributed at the top and/or bottom water of the aquarium, and showed a clear polarized distribution pattern at 12 h post-exposure. Further analysis of neurological function demonstrated that both aphantoxin doses inhibited brain acetylcholinesterase activity. All these changes were dose- and time-dependent. These results demonstrate that aphantoxins can alter locomotor capacity, touch responses and distribution patterns by damaging the cholinergic system of zebrafish, and suggest that zebrafish locomotor behavior and acetylcholinesterase can be used as indicators for investigating aphantoxins and blooms in nature.

  2. Expression and cell localization of brain-derived neurotrophic factor and TrkB during zebrafish retinal development.

    PubMed

    Germanà, A; Sánchez-Ramos, C; Guerrera, M C; Calavia, M G; Navarro, M; Zichichi, R; García-Suárez, O; Pérez-Piñera, P; Vega, Jose A

    2010-09-01

    Brain-derived neurotrophic factor (BDNF) signaling through TrkB regulates different aspects of neuronal development, including survival, axonal and dendritic growth, and synapse formation. Despite recent advances in our understanding of the functional significance of BDNF and TrkB in the retina, the cell types in the retina that express BDNF and TrkB, and the variations in their levels of expression during development, remain poorly defined. The goal of the present study is to determine the age-dependent changes in the levels of expression and localization of BDNF and TrkB in the zebrafish retina. Zebrafish retinas from 10 days post-fertilization (dpf) to 180 dpf were used to perform PCR, Western blot and immunohistochemistry. Both BDNF and TrkB mRNAs, and BDNF and full-length TrkB proteins were detected at all ages sampled. The localization of these proteins in the retina was very similar at all time points studied. BDNF immunoreactivity was found in the outer nuclear layer, the outer plexiform layer and the inner plexiform layer, whereas TrkB immunoreactivity was observed in the inner plexiform layer and, to a lesser extent, in the ganglion cell layer. These results demonstrate that the pattern of expression of BDNF and TrkB in the retina of zebrafish remains unchanged during postembryonic development and adult life. Because TrkB expression in retina did not change with age, cells expressing TrkB may potentially be able to respond during the entire lifespan of zebrafish to BDNF either exogenously administered or endogenously produced, acting through paracrine mechanisms.

  3. Cloning and expression of tachykinins and their association with kisspeptins in the brains of zebrafish.

    PubMed

    Ogawa, Satoshi; Ramadasan, Priveena Nair; Goschorska, Maja; Anantharajah, Aveena; Ng, Kai We; Parhar, Ishwar S

    2012-09-01

    The tachykinins are a family of neuropeptides, including substance P (SP), neurokinin A (NKA), and neurokinin B (NKB), that are encoded by the tac1 (SP and NKA) or tac2/3 (NKB) genes. Tachykinins are widely distributed in the central nervous system and have roles as neurotransmitters and/or neuromodulators. Recent studies in mammals have demonstrated the coexpression of NKB and kisspeptin and their comodulatory roles over the control of reproduction. We have recently identified two kisspeptin-encoding genes, kiss1 and kiss2, in teleosts. However, such relationship between tachykinins and kisspeptins has not been demonstrated in non-mammalian species. To determine the involvement of tachykinins in the reproduction in teleosts, we identified tac1 and two tac2 (tac2a and tac2b) sequences in the zebrafish genome using in silico data mining. Zebrafish tac1 encodes SP and NKA, whereas the tac2 sequences encode NKB and an additional peptide homologous to NKB (NKB-related peptide). Digoxigenin in situ hybridization in the brain of zebrafish showed tac1 mRNA-containing cells in the olfactory bulb, telencephalon, preoptic region, hypothalamus, mesencephalon, and rhombencephalon. The zebrafish tac2a mRNA-containing cells were observed in the preoptic region, habenula, and hypothalamus, whereas the tac2b mRNA-containing cells were predominantly observed in the dorsal telencephalic area. Furthermore, we examined the coexpression of tachykinins and two kisspeptin genes in the brain of zebrafish. Dual fluorescent in situ hybridization showed no coexpression of tachykinins mRNA with kisspeptins mRNA in hypothalamic nuclei or the habenula. These results suggest the presence of independent pathways for kisspeptins and NKB neurons in the brain of zebrafish.

  4. Identifying proteins in zebrafish embryos using spectral libraries generated from dissected adult organs and tissues.

    PubMed

    van der Plas-Duivesteijn, Suzanne J; Mohammed, Yassene; Dalebout, Hans; Meijer, Annemarie; Botermans, Anouk; Hoogendijk, Jordy L; Henneman, Alex A; Deelder, André M; Spaink, Herman P; Palmblad, Magnus

    2014-03-07

    Spectral libraries provide a sensitive and accurate method for identifying peptides from tandem mass spectra, complementary to searching genome-derived databases or sequencing de novo. Their application requires comprehensive libraries including peptides from low-abundant proteins. Here we describe a method for constructing such libraries using biological differentiation to "fractionate" the proteome by harvesting adult organs and tissues and build comprehensive libraries for identifying proteins in zebrafish (Danio rerio) embryos and larvae (an important and widely used model system). Hierarchical clustering using direct comparison of spectra was used to prioritize organ selection. The resulting and publicly available library covers 14,164 proteins, significantly improved the number of peptide-spectrum matches in zebrafish developmental stages, and can be used on data from different instruments and laboratories. The library contains information on tissue and organ expression of these proteins and is also applicable for adult experiments. The approach itself is not limited to zebrafish but would work for any model system.

  5. Nonhatching Decapsulated Artemia Cysts As a Replacement to Artemia Nauplii in Juvenile and Adult Zebrafish Culture.

    PubMed

    Tye, Marc; Rider, Dana; Duffy, Elizabeth A; Seubert, Adam; Lothert, Brogen; Schimmenti, Lisa A

    2015-12-01

    Feeding Artemia nauplii as the main nutrition source for zebrafish is a common practice for many research facilities. Culturing live feed can be time-consuming and requires additional equipment to be purchased, maintained, and cleaned. Nonhatching decapsulated Artemia cysts (decaps) are a commercially available product that can be fed directly to fish. Several other ornamental fish species have been successfully cultured using decaps. Replacing Artemia nauplii with decaps could reduce the overall time and costs associated with the operation of a zebrafish facility. The objective of this study was to determine if decaps could be a suitable replacement to Artemia nauplii in juvenile and adult zebrafish culture. Wild-type zebrafish were fed one of three dietary treatments: decaps only, nauplii only, or a standard consisting of nauplii plus a commercially prepared pellet food. Survival, growth (length and weight), and embryo production were analyzed between the treatments. Fish receiving the decap diet demonstrated a significantly higher growth and embryo production when compared to the fish receiving the nauplii-only diet. When comparing the decap fish to the standard fish, no significant difference was found in mean survival, mean weight at 90 days postfertilization, or mean embryo production. It was determined that nonhatching decapsulated Artemia cysts can be used as a suitable replacement to Artemia nauplii in juvenile and adult zebrafish culture.

  6. Phylostratigraphic profiles in zebrafish uncover chordate origins of the vertebrate brain.

    PubMed

    Šestak, Martin Sebastijan; Domazet-Lošo, Tomislav

    2015-02-01

    An elaborated tripartite brain is considered one of the important innovations of vertebrates. Other extant chordate groups have a more basic brain organization. For instance, cephalochordates possess a relatively simple brain possibly homologous to the vertebrate forebrain and hindbrain, whereas tunicates display the tripartite organization, but without the specialized brain centers. The difference in anatomical complexity is even more pronounced if one compares chordates with other deuterostomes that have only a diffuse nerve net or alternatively a rather simple central nervous system. To gain a new perspective on the evolutionary roots of the complex vertebrate brain, we made here a phylostratigraphic analysis of gene expression patterns in the developing zebrafish (Danio rerio). The recovered adaptive landscape revealed three important periods in the evolutionary history of the zebrafish brain. The oldest period corresponds to preadaptive events in the first metazoans and the emergence of the nervous system at the metazoan-eumetazoan transition. The origin of chordates marks the next phase, where we found the overall strongest adaptive imprint in almost all analyzed brain regions. This finding supports the idea that the vertebrate brain evolved independently of the brains within the protostome lineage. Finally, at the origin of vertebrates we detected a pronounced signal coming from the dorsal telencephalon, in agreement with classical theories that consider this part of the cerebrum a genuine vertebrate innovation. Taken together, these results reveal a stepwise adaptive history of the vertebrate brain where most of its extant organization was already present in the chordate ancestor.

  7. Standardized echocardiographic assessment of cardiac function in normal adult zebrafish and heart disease models.

    PubMed

    Wang, Louis W; Huttner, Inken G; Santiago, Celine F; Kesteven, Scott H; Yu, Ze-Yan; Feneley, Michael P; Fatkin, Diane

    2017-01-01

    The zebrafish (Danio rerio) is an increasingly popular model organism in cardiovascular research. Major insights into cardiac developmental processes have been gained by studies of embryonic zebrafish. However, the utility of zebrafish for modeling adult-onset heart disease has been limited by a lack of robust methods for in vivo evaluation of cardiac function. We established a physiological protocol for underwater zebrafish echocardiography using high frequency ultrasound, and evaluated its reliability in detecting altered cardiac function in two disease models. Serial assessment of cardiac function was performed in wild-type zebrafish aged 3 to 12 months and the effects of anesthetic agents, age, sex and background strain were evaluated. There was a varying extent of bradycardia and ventricular contractile impairment with different anesthetic drugs and doses, with tricaine 0.75 mmol l(-1) having a relatively more favorable profile. When compared with males, female fish were larger and had more measurement variability. Although age-related increments in ventricular chamber size were greater in females than males, there were no sex differences when data were normalized to body size. Systolic ventricular function was similar in both sexes at all time points, but differences in diastolic function were evident from 6 months onwards. Wild-type fish of both sexes showed a reliance on atrial contraction for ventricular diastolic filling. Echocardiographic evaluation of adult zebrafish with diphtheria toxin-induced myocarditis or anemia-induced volume overload accurately identified ventricular dilation and altered contraction, with suites of B-mode, ventricular strain, pulsed-wave Doppler and tissue Doppler indices showing concordant changes indicative of myocardial hypocontractility or hypercontractility, respectively. Repeatability, intra-observer and inter-observer correlations for echocardiographic measurements were high. We demonstrate that high frequency

  8. Standardized echocardiographic assessment of cardiac function in normal adult zebrafish and heart disease models

    PubMed Central

    Wang, Louis W.; Huttner, Inken G.; Santiago, Celine F.; Kesteven, Scott H.; Yu, Ze-Yan; Feneley, Michael P.

    2017-01-01

    ABSTRACT The zebrafish (Danio rerio) is an increasingly popular model organism in cardiovascular research. Major insights into cardiac developmental processes have been gained by studies of embryonic zebrafish. However, the utility of zebrafish for modeling adult-onset heart disease has been limited by a lack of robust methods for in vivo evaluation of cardiac function. We established a physiological protocol for underwater zebrafish echocardiography using high frequency ultrasound, and evaluated its reliability in detecting altered cardiac function in two disease models. Serial assessment of cardiac function was performed in wild-type zebrafish aged 3 to 12 months and the effects of anesthetic agents, age, sex and background strain were evaluated. There was a varying extent of bradycardia and ventricular contractile impairment with different anesthetic drugs and doses, with tricaine 0.75 mmol l−1 having a relatively more favorable profile. When compared with males, female fish were larger and had more measurement variability. Although age-related increments in ventricular chamber size were greater in females than males, there were no sex differences when data were normalized to body size. Systolic ventricular function was similar in both sexes at all time points, but differences in diastolic function were evident from 6 months onwards. Wild-type fish of both sexes showed a reliance on atrial contraction for ventricular diastolic filling. Echocardiographic evaluation of adult zebrafish with diphtheria toxin-induced myocarditis or anemia-induced volume overload accurately identified ventricular dilation and altered contraction, with suites of B-mode, ventricular strain, pulsed-wave Doppler and tissue Doppler indices showing concordant changes indicative of myocardial hypocontractility or hypercontractility, respectively. Repeatability, intra-observer and inter-observer correlations for echocardiographic measurements were high. We demonstrate that high

  9. Left Brain/Right Brain Learning for Adult Education.

    ERIC Educational Resources Information Center

    Garvin, Barbara

    1986-01-01

    Contrasts and compares the theory and practice of adult education as it relates to the issue of right brain/left brain learning. The author stresses the need for a whole-brain approach to teaching and suggests that adult educators, given their philosophical directions, are the perfect potential users of this integrated system. (Editor/CT)

  10. Brain and Spinal Cord Tumors in Adults

    MedlinePlus

    ... Search Search En Español Category Cancer A-Z Brain and Spinal Cord Tumors in Adults If you have a brain or spinal cord tumor or are close to ... cope. Here you can find out all about brain and spinal cord tumors in adults, including risk ...

  11. Morphological and molecular evidence for functional organization along the rostrocaudal axis of the adult zebrafish intestine

    PubMed Central

    2010-01-01

    Background The zebrafish intestine is a simple tapered tube that is folded into three sections. However, whether the intestine is functionally similar along its length remains unknown. Thus, a systematic structural and functional characterization of the zebrafish intestine is desirable for future studies of the digestive tract and the intestinal biology and development. Results To characterize the structure and function of the adult zebrafish intestine, we divided the intestine into seven roughly equal-length segments, S1-S7, and systematically examined the morphology of the mucosal lining, histology of the epithelium, and molecular signatures from transcriptome analysis. Prominent morphological features are circumferentially-oriented villar ridges in segments S1-S6 and the absence of crypts. Molecular characterization of the transcriptome from each segment shows that segments S1-S5 are very similar while S6 and S7 unique. Gene ontology analyses reveal that S1-S5 express genes whose functions involve metabolism of carbohydrates, transport of lipids and energy generation, while the last two segments display relatively limited function. Based on comparative Gene Set Enrichment Analysis, the first five segments share strong similarity with human and mouse small intestine while S6 shows similarity with human cecum and rectum, and S7 with human rectum. The intestinal tract does not display the anatomical, morphological, and molecular signatures of a stomach and thus we conclude that this organ is absent from the zebrafish digestive system. Conclusions Our genome-wide gene expression data indicate that, despite the lack of crypts, the rostral, mid, and caudal portions of the zebrafish intestine have distinct functions analogous to the mammalian small and large intestine, respectively. Organization of ridge structures represents a unique feature of zebrafish intestine, though they produce similar cross sections to mammalian intestines. Evolutionary lack of stomach, crypts

  12. Distinct effects of inflammation on preconditioning and regeneration of the adult zebrafish heart

    PubMed Central

    de Preux Charles, Anne-Sophie; Bise, Thomas; Baier, Felix; Marro, Jan; Jaźwińska, Anna

    2016-01-01

    The adult heart is able to activate cardioprotective programmes and modifies its architecture in response to physiological or pathological changes. While mammalian cardiac remodelling often involves hypertrophic expansion, the adult zebrafish heart exploits hyperplastic growth. This capacity depends on the responsiveness of zebrafish cardiomyocytes to mitogenic signals throughout their entire life. Here, we have examined the role of inflammation on the stimulation of cell cycle activity in the context of heart preconditioning and regeneration. We used thoracotomy as a cardiac preconditioning model and cryoinjury as a model of cardiac infarction in the adult zebrafish. First, we performed a spatio-temporal characterization of leucocytes and cycling cardiac cells after thoracotomy. This analysis revealed a concomitance between the infiltration of inflammatory cells and the stimulation of the mitotic activity. However, decreasing the immune response using clodronate liposome injection, PLX3397 treatment or anti-inflammatory drugs surprisingly had no effect on the re-entry of cardiac cells into the cell cycle. In contrast, reducing inflammation using the same strategies after cryoinjury strongly impaired cardiac cell mitotic activity and the regenerative process. Taken together, our results show that, while the immune response is not necessary to induce cell-cycle activity in intact preconditioned hearts, inflammation is required for the regeneration of injured hearts in zebrafish. PMID:27440424

  13. Acute restraint stress induces an imbalance in the oxidative status of the zebrafish brain.

    PubMed

    Dal Santo, Glaucia; Conterato, Greicy M M; Barcellos, Leonardo J G; Rosemberg, Denis B; Piato, Angelo L

    2014-01-13

    The zebrafish (Danio rerio) has become an emergent model organism for translational approaches focused on the neurobiology of stress due to its genetic, neuroanatomical, and histological similarities with mammalian systems. However, despite the increasing number of studies using zebrafish, reports examining the impact of stress on relevant neurochemical parameters are still elementary when compared to studies using rodents. Additionally, it is important to further validate this model organism by comparing its stress response with those described in other species. Here, we evaluated the effects of an acute restraint stress (ARS) protocol on oxidative stress-related parameters in the zebrafish brain. Our data revealed that ARS significantly decreased catalase activity without altering the activity of superoxide dismutase. Oxidative stress was also indicated by increased levels of lipid peroxides. ARS significantly increased the levels of non-protein thiols, although significant changes in total reduced sulfhydryl content were not detected. These results suggest that ARS is an interesting strategy for evaluating the mechanisms underlying the neurochemical basis of the oxidative profile triggered by acute stressors in the zebrafish brain. Furthermore, this protocol may be suitable for screening new compounds with protective properties against oxidative stress, which plays an increasingly important role in many psychiatric disorders.

  14. Chronic and acute alcohol administration induced neurochemical changes in the brain: comparison of distinct zebrafish populations.

    PubMed

    Chatterjee, Diptendu; Shams, Soaleha; Gerlai, Robert

    2014-04-01

    The zebrafish is increasingly utilized in the analysis of the effects of ethanol (alcohol) on brain function and behavior. We have shown significant population-dependent alcohol-induced changes in zebrafish behavior and have started to analyze alterations in dopaminergic and serotoninergic responses. Here, we analyze the effects of alcohol on levels of selected neurochemicals using a 2 × 3 (chronic × acute) between-subject alcohol exposure paradigm randomized for two zebrafish populations, AB and SF. Each fish first received the particular chronic treatment (0 or 0.5 vol/vol% alcohol) and subsequently the acute exposure (0, 0.5 or 1.0% alcohol). We report changes in levels of dopamine, DOPAC, serotonin, 5HIAA, glutamate, GABA, aspartate, glycine and taurine as quantified from whole brain extracts using HPLC. We also analyze monoamine oxidase and tyrosine hydroxylase enzymatic activity. The results demonstrate that compared to SF, AB is more responsive to both acute alcohol exposure and acute alcohol withdrawal at the level of neurochemistry, a finding that correlates well with prior behavioral observations and one which suggests the involvement of genes in the observed alcohol effects. We discuss correlations between the current results and prior behavioral findings, and stress the importance of characterization of zebrafish strains for future behavior genetic and psychopharmacology studies.

  15. GLUT2-mediated glucose uptake and availability are required for embryonic brain development in zebrafish

    PubMed Central

    Marín-Juez, Rubén; Rovira, Mireia; Crespo, Diego; van der Vaart, Michiel; Spaink, Herman P; Planas, Josep V

    2015-01-01

    Glucose transporter 2 (GLUT2; gene name SLC2A2) has a key role in the regulation of glucose dynamics in organs central to metabolism. Although GLUT2 has been studied in the context of its participation in peripheral and central glucose sensing, its role in the brain is not well understood. To decipher the role of GLUT2 in brain development, we knocked down slc2a2 (glut2), the functional ortholog of human GLUT2, in zebrafish. Abrogation of glut2 led to defective brain organogenesis, reduced glucose uptake and increased programmed cell death in the brain. Coinciding with the observed localization of glut2 expression in the zebrafish hindbrain, glut2 deficiency affected the development of neural progenitor cells expressing the proneural genes atoh1b and ptf1a but not those expressing neurod. Specificity of the morphant phenotype was demonstrated by the restoration of brain organogenesis, whole-embryo glucose uptake, brain apoptosis, and expression of proneural markers in rescue experiments. These results indicate that glut2 has an essential role during brain development by facilitating the uptake and availability of glucose and support the involvement of glut2 in brain glucose sensing. PMID:25294126

  16. Acetylcholinesterase activity and antioxidant capacity of zebrafish brain is altered by heavy metal exposure.

    PubMed

    Richetti, S K; Rosemberg, D B; Ventura-Lima, J; Monserrat, J M; Bogo, M R; Bonan, C D

    2011-01-01

    Pollution is a world problem with immeasurable consequences. Heavy metal compounds are frequently found as components of anthropogenic pollution. Here we evaluated the effects of the treatment with cadmium acetate, lead acetate, mercury chloride, and zinc chloride in acetylcholinesterase activity and gene expression pattern, as well as the effects of these treatments in antioxidant competence in the brain of an aquatic and well-established organism for toxicological analysis, zebrafish (Danio rerio, Cyprinidae). Mercury chloride and lead acetate promoted a significant decrease in acetylcholinesterase activity whereas they did not alter the gene expression pattern. In addition, the antioxidant competence was decreased after exposure to mercury chloride. The data presented here allowed us to hypothesize a signal transmission impairment, through alterations in cholinergic transmission, and also in the antioxidant competence of zebrafish brain tissue as some of the several effects elicited by these pollutants.

  17. Enantioselective bioaccumulation of hexaconazole and its toxic effects in adult zebrafish (Danio rerio).

    PubMed

    Wang, Yao; Xu, Li; Li, Dongzhi; Teng, Miaomiao; Zhang, Renke; Zhou, Zhiqiang; Zhu, Wentao

    2015-11-01

    Little is known about the bioaccumulation and toxicity of hexaconazole (HEX) in spite of the fact that they are indispensable parts for a comprehensive assessment of its environmental behavior and toxic effects in organisms of freshwater ecosystems. In this study, adult zebrafish were used to study the enantioselective bioaccumulation of HEX and its effect endpoints in liver, including oxidative stress and the regulation of apoptosis-related gene expression. Significant enantioselective bioaccumulation was demonstrated when exposed to HEX of 100 and 200 μg L(-)(1), finding that the (-)-enantiomer tended to accumulate in zebrafish more easily than (+)-enantiomer. Activities of antioxidant enzymes (SOD, CAT and GPx) and GSH content were all significantly decreased when zebrafish were exposed to 50 and 200 μg L(-1) HEX for 21 d. A series of genes of the apoptosis pathway were examined in groups treated with 50 and 200 μg L(-)(1) HEX for 21 d using real-time PCR. Significant up-regulation of p53, Puma, Apaf-1, caspase-3 and caspase-9 expression and down-regulation of Bcl-2/Bax expression ratio were proved. The overall results indicated that waterborne HEX was able to produce oxidative stress and induce apoptosis through the involvement of caspases in adult zebrafish. The above information will play a vital role in the integrated environmental risk assessment of HEX and make its toxic mechanism in fish clear.

  18. Quantitative in vivo optical tomography of cancer progression & vasculature development in adult zebrafish

    PubMed Central

    Kumar, Sunil; Lockwood, Nicola; Ramel, Marie-Christine; Correia, Teresa; Ellis, Matthew; Alexandrov, Yuriy; Andrews, Natalie; Patel, Rachel; Bugeon, Laurence; Dallman, Margaret J.; Brandner, Sebastian; Arridge, Simon; Katan, Matilda; McGinty, James; Frankel, Paul; French, Paul M.W.

    2016-01-01

    We describe a novel approach to study tumour progression and vasculature development in vivo via global 3-D fluorescence imaging of live non-pigmented adult zebrafish utilising angularly multiplexed optical projection tomography with compressive sensing (CS-OPT). This “mesoscopic” imaging method bridges a gap between established ~μm resolution 3-D fluorescence microscopy techniques and ~mm-resolved whole body planar imaging and diffuse tomography. Implementing angular multiplexing with CS-OPT, we demonstrate the in vivo global imaging of an inducible fluorescently labelled genetic model of liver cancer in adult non-pigmented zebrafish that also present fluorescently labelled vasculature. In this disease model, addition of a chemical inducer (doxycycline) drives expression of eGFP tagged oncogenic K-RASV12 in the liver of immune competent animals. We show that our novel in vivo global imaging methodology enables non-invasive quantitative imaging of the development of tumour and vasculature throughout the progression of the disease, which we have validated against established methods of pathology including immunohistochemistry. We have also demonstrated its potential for longitudinal imaging through a study of vascular development in the same zebrafish from early embryo to adulthood. We believe that this instrument, together with its associated analysis and data management tools, constitute a new platform for in vivo cancer studies and drug discovery in zebrafish disease models. PMID:27259259

  19. Quantitative in vivo optical tomography of cancer progression & vasculature development in adult zebrafish.

    PubMed

    Kumar, Sunil; Lockwood, Nicola; Ramel, Marie-Christine; Correia, Teresa; Ellis, Matthew; Alexandrov, Yuriy; Andrews, Natalie; Patel, Rachel; Bugeon, Laurence; Dallman, Margaret J; Brandner, Sebastian; Arridge, Simon; Katan, Matilda; McGinty, James; Frankel, Paul; French, Paul M W

    2016-07-12

    We describe a novel approach to study tumour progression and vasculature development in vivo via global 3-D fluorescence imaging of live non-pigmented adult zebrafish utilising angularly multiplexed optical projection tomography with compressive sensing (CS-OPT). This "mesoscopic" imaging method bridges a gap between established ~μm resolution 3-D fluorescence microscopy techniques and ~mm-resolved whole body planar imaging and diffuse tomography. Implementing angular multiplexing with CS-OPT, we demonstrate the in vivo global imaging of an inducible fluorescently labelled genetic model of liver cancer in adult non-pigmented zebrafish that also present fluorescently labelled vasculature. In this disease model, addition of a chemical inducer (doxycycline) drives expression of eGFP tagged oncogenic K-RASV12 in the liver of immune competent animals. We show that our novel in vivo global imaging methodology enables non-invasive quantitative imaging of the development of tumour and vasculature throughout the progression of the disease, which we have validated against established methods of pathology including immunohistochemistry. We have also demonstrated its potential for longitudinal imaging through a study of vascular development in the same zebrafish from early embryo to adulthood. We believe that this instrument, together with its associated analysis and data management tools, constitute a new platform for in vivo cancer studies and drug discovery in zebrafish disease models.

  20. Whole adult organism transcriptional profiling of acute metal exposures in male Zebrafish

    PubMed Central

    2014-01-01

    Background A convergence of technological breakthroughs in the past decade has facilitated the development of rapid screening tools for biomarkers of toxicant exposure and effect. Platforms using the whole adult organism to evaluate the genome-wide response to toxicants are especially attractive. Recent work demonstrates the feasibility of this approach in vertebrates using the experimentally robust zebrafish model. In the present study, we evaluated gene expression changes in whole adult male zebrafish following an acute 24 hr high dose exposure to three metals with known human health risks. Male adult zebrafish were exposed to nickel chloride, cobalt chloride or sodium dichromate concentrations corresponding to their respective 96 hr LC20, LC40 and LC60. Histopathology was performed on a subset of metal-exposed zebrafish to phenotypically anchor transcriptional changes associated with each metal. Results Comparative analysis identified subsets of differentially expressed transcripts both overlapping and unique to each metal. Application of gene ontology (GO) and transcription factor (TF) enrichment algorithms revealed a number of key biological processes perturbed by metal poisonings and the master transcriptional regulators mediating gene expression changes. Metal poisoning differentially activated biological processes associated with ribosome biogenesis, proteosomal degradation, and p53 signaling cascades, while repressing oxygen-generating pathways associated with amino acid and lipid metabolism. Despite appreciable effects on gene regulation, nickel poisoning did not induce any morphological alterations in male zebrafish organs and tissues. Histopathological effects of cobalt remained confined to the olfactory system, while chromium targeted the gills, pharynx, and intestinal mucosa. A number of enriched transcription factors mediated the observed gene response to metal poisoning, including known targets such as p53, HIF1α, and the myc oncogene, and novel

  1. Primary brain tumours in adults.

    PubMed

    Ricard, Damien; Idbaih, Ahmed; Ducray, François; Lahutte, Marion; Hoang-Xuan, Khê; Delattre, Jean-Yves

    2012-05-26

    Important advances have been made in the understanding and management of adult gliomas and primary CNS lymphomas--the two most common primary brain tumours. Progress in imaging has led to a better analysis of the nature and grade of these tumours. Findings from large phase 3 studies have yielded some standard treatments for gliomas, and have confirmed the prognostic value of specific molecular alterations. High-throughput methods that enable genome-wide analysis of tumours have improved the knowledge of tumour biology, which should lead to a better classification of gliomas and pave the way for so-called targeted therapy trials. Primary CNS lymphomas are a group of rare non-Hodgkin lymphomas. High-dose methotrexate-based regimens increase survival, but the standards of care and the place of whole-brain radiotherapy remain unclear, and are likely to depend on the age of the patient. The focus now is on the development of new polychemotherapy regimens to reduce or defer whole-brain radiotherapy and its delayed complications.

  2. Improvement of surface ECG recording in adult zebrafish reveals that the value of this model exceeds our expectation

    PubMed Central

    Liu, Chi Chi; Li, Li; Lam, Yun Wah; Siu, Chung Wah; Cheng, Shuk Han

    2016-01-01

    The adult zebrafish has been used to model the electrocardiogram (ECG) for human cardiovascular studies. Nonetheless huge variations are observed among studies probably because of the lack of a reliable and reproducible recording method. In our study, an adult zebrafish surface ECG recording technique was improved using a multi-electrode method and by pre-opening the pericardial sac. A convenient ECG data analysis method without wavelet transform was also established. Intraperitoneal injection of KCl in zebrafish induced an arrhythmia similar to that of humans, and the arrhythmia was partially rescued by calcium gluconate. Amputation and cryoinjury of the zebrafish heart induced ST segment depression and affected QRS duration after injury. Only cryoinjury decelerated the heart rate. Different changes were also observed in the QT interval during heart regeneration in these two injury models. We also characterized the electrocardiophysiology of breakdance zebrafish mutant with a prolonged QT interval, that has not been well described in previous studies. Our study provided a reliable and reproducible means to record zebrafish ECG and analyse data. The detailed characterization of the cardiac electrophysiology of zebrafish and its mutant revealed that the potential of the zebrafish in modeling the human cardiovascular system exceeds expectations. PMID:27125643

  3. The utility of zebrafish to study the mechanisms by which ethanol affects social behavior and anxiety during early brain development

    PubMed Central

    Parker, Matthew O.; Annan, Leonette V.; Kanellopoulos, Alexandros H.; Brock, Alistair J.; Combe, Fraser J.; Baiamonte, Matteo; Teh, Muy-Teck; Brennan, Caroline H.

    2014-01-01

    Exposure to moderate levels of ethanol during brain development has a number of effects on social behavior but the molecular mechanisms that mediate this are not well understood. Gaining a better understanding of these factors may help to develop therapeutic interventions in the future. Zebrafish offer a potentially useful model in this regard. Here, we introduce a zebrafish model of moderate prenatal ethanol exposure. Embryos were exposed to 20 mM ethanol for seven days (48hpfs–9dpf) and tested as adults for individual social behavior and shoaling. We also tested their basal anxiety with the novel tank diving test. We found that the ethanol-exposed fish displayed reductions in social approach and shoaling, and an increase in anxiety in the novel tank test. These behavioral differences corresponded to differences in hrt1aa, slc6a4 and oxtr expression. Namely, acute ethanol caused a spike in oxtr and ht1aa mRNA expression, which was followed by down-regulation at 7dpf, and an up-regulation in slc6a4 at 72hpf. This study confirms the utility of zebrafish as a model system for studying the molecular basis of developmental ethanol exposure. Furthermore, it proposes a putative developmental mechanism characterized by ethanol-induced OT inhibition leading to suppression of 5-HT and up-regulation of 5-HT1A, which leads, in turn, to possible homeostatic up-regulation of 5-HTT at 72hpf and subsequent imbalance of the 5-HT system. PMID:24690524

  4. zebraflash transgenic lines for in vivo bioluminescence imaging of stem cells and regeneration in adult zebrafish.

    PubMed

    Chen, Chen-Hui; Durand, Ellen; Wang, Jinhu; Zon, Leonard I; Poss, Kenneth D

    2013-12-01

    The zebrafish has become a standard model system for stem cell and tissue regeneration research, based on powerful genetics, high tissue regenerative capacity and low maintenance costs. Yet, these studies can be challenged by current limitations of tissue visualization techniques in adult animals. Here we describe new imaging methodology and present several ubiquitous and tissue-specific luciferase-based transgenic lines, which we have termed zebraflash, that facilitate the assessment of regeneration and engraftment in freely moving adult zebrafish. We show that luciferase-based live imaging reliably estimates muscle quantity in an internal organ, the heart, and can longitudinally follow cardiac regeneration in individual animals after major injury. Furthermore, luciferase-based detection enables visualization and quantification of engraftment in live recipients of transplanted hematopoietic stem cell progeny, with advantages in sensitivity and gross spatial resolution over fluorescence detection. Our findings present a versatile resource for monitoring and dissecting vertebrate stem cell and regeneration biology.

  5. Time-Gated Optical Projection Tomography Allows Visualization of Adult Zebrafish Internal Structures

    PubMed Central

    Foglia, Efrem Alessandro; Pistocchi, Anna; D'Andrea, Cosimo; Valentini, Gianluca; Cubeddu, Rinaldo; De Silvestri, Sandro; Cerullo, Giulio; Cotelli, Franco

    2012-01-01

    Optical imaging through biological samples is compromised by tissue scattering and currently various approaches aim to overcome this limitation. In this paper we demonstrate that an all optical technique, based on non-linear upconversion of infrared ultrashort laser pulses and on multiple view acquisition, allows the reduction of scattering effects in tomographic imaging. This technique, namely Time-Gated Optical Projection Tomography (TGOPT), is used to reconstruct three dimensionally the internal structure of adult zebrafish without staining or clearing agents. This method extends the use of Optical Projection Tomography to optically diffusive samples yielding reconstructions with reduced artifacts, increased contrast and improved resolution with respect to those obtained with non-gated techniques. The paper shows that TGOPT is particularly suited for imaging the skeletal system and nervous structures of adult zebrafish. PMID:23185643

  6. Effect of radiation dose-rate on hematopoietic cell engraftment in adult zebrafish.

    PubMed

    Glass, Tiffany J; Hui, Susanta K; Blazar, Bruce R; Lund, Troy C

    2013-01-01

    Although exceptionally high radiation dose-rates are currently attaining clinical feasibility, there have been relatively few studies reporting the biological consequences of these dose-rates in hematopoietic cell transplant (HCT). In zebrafish models of HCT, preconditioning before transplant is typically achieved through radiation alone. We report the comparison of outcomes in adult zebrafish irradiated with 20 Gy at either 25 or 800 cGy/min in the context of experimental HCT. In non-transplanted irradiated fish we observed no substantial differences between dose-rate groups as assessed by fish mortality, cell death in the kidney, endogenous hematopoietic reconstitution, or gene expression levels of p53 and ddb2 (damage-specific DNA binding protein 2) in the kidney. However, following HCT, recipients conditioned with the higher dose rate showed significantly improved donor-derived engraftment at 9 days post transplant (p ≤ 0.0001), and improved engraftment persisted at 31 days post transplant. Analysis for sdf-1a expression, as well as transplant of hematopoietic cells from cxcr4b -/- zebrafish, (odysseus), cumulatively suggest that the sdf-1a/cxcr4b axis is not required of donor-derived cells for the observed dose-rate effect on engraftment. Overall, the adult zebrafish model of HCT indicates that exceptionally high radiation dose-rates can impact HCT outcome, and offers a new system for radiobiological and mechanistic interrogation of this phenomenon. Key words: Radiation dose rate, Total Marrow Irradiation (TMI), Total body irradiation (TBI), SDF-1, Zebrafish, hematopoietic cell transplant.

  7. Novel approaches to determine contractile function of the isolated adult zebrafish ventricular cardiac myocyte

    PubMed Central

    Dvornikov, Alexey V; Dewan, Sukriti; Alekhina, Olga V; Pickett, F Bryan; de Tombe, Pieter P

    2014-01-01

    The zebrafish (Danio rerio) has been used extensively in cardiovascular biology, but mainly in the study of heart development. The relative ease of its genetic manipulation may indicate the suitability of this species as a cost-effective model system for the study of cardiac contractile biology. However, whether the zebrafish heart is an appropriate model system for investigations pertaining to mammalian cardiac contractile structure–function relationships remains to be resolved. Myocytes were isolated from adult zebrafish hearts by enzymatic digestion, attached to carbon rods, and twitch force and intracellular Ca2+ were measured. We observed the modulation of twitch force, but not of intracellular Ca2+, by both extracellular [Ca2+] and sarcomere length. In permeabilized cells/myofibrils, we found robust myofilament length-dependent activation. Moreover, modulation of myofilament activation–relaxation and force redevelopment kinetics by varied Ca2+ activation levels resembled that found previously in mammalian myofilaments. We conclude that the zebrafish is a valid model system for the study of cardiac contractile structure–function relationships. PMID:24591576

  8. The Behavioral Effects of Single Housing and Environmental Enrichment on Adult Zebrafish (Danio rerio)

    PubMed Central

    Collymore, Chereen; Tolwani, Ravi J; Rasmussen, Skye

    2015-01-01

    Environmental enrichment provides laboratory-housed species the opportunity to express natural behavior and exert control over their home environment, thereby minimizing stress. We sought to determine whether providing an artificial plant in the holding tank as enrichment influenced anxiety-like behaviors and place-preference choice in adult zebrafish. Fish were housed singly or in social groups of 5 for 3 wk in 1 of 4 experimental housing environments: single-housed enriched (n = 30), single-housed barren (n = 30), group-housed enriched (n = 30), and group-housed barren (n = 30). On week 4, individual fish were selected randomly from each of the experimental housing environments and tested by using novel-tank, light–dark, and place-preference tests. Housing fish singly in a barren environment increased anxiety-like behaviors in the novel-tank and light–dark behavioral tests. Single-housed zebrafish in barren tanks as well as zebrafish group-housed with conspecifics, both with and without plant enrichment, spent more time associating with conspecifics than with the artificial plant enrichment device during the place-preference test. Single-housed fish maintained in enriched tanks displayed no preference between a compartment with conspecifics or an artificial plant. Our results suggest the addition of an artificial plant as enrichment may benefit single-housed zebrafish when social housing is not possible. PMID:26045453

  9. Changes in the social environment induce neurogenic plasticity predominantly in niches residing in sensory structures of the zebrafish brain independently of cortisol levels.

    PubMed

    Lindsey, Benjamin W; Tropepe, Vincent

    2014-11-01

    The social environment is known to modulate adult neurogenesis. Studies in mammals and birds have shown a strong correlation between social isolation and decreases in neurogenesis, whereas time spent in an enriched environment has been shown to restore these deficits and enhance neurogenesis. These data suggest that there exists a common adaptive response among neurogenic niches to each extreme of the social environment. We sought to further test this hypothesis in zebrafish, a social species with distinct neurogenic niches within primary sensory structures and telencephalic nuclei of the brain. By examining stages of adult neurogenesis, including the proliferating stem/progenitor population, their surviving cohort, and the resulting newly differentiated neuronal population, we show that niches residing in sensory structures are most sensitive to changes in the social context, and that social isolation or novelty are both capable of decreasing the number of proliferating cells while increasing the number of newborn neurons within a single niche. Contrary to observations in rodents, we demonstrate that social novelty, a form of enrichment, does not consistently rescue deficits in cell proliferation following social isolation, and that cortisol levels do not negatively regulate changes in adult neurogenesis, but are correlated with the social context. We propose that enhancement or suppression of adult neurogenesis in the zebrafish brain under different social contexts depends largely on the type of niche (sensory or telencephalic), experience from the preceding social environment, and occurs independently of changes in cortisol levels.

  10. In Vivo toxicological assessment of biologically synthesized silver nanoparticles in adult Zebrafish (Danio rerio).

    PubMed

    Krishnaraj, Chandran; Harper, Stacey L; Yun, Soon-Il

    2016-01-15

    The present study examines the deleterious effect of biologically synthesized silver nanoparticles in adult zebrafish. Silver nanoparticles (AgNPs) used in the study were synthesized by treating AgNO3 with aqueous leaves extract of Malva crispa Linn., a medicinal herb as source of reductants. LC50 concentration of AgNPs at 96 h was observed as 142.2 μg/l. In order to explore the underlying toxicity mechanisms of AgNPs, half of the LC50 concentration (71.1 μg/l) was exposed to adult zebrafish for 14 days. Cytological changes and intrahepatic localization of AgNPs were observed in gills and liver tissues respectively, and the results concluded a possible sign for oxidative stress. In addition to oxidative stress the genotoxic effect was observed in peripheral blood cells like presence of micronuclei, nuclear abnormalities and also loss in cell contact with irregular shape was observed in liver parenchyma cells. Hence to confirm the oxidative stress and genotoxic effects the mRNA expression of stress related (MTF-1, HSP70) and immune response related (TLR4, NFKB, IL1B, CEBP, TRF, TLR22) genes were analyzed in liver tissues and the results clearly concluded that the plant extract mediated synthesis of AgNPs leads to oxidative stress and immunotoxicity in adult zebrafish.

  11. Differential Requirement for irf8 in Formation of Embryonic and Adult Macrophages in Zebrafish

    PubMed Central

    Shiau, Celia E.; Kaufman, Zoe; Meireles, Ana M.; Talbot, William S.

    2015-01-01

    Interferon regulatory factor 8 (Irf8) is critical for mammalian macrophage development and innate immunity, but its role in teleost myelopoiesis remains incompletely understood. In particular, genetic tools to analyze the role of Irf8 in zebrafish macrophage development at larval and adult stages are lacking. We generated irf8 null mutants in zebrafish using TALEN-mediated targeting. Our analysis defines different requirements for irf8 at different stages. irf8 is required for formation of all macrophages during primitive and transient definitive hematopoiesis, but not during adult-phase definitive hematopoiesis starting at 5-6 days postfertilization. At early stages, irf8 mutants have excess neutrophils and excess cell death in pu.1-expressing myeloid cells. Macrophage fates were recovered in irf8 mutants after wildtype irf8 expression in neutrophil and macrophage lineages, suggesting that irf8 regulates macrophage specification and survival. In juvenile irf8 mutant fish, mature macrophages are present, but at numbers significantly reduced compared to wildtype, indicating an ongoing requirement for irf8 after embryogenesis. As development progresses, tissue macrophages become apparent in zebrafish irf8 mutants, with the possible exception of microglia. Our study defines distinct requirement for irf8 in myelopoiesis before and after transition to the adult hematopoietic system. PMID:25615614

  12. The role of Rho kinase (Rock) in re-epithelialization of adult zebrafish skin wounds.

    PubMed

    Richardson, Rebecca; Hammerschmidt, Matthias

    2016-08-03

    Complete re-epithelialization of full-thickness skin wounds in adult mammals takes days to complete and relies on numerous signaling cues and multiple overlapping cellular processes that take place both within the epidermis itself and in other participating tissues. We have previously shown that re-epithelialization of full-thickness skin wounds of adult zebrafish, however, is extremely rapid and largely independent of the other processes of wound healing allowing for the dissection of specific processes that occur in, or have a direct effect on, re-epithelializing keratinocytes. Recently, we have shown that, in addition to lamellipodial crawling at the leading edge, re-epithelialization of zebrafish partial- and full-thickness wounds requires long-range epithelial rearrangements including radial intercalations, flattening and directed elongation and that each of these processes involves Rho kinase (Rock) signaling. Our studies demonstrate how these coordinated signaling events allow for the rapid collective cell migration observed in adult zebrafish wound healing. Here we discuss the particular contribution of Rock to each of these processes.

  13. Differential requirement for irf8 in formation of embryonic and adult macrophages in zebrafish

    DOE PAGES

    Shiau, Celia E.; Kaufman, Zoe; Meireles, Ana M.; ...

    2015-01-23

    Interferon regulatory factor 8 (Irf8) is critical for mammalian macrophage development and innate immunity, but its role in teleost myelopoiesis remains incompletely understood. Specifically, genetic tools to analyze the role of irf8 in zebrafish macrophage development at larval and adult stages are lacking. In this study, we generated irf8 null mutants in zebrafish using TALEN-mediated targeting. Our analysis defines different requirements for irf8 at different stages. irf8 is required for formation of all macrophages during primitive and transient definitive hematopoiesis, but not during adult-phase definitive hematopoiesis starting at 5-6 days postfertilization. At early stages, irf8 mutants have excess neutrophils andmore » excess cell death in pu.1-expressing myeloid cells. Macrophage fates were recovered in irf8 mutants after wildtype irf8 expression in neutrophil and macrophage lineages, suggesting that irf8 regulates macrophage specification and survival. In juvenile irf8 mutant fish, mature macrophages are present, but at numbers significantly reduced compared to wildtype, indicating an ongoing requirement for irf8 after embryogenesis. As development progresses, tissue macrophages become apparent in zebrafish irf8 mutants, with the possible exception of microglia. Our study defines distinct requirement for irf8 in myelopoiesis before and after transition to the adult hematopoietic system.« less

  14. Amigo Adhesion Protein Regulates Development of Neural Circuits in Zebrafish Brain*

    PubMed Central

    Zhao, Xiang; Kuja-Panula, Juha; Sundvik, Maria; Chen, Yu-Chia; Aho, Vilma; Peltola, Marjaana A.; Porkka-Heiskanen, Tarja; Panula, Pertti; Rauvala, Heikki

    2014-01-01

    The Amigo protein family consists of three transmembrane proteins characterized by six leucine-rich repeat domains and one immunoglobulin-like domain in their extracellular moieties. Previous in vitro studies have suggested a role as homophilic adhesion molecules in brain neurons, but the in vivo functions remain unknown. Here we have cloned all three zebrafish amigos and show that amigo1 is the predominant family member expressed during nervous system development in zebrafish. Knockdown of amigo1 expression using morpholino oligonucleotides impairs the formation of fasciculated tracts in early fiber scaffolds of brain. A similar defect in fiber tract development is caused by mRNA-mediated expression of the Amigo1 ectodomain that inhibits adhesion mediated by the full-length protein. Analysis of differentiated neural circuits reveals defects in the catecholaminergic system. At the behavioral level, the disturbed formation of neural circuitry is reflected in enhanced locomotor activity and in the inability of the larvae to perform normal escape responses. We suggest that Amigo1 is essential for the development of neural circuits of zebrafish, where its mechanism involves homophilic interactions within the developing fiber tracts and regulation of the Kv2.1 potassium channel to form functional neural circuitry that controls locomotion. PMID:24904058

  15. Amigo adhesion protein regulates development of neural circuits in zebrafish brain.

    PubMed

    Zhao, Xiang; Kuja-Panula, Juha; Sundvik, Maria; Chen, Yu-Chia; Aho, Vilma; Peltola, Marjaana A; Porkka-Heiskanen, Tarja; Panula, Pertti; Rauvala, Heikki

    2014-07-18

    The Amigo protein family consists of three transmembrane proteins characterized by six leucine-rich repeat domains and one immunoglobulin-like domain in their extracellular moieties. Previous in vitro studies have suggested a role as homophilic adhesion molecules in brain neurons, but the in vivo functions remain unknown. Here we have cloned all three zebrafish amigos and show that amigo1 is the predominant family member expressed during nervous system development in zebrafish. Knockdown of amigo1 expression using morpholino oligonucleotides impairs the formation of fasciculated tracts in early fiber scaffolds of brain. A similar defect in fiber tract development is caused by mRNA-mediated expression of the Amigo1 ectodomain that inhibits adhesion mediated by the full-length protein. Analysis of differentiated neural circuits reveals defects in the catecholaminergic system. At the behavioral level, the disturbed formation of neural circuitry is reflected in enhanced locomotor activity and in the inability of the larvae to perform normal escape responses. We suggest that Amigo1 is essential for the development of neural circuits of zebrafish, where its mechanism involves homophilic interactions within the developing fiber tracts and regulation of the Kv2.1 potassium channel to form functional neural circuitry that controls locomotion.

  16. Fast functional imaging of multiple brain regions in intact zebrafish larvae using selective plane illumination microscopy.

    PubMed

    Panier, Thomas; Romano, Sebastián A; Olive, Raphaël; Pietri, Thomas; Sumbre, Germán; Candelier, Raphaël; Debrégeas, Georges

    2013-01-01

    The optical transparency and the small dimensions of zebrafish at the larval stage make it a vertebrate model of choice for brain-wide in-vivo functional imaging. However, current point-scanning imaging techniques, such as two-photon or confocal microscopy, impose a strong limit on acquisition speed which in turn sets the number of neurons that can be simultaneously recorded. At 5 Hz, this number is of the order of one thousand, i.e., approximately 1-2% of the brain. Here we demonstrate that this limitation can be greatly overcome by using Selective-plane Illumination Microscopy (SPIM). Zebrafish larvae expressing the genetically encoded calcium indicator GCaMP3 were illuminated with a scanned laser sheet and imaged with a camera whose optical axis was oriented orthogonally to the illumination plane. This optical sectioning approach was shown to permit functional imaging of a very large fraction of the brain volume of 5-9-day-old larvae with single- or near single-cell resolution. The spontaneous activity of up to 5,000 neurons was recorded at 20 Hz for 20-60 min. By rapidly scanning the specimen in the axial direction, the activity of 25,000 individual neurons from 5 different z-planes (approximately 30% of the entire brain) could be simultaneously monitored at 4 Hz. Compared to point-scanning techniques, this imaging strategy thus yields a ≃20-fold increase in data throughput (number of recorded neurons times acquisition rate) without compromising the signal-to-noise ratio (SNR). The extended field of view offered by the SPIM method allowed us to directly identify large scale ensembles of neurons, spanning several brain regions, that displayed correlated activity and were thus likely to participate in common neural processes. The benefits and limitations of SPIM for functional imaging in zebrafish as well as future developments are briefly discussed.

  17. Breaking symmetry: the zebrafish as a model for understanding left-right asymmetry in the developing brain.

    PubMed

    Roussigne, Myriam; Blader, Patrick; Wilson, Stephen W

    2012-03-01

    How does left-right asymmetry develop in the brain and how does the resultant asymmetric circuitry impact on brain function and lateralized behaviors? By enabling scientists to address these questions at the levels of genes, neurons, circuitry and behavior,the zebrafish model system provides a route to resolve the complexity of brain lateralization. In this review, we present the progress made towards characterizing the nature of the gene networks and the sequence of morphogenetic events involved in the asymmetric development of zebrafish epithalamus. In an attempt to integrate the recent extensive knowledge into a working model and to identify the future challenges,we discuss how insights gained at a cellular/developmental level can be linked to the data obtained at a molecular/genetic level. Finally, we present some evolutionary thoughts and discuss how significant discoveries made in zebrafish should provide entry points to better understand the evolutionary origins of brain lateralization.

  18. Basal keratinocytes contribute to all strata of the adult zebrafish epidermis.

    PubMed

    Lee, Raymond T H; Asharani, P V; Carney, Thomas J

    2014-01-01

    The epidermis of terrestrial vertebrates is a stratified epithelium and forms an essential protective barrier. It is continually renewed, with dead corneocytes shed from the surface and replaced from a basal keratinocyte stem cell population. Whilst mouse is the prime model system used for epidermal studies, there is increasing employment of the zebrafish to analyse epidermis development and homeostasis, however the architecture and ontogeny of the epidermis in this system are incompletely described. In particular, it is unclear if adult zebrafish epidermis is derived entirely from the basal epidermal stem cell layer, as in the mouse, or if the most superficial keratinocyte layer is a remnant of the embryonic periderm. Furthermore, a relative paucity of cellular markers and genetic reagents to label and manipulate the basal epidermal stem cell compartment has hampered research. Here we show that the type I keratin, krtt1c19e, is a suitable marker of the basal epidermal layer and identify a krtt1c19e promoter fragment able to drive strong and specific expression in this cell type. Use of this promoter to express an inducible Cre recombinase allowed permanent labelling of basal cells during embryogenesis, and demonstrated that these cells do indeed generate keratinocytes of all strata in the adult epidermis. Further deployment of the Cre-Lox system highlighted the transient nature of the embryonic periderm. We thus show that the epidermis of adult zebrafish, as in the mouse, derives from basal stem cells, further expanding the similarities of epidermal ontogeny across vertebrates. Future use of this promoter will assist genetic analysis of basal keratinocyte biology in zebrafish.

  19. Basal Keratinocytes Contribute to All Strata of the Adult Zebrafish Epidermis

    PubMed Central

    Carney, Thomas J.

    2014-01-01

    The epidermis of terrestrial vertebrates is a stratified epithelium and forms an essential protective barrier. It is continually renewed, with dead corneocytes shed from the surface and replaced from a basal keratinocyte stem cell population. Whilst mouse is the prime model system used for epidermal studies, there is increasing employment of the zebrafish to analyse epidermis development and homeostasis, however the architecture and ontogeny of the epidermis in this system are incompletely described. In particular, it is unclear if adult zebrafish epidermis is derived entirely from the basal epidermal stem cell layer, as in the mouse, or if the most superficial keratinocyte layer is a remnant of the embryonic periderm. Furthermore, a relative paucity of cellular markers and genetic reagents to label and manipulate the basal epidermal stem cell compartment has hampered research. Here we show that the type I keratin, krtt1c19e, is a suitable marker of the basal epidermal layer and identify a krtt1c19e promoter fragment able to drive strong and specific expression in this cell type. Use of this promoter to express an inducible Cre recombinase allowed permanent labelling of basal cells during embryogenesis, and demonstrated that these cells do indeed generate keratinocytes of all strata in the adult epidermis. Further deployment of the Cre-Lox system highlighted the transient nature of the embryonic periderm. We thus show that the epidermis of adult zebrafish, as in the mouse, derives from basal stem cells, further expanding the similarities of epidermal ontogeny across vertebrates. Future use of this promoter will assist genetic analysis of basal keratinocyte biology in zebrafish. PMID:24400120

  20. Novel function of vitamin E in regulation of zebrafish (Danio rerio) brain lysophospholipids discovered using lipidomics

    PubMed Central

    Choi, Jaewoo; Leonard, Scott W.; Kasper, Katherine; McDougall, Melissa; Stevens, Jan F.; Tanguay, Robert L.; Traber, Maret G.

    2015-01-01

    We hypothesized that brains from vitamin E-deficient (E−) zebrafish (Danio rerio) would undergo increased lipid peroxidation because they contain highly polyunsaturated fatty acids, thus susceptible lipids could be identified. Brains from zebrafish fed for 9 months defined diets without (E−) or with (E+) added vitamin E (500 mg RRR-α-tocopheryl acetate per kilogram diet) were studied. Using an untargeted approach, 1-hexadecanoyl-2-docosahexaenoyl-sn-glycero-3-phosphocholine [DHA-PC 38:6, PC 16:0/22:6]was the lipid that showed the most significant and greatest fold-differences between groups. DHA-PC concentrations were approximately 1/3 lower in E− (4.3 ± 0.6 mg/g) compared with E+ brains (6.5 ± 0.9 mg/g, mean ± SEM, n = 10 per group, P = 0.04). Using lipidomics, 155 lipids in brain extracts were identified. Only four phospholipids (PLs) were different (P < 0.05) between groups; they were lower in E− brains and contained DHA with DHA-PC 38:6 at the highest abundances. Moreover, hydroxy-DHA-PC 38:6 was increased in E− brains (P = 0.0341) supporting the hypothesis of DHA peroxidation. More striking was the depletion in E− brains of nearly 60% of 19 different lysophospholipids (lysoPLs) (combined P = 0.0003), which are critical for membrane PL remodeling. Thus, E− brains contained fewer DHA-PLs, more hydroxy-DHA-PCs, and fewer lysoPLs, suggesting that lipid peroxidation depletes membrane DHA-PC and homeostatic mechanisms to repair the damage resulting in lysoPL depletion. PMID:25855633

  1. Brain zinc chelation by diethyldithiocarbamate increased the behavioral and mitochondrial damages in zebrafish subjected to hypoxia

    PubMed Central

    Braga, Marcos M.; Silva, Emerson S.; Moraes, Tarsila B.; Schirmbeck, Gabriel Henrique; Rico, Eduardo P.; Pinto, Charles B.; Rosemberg, Denis B.; Dutra-Filho, Carlos S.; Dias, Renato D.; Oliveira, Diogo L.; T. Rocha, João Batista; Souza, Diogo O.

    2016-01-01

    The increase in brain levels of chelatable zinc (Zn) in dysfunctions involving oxygen deprivation has stimulated the treatment with Zn chelators, such as diethyldithiocarbamate (DEDTC). However, DEDTC is a redox-active compound and it should be better evaluated during hypoxia. We use the hypoxia model in zebrafish to evaluate DEDTC effects. The exploratory behavior, chelatable Zn content, activities of mitochondrial dehydrogenases, reactive species levels (nitric oxide, superoxide anion, hydroxyl radical scavenger capacity) and cellular antioxidants (sulfhydryl, superoxide dismutase) of zebrafish brain were assessed after recovery, with or without 0.2 mM DEDTC. The increased brain levels of chelatable Zn induced by hypoxia were mitigated by DEDTC. However, the novel tank task indicated that DEDTC did further enhance the exploratory deficit caused by hypoxia. Furthermore, these behavioral impairments caused by DEDTC were more associated with a negative action on mitochondrial activity and brain oxidative balance. Thus, due to apparent pro-oxidant action of DEDTC, our data do not support its use for neuroprotection in neuropathologies involving oxygen deprivation. PMID:26854133

  2. Low dose of arsenic trioxide triggers oxidative stress in zebrafish brain: expression of antioxidant genes.

    PubMed

    Sarkar, Shuvasree; Mukherjee, Sandip; Chattopadhyay, Ansuman; Bhattacharya, Shelley

    2014-09-01

    Occurrence of arsenic in the aquatic environment of West Bengal (India), Bangladesh and other countries are of immediate environmental concern. In the present study, zebrafish (Danio rerio) was used as a model to investigate oxidative stress related enzyme activities and expression of antioxidant genes in the brain to 50µg/L arsenic trioxide for 90 days. In treated fish, generation of reactive oxygen species (ROS), malondialdehyde (MDA) and conjugated diene (CD) showed a triphasic response attaining a peak at the end of the exposure. In addition, a gradual increase in GSH level was noted until 60 days and at 90 days, a sudden fall was recorded which heightened arsenic toxicity. However, GSH level does not correlate well with the glutathione reductase (GR) activity. Generation of ROS in zebrafish brain due to As2O3 exposure was further evidenced by significant alteration of glutathione peroxidase (GPx) and catalase (CAT) activity, which converts H2O2 to water and helps in detoxication. Moreover, enhanced mRNA level of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) in As2O3 exposed zebrafish indicates a protective role of Nrf2. kelch-like ECH-associated protein 1 (Keap1), a negative regulator of Nrf2, inversely correlates with the mRNA expression of Nrf2. As2O3 induced toxicity was also validated by the alteration in NRF2 and NRF2 dependent expression of proteins such as heme oxygenase1 (HO1) and NAD(P)H dehydrogenase quinone1 (NQO1). The mRNA expression of glutathione peroxidase (Gpx1), catalase (Cat), manganese superoxide dismutase (Mn-Sod), copper/zinc superoxide dismutase (Cu/Zn Sod) and cytochrome c oxidase1 (Cox1) were also up regulated. The expression of uncoupling protein 2 (Ucp2), an important mitochondrial enzyme was also subdued in arsenic exposed zebrafish. The oxidative stress induced by arsenic also cause reduced mRNA expression of B-cell lymphoma 2 (Bcl2) present in the inner mitochondrial membrane and thereby indicating onset of apoptosis in

  3. Imaging Beta Cell Regeneration and Interactions with Islet Vasculature in Transparent Adult Zebrafish

    PubMed Central

    Moss, Larry G.; Caplan, Tanner V.

    2013-01-01

    Abstract Blood vessel networks provide nutrients and gaseous exchange that are essential for functions. Pancreatic islet capillaries deliver oxygen to endocrine cells while transporting hormones to organs and peripheral locations throughout the body. We have developed a zebrafish diabetes model in which adult islets can be followed in vivo during beta cell regeneration while calibrating changes in beta cell mass and fasting blood glucose levels. After genetic ablation, beta cells are initially dysfunctional or dying, and blood glucose levels increase fourfold. During a 2-week period, hyperglycemia eventually normalizes as beta cell mass regenerates. We show that mCherry-fluorescent, insulin-positive beta cells re-emerge in close contact with the vascular endothelium. Alterations in the dense vascular network of zebrafish islets were visualized by the expression of green fluorescent protein (GFP) in endothelial cells derived from the Fli transcription factor promoter. The rapid destruction and regeneration of beta cell mass was evaluated in the same animal over time, providing a functional model for investigating the interactions of islet cell types with vascular cells as well as the consequences of hyperglycemia on other tissues. Regenerating adult zebrafish can be utilized as vertebrate, metabolically active models for generating new insights into treatments for type 2 diabetes. PMID:23682836

  4. Dopamine from the brain promotes spinal motor neuron generation during development and adult regeneration.

    PubMed

    Reimer, Michell M; Norris, Anneliese; Ohnmacht, Jochen; Patani, Rickie; Zhong, Zhen; Dias, Tatyana B; Kuscha, Veronika; Scott, Angela L; Chen, Yu-Chia; Rozov, Stanislav; Frazer, Sarah L; Wyatt, Cameron; Higashijima, Shin-ichi; Patton, E Elizabeth; Panula, Pertti; Chandran, Siddharthan; Becker, Thomas; Becker, Catherina G

    2013-06-10

    Coordinated development of brain stem and spinal target neurons is pivotal for the emergence of a precisely functioning locomotor system. Signals that match the development of these far-apart regions of the central nervous system may be redeployed during spinal cord regeneration. Here we show that descending dopaminergic projections from the brain promote motor neuron generation at the expense of V2 interneurons in the developing zebrafish spinal cord by activating the D4a receptor, which acts on the hedgehog pathway. Inhibiting this essential signal during early neurogenesis leads to a long-lasting reduction of motor neuron numbers and impaired motor responses of free-swimming larvae. Importantly, during successful spinal cord regeneration in adult zebrafish, endogenous dopamine promotes generation of spinal motor neurons, and dopamine agonists augment this process. Hence, we describe a supraspinal control mechanism for the development and regeneration of specific spinal cell types that uses dopamine as a signal.

  5. Dietary Intake Influences Adult Fertility and Offspring Fitness in Zebrafish

    PubMed Central

    Jhinku, Noel; Meier, Michael; Horsfield, Julia

    2016-01-01

    The burden of malnutrition, including both over- and undernutrition, is a major public health concern. Here we used a zebrafish model of diet-induced obesity to analyze the impact of dietary intake on fertility and the phenotype of the next generation. Over an eight-week period, one group received 60 mg of food each day (60 mg arm), while another received 5 mg (5 mg arm). At the end of the diet, the body mass index of the 60 mg arm was 1.5 fold greater than the 5 mg arm. The intervention also had a marked impact on fertility; breeding success and egg production in the 60 mg arm were increased 2.1- and 6.2-fold compared to the 5 mg arm, respectively. Transcriptome analysis of eggs revealed that transcripts involved in metabolic biological processes differed according to dietary intake. The progeny from the differentially fed fish were more likely to survive when the parents had access to more food. An intergenerational crossover study revealed that while parental diet did not influence weight gain in the offspring, the progeny of well-fed parents had increased levels of physical activity when exposed again to high nutrient availability. We conclude that dietary intake has an important influence on fertility and the subsequent fitness of offspring, even prior to breeding. PMID:27870856

  6. The microcephaly gene aspm is involved in brain development in zebrafish

    SciTech Connect

    Kim, Hyun-Taek; Lee, Mi-Sun; Choi, Jung-Hwa; Jung, Ju-Yeon; Ahn, Dae-Gwon; Yeo, Sang-Yeob; Choi, Dong-Kug; Kim, Cheol-Hee

    2011-06-17

    Highlights: {yields} We identified a zebrafish aspm/mcph5 gene that is expressed in proliferating cells in the CNS during early development. {yields} Embryos injected with the aspm MO consistently showed a reduced head and eye size but were otherwise grossly normal, closely mimicking the known phenotypes of human microcephaly patients. {yields} Knock-down of aspm causes cell cycle arrest and apoptotic cell death during early development. -- Abstract: MCPH is a neurodevelopmental disorder characterized by a global reduction in cerebral cortical volume. Homozygous mutation of the MCPH5 gene, also known as ASPM, is the most common cause of the MCPH phenotype. To elucidate the roles of ASPM during embryonic development, the zebrafish aspm was identified, which is specifically expressed in proliferating cells in the CNS. Morpholino-mediated knock-down of aspm resulted in a significant reduction in head size. Furthermore, aspm-deficient embryos exhibited a mitotic arrest during early development. These findings suggest that the reduction in brain size in MCPH might be caused by lack of aspm function in the mitotic cell cycle and demonstrate that the zebrafish can provide a model system for congenital diseases of the human nervous system.

  7. A High-Content Larval Zebrafish Brain Imaging Method for Small Molecule Drug Discovery.

    PubMed

    Liu, Harrison; Chen, Steven; Huang, Kevin; Kim, Jeffrey; Mo, Han; Iovine, Raffael; Gendre, Julie; Pascal, Pauline; Li, Qiang; Sun, Yaping; Dong, Zhiqiang; Arkin, Michelle; Guo, Su; Huang, Bo

    2016-01-01

    Drug discovery in whole-organisms such as zebrafish is a promising approach for identifying biologically-relevant lead compounds. However, high content imaging of zebrafish at cellular resolution is challenging due to the difficulty in orienting larvae en masse such that the cell type of interest is in clear view. We report the development of the multi-pose imaging method, which uses 96-well round bottom plates combined with a standard liquid handler to repose the larvae within each well multiple times, such that an image in a specific orientation can be acquired. We have validated this method in a chemo-genetic zebrafish model of dopaminergic neuron degeneration. For this purpose, we have developed an analysis pipeline that identifies the larval brain in each image and then quantifies neuronal health in CellProfiler. Our method achieves a SSMD* score of 6.96 (robust Z'-factor of 0.56) and is suitable for screening libraries up to 105 compounds in size.

  8. A High-Content Larval Zebrafish Brain Imaging Method for Small Molecule Drug Discovery

    PubMed Central

    Liu, Harrison; Chen, Steven; Huang, Kevin; Kim, Jeffrey; Mo, Han; Iovine, Raffael; Gendre, Julie; Pascal, Pauline; Li, Qiang; Sun, Yaping; Dong, Zhiqiang; Arkin, Michelle; Guo, Su

    2016-01-01

    Drug discovery in whole-organisms such as zebrafish is a promising approach for identifying biologically-relevant lead compounds. However, high content imaging of zebrafish at cellular resolution is challenging due to the difficulty in orienting larvae en masse such that the cell type of interest is in clear view. We report the development of the multi-pose imaging method, which uses 96-well round bottom plates combined with a standard liquid handler to repose the larvae within each well multiple times, such that an image in a specific orientation can be acquired. We have validated this method in a chemo-genetic zebrafish model of dopaminergic neuron degeneration. For this purpose, we have developed an analysis pipeline that identifies the larval brain in each image and then quantifies neuronal health in CellProfiler. Our method achieves a SSMD* score of 6.96 (robust Z’-factor of 0.56) and is suitable for screening libraries up to 105 compounds in size. PMID:27732643

  9. Large-scale Scanning Transmission Electron Microscopy (Nanotomy) of Healthy and Injured Zebrafish Brain

    PubMed Central

    Kuipers, Jeroen; Kalicharan, Ruby D.; Wolters, Anouk H. G.

    2016-01-01

    Large-scale 2D electron microscopy (EM), or nanotomy, is the tissue-wide application of nanoscale resolution electron microscopy. Others and we previously applied large scale EM to human skin pancreatic islets, tissue culture and whole zebrafish larvae1-7. Here we describe a universally applicable method for tissue-scale scanning EM for unbiased detection of sub-cellular and molecular features. Nanotomy was applied to investigate the healthy and a neurodegenerative zebrafish brain. Our method is based on standardized EM sample preparation protocols: Fixation with glutaraldehyde and osmium, followed by epoxy-resin embedding, ultrathin sectioning and mounting of ultrathin-sections on one-hole grids, followed by post staining with uranyl and lead. Large-scale 2D EM mosaic images are acquired using a scanning EM connected to an external large area scan generator using scanning transmission EM (STEM). Large scale EM images are typically ~ 5 - 50 G pixels in size, and best viewed using zoomable HTML files, which can be opened in any web browser, similar to online geographical HTML maps. This method can be applied to (human) tissue, cross sections of whole animals as well as tissue culture1-5. Here, zebrafish brains were analyzed in a non-invasive neuronal ablation model. We visualize within a single dataset tissue, cellular and subcellular changes which can be quantified in various cell types including neurons and microglia, the brain's macrophages. In addition, nanotomy facilitates the correlation of EM with light microscopy (CLEM)8 on the same tissue, as large surface areas previously imaged using fluorescent microscopy, can subsequently be subjected to large area EM, resulting in the nano-anatomy (nanotomy) of tissues. In all, nanotomy allows unbiased detection of features at EM level in a tissue-wide quantifiable manner. PMID:27285162

  10. Large-scale Scanning Transmission Electron Microscopy (Nanotomy) of Healthy and Injured Zebrafish Brain.

    PubMed

    Kuipers, Jeroen; Kalicharan, Ruby D; Wolters, Anouk H G; van Ham, Tjakko J; Giepmans, Ben N G

    2016-05-25

    Large-scale 2D electron microscopy (EM), or nanotomy, is the tissue-wide application of nanoscale resolution electron microscopy. Others and we previously applied large scale EM to human skin pancreatic islets, tissue culture and whole zebrafish larvae(1-7). Here we describe a universally applicable method for tissue-scale scanning EM for unbiased detection of sub-cellular and molecular features. Nanotomy was applied to investigate the healthy and a neurodegenerative zebrafish brain. Our method is based on standardized EM sample preparation protocols: Fixation with glutaraldehyde and osmium, followed by epoxy-resin embedding, ultrathin sectioning and mounting of ultrathin-sections on one-hole grids, followed by post staining with uranyl and lead. Large-scale 2D EM mosaic images are acquired using a scanning EM connected to an external large area scan generator using scanning transmission EM (STEM). Large scale EM images are typically ~ 5 - 50 G pixels in size, and best viewed using zoomable HTML files, which can be opened in any web browser, similar to online geographical HTML maps. This method can be applied to (human) tissue, cross sections of whole animals as well as tissue culture(1-5). Here, zebrafish brains were analyzed in a non-invasive neuronal ablation model. We visualize within a single dataset tissue, cellular and subcellular changes which can be quantified in various cell types including neurons and microglia, the brain's macrophages. In addition, nanotomy facilitates the correlation of EM with light microscopy (CLEM)(8) on the same tissue, as large surface areas previously imaged using fluorescent microscopy, can subsequently be subjected to large area EM, resulting in the nano-anatomy (nanotomy) of tissues. In all, nanotomy allows unbiased detection of features at EM level in a tissue-wide quantifiable manner.

  11. Brain transcriptome variation among behaviorally distinct strains of zebrafish (Danio rerio)

    PubMed Central

    2012-01-01

    Background Domesticated animal populations often show profound reductions in predator avoidance and fear-related behavior compared to wild populations. These reductions are remarkably consistent and have been observed in a diverse array of taxa including fish, birds, and mammals. Experiments conducted in common environments indicate that these behavioral differences have a genetic basis. In this study, we quantified differences in fear-related behavior between wild and domesticated zebrafish strains and used microarray analysis to identify genes that may be associated with this variation. Results Compared to wild zebrafish, domesticated zebrafish spent more time near the water surface and were more likely to occupy the front of the aquarium nearest a human observer. Microarray analysis of the brain transcriptome identified high levels of population variation in gene expression, with 1,749 genes significantly differentially expressed among populations. Genes that varied among populations belonged to functional categories that included DNA repair, DNA photolyase activity, response to light stimulus, neuron development and axon guidance, cell death, iron-binding, chromatin reorganization, and homeobox genes. Comparatively fewer genes (112) differed between domesticated and wild strains with notable genes including gpr177 (wntless), selenoprotein P1a, synaptophysin and synaptoporin, and acyl-CoA binding domain containing proteins (acbd3 and acbd4). Conclusions Microarray analysis identified a large number of genes that differed among zebrafish populations and may underlie behavioral domestication. Comparisons with similar microarray studies of domestication in rainbow trout and canids identified sixteen evolutionarily or functionally related genes that may represent components of shared molecular mechanisms underlying convergent behavioral evolution during vertebrate domestication. However, this conclusion must be tempered by limitations associated with comparisons

  12. Anti-oxidative responses of zebrafish (Danio rerio) gill, liver and brain tissues upon acute cold shock.

    PubMed

    Wu, Su Mei; Liu, Jia-Hao; Shu, Li-Hsin; Chen, Ching Hsein

    2015-09-01

    The present study seeks to detect oxidative damage and to compare anti-oxidative responses among liver, gills and brain of adult zebrafish that were cooled from 28 °C (control) to 12 °C (treatment) for 0-24 h. The lipid peroxidation of liver, gill and brain tissues significantly increased at 1h after transfer, but reactive oxygen species in the treatment group increased significantly after 24 h as compared to the control. The fish were found to develop a cascading anti-oxidative mechanism beginning with an increase in Cu/Zn-SOD levels, followed by increased CAT and GPx mRNA expressions in the three tissue types. Both smtB and mt2 mRNAs increased in the hepatic and brain tissues following 1h of cold stress, but only smtB exhibited a significant increase in the gills at 1 h and 6 h after transfer to 12 °C. Furthermore, cellular apoptosis in the brain was not evident after cold shock, but liver and gills showed cellular apoptosis at 1-3 h, with another peak in the liver at 6 h after cold shock. The results suggest that the cold shock induced oxidative stress, and the enzymatic (SOD, GPx and CAT) and non-enzymatic (mt-2 and smt-B) mRNA expressions all play a role in the resulting anti-oxidation within 1-6 h of cold shock. A functional comparison showed that the brain had the most powerful antioxidant defense system of the three tissue types since it had the highest smtB mRNA expression and a lower level of cell apoptosis than the liver and gills after exposure to cold stress.

  13. A novel protocol for the oral administration of test chemicals to adult zebrafish.

    PubMed

    Zang, Liqing; Morikane, Daizo; Shimada, Yasuhito; Tanaka, Toshio; Nishimura, Norihiro

    2011-12-01

    A novel protocol using gluten as a carrier material was developed to administer chemicals to adult zebrafish, per os (p.o.). To evaluate the capacity of gluten to retain chemicals, we prepared gluten granules containing eight types of chemicals with different Log P(ow) values and immersed them in water. Less than 5% of chemicals were eluted from gluten granules within 5 min, a standard feeding time for zebrafish. Although retention capability was dependent on the hydrophilicity and hydrophobicity of the chemicals, the gluten granules retained 62%-99% of the total amount of chemical, even after immersion in water for 60 min. Vital staining dyes, such as 4-Di-2-Asp and Nile red, administered p.o., were delivered into the gastrointestinal tract where they were digested and secreted. Subsequently, we conducted a pharmacokinetic study of oral administration of felbinac and confirmed that it was successfully delivered into the blood of zebrafish. This indicates that chemicals administered using gluten granules are satisfactorily absorbed from the digestive tract and delivered into the metabolic system. The absorption, distribution, and pharmacokinetics of chemicals given by oral administration were also compared with those of chemicals given by alternative administration routes such as intraperitoneal injection and exposure to chemical solution.

  14. Using an automated 3D-tracking system to record individual and shoals of adult zebrafish.

    PubMed

    Maaswinkel, Hans; Zhu, Liqun; Weng, Wei

    2013-12-05

    Like many aquatic animals, zebrafish (Danio rerio) moves in a 3D space. It is thus preferable to use a 3D recording system to study its behavior. The presented automatic video tracking system accomplishes this by using a mirror system and a calibration procedure that corrects for the considerable error introduced by the transition of light from water to air. With this system it is possible to record both single and groups of adult zebrafish. Before use, the system has to be calibrated. The system consists of three modules: Recording, Path Reconstruction, and Data Processing. The step-by-step protocols for calibration and using the three modules are presented. Depending on the experimental setup, the system can be used for testing neophobia, white aversion, social cohesion, motor impairments, novel object exploration etc. It is especially promising as a first-step tool to study the effects of drugs or mutations on basic behavioral patterns. The system provides information about vertical and horizontal distribution of the zebrafish, about the xyz-components of kinematic parameters (such as locomotion, velocity, acceleration, and turning angle) and it provides the data necessary to calculate parameters for social cohesions when testing shoals.

  15. Assessment of fight outcome is needed to activate socially driven transcriptional changes in the zebrafish brain.

    PubMed

    Oliveira, Rui F; Simões, José M; Teles, Magda C; Oliveira, Catarina R; Becker, Jorg D; Lopes, João S

    2016-02-02

    Group living animals must be able to express different behavior profiles depending on their social status. Therefore, the same genotype may translate into different behavioral phenotypes through socially driven differential gene expression. However, how social information is translated into a neurogenomic response and what are the specific cues in a social interaction that signal a change in social status are questions that have remained unanswered. Here, we show for the first time, to our knowledge, that the switch between status-specific neurogenomic states relies on the assessment of fight outcome rather than just on self- or opponent-only assessment of fighting ability. For this purpose, we manipulated the perception of fight outcome in male zebrafish and measured its impact on the brain transcriptome using a zebrafish whole genome gene chip. Males fought either a real opponent, and a winner and a loser were identified, or their own image on a mirror, in which case, despite expressing aggressive behavior, males did not experience either a victory or a defeat. Massive changes in the brain transcriptome were observed in real opponent fighters, with losers displaying both a higher number of differentially expressed genes and of coexpressed gene modules than winners. In contrast, mirror fighters expressed a neurogenomic state similar to that of noninteracting fish. The genes that responded to fight outcome included immediate early genes and genes involved in neuroplasticity and epigenetic modifications. These results indicate that, even in cognitively simple organisms such as zebrafish, neurogenomic responses underlying changes in social status rely on mutual assessment of fighting ability.

  16. Strong Static Magnetic Fields Elicit Swimming Behaviors Consistent with Direct Vestibular Stimulation in Adult Zebrafish

    PubMed Central

    Ward, Bryan K.; Tan, Grace X-J; Roberts, Dale C.; Della Santina, Charles C.; Zee, David S.; Carey, John P.

    2014-01-01

    Zebrafish (Danio rerio) offer advantages as model animals for studies of inner ear development, genetics and ototoxicity. However, traditional assessment of vestibular function in this species using the vestibulo-ocular reflex requires agar-immobilization of individual fish and specialized video, which are difficult and labor-intensive. We report that using a static magnetic field to directly stimulate the zebrafish labyrinth results in an efficient, quantitative behavioral assay in free-swimming fish. We recently observed that humans have sustained nystagmus in high strength magnetic fields, and we attributed this observation to magnetohydrodynamic forces acting on the labyrinths. Here, fish were individually introduced into the center of a vertical 11.7T magnetic field bore for 2-minute intervals, and their movements were tracked. To assess for heading preference relative to a magnetic field, fish were also placed in a horizontally oriented 4.7T magnet in infrared (IR) light. A sub-population was tested again in the magnet after gentamicin bath to ablate lateral line hair cell function. Free-swimming adult zebrafish exhibited markedly altered swimming behavior while in strong static magnetic fields, independent of vision or lateral line function. Two-thirds of fish showed increased swimming velocity or consistent looping/rolling behavior throughout exposure to a strong, vertically oriented magnetic field. Fish also demonstrated altered swimming behavior in a strong horizontally oriented field, demonstrating in most cases preferred swimming direction with respect to the field. These findings could be adapted for ‘high-throughput’ investigations of the effects of environmental manipulations as well as for changes that occur during development on vestibular function in zebrafish. PMID:24647586

  17. Culture of Adult Transgenic Zebrafish Retinal Explants for Live-cell Imaging by Multiphoton Microscopy.

    PubMed

    Lahne, Manuela; Gorsuch, Ryne A; Nelson, Craig M; Hyde, David R

    2017-02-24

    An endogenous regeneration program is initiated by Müller glia in the adult zebrafish (Danio rerio) retina following neuronal damage and death. The Müller glia re-enter the cell cycle and produce neuronal progenitor cells that undergo subsequent rounds of cell divisions and differentiate into the lost neuronal cell types. Both Müller glia and neuronal progenitor cell nuclei replicate their DNA and undergo mitosis in distinct locations of the retina, i.e. they migrate between the basal Inner Nuclear Layer (INL) and the Outer Nuclear Layer (ONL), respectively, in a process described as Interkinetic Nuclear Migration (INM). INM has predominantly been studied in the developing retina. To examine the dynamics of INM in the adult regenerating zebrafish retina in detail, live-cell imaging of fluorescently-labeled Müller glia/neuronal progenitor cells is required. Here, we provide the conditions to isolate and culture dorsal retinas from Tg[gfap:nGFP](mi2004) zebrafish that were exposed to constant intense light for 35 h. We also show that these retinal cultures are viable to perform live-cell imaging experiments, continuously acquiring z-stack images throughout the thickness of the retinal explant for up to 8 h using multiphoton microscopy to monitor the migratory behavior of gfap:nGFP-positive cells. In addition, we describe the details to perform post-imaging analysis to determine the velocity of apical and basal INM. To summarize, we established conditions to study the dynamics of INM in an adult model of neuronal regeneration. This will advance our understanding of this crucial cellular process and allow us to determine the mechanisms that control INM.

  18. Aquatic surface respiration and swimming behaviour in adult and developing zebrafish exposed to hypoxia.

    PubMed

    Abdallah, Sara J; Thomas, Benjamin S; Jonz, Michael G

    2015-06-01

    Severe hypoxia elicits aquatic surface respiration (ASR) behaviour in many species of fish, where ventilation of the gills at the air-water interface improves O2 uptake and survival. ASR is an important adaptation that may have given rise to air breathing in vertebrates. The neural substrate of this behaviour, however, is not defined. We characterized ASR in developing and adult zebrafish (Danio rerio) to ascertain a potential role for peripheral chemoreceptors in initiation or modulation of this response. Adult zebrafish exposed to acute, progressive hypoxia (PO2 from 158 to 15 mmHg) performed ASR with a threshold of 30 mmHg, and spent more time at the surface as PO2 decreased. Acclimation to hypoxia attenuated ASR responses. In larvae, ASR behaviour was observed between 5 and 21 days postfertilization with a threshold of 16 mmHg. Zebrafish decreased swimming behaviour (i.e. distance, velocity and acceleration) as PO2 was decreased, with a secondary increase in behaviour near or below threshold PO2 . In adults that underwent a 10-day intraperitoneal injection regime of 10 μg g(-1) serotonin (5-HT) or 20 μg g(-1) acetylcholine (ACh), an acute bout of hypoxia (15 mmHg) increased the time engaged in ASR by 5.5 and 4.9 times, respectively, compared with controls. Larvae previously immersed in 10 μmol l(-1) 5-HT or ACh also displayed an increased ASR response. Our results support the notion that ASR is a behavioural response that is reliant upon input from peripheral O2 chemoreceptors. We discuss implications for the role of chemoreceptors in the evolution of air breathing.

  19. Pattern of innervation and recruitment of different classes of motoneurons in adult zebrafish.

    PubMed

    Ampatzis, Konstantinos; Song, Jianren; Ausborn, Jessica; El Manira, Abdeljabbar

    2013-06-26

    In vertebrates, spinal circuits drive rhythmic firing in motoneurons in the appropriate sequence to produce locomotor movements. These circuits become active early during development and mature gradually to acquire the flexibility necessary to accommodate the increased behavioral repertoire of adult animals. The focus here is to elucidate how different pools of motoneurons are organized and recruited and how membrane properties contribute to their mode of operation. For this purpose, we have used the in vitro preparation of adult zebrafish. We show that different motoneuron pools are organized in a somatotopic fashion in the motor column related to the type of muscle fibers (slow, intermediate, fast) they innervate. During swimming, the different motoneuron pools are recruited in a stepwise manner from slow, to intermediate, to fast to cover the full range of locomotor frequencies seen in intact animals. The spike threshold, filtering properties, and firing patterns of the different motoneuron pools are graded in a manner that relates to their order of recruitment. Our results thus show that motoneurons in adult zebrafish are organized into distinct modules, each with defined locations, properties, and recruitment patterns tuned to precisely match the muscle properties and hence produce swimming of different speeds and modalities.

  20. Loss of Gspt1l disturbs the patterning of the brain central arteries in zebrafish.

    PubMed

    Wang, Hongcheng; Luo, Lingfei; Yang, Deqin

    2017-04-22

    The cranial vasculature is crucial for the survival and development of the central nervous system and is closely related to brain pathologies. Characterizations of the underlying mechanisms by which cranial vessels acquire their stereotypic patterning remain to be the key interest in the cerebrovascular research. In this report, we show an interesting zebrafish cq37 mutant displaying aberrant patterning of the central arteries. Genetic mapping results indicate that the gene responsible for cq37 encodes G1 to S phase transition 1, like (Gspt1l) with a nonsense mutation. Complementation studies with a CRISPR-generated allele, as well as mRNA rescues, together strongly demonstrate that gspt1l is the cq37 gene. Zebrafish gspt1l is broadly expressed in the brain with enhanced expression in hindbrain during central artery sprouting. Further studies reveal that vascular endothelial growth factor (VEGF) signaling and unfolded protein response (UPR) pathway are activated in gspt1l(cq37) mutants. In addition, expression analysis shows that vegfa and activating transcription factor-4 (atf4) are strongly upregulated in regions of gspt1l expression. Our results suggest that loss of Gspt1l activates the UPR pathway, which in turn induces ectopic expression of vegfa via Atf4, thus disturbing the patterning of the central arteries.

  1. Re-epithelialization of cutaneous wounds in adult zebrafish combines mechanisms of wound closure in embryonic and adult mammals.

    PubMed

    Richardson, Rebecca; Metzger, Manuel; Knyphausen, Philipp; Ramezani, Thomas; Slanchev, Krasimir; Kraus, Christopher; Schmelzer, Elmon; Hammerschmidt, Matthias

    2016-06-15

    Re-epithelialization of cutaneous wounds in adult mammals takes days to complete and relies on numerous signalling cues and multiple overlapping cellular processes that take place both within the epidermis and in other participating tissues. Re-epithelialization of partial- or full-thickness skin wounds of adult zebrafish, however, is extremely rapid and largely independent of the other processes of wound healing. Live imaging after treatment with transgene-encoded or chemical inhibitors reveals that re-epithelializing keratinocytes repopulate wounds by TGF-β- and integrin-dependent lamellipodial crawling at the leading edges of the epidermal tongue. In addition, re-epithelialization requires long-range epithelial rearrangements, involving radial intercalations, flattening and directed elongation of cells - processes that are dependent on Rho kinase, JNK and, to some extent, planar cell polarity within the epidermis. These rearrangements lead to a massive recruitment of keratinocytes from the adjacent epidermis and make re-epithelialization independent of keratinocyte proliferation and the mitogenic effect of FGF signalling, which are only required after wound closure, allowing the epidermis outside the wound to re-establish its normal thickness. Together, these results demonstrate that the adult zebrafish is a valuable in vivo model for studying and visualizing the processes involved in cutaneous wound closure, facilitating the dissection of direct from indirect and motogenic from mitogenic effects of genes and molecules affecting wound re-epithelialization.

  2. Contrast-Enhanced X-Ray Micro-Computed Tomography as a Versatile Method for Anatomical Studies of Adult Zebrafish.

    PubMed

    Babaei, Fatemeh; Hong, Tony Liu Chi; Yeung, Kelvin; Cheng, Shuk Han; Lam, Yun Wah

    2016-08-01

    One attractive quality of zebrafish as a model organism for biological research is that transparency at early developmental stages allows the optical imaging of cellular and molecular events. However, this advantage cannot be applied to adult zebrafish. In this study, we explored the use of contrast-enhanced X-ray micro-computed tomography (microCT) on adult zebrafish in which the organism was stained with iodine, a simple and economical contrasting agent, after fixation. Tomographic reconstruction of the microCT data allowed the three-dimensional (3D) volumetric analyses of individual organs in adult zebrafish. Adipose tissues showed a higher affinity to iodine and were more strongly contrasted in microCT. As traditional histological techniques often involve dehydration steps that remove tissue lipids, iodine-contrasted microCT offers a convenient method for visualizing fat deposition in fish. Utilizing this advantage, we discovered a transient accumulation of lipids around the heart after ventricular amputation, suggesting a correlation between lipid distribution and heart regeneration. Taken together, microCT is a versatile technique that enables the 3D visualization of zebrafish organs, as well as other fish models, in their anatomical context. This simple method is a valuable new addition to the arsenal of techniques available to this model organism.

  3. In vivo electroporation of morpholinos into the regenerating adult zebrafish tail fin.

    PubMed

    Hyde, David R; Godwin, Alan R; Thummel, Ryan

    2012-03-29

    Certain species of urodeles and teleost fish can regenerate their tissues. Zebrafish have become a widely used model to study the spontaneous regeneration of adult tissues, such as the heart, retina, spinal cord, optic nerve, sensory hair cells, and fins. The zebrafish fin is a relatively simple appendage that is easily manipulated to study multiple stages in epimorphic regeneration. Classically, fin regeneration was characterized by three distinct stages: wound healing, blastema formation, and fin outgrowth. After amputating part of the fin, the surrounding epithelium proliferates and migrates over the wound. At 33 °C, this process occurs within six hours post-amputation (hpa, Figure 1B). Next, underlying cells from different lineages (ex. bone, blood, glia, fibroblast) re-enter the cell cycle to form a proliferative blastema, while the overlying epidermis continues to proliferate (Figure 1D). Outgrowth occurs as cells proximal to the blastema re-differentiate into their respective lineages to form new tissue (Figure 1E). Depending on the level of the amputation, full regeneration is completed in a week to a month. The expression of a large number of gene families, including wnt, hox, fgf, msx, retinoic acid, shh, notch, bmp, and activin-betaA genes, is up-regulated during specific stages of fin regeneration. However, the roles of these genes and their encoded proteins during regeneration have been difficult to assess, unless a specific inhibitor for the protein exists, a temperature-sensitive mutant exists or a transgenic animal (either overexpressing the wild-type protein or a dominant-negative protein) was generated. We developed a reverse genetic technique to quickly and easily test the function of any gene during fin regeneration. Morpholino oligonucleotides are widely used to study loss of specific proteins during zebrafish, Xenopus, chick, and mouse development. Morpholinos basepair with a complementary RNA sequence to either block pre-mRNA splicing or m

  4. Neural repair in the adult brain

    PubMed Central

    Jessberger, Sebastian

    2016-01-01

    Acute or chronic injury to the adult brain often results in substantial loss of neural tissue and subsequent permanent functional impairment. Over the last two decades, a number of approaches have been developed to harness the regenerative potential of neural stem cells and the existing fate plasticity of neural cells in the nervous system to prevent tissue loss or to enhance structural and functional regeneration upon injury. Here, we review recent advances of stem cell-associated neural repair in the adult brain, discuss current challenges and limitations, and suggest potential directions to foster the translation of experimental stem cell therapies into the clinic. PMID:26918167

  5. A role for GnRH in early brain regionalization and eye development in zebrafish.

    PubMed

    Wu, Sheng; Page, Louise; Sherwood, Nancy M

    2006-09-26

    Gonadotropin-releasing hormone (GnRH) is a highly conserved peptide that is expressed early in brain development in vertebrates. In zebrafish, we detected GnRH mRNA within 2h post fertilization by RT-PCR. To determine if GnRH is involved in development, we used gene knockdown techniques to block translation of gnrh2 or gnrh3 mRNA after which the expression patterns for gene markers were examined at 24h post fertilization with in situ hybridization. First, loss of either GnRH2 or GnRH3 affected regionalization of the brain as shown by a change in expression of fgf8 or pax2.1 genes in the midbrain-hindbrain boundary or diencephalon-midbrain boundary. Second, lack of GnRH2 and/or GnRH3 altered gene markers expressed in the formation of the eye cup (pax2.1, pax6.1, mab21l2 and meis1.1) or eye stalk (fgf8 and pax2.1). Third, knockdown of GnRH2 affected the size and shape of the midbrain and expression of gene markers therein. Results from assays with the TUNEL method and caspase-3 and -9 activity showed the brain and eye changes were unlikely to result from secondary apoptotic cell death before 24h post fertilization. These experiments suggest that GnRH loss-of-function affects early brain and eye formation during development.

  6. Triclosan Exposure Is Associated with Rapid Restructuring of the Microbiome in Adult Zebrafish

    PubMed Central

    Barton, Carrie L.; Proffitt, Sarah; Tanguay, Robert L.; Sharpton, Thomas J.

    2016-01-01

    Growing evidence indicates that disrupting the microbial community that comprises the intestinal tract, known as the gut microbiome, can contribute to the development or severity of disease. As a result, it is important to discern the agents responsible for microbiome disruption. While animals are frequently exposed to a diverse array of environmental chemicals, little is known about their effects on gut microbiome stability and structure. Here, we demonstrate how zebrafish can be used to glean insight into the effects of environmental chemical exposure on the structure and ecological dynamics of the gut microbiome. Specifically, we exposed forty-five adult zebrafish to triclosan-laden food for four or seven days or a control diet, and analyzed their microbial communities using 16S rRNA amplicon sequencing. Triclosan exposure was associated with rapid shifts in microbiome structure and diversity. We find evidence that several operational taxonomic units (OTUs) associated with the family Enterobacteriaceae appear to be susceptible to triclosan exposure, while OTUs associated with the genus Pseudomonas appeared to be more resilient and resistant to exposure. We also found that triclosan exposure is associated with topological alterations to microbial interaction networks and results in an overall increase in the number of negative interactions per microbe in these networks. Together these data indicate that triclosan exposure results in altered composition and ecological dynamics of microbial communities in the gut. Our work demonstrates that because zebrafish afford rapid and inexpensive interrogation of a large number of individuals, it is a useful experimental system for the discovery of the gut microbiome’s interaction with environmental chemicals. PMID:27191725

  7. INSL3 stimulates spermatogonial differentiation in testis of adult zebrafish (Danio rerio).

    PubMed

    Assis, L H C; Crespo, D; Morais, R D V S; França, L R; Bogerd, J; Schulz, R W

    2016-02-01

    INSL3 (insulin-like peptide 3) is a relaxin peptide family member expressed by Leydig cells in the vertebrate testis. In mammals, INSL3 mediates testicular descent during embryogenesis but information on its function in adults is limited. In fish, the testes remain in the body cavity, although the insl3 gene is still expressed, suggesting yet undiscovered, evolutionary older functions. Anti-Müllerian hormone (Amh), in addition to inhibiting spermatogonial differentiation and androgen release, inhibits the Fsh (follicle-stimulating hormone)-induced increase in insl3 transcript levels in zebrafish testis. Therefore, the two growth factors might have antagonistic effects. We examine human INSL3 (hINSL3) effects on zebrafish germ cell proliferation/differentiation and androgen release by using a testis tissue culture system. hINSL3 increases the proliferation of type A undifferentiated (Aund) but not of type A differentiating (Adiff) spermatogonia, while reducing the proliferation of Sertoli cells associated with proliferating Aund. Since the area occupied by Aund decreases and that of Adiff increases, we conclude that hINSL3 recruits Aund into differentiation; this is supported by the hINSL3-induced down-regulation of nanos2 transcript levels, a marker of single Aund spermatogonia in zebrafish and other vertebrates. Pulse-chase experiments with a mitosis marker also indicate that hINSL3 promotes spermatogonial differentiation. However, hINSL3 does not modulate basal or Fsh-stimulated androgen release or growth factor transcript levels, including those of amh. Thus, hINSL3 seems to recruit Aund spermatogonia into differentiation, potentially mediating an Fsh effect on spermatogenesis.

  8. Differential expression profile of membrane proteins in zebrafish (Danio rerio) brain exposed to methyl parathion.

    PubMed

    Huang, Qing-Yu; Huang, He-Qing

    2011-09-01

    Methyl parathion (MP) is a widely used organophosphorus pesticide, which has been related to a broad spectrum of toxic effects on environmental organisms. The present study investigated the changes in the protein profile of enriched membrane fraction from zebrafish (Danio rerio) brain exposed to three concentrations (0.5, 1 and 2 mg/L) of MP. 2-DE revealed that the abundance of 21 protein spots was significantly changed by MP stress. By matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and database search, 16 protein spots were identified as membrane proteins, among which 8 were down-regulated, while 8 were up-regulated. These proteins are mainly involved in oxidative stress response, signal transduction, metabolism, protein synthesis and degradation, neuroplasticity and regeneration as well as synaptic transmission. These results may aid our understanding of the mechanism of MP-induced neurotoxicity and provide the possibility of the establishment of candidate biomarkers of MP.

  9. A Novel Light Damage Paradigm for Use in Retinal Regeneration Studies in Adult Zebrafish

    PubMed Central

    Thomas, Jennifer L.; Thummel, Ryan

    2013-01-01

    Light-induced retinal degeneration (LIRD) is commonly used in both rodents and zebrafish to damage rod and cone photoreceptors. In adult zebrafish, photoreceptor degeneration triggers Müller glial cells to re-enter the cell cycle and produce transient-amplifying progenitors. These progenitors continue to proliferate as they migrate to the damaged area, where they ultimately give rise to new photoreceptors. Currently, there are two widely-used LIRD paradigms, each of which results in varying degrees of photoreceptor loss and corresponding differences in the regeneration response. As more genetic and pharmacological tools are available to test the role of individual genes of interest during regeneration, there is a need to develop a robust LIRD paradigm. Here we describe a LIRD protocol that results in widespread and consistent loss of both rod and cone photoreceptors in which we have combined the use of two previously established LIRD techniques. Furthermore, this protocol can be extended for use in pigmented animals, which eliminates the need to maintain transgenic lines of interest on the albino background for LIRD studies. PMID:24192580

  10. Exposure to Zinc Sulfate Results in Differential Effects on Olfactory Sensory Neuron Subtypes in Adult Zebrafish

    PubMed Central

    Hentig, James T.; Byrd-Jacobs, Christine A.

    2016-01-01

    Zinc sulfate is a known olfactory toxicant, although its specific effects on the olfactory epithelium of zebrafish are unknown. Olfactory organs of adult zebrafish were exposed to zinc sulfate and, after 2, 3, 5, 7, 10 or 14 days, fish were processed for histological, immunohistochemical, ultrastructural, and behavioral analyses. Severe morphological disruption of the olfactory organ was observed two days following zinc sulfate exposure, including fusion of lamellae, epithelial inflammation, and significant loss of anti-calretinin labeling. Scanning electron microscopy revealed the apical surface of the sensory region was absent of ciliated structures, but microvilli were still present. Behavioral analysis showed significant loss of the ability to perceive bile salts and some fish also had no response to amino acids. Over the next several days, olfactory organ morphology, epithelial structure, and anti-calretinin labeling returned to control-like conditions, although the ability to perceive bile salts remained lost until day 14. Thus, exposure to zinc sulfate results in rapid degeneration of the olfactory organ, followed by restoration of morphology and function within two weeks. Zinc sulfate appears to have a greater effect on ciliated olfactory sensory neurons than on microvillous olfactory sensory neurons, suggesting differential effects on sensory neuron subtypes. PMID:27589738

  11. Expression of sept3, sept5a and sept5b in the Developing and Adult Nervous System of the Zebrafish (Danio rerio)

    PubMed Central

    Helmprobst, Frederik; Lillesaar, Christina; Stigloher, Christian

    2017-01-01

    Septins are a highly conserved family of small GTPases that form cytoskeletal filaments. Their cellular functions, especially in the nervous system, still remain largely enigmatic, but there are accumulating lines of evidence that septins play important roles in neuronal physiology and pathology. In order to further dissect septin function in the nervous system a detailed temporal resolved analysis in the genetically well tractable model vertebrate zebrafish (Danio rerio) is crucially necessary. To close this knowledge gap we here provide a reference dataset describing the expression of selected septins (sept3, sept5a and sept5b) in the zebrafish central nervous system. Strikingly, proliferation zones are devoid of expression of all three septins investigated, suggesting that they have a role in post-mitotic neural cells. Our finding that three septins are mainly expressed in non-proliferative regions was further confirmed by double-stainings with a proliferative marker. Our RNA in situ hybridization (ISH) study, detecting sept3, sept5a and sept5b mRNAs, shows that all three septins are expressed in largely overlapping regions of the developing brain. However, the expression of sept5a is much more confined compared to sept3 and sept5b. In contrast, the expression of all the three analyzed septins is largely similar in the adult brain. PMID:28261064

  12. Startle response memory and hippocampal changes in adult zebrafish pharmacologically-induced to exhibit anxiety/depression-like behaviors.

    PubMed

    Pittman, Julian T; Lott, Chad S

    2014-01-17

    Zebrafish (Danio rerio) are rapidly becoming a popular animal model for neurobehavioral and psychopharmacological research. While startle testing is a well-established assay to investigate anxiety-like behaviors in different species, screening of the startle response and its habituation in zebrafish is a new direction of translational biomedical research. This study focuses on a novel behavioral protocol to assess a tapping-induced startle response and its habituation in adult zebrafish that have been pharmacologically-induced to exhibit anxiety/depression-like behaviors. We demonstrated that zebrafish exhibit robust learning performance in a task adapted from the mammalian literature, a modified plus maze, and showed that ethanol and fluoxetine impair memory performance in this maze when administered after training at a dose that does not impair motor function, however, leads to significant upregulation of hippocampal serotoninergic neurons. These results suggest that the maze associative learning paradigm has face and construct validity and that zebrafish may become a translationally relevant study species for the analysis of the mechanisms of learning and memory changes associated with psychopharmacological treatment of anxiety/depression.

  13. Age- and size-related changes in the inner ear and hearing ability of the adult zebrafish (Danio rerio).

    PubMed

    Higgs, Dennis M; Souza, Marcy J; Wilkins, Heather R; Presson, Joelle C; Popper, Arthur N

    2002-06-01

    Fishes, unlike most other vertebrate groups, continue to add sensory hair cells to their ears for much of their lives. However, it is not clear whether the addition ever stops or how the addition of sensory cells impacts hearing ability. In this article, we tested both questions using the zebrafish, Danio rerio. Our results not only have important implications for understanding the consequences of adding sensory receptors, but these results for normal zebrafish also serve as valuable baseline information for future studies of select mutations on the ear and hearing of this species. Our results show that hair cell production continues in uncrowded zebrafish up to 10 months of age (about one-third of a normal life span), but despite this addition there is no change in hearing sensitivity or bandwidth. Therefore, hearing is not related to the number of sensory cells in the ear in juvenile and adult animals. We also show that despite no net addition of hair cells after about 10 months, hair cells are still being produced, but at a lower rate, presumably to replace cells that are dying. Moreover, crowding of zebrafish has a marked impact on the growth of the fish and on the addition of sensory cells to the ear. We also demonstrate that fish size, not age, is a better indicator of developmental state of zebrafish.

  14. Acupuncture stimulation induces neurogenesis in adult brain.

    PubMed

    Nam, Min-Ho; Ahn, Kwang Seok; Choi, Seung-Hoon

    2013-01-01

    The discovery of adult neurogenesis was a turning point in the field of neuroscience. Adult neurogenesis offers an enormous possibility to open a new therapeutic paradigm of neurodegenerative diseases and stroke. Recently, several studies suggested that acupuncture may enhance adult neurogenesis. Acupuncture has long been an important treatment for brain diseases in the East Asia. The scientific mechanisms of acupuncture treatment for the diseases, such as Alzheimer's disease, Parkinson's disease, and stroke, have not been clarified yet; however, the neurogenic effect of acupuncture can be a possible reason. Here, we have reviewed the studies on the effect of stimulation at various acupoints for neurogenesis, such as ST36 and GV20. The suggested mechanisms are also discussed including upregulation of brain-derived neurotrophic factor, glial cell line-derived neurotrophic factor, basic fibroblast growth factor and neuropeptide Y, and activation of the function of primo vascular system.

  15. V-ATPase Proton Pumping Activity Is Required for Adult Zebrafish Appendage Regeneration

    PubMed Central

    Monteiro, Joana; Aires, Rita; Becker, Jörg D.; Jacinto, António; Certal, Ana C.; Rodríguez-León, Joaquín

    2014-01-01

    The activity of ion channels and transporters generates ion-specific fluxes that encode electrical and/or chemical signals with biological significance. Even though it is long known that some of those signals are crucial for regeneration, only in recent years the corresponding molecular sources started to be identified using mainly invertebrate or larval vertebrate models. We used adult zebrafish caudal fin as a model to investigate which and how ion transporters affect regeneration in an adult vertebrate model. Through the combined use of biophysical and molecular approaches, we show that V-ATPase activity contributes to a regeneration-specific H+ ef`flux. The onset and intensity of both V-ATPase expression and H+ efflux correlate with the different regeneration rate along the proximal-distal axis. Moreover, we show that V-ATPase inhibition impairs regeneration in adult vertebrate. Notably, the activity of this H+ pump is necessary for aldh1a2 and mkp3 expression, blastema cell proliferation and fin innervation. To the best of our knowledge, this is the first report on the role of V-ATPase during adult vertebrate regeneration. PMID:24671205

  16. V-ATPase proton pumping activity is required for adult zebrafish appendage regeneration.

    PubMed

    Monteiro, Joana; Aires, Rita; Becker, Jörg D; Jacinto, António; Certal, Ana C; Rodríguez-León, Joaquín

    2014-01-01

    The activity of ion channels and transporters generates ion-specific fluxes that encode electrical and/or chemical signals with biological significance. Even though it is long known that some of those signals are crucial for regeneration, only in recent years the corresponding molecular sources started to be identified using mainly invertebrate or larval vertebrate models. We used adult zebrafish caudal fin as a model to investigate which and how ion transporters affect regeneration in an adult vertebrate model. Through the combined use of biophysical and molecular approaches, we show that V-ATPase activity contributes to a regeneration-specific H+ ef`flux. The onset and intensity of both V-ATPase expression and H+ efflux correlate with the different regeneration rate along the proximal-distal axis. Moreover, we show that V-ATPase inhibition impairs regeneration in adult vertebrate. Notably, the activity of this H+ pump is necessary for aldh1a2 and mkp3 expression, blastema cell proliferation and fin innervation. To the best of our knowledge, this is the first report on the role of V-ATPase during adult vertebrate regeneration.

  17. Cortisol-treated zebrafish embryos develop into pro-inflammatory adults with aberrant immune gene regulation

    PubMed Central

    Hartig, Ellen I.; Zhu, Shusen; King, Benjamin L.

    2016-01-01

    ABSTRACT Chronic early-life stress increases adult susceptibility to numerous health problems linked to chronic inflammation. One way that this may occur is via glucocorticoid-induced developmental programming. To gain insight into such programming we treated zebrafish embryos with cortisol and examined the effects on both larvae and adults. Treated larvae had elevated whole-body cortisol and glucocorticoid signaling, and upregulated genes associated with defense response and immune system processes. In adulthood the treated fish maintained elevated basal cortisol levels in the absence of exogenous cortisol, and constitutively mis-expressed genes involved in defense response and its regulation. Adults derived from cortisol-treated embryos displayed defective tailfin regeneration, heightened basal expression of pro-inflammatory genes, and failure to appropriately regulate those genes following injury or immunological challenge. These results support the hypothesis that chronically elevated glucocorticoid signaling early in life directs development of a pro-inflammatory adult phenotype, at the expense of immunoregulation and somatic regenerative capacity. PMID:27444789

  18. Role of two genes encoding PACAP in early brain development in zebrafish.

    PubMed

    Wu, Sheng; Adams, Bruce A; Fradinger, Erica A; Sherwood, Nancy M

    2006-07-01

    To study the role of pituitary adenylate cyclase-activating polypeptide (PACAP) in early brain development, we examined PACAP and its receptors for first expression and then separately knocked down the two forms of PACAP in zebrafish where development is rapid and observable. We injected morpholinos (antisense oligonucleotides) into fertilized eggs to block PACAP. Morphological changes in the brain were observed in embryos at 27 h post fertilization (hpf). Using in situ hybridization of early brain marker genes, we found that the most striking effects were an increase in pax2.1 expression in eye stalks associated with absence of either form of PACAP or an increase in eng2 and fgf8 in the midbrain-hindbrain boundary after loss of PACAP2. These marker genes are among the earliest factors in the formation of the midbrain-hindbrain boundary, an early organizing center. We suggest that PACAP is a target gene with feedback inhibition on pax2.1, eng2, or fgf8 in specific brain areas. In the hindbrain, the absence of either form of PACAP had little effect, as shown by expression of ephA4 and meis1.1. During midbrain development, our evidence suggests that PACAP1 can activate mbx. In both the diencephalon and/or forebrain, lack of PACAP1 or PACAP2 led to an increase in fgf8, again suggesting a suppressive effect of PACAP during development on these important genes that help to define cells in the forebrain. The early expression of transcripts for PACAP and its receptors by 0.5-6 hpf make both PACAP1 and PACAP2 candidates for factors that influence brain development.

  19. Peripheral Axons of the Adult Zebrafish Maxillary Barbel Extensively Remyelinate During Sensory Appendage Regeneration

    PubMed Central

    Moore, Alex C.; Mark, Tiffany E.; Hogan, Ann K.; Topczewski, Jacek; LeClair, Elizabeth E.

    2013-01-01

    Myelination is a cellular adaptation allowing rapid conduction along axons. We have investigated peripheral axons of the zebrafish maxillary barbel (ZMB), an optically clear sensory appendage. Each barbel carries taste buds, solitary chemosensory cells, and epithelial nerve endings, all of which regenerate after amputation (LeClair and Topczewski [2010] PLoS One 5:e8737). The ZMB contains axons from the facial nerve; however, myelination within the barbel itself has not been established. Transcripts of myelin basic protein (mbp) are expressed in normal and regenerating adult barbels, indicating activity in both maintenance and repair. Myelin was confirmed in situ by using toluidine blue, an anti-MBP antibody, and transmission electron microscopy (TEM). The adult ZMB contains ~180 small-diameter axons (<2 μm), approximately 60% of which are myelinated. Developmental myelination was observed via whole-mount immunohistochemistry 4-6 weeks postfertilization, showing myelin sheaths lagging behind growing axons. Early-regenerating axons (10 days postsurgery), having no or few myelin layers, were disorganized within a fibroblast-rich collagenous scar. Twenty-eight days postsurgery, barbel axons had grown out several millimeters and were organized with compact myelin sheaths. Fiber types and axon areas were similar between normal and regenerated tissue; within 4 weeks, regenerating axons restored ~85% of normal myelin thickness. Regenerating barbels express multiple promyelinating transcription factors (sox10, oct6 = pou3f1; krox20a/b = egr2a/b) typical of Schwann cells. These observations extend our understanding of the zebrafish peripheral nervous system within a little-studied sensory appendage. The accessible ZMB provides a novel context for studying axon regeneration, Schwann cell migration, and remyelination in a model vertebrate. PMID:22592645

  20. The contribution of the swimbladder to buoyancy in the adult zebrafish (Danio rerio): a morphometric analysis.

    PubMed

    Robertson, George N; Lindsey, Benjamin W; Dumbarton, Tristan C; Croll, Roger P; Smith, Frank M

    2008-06-01

    Many teleost fishes use a swimbladder, a gas-filled organ in the coelomic cavity, to reduce body density toward neutral buoyancy, thus minimizing the locomotory cost of maintaining a constant depth in the water column. However, for most swimbladder-bearing teleosts, the contribution of this organ to the attainment of neutral buoyancy has not been quantified. Here, we examined the quantitative contribution of the swimbladder to buoyancy and three-dimensional stability in a small cyprinid, the zebrafish (Danio rerio). In aquaria during daylight hours, adult animals were observed at mean depths from 10.1 +/- 6.0 to 14.2 +/- 5.6 cm below the surface. Fish mass and whole-body volume were linearly correlated (r(2) = 0.96) over a wide range of body size (0.16-0.73 g); mean whole-body density was 1.01 +/- 0.09 g cm(-3). Stereological estimations of swimbladder volume from linear dimensions of lateral X-ray images and direct measurements of gas volumes recovered by puncture from the same swimbladders showed that results from these two methods were highly correlated (r(2) = 0.85). The geometric regularity of the swimbladder thus permitted its volume to be accurately estimated from a single lateral image. Mean body density in the absence of the swimbladder was 1.05 +/- 0.04 g cm(-3). The swimbladder occupied 5.1 +/- 1.4% of total body volume, thus reducing whole-body density significantly. The location of the centers of mass and buoyancy along rostro-caudal and dorso-ventral axes overlapped near the ductus communicans, a constriction between the anterior and posterior swimbladder chambers. Our work demonstrates that the swimbladder of the adult zebrafish contributes significantly to buoyancy and attitude stability. Furthermore, we describe and verify a stereological method for estimating swimbladder volume that will aid future studies of the functions of this organ.

  1. BISPHENOL A EXPOSURE DURING EARLY DEVELOPMENT INDUCES SEX-SPECIFIC CHANGES IN ADULT ZEBRAFISH SOCIAL INTERACTIONS

    PubMed Central

    Weber, Daniel N.; Hoffmann, Raymond G.; Hoke, Elizabeth S.; Tanguay, Robert L.

    2014-01-01

    Developmental bisphenol A (BPA) exposure is associated with adverse behavioral effects, although underlying modes of action remain unclear. Because BPA is a suspected xenoestrogen, the objective was to identify sex-based changes in adult zebrafish social behavior developmentally exposed to BPA (0.0, 0.1 or 1 μM) or one of two control compounds (0.1μM 17β-estradiol [E2], and 0.1 μM GSK4716, a synthetic estrogen-related receptor γ ligand). A test chamber was divided lengthwise so each arena held one fish unable to detect the presence of the other fish. A mirror was inserted at one end of each arena; baseline activity levels were determined without mirror. Arenas were divided into 3, computer-generated zones to represent different distances from mirror image. Circadian rhythm patterns were evaluated at 1–3 (= AM) and 5–8 (= PM) hr postprandial. Adult zebrafish were placed into arenas and monitored by digital camera for 5 min. Total distance traveled, % time spent at mirror image, and number of attacks on mirror image were quantified. E2, GSK4716, and all BPA treatments dampened male activity and altered male circadian activity patterns; there was no marked effect on female activity. BPA induced non-monotonic effects (response curve changes direction within range of concentrations examined) on male % time at mirror only in AM. All treatments produced increased % time at the mirror during PM. Male attacks on the mirror were reduced by BPA exposure only during AM. There were sex-specific effects of developmental BPA on social interactions and time-of-day of observation affected results. PMID:25424546

  2. Delivery of Small Interfering RNA to Inhibit Vascular Endothelial Growth Factor in Zebrafish Using Natural Brain Endothelia Cell-Secreted Exosome Nanovesicles for the Treatment of Brain Cancer.

    PubMed

    Yang, Tianzhi; Fogarty, Brittany; LaForge, Bret; Aziz, Salma; Pham, Thuy; Lai, Leanne; Bai, Shuhua

    2017-03-01

    Although small interfering RNA (siRNA) holds great therapeutic promise, its delivery to the disease site remains a paramount obstacle. In this study, we tested whether brain endothelial cell-derived exosomes could deliver siRNA across the blood-brain barrier (BBB) in zebrafish. Natural exosomes were isolated from brain endothelial bEND.3 cell culture media and vascular endothelial growth factor (VEGF) siRNA was loaded in exosomes with the assistance of a transfection reagent. While fluorescence-activated cell flow cytometry and immunocytochemistry staining studies indicated that wild-type exosomes significantly increased the uptake of fluorescence-labeled siRNA in the autologous brain endothelial cells, decreased fluorescence intensity was observed in the cells treated with the tetraspanin CD63 antibody-blocked exosome-delivered formulation (p < 0.05). In the transport study, exosomes also enhanced the permeability of rhodamine 123 in a co-cultured monolayer of brain endothelial bEND.3 cell and astrocyte. Inhibition at the expression of VEGF RNA and protein levels was observed in glioblastoma-astrocytoma U-87 MG cells treated with exosome-delivered siRNAs. Imaging results showed that exosome delivered more siRNAs across the BBB in Tg(fli1:GFP) zebrafish. In a xenotransplanted brain tumor model, exosome-delivered VEGF siRNAs decreased the fluorescence intensity of labeled cancer cells in the brain of zebrafish. Brain endothelial cell-derived exosomes could be potentially used as a natural carrier for the brain delivery of exogenous siRNA.

  3. Acute exposure to waterborne cadmium induced oxidative stress and immunotoxicity in the brain, ovary and liver of zebrafish (Danio rerio).

    PubMed

    Zheng, Jia-Lang; Yuan, Shuang-Shuang; Wu, Chang-Wen; Lv, Zhen-Ming

    2016-11-01

    Cadmium (Cd) is an environmental contaminant that poses serious risks to aquatic organisms and their associated ecosystem. The mechanisms underlying Cd-induced oxidative stress and immunotoxicity in fish remain largely unknown. In this study, adult female zebrafish were exposed to 0 (control), 1mgL(-1) Cd for 24h and 96h, and the oxidative stress and inflammatory responses induced by Cd were evaluated in the brain, liver and ovary. Reactive oxygen species (ROS), nitric oxide (NO), and malondialdehyde (MDA) increased in a time-dependent manner after treatment with Cd in the brain and liver. The increase may result from the disturbance of genes including copper and zinc superoxide dismutase (Cu/Zn-SOD), catalase (CAT), inducible nitric oxide synthase (iNOS), and ciclooxigenase-2 (COX-2) at mRNA, protein and activity levels. Although ROS, NO and MDA were not significantly affected by Cd in the ovary, the up-regulation of Cu/Zn-SOD, CAT, iNOS, and COX-2 was observed. Exposure to Cd induced a sharp increase in the protein levels of tumor necrosis factor alpha (TNF-α) in the brain, liver and ovary, possibly contributing to activate inflammatory responses. Furthermore, we also found a dramatic increase in mRNA levels of NF-E2-related factor 2 (Nrf2) and nuclear transcription factor κB (NF-κB) at 24h in the liver and ovary. The corresponding changes in the mRNA levels of Kelch-like-ECH-associated protein 1 (Keap1a and Keap1b) and the inhibitor of κBα (IκBαa and IκBαb) may contribute to regulate the transcriptional activity of Nrf2 and NF-κB, respectively. Contrarily, mRNA levels of Nrf2, NF-κB, Keap1, Keap1b, IκBαa and IκBαb remained stable at 24 and 96h in the brain. Taken together, we demonstrated Cd-induced oxidative stress and immunotoxicity in fish, possibly through transcriptional regulation of Nrf2 and NF-κB and gene modifications at transcriptional, translational, post-translational levels, which would greatly extend our understanding on the Cd

  4. Chondroitin sulfate and keratan sulfate are the major glycosaminoglycans present in the adult zebrafish Danio rerio (Chordata-Cyprinidae).

    PubMed

    Souza, Aline R C; Kozlowski, Eliene O; Cerqueira, Vinicius R; Castelo-Branco, Morgana T L; Costa, Manoel L; Pavão, Mauro S G

    2007-12-01

    The zebrafish Danio rerio (Chordata-Cyprinidae) is a model organism frequently used to study the functions of proteoglycans and their glycosaminoglycan (GAG) chains. Although several studies clearly demonstrate the participation of these polymers in different biological and cellular events that take place during embryonic development, little is known about the GAGs in adult zebrafish. In the present study, the total GAGs were extracted from the whole fish by proteolytic digestion, purified by anion-exchange chromatography and characterized by electrophoresis after degradation with specific enzymes and/or by high-performance liquid chromatography (HPLC) analysis of the disaccharides. Two GAGs were identified: a low-molecular-weight chondroitin sulfate (CS) and keratan sulfate (KS), corresponding to approximately 80% and 20% of the total GAGs, respectively. In the fish eye, KS represents approximately 80% of total GAGs. Surprisingly, no heparinoid was detected, but may be present in the fish at concentrations lower than the limit of the method used. HPLC of the disaccharides formed after chondroitin AC or ABC lyase degradation revealed that the zebrafish CS is composed by DeltaUA-1-->3-GalNAc(4SO4) (59.4%), DeltaUA-1-->3-GalNAc(6SO4) (23.1%), and DeltaUA-1-->3-GalNAc (17.5%) disaccharide units. No disulfated disaccharides were detected. Immunolocalization on sections from zebrafish retina using monoclonal antibodies against CS4- or 6-sulfate showed that in the retina these GAGs are restricted to the outer and inner plexiform layers. This is the first report showing the presence of KS in zebrafish eye, and the structural characterization of CS and its localization in the zebrafish retina. Detailed information about the structure and tissue localization of GAGs is important to understand the functions of these polymers in this model organism.

  5. Depleted uranium induces sex- and tissue-specific methylation patterns in adult zebrafish.

    PubMed

    Gombeau, Kewin; Pereira, Sandrine; Ravanat, Jean-Luc; Camilleri, Virginie; Cavalie, Isabelle; Bourdineaud, Jean-Paul; Adam-Guillermin, Christelle

    2016-04-01

    We examined the effects of chronic exposure to different concentrations (2 and 20 μg L(-)(1)) of environmentally relevant waterborne depleted uranium (DU) on the DNA methylation patterns both at HpaII restriction sites (5'-CCGG-3') and across the whole genome in the zebrafish brain, gonads, and eyes. We first identified sex-dependent differences in the methylation level of HpaII sites after exposure. In males, these effects were present as early as 7 days after exposure to 20 μg L(-)(1) DU, and were even more pronounced in the brain, gonads, and eyes after 24 days. However, in females, hypomethylation was only observed in the gonads after exposure to 20 μg L(-)(1) DU for 24 days. Sex-specific effects of DU were also apparent at the whole-genome level, because in males, exposure to 20 μg L(-)(1) DU for 24 days resulted in cytosine hypermethylation in the brain and eyes and hypomethylation in the gonads. In contrast, in females, hypermethylation was observed in the brain after exposure to both concentrations of DU for 7 days. Based on our current knowledge of uranium toxicity, several hypotheses are proposed to explain these findings, including the involvement of oxidative stress, alteration of demethylation enzymes and the calcium signaling pathway. This study reports, for the first time, the sex- and tissue-specific epigenetic changes that occur in a nonhuman organism after exposure to environmentally relevant concentrations of uranium, which could induce transgenerational epigenetic effects.

  6. Single Low-Dose Ionizing Radiation Induces Genotoxicity in Adult Zebrafish and its Non-Irradiated Progeny.

    PubMed

    Lemos, J; Neuparth, T; Trigo, M; Costa, P; Vieira, D; Cunha, L; Ponte, F; Costa, P S; Metello, L F; Carvalho, A P

    2017-02-01

    This study investigated to what extent a single exposure to low doses of ionizing radiation can induce genotoxic damage in irradiated adult zebrafish (Danio rerio) and its non-irradiated F1 progeny. Four groups of adult zebrafish were irradiated with a single dose of X-rays at 0 (control), 100, 500 and 1000 mGy, respectively, and couples of each group were allowed to reproduce following irradiation. Blood of parental fish and whole-body offspring were analysed by the comet assay for detection of DNA damage. The level of DNA damage in irradiated parental fish increased in a radiation dose-dependent manner at day 1 post-irradiation, but returned to the control level thereafter. The level of DNA damage in the progeny was directly correlated with the parental irradiation dose. Results highlight the genotoxic risk of a single exposure to low-dose ionizing radiation in irradiated individuals and also in its non-irradiated progeny.

  7. Neurobehavioural Changes and Brain Oxidative Stress Induced by Acute Exposure to GSM900 Mobile Phone Radiations in Zebrafish (Danio rerio)

    PubMed Central

    Nirwane, Abhijit; Sridhar, Vinay; Majumdar, Anuradha

    2016-01-01

    The impact of mobile phone (MP) radiation on the brain is of specific interest to the scientific community and warrants investigations, as MP is held close to the head. Studies on humans and rodents revealed hazards MP radiation associated such as brain tumors, impairment in cognition, hearing etc. Melatonin (MT) is an important modulator of CNS functioning and is a neural antioxidant hormone. Zebrafish has emerged as a popular model organism for CNS studies. Herein, we evaluated the impact of GSM900MP (GSM900MP) radiation exposure daily for 1 hr for 14 days with the SAR of 1.34W/Kg on neurobehavioral and oxidative stress parameters in zebrafish. Our study revealed that, GSM900MP radiation exposure, significantly decreased time spent near social stimulus zone and increased total distance travelled, in social interaction test. In the novel tank dive test, the GSM900MP radiation exposure elicited anxiety as revealed by significantly increased time spent in bottom half; freezing bouts and duration and decreased distance travelled, average velocity, and number of entries to upper half of the tank. Exposed zebrafish spent less time in the novel arm of the Y-Maze, corroborating significant impairment in learning as compared to the control group. Exposure decreased superoxide dismutase (SOD), catalase (CAT) activities whereas, increased levels of reduced glutathione (GSH) and lipid peroxidation (LPO) was encountered showing compromised antioxidant defense. Treatment with MT significantly reversed the above neurobehavioral and oxidative derangements induced by GSM900MP radiation exposure. This study traced GSM900MP radiation exposure induced neurobehavioral aberrations and alterations in brain oxidative status. Furthermore, MT proved to be a promising therapeutic candidate in ameliorating such outcomes in zebrafish. PMID:27123163

  8. Reduced swim performance and aerobic capacity in adult zebrafish exposed to waterborne selenite.

    PubMed

    Massé, Anita J; Thomas, Jith K; Janz, David M

    2013-04-01

    Although dietary exposure of adult fish to organoselenium in contaminated aquatic ecosystems has been reported to bioaccumulate and cause larval deformities in offspring, subtle physiological effects produced through low level waterborne selenium exposure in fish such as swim performance and aerobic capacity have not been investigated. To evaluate potential effects of selenite on these responses, adult zebrafish (Danio rerio) were exposed to nominal aqueous concentrations of 0, 10 or 100 μg/L sodium selenite for 14 days. Upon completion of the exposure period, fish underwent two successive swim trials in a swim tunnel respirometer to determine critical swim speed (Ucrit), oxygen consumption (MO2), standard and active metabolic rates, aerobic scope (AS) and cost of transport (COT) followed by analysis of whole body triglyceride and glycogen concentrations. Selenite exposure had a significant negative effect on Ucrit and aerobic capacity. Active metabolic rates and AS significantly decreased in both selenite exposure groups after the second swim trial. No significant effect was observed in MO2, standard metabolic rate, COT, triglyceride and glycogen levels, or condition factor between groups. These results suggest that aqueous selenite exposure at environmentally relevant concentrations produces adverse effects on aerobic capacity that can diminish endurance and maximum swim speeds, which may lower fish survivability.

  9. Feed and feeding regime affect growth rate and gonadosomatic index of adult zebrafish (Danio rerio).

    PubMed

    Gonzales, John M; Law, Sheran Hiu Wan

    2013-12-01

    A 5-week study was conducted to evaluate commercially available Artemia, Ziegler zebrafish diet, and Calamac diet fed in five different feeding regimes on the growth and reproductive development of 7-month-old zebrafish. Zebrafish were fed to satiation three times daily during the normal work week and twice daily during the weekend and holidays. Zebrafish in dietary groups CCC (Calamac three times daily) and CCA (Calamac twice daily, Artemia once daily) had a significantly (p<0.05) greater weight gain and specific growth rate as compared to all other dietary groups. Male zebrafish in dietary group 5 had significantly larger gonadosomatic index (GSI) values than all other groups, while female zebrafish in dietary group CCC had significantly larger GSI values than all other groups. No differences in the fatty acid content of female gonads were detected. Zebrafish fed solely Artemia had the greatest weight loss and lowest GSI values. Preliminary evidence of protein sparing in zebrafish is reported. Collectively, this study sheds more light into the effects of the use of commercially available feeds and feeding regime on the rearing of zebrafish.

  10. Adult zebrafish intestine resection: a novel model of short bowel syndrome, adaptation, and intestinal stem cell regeneration.

    PubMed

    Schall, K A; Holoyda, K A; Grant, C N; Levin, D E; Torres, E R; Maxwell, A; Pollack, H A; Moats, R A; Frey, M R; Darehzereshki, A; Al Alam, D; Lien, C; Grikscheit, T C

    2015-08-01

    Loss of significant intestinal length from congenital anomaly or disease may lead to short bowel syndrome (SBS); intestinal failure may be partially offset by a gain in epithelial surface area, termed adaptation. Current in vivo models of SBS are costly and technically challenging. Operative times and survival rates have slowed extension to transgenic models. We created a new reproducible in vivo model of SBS in zebrafish, a tractable vertebrate model, to facilitate investigation of the mechanisms of intestinal adaptation. Proximal intestinal diversion at segment 1 (S1, equivalent to jejunum) was performed in adult male zebrafish. SBS fish emptied distal intestinal contents via stoma as in the human disease. After 2 wk, S1 was dilated compared with controls and villus ridges had increased complexity, contributing to greater villus epithelial perimeter. The number of intervillus pockets, the intestinal stem cell zone of the zebrafish increased and contained a higher number of bromodeoxyuridine (BrdU)-labeled cells after 2 wk of SBS. Egf receptor and a subset of its ligands, also drivers of adaptation, were upregulated in SBS fish. Igf has been reported as a driver of intestinal adaptation in other animal models, and SBS fish exposed to a pharmacological inhibitor of the Igf receptor failed to demonstrate signs of intestinal adaptation, such as increased inner epithelial perimeter and BrdU incorporation. We describe a technically feasible model of human SBS in the zebrafish, a faster and less expensive tool to investigate intestinal stem cell plasticity as well as the mechanisms that drive intestinal adaptation.

  11. Delayed effects of developmental exposure to low levels of the aryl hydrocarbon receptor agonist 3,3′,4,4′,5-pentachlorobiphenyl (PCB126) on adult zebrafish behavior

    PubMed Central

    Glazer, Lilah; Hahn, Mark E.; Aluru, Neelakanteswar

    2015-01-01

    Polychlorinated biphenyls (PCBs) are ubiquitous environmental contaminants. The most toxic PCBs are the non-ortho-substituted (“dioxin-like”) congeners that act through the aryl hydrocarbon receptor (AHR) pathway. In humans, perinatal exposure to dioxin-like PCBs is associated with neurodevelopmental toxicity in children. Yet, the full potential for later-life neurobehavioral effects that result from early-life low level exposure to dioxin-like PCBs is not well understood. The objective of this study was to determine the effects of developmental exposure to low levels of dioxin-like PCBs on early-and later-life behavioral phenotypes using zebrafish as a model system. We exposed zebrafish embryos to either vehicle (DMSO) or low concentrations of PCB126 (0.3, 0.6, 1.2 nM) for 20 hours (4–24 hours post fertilization), and then reared them to adulthood in clean water. Locomotor activity was tested at two larval stages (7 and 14 days post fertilization). Adult fish were tested for anxiety-related behavior using the novel tank and shoaling assays. Adult behavioral assays were repeated several times on the same group of fish and effects on intra-and inter-trial habituation were determined. While there was no effect of PCB126 on larval locomotor activity in response to changes in light conditions, developmental exposure to PCB126 resulted in impaired short-and long-term habituation to a novel environment in adult zebrafish. Cyp1a induction was measured as an indicator for AHR activation. Despite high induction at early stages, cyp1a expression was not induced in the brains of developmentally exposed adult fish that showed altered behavior, suggesting that AHR was not activated at this stage. Our results demonstrate the effectiveness of the zebrafish model in detecting subtle and delayed behavioral effects resulting from developmental exposure to an environmental contaminant. PMID:26616910

  12. Differential requirement for irf8 in formation of embryonic and adult macrophages in zebrafish

    SciTech Connect

    Shiau, Celia E.; Kaufman, Zoe; Meireles, Ana M.; Talbot, William S.

    2015-01-23

    Interferon regulatory factor 8 (Irf8) is critical for mammalian macrophage development and innate immunity, but its role in teleost myelopoiesis remains incompletely understood. Specifically, genetic tools to analyze the role of irf8 in zebrafish macrophage development at larval and adult stages are lacking. In this study, we generated irf8 null mutants in zebrafish using TALEN-mediated targeting. Our analysis defines different requirements for irf8 at different stages. irf8 is required for formation of all macrophages during primitive and transient definitive hematopoiesis, but not during adult-phase definitive hematopoiesis starting at 5-6 days postfertilization. At early stages, irf8 mutants have excess neutrophils and excess cell death in pu.1-expressing myeloid cells. Macrophage fates were recovered in irf8 mutants after wildtype irf8 expression in neutrophil and macrophage lineages, suggesting that irf8 regulates macrophage specification and survival. In juvenile irf8 mutant fish, mature macrophages are present, but at numbers significantly reduced compared to wildtype, indicating an ongoing requirement for irf8 after embryogenesis. As development progresses, tissue macrophages become apparent in zebrafish irf8 mutants, with the possible exception of microglia. Our study defines distinct requirement for irf8 in myelopoiesis before and after transition to the adult hematopoietic system.

  13. Towards a comprehensive catalog of zebrafish behavior 1.0 and beyond.

    PubMed

    Kalueff, Allan V; Gebhardt, Michael; Stewart, Adam Michael; Cachat, Jonathan M; Brimmer, Mallorie; Chawla, Jonathan S; Craddock, Cassandra; Kyzar, Evan J; Roth, Andrew; Landsman, Samuel; Gaikwad, Siddharth; Robinson, Kyle; Baatrup, Erik; Tierney, Keith; Shamchuk, Angela; Norton, William; Miller, Noam; Nicolson, Teresa; Braubach, Oliver; Gilman, Charles P; Pittman, Julian; Rosemberg, Denis B; Gerlai, Robert; Echevarria, David; Lamb, Elisabeth; Neuhauss, Stephan C F; Weng, Wei; Bally-Cuif, Laure; Schneider, Henning

    2013-03-01

    Zebrafish (Danio rerio) are rapidly gaining popularity in translational neuroscience and behavioral research. Physiological similarity to mammals, ease of genetic manipulations, sensitivity to pharmacological and genetic factors, robust behavior, low cost, and potential for high-throughput screening contribute to the growing utility of zebrafish models in this field. Understanding zebrafish behavioral phenotypes provides important insights into neural pathways, physiological biomarkers, and genetic underpinnings of normal and pathological brain function. Novel zebrafish paradigms continue to appear with an encouraging pace, thus necessitating a consistent terminology and improved understanding of the behavioral repertoire. What can zebrafish 'do', and how does their altered brain function translate into behavioral actions? To help address these questions, we have developed a detailed catalog of zebrafish behaviors (Zebrafish Behavior Catalog, ZBC) that covers both larval and adult models. Representing a beginning of creating a more comprehensive ethogram of zebrafish behavior, this effort will improve interpretation of published findings, foster cross-species behavioral modeling, and encourage new groups to apply zebrafish neurobehavioral paradigms in their research. In addition, this glossary creates a framework for developing a zebrafish neurobehavioral ontology, ultimately to become part of a unified animal neurobehavioral ontology, which collectively will contribute to better integration of biological data within and across species.

  14. Towards a Comprehensive Catalog of Zebrafish Behavior 1.0 and Beyond

    PubMed Central

    Gebhardt, Michael; Stewart, Adam Michael; Cachat, Jonathan M.; Brimmer, Mallorie; Chawla, Jonathan S.; Craddock, Cassandra; Kyzar, Evan J.; Roth, Andrew; Landsman, Samuel; Gaikwad, Siddharth; Robinson, Kyle; Baatrup, Erik; Tierney, Keith; Shamchuk, Angela; Norton, William; Miller, Noam; Nicolson, Teresa; Braubach, Oliver; Gilman, Charles P.; Pittman, Julian; Rosemberg, Denis B.; Gerlai, Robert; Echevarria, David; Lamb, Elisabeth; Neuhauss, Stephan C.F.; Weng, Wei; Bally-Cuif, Laure; Schneider, Henning

    2013-01-01

    Abstract Zebrafish (Danio rerio) are rapidly gaining popularity in translational neuroscience and behavioral research. Physiological similarity to mammals, ease of genetic manipulations, sensitivity to pharmacological and genetic factors, robust behavior, low cost, and potential for high-throughput screening contribute to the growing utility of zebrafish models in this field. Understanding zebrafish behavioral phenotypes provides important insights into neural pathways, physiological biomarkers, and genetic underpinnings of normal and pathological brain function. Novel zebrafish paradigms continue to appear with an encouraging pace, thus necessitating a consistent terminology and improved understanding of the behavioral repertoire. What can zebrafish ‘do’, and how does their altered brain function translate into behavioral actions? To help address these questions, we have developed a detailed catalog of zebrafish behaviors (Zebrafish Behavior Catalog, ZBC) that covers both larval and adult models. Representing a beginning of creating a more comprehensive ethogram of zebrafish behavior, this effort will improve interpretation of published findings, foster cross-species behavioral modeling, and encourage new groups to apply zebrafish neurobehavioral paradigms in their research. In addition, this glossary creates a framework for developing a zebrafish neurobehavioral ontology, ultimately to become part of a unified animal neurobehavioral ontology, which collectively will contribute to better integration of biological data within and across species. PMID:23590400

  15. A Model of Excitotoxic Brain Injury in Larval Zebrafish: Potential Application for High-Throughput Drug Evaluation to Treat Traumatic Brain Injury.

    PubMed

    McCutcheon, Victoria; Park, Eugene; Liu, Elaine; Wang, Youdong; Wen, Xiao-Yan; Baker, Andrew J

    2016-06-01

    Traumatic brain injury (TBI) is a leading cause of death and morbidity with no effective therapeutic treatments for secondary injury. Preclinical drug evaluation in rodent models of TBI is a lengthy process. In this regard, the zebrafish has numerous advantages to address the technical and time-dependent obstacles associated with drug evaluation. We developed a reproducible brain injury using glutamate excitoxicity in zebrafish larvae, a known initiator of delayed cell death in TBI. Glutamate challenge resulted in dose-dependent lethality over an 84-h observation period. We report significant decrease in locomotion (p < 0.0001) and mean velocity (p < 0.001) with 10 μM glutamate application as measured through automated 96-well plate behavioral analysis. Application of the NMDA receptor antagonist MK-801 (400 nM) or the calpain inhibitor, MDL-28170 (20 μM), resulted in significant recovery of locomotor function. A secA5-YFP transgenic line was used to visualize the localization of cell death due to glutamate exposure in vivo using confocal fluorescence microscopy. Our results indicate that zebrafish larvae exhibit responses to excitotoxic injury and pharmacotherapeutic intervention with pathophysiological relevance to mammalian excitotoxic brain injury. This system has potential to be applied as a high-throughput drug screening model to quickly identify candidate lead compounds for further evaluation.

  16. Behind melanocortin antagonist overexpression in the zebrafish brain: A behavioral and transcriptomic approach.

    PubMed

    Guillot, Raúl; Cortés, Raúl; Navarro, Sandra; Mischitelli, Morena; García-Herranz, Víctor; Sánchez, Elisa; Cal, Laura; Navarro, Juan Carlos; Míguez, Jesús M; Afanasyev, Sergey; Krasnov, Aleksei; Cone, Roger D; Rotllant, Josep; Cerdá-Reverter, Jose Miguel

    2016-06-01

    Melanocortin signaling is regulated by the binding of naturally occurring antagonists, agouti-signaling protein (ASIP) and agouti-related protein (AGRP) that compete with melanocortin peptides by binding to melanocortin receptors to regulate energy balance and growth. Using a transgenic model overexpressing ASIP, we studied the involvement of melanocortin system in the feeding behaviour, growth and stress response of zebrafish. Our data demonstrate that ASIP overexpression results in enhanced growth but not obesity. The differential growth is explained by increased food intake and feeding efficiency mediated by a differential sensitivity of the satiety system that seems to involve the cocaine- and amphetamine- related transcript (CART). Stress response was similar in both genotypes. Brain transcriptome of transgenic (ASIP) vs wild type (WT) fish was compared using microarrays. WT females and males exhibited 255 genes differentially expressed (DEG) but this difference was reduced to 31 after ASIP overexpression. Statistical analysis revealed 1122 DEG when considering only fish genotype but 1066 and 981 DEG when comparing ASIP males or females with their WT counterparts, respectively. Interaction between genotype and sex significantly affected the expression of 97 genes. Several neuronal systems involved in the control of food intake were identified which displayed a differential expression according to the genotype of the fish that unravelling the flow of melanocortinergic information through the central pathways that controls the energy balance. The information provided herein will help to elucidate new central systems involved in control of obesity and should be of invaluable use for sustaining fish production systems.

  17. Brain-wide mapping of neural activity controlling zebrafish exploratory locomotion

    PubMed Central

    Dunn, Timothy W; Mu, Yu; Narayan, Sujatha; Randlett, Owen; Naumann, Eva A; Yang, Chao-Tsung; Schier, Alexander F

    2016-01-01

    In the absence of salient sensory cues to guide behavior, animals must still execute sequences of motor actions in order to forage and explore. How such successive motor actions are coordinated to form global locomotion trajectories is unknown. We mapped the structure of larval zebrafish swim trajectories in homogeneous environments and found that trajectories were characterized by alternating sequences of repeated turns to the left and to the right. Using whole-brain light-sheet imaging, we identified activity relating to the behavior in specific neural populations that we termed the anterior rhombencephalic turning region (ARTR). ARTR perturbations biased swim direction and reduced the dependence of turn direction on turn history, indicating that the ARTR is part of a network generating the temporal correlations in turn direction. We also find suggestive evidence for ARTR mutual inhibition and ARTR projections to premotor neurons. Finally, simulations suggest the observed turn sequences may underlie efficient exploration of local environments. DOI: http://dx.doi.org/10.7554/eLife.12741.001 PMID:27003593

  18. Identification of initially appearing glycine-immunoreactive neurons in the embryonic zebrafish brain.

    PubMed

    Moly, Pricila Khan; Ikenaga, Takanori; Kamihagi, Chihiro; Islam, A F M Tariqul; Hatta, Kohei

    2014-06-01

    Glycine is a major inhibitory neurotransmitter in the central nervous system of vertebrates. Here, we report the initial development of glycine-immunoreactive (Gly-ir) neurons and fibers in zebrafish. The earliest Gly-ir cells were found in the hindbrain and rostral spinal cord by 20 h post-fertilization (hpf). Gly-ir cells in rhombomeres 5 and 6 that also expressed glycine transporter 2 (glyt2) mRNA were highly stereotyped; they were bilaterally located and their axons ran across the midline and gradually turned caudally, joining the medial longitudinal fascicles in the spinal cord by 24 hpf. Gly-ir neurons in rhombomere 5 were uniquely identified, since there was one per hemisegment, whereas the number of Gly-ir neurons in rhombomere 6 were variable from one to three per hemisegment. Labeling of these neurons by single-cell electroporation and tracing them until the larval stage revealed that they became MiD2cm and MiD3cm, respectively. The retrograde labeling of reticulo-spinal neurons in Tg(glyt2:gfp) larva, which express GFP in Gly-ir cells, and a genetic mosaic analysis with glyt2:gfp DNA construct also supported this notion. Gly-ir cells were also distributed widely in the anterior brain by 27 hpf, whereas glyt2 was hardly expressed. Double staining with anti-glycine and anti-GABA antibodies demonstrated distinct distributions of Gly-ir and GABA-ir cells, as well as the presence of doubly immunoreactive cells in the brain and placodes. These results provide evidence of identifiable glycinergic (Gly-ir/glyt2-positive) neurons in vertebrate embryos, and they can be used in further studies of the neurons' development and function at the single-cell level.

  19. The UV-absorber benzophenone-4 alters transcripts of genes involved in hormonal pathways in zebrafish (Danio rerio) eleuthero-embryos and adult males

    SciTech Connect

    Zucchi, Sara; Bluethgen, Nancy; Ieronimo, Andrea; Fent, Karl

    2011-01-15

    Benzophenone-4 (BP-4) is frequently used as UV-absorber in cosmetics and materials protection. Despite its frequent detection in the aquatic environment potential effects on aquatic life are unknown. In this study, we evaluate the effects of BP-4 in eleuthero-embryos and in the liver, testis and brain of adult male fish on the transcriptional level by focusing on target genes involved in hormonal pathways to provide a more complete toxicological profile of this important UV-absorber. Eleuthero-embryos and males of zebrafish were exposed up to 3 days after hatching and for 14 days, respectively, to BP-4 concentrations between 30 and 3000 {mu}g/L. In eleuthero-embryos transcripts of vtg1, vtg3, esr1, esr2b, hsd17ss3, cyp19b cyp19a, hhex and pax8 were induced at 3000 {mu}g/L BP-4, which points to a low estrogenic activity and interference with early thyroid development, respectively. In adult males BP-4 displayed multiple effects on gene expression in different tissues. In the liver vtg1, vtg3, esr1 and esr2b were down-regulated, while in the brain, vtg1, vtg3 and cyp19b transcripts were up-regulated. In conclusion, the transcription profile revealed that BP-4 interferes with the expression of genes involved in hormonal pathways and steroidogenesis. The effects of BP-4 differ in life stages and adult tissues and point to an estrogenic activity in eleuthero-embryos and adult brain, and an antiestrogenic activity in the liver. The results indicate that BP-4 interferes with the sex hormone system of fish, which is important for the risk assessment of this UV-absorber.

  20. Bmp15 Is an Oocyte-Produced Signal Required for Maintenance of the Adult Female Sexual Phenotype in Zebrafish

    PubMed Central

    Hu, Kevin; Lawry, S. Terese; Sanchez, Angelica; Amatruda, James F.

    2016-01-01

    Although the zebrafish is a major model organism, how they determine sex is not well understood. In domesticated zebrafish, sex determination appears to be polygenic, being influenced by multiple genetic factors that may vary from strain to strain, and additionally can be influenced by environmental factors. However, the requirement of germ cells for female sex determination is well documented: animals that lack germ cells, or oocytes in particular, develop exclusively as males. Recently, it has been determined that oocytes are also required throughout the adult life of the animal to maintain the differentiated female state. How oocytes control sex differentiation and maintenance of the sexual phenotype is unknown. We therefore generated targeted mutations in genes for two oocyte produced signaling molecules, Bmp15 and Gdf9 and here report a novel role for Bmp15 in maintaining adult female sex differentiation in zebrafish. Females deficient in Bmp15 begin development normally but switch sex during the mid- to late- juvenile stage, and become fertile males. Additionally, by generating mutations in the aromatase cyp19a1a, we show that estrogen production is necessary for female development and that the function of Bmp15 in female sex maintenance is likely linked to the regulation of estrogen biosynthesis via promoting the development of estrogen-producing granulosa cells in the oocyte follicle. PMID:27642754

  1. Neurotoxicity of neem commercial formulation (Azadirachta indica A. Juss) in adult zebrafish (Danio rerio).

    PubMed

    Bernardi, M M; Dias, S G; Barbosa, V E

    2013-11-01

    The neurotoxic effects of a commercial formulation of Azadirachta indica A. Juss, also called neem or nim, in adult zebrafish were determined using behavioral models. General activity, anxiety-like effects, and learning and memory in a passive avoidance task were assessed after exposure to 20 or 40 μl/L neem. The results showed that 20 μl/L neem reduced the number of runs. Both neem concentrations increased the number of climbs to the water surface, and 40 μl/L increased the number of tremors. In the anxiety test, the 20 μl/L dose increased the number of entries in the light side compared with controls, but the latency to enter the dark side and the freezing behavior in this side did not changed. In relation to controls, the 40 μl/L neem reduced the latency to enter in the light side, did not change the number of entries in this side and increased freezing behavior in the light side. In the passive avoidance test, pre-training and pre-test neem exposure to 40 μl/L decreased the response to the learning task. Thus, no impairment was observed in this behavioral test. We conclude that neem reduced general activity and increased anxiety-like behavior but did not affect learning and memory.

  2. Reproduction impairment and endocrine disruption in adult zebrafish (Danio rerio) after waterborne exposure to TBOEP.

    PubMed

    Xu, Qinglong; Wu, Ding; Dang, Yao; Yu, Liqin; Liu, Chunsheng; Wang, Jianghua

    2017-01-01

    Tris (2-butoxyethyl) phosphate (TBOEP) is widely used as a substitute of polybrominated diphenyl ethers (PBDEs). It has been frequently measured at concentrations of micrograms per liter (μg/L) in surface waters and waste water. However, limited information is available about the reproduction toxicology of TBOEP. In this study, adult zebrafish pairs were exposed to TBOEP at concentrations of 0, 5, 50, and 500μg/L for 21days. The effects on reproduction, hormone concentration, transcription of genes along the hypothalamic-pituitary-gonadal (HPG) axis, and gonadal development were investigated. After exposure to TBOEP, plasma concentrations of 17β-estradiol were significantly increased in both sexes of fish, while increase of testosterone was observed only in male fish. Transcription of genes along the HPG axis was significantly influenced by exposure to TBOEP in both male and female fish. Moreover, TBOEP decreases the average number of eggs production, as well as hatching success and survival rates in offspring. Histological examination shows inhibition of oocyte maturation in females and retardation spermiation in males, respectively. The results demonstrate that TBOEP could disturb the sex hormone balance by altering regulatory circuits of the HPG axis, affect gonadal development, eventually leading to disruption of reproductive performance and the development of progeny.

  3. Transcription of the SCL/TAL1 Interrupting Locus (Stil) Is Required for Cell Proliferation in Adult Zebrafish Retinas*

    PubMed Central

    Sun, Lei; Li, Ping; Carr, Aprell L.; Gorsuch, Ryne; Yarka, Clare; Li, Jingling; Bartlett, Michael; Pfister, Delaney; Hyde, David R.; Li, Lei

    2014-01-01

    The human oncogene SCL/TAL1 interrupting locus (Stil) is highly conserved in vertebrate species. Previously, we identified a homolog of the Stil gene in zebrafish mutant (night blindness b, nbb), which showed neural defects in the retina (e.g. dopaminergic cell degeneration and/or lack of regeneration). In this research, we examined the roles of Stil in cell proliferation after degeneration in adult zebrafish retinas. We demonstrated that knockdown of Stil gene expression or inhibition of Sonic hedgehog (Shh) signaling transduction decreases the rate of cell proliferation. In contrast, activation of Shh signal transduction promotes cell proliferation. In nbb+/− retinas, inhibition of SUFU (a repressor in the Shh pathway) rescues the defects in cell proliferation due to down-regulation of Stil gene expression. The latter data suggest that Stil play a role in cell proliferation through the Shh signal transduction pathway. PMID:24469449

  4. Transcription of the SCL/TAL1 interrupting Locus (Stil) is required for cell proliferation in adult Zebrafish Retinas.

    PubMed

    Sun, Lei; Li, Ping; Carr, Aprell L; Gorsuch, Ryne; Yarka, Clare; Li, Jingling; Bartlett, Michael; Pfister, Delaney; Hyde, David R; Li, Lei

    2014-03-07

    The human oncogene SCL/TAL1 interrupting locus (Stil) is highly conserved in vertebrate species. Previously, we identified a homolog of the Stil gene in zebrafish mutant (night blindness b, nbb), which showed neural defects in the retina (e.g. dopaminergic cell degeneration and/or lack of regeneration). In this research, we examined the roles of Stil in cell proliferation after degeneration in adult zebrafish retinas. We demonstrated that knockdown of Stil gene expression or inhibition of Sonic hedgehog (Shh) signaling transduction decreases the rate of cell proliferation. In contrast, activation of Shh signal transduction promotes cell proliferation. In nbb(+/-) retinas, inhibition of SUFU (a repressor in the Shh pathway) rescues the defects in cell proliferation due to down-regulation of Stil gene expression. The latter data suggest that Stil play a role in cell proliferation through the Shh signal transduction pathway.

  5. Brief Embryonic Strychnine Exposure in Zebrafish Causes Long-Term Adult Behavioral Impairment with Indications of Embryonic Synaptic Changes

    PubMed Central

    Roy, Nicole M.; Arpie, Brianna; Lugo, Joseph; Linney, Elwood; Levin, Edward D.; Cerutti, Daniel

    2015-01-01

    Zebrafish provide a powerful model of the impacts of embryonic toxicant exposure on neural development that may result in long-term behavioral dysfunction. In this study, zebrafish embryos were treated with 1.5 mM strychnine for short embryonic time windows to induce transient changes in inhibitory neural signaling, and were subsequently raised in untreated water until adulthood. PCR analysis showed indications that strychnine exposure altered expression of some genes related to glycinergic, GABAergic and glutamatergic neuronal synapses during embryonic development. In adulthood, treated fish showed significant changes in swimming speed and tank diving behavior compared to controls. Taken together, these data show that a short embryonic exposure to a neurotoxicant can alter development of neural synapses and lead to changes in adult behavior. PMID:23022260

  6. Guidelines for Better Communication with Brain Impaired Adults

    MedlinePlus

    ... are here Home Guidelines for Better Communication with Brain Impaired Adults Printer-friendly version Communicating with a loved one with a brain disorder can indeed be challenging. Finding the right ...

  7. A rapid throughput approach identifies cognitive deficits in adult zebrafish from developmental exposure to polybrominated flame retardants.

    PubMed

    Truong, Lisa; Mandrell, David; Mandrell, Rick; Simonich, Michael; Tanguay, Robert L

    2014-07-01

    A substantial body of evidence has correlated the human body burdens of some polybrominated diphenyl ether (PBDE) flame retardants with cognitive and other behavioral deficits. Adult zebrafish exhibit testable learning and memory, making them an increasingly attractive model for neurotoxicology. Our goal was to develop a rapid throughput means of identifying the cognitive impact of developmental exposure to flame retardants in the zebrafish model. We exposed embryos from 6h post fertilization to 5 days post fertilization to either PBDE 47 (0.1μM), PBDE 99 (0.1μM) or PBDE 153 (0.1μM), vehicle (0.1% DMSO), or embryo medium (EM). The larvae were grown to adulthood and evaluated for the rate at which they learned an active-avoidance response in an automated shuttle box array. Zebrafish developmentally exposed to PBDE 47 learned the active avoidance paradigm significantly faster than the 0.1% DMSO control fish (P<0.0001), but exhibited significantly poorer performance when retested suggestive of impaired memory retention or altered neuromotor activity. Learning in the PBDE 153 group was not significantly different from the DMSO group. Developmental exposure to 0.1% DMSO impaired adult active avoidance learning relative to the sham group (n=39; P<0.0001). PBDE 99 prevented the DMSO effect, yielding a learning rate not significantly different from the sham group (n=36; P>0.9). Our results underscore the importance of vehicle choice in accurately assessing chemical effects on behavior. Active avoidance response in zebrafish is an effective model of learning that, combined with automated shuttle box testing, will provide a highly efficient platform for evaluating persistent neurotoxic hazard from many chemicals.

  8. Developmental benzo[a]pyrene (B[a]P) exposure impacts larval behavior and impairs adult learning in zebrafish.

    PubMed

    Knecht, Andrea L; Truong, Lisa; Simonich, Michael T; Tanguay, Robert L

    Polycyclic aromatic hydrocarbons (PAHs) are produced from incomplete combustion of organic materials or fossil fuels, and are present in crude oil and coal; therefore, they are ubiquitous environmental contaminants present in urban air, dust, soil, and water. It is widely recognized that PAHs pose risks to human health, especially for the developing fetus and infant where PAH exposures have been linked to in-utero mortality, cardiovascular effects, and lower intelligence. Using the zebrafish model, we evaluated the developmental toxicity of benzo[a]pyrene (B[a]P). Zebrafish embryos were exposed from 6 to 120h post fertilization (hpf) to 0.4 and 4μM B[a]P. The Viewpoint Zebrabox systems were used to evaluate larval photomotor response (LPR) activity and we identified that exposure to 4μM B[a]P resulted in a hyperactive LPR phenotype. To evaluate the role of aryl hydrocarbon receptor (AHR) in this larval phenotype, we exposed ahr2(hu2334) null larvae to 4μM B[a]P. Though ahr2(hu2334) larvae did not display hyperactive swimming, these larvae had a decrease in LPR activity, suggesting that AHR2 plays a role in B[a]P induced larval hyperactivity. To determine if developmental B[a]P exposures would produce adult behavioral deficits, a subset of exposed animals was raised to adulthood and tested in a conditioned stimulus test using shuttleboxes. Developmentally exposed B[a]P zebrafish exhibited decreased learning and memory. Together this data demonstrates that developmental B[a]P exposure adversely impacts larval behavior, and learning in adult zebrafish.

  9. Expression of brain-derived neurotrophic factor and TrkB in the lateral line system of zebrafish during development.

    PubMed

    Germanà, A; Laurà, R; Montalbano, G; Guerrera, M C; Amato, V; Zichichi, R; Campo, S; Ciriaco, E; Vega, J A

    2010-07-01

    The neuromasts of the lateral line system are regarded as a model to study the mechanisms of hearing, deafness, and ototoxicity. The neurotrophins (NTs), especially brain-derived neurotrophic factor (BDNF), and its signaling receptor TrkB are involved in the development and maintenance of neuromasts. To know the period in which the BDNF/TrkB complex has more effects in the neuromast biology, the age-related changes were studied. Normal zebrafish from 10 to 180 days post-fertilization (dpf), as well as transgenic ET4 zebrafish 10 and 20 dpf, was analyzed using qRT-PCR, western blot, and immunohistochemistry. BDNF and TrkB mRNAs followed a parallel course, peaking at 20 dpf, and thereafter progressively decreased. Specific immunoreactivity for BDNF and TrkB was found co-localized in all hairy cells of neuromasts in 20 and 30 dpf; then, the number of immunoreactive cells decreased, and by 180 dpf BDNF remains restricted to a subpopulation of hairy cells, and TrkB to a few number of sensory and non-sensory cells. At all ages examined, TrkB immunoreactivity was detected in sensory ganglia innervating the neuromasts. The present results demonstrate that there is a parallel time-related decline in the expression of BDNF and TrkB in zebrafish. Also, the patterns of cell expression suggest that autocrine/paracrine mechanisms for this NT system might occur within the neuromasts. Because TrkB in lateral line ganglia did not vary with age, their neurons are potentially capable to respond to BDNF during the entire lifespan of zebrafish.

  10. Strain dependent gene expression and neurochemical levels in the brain of zebrafish: focus on a few alcohol related targets.

    PubMed

    Pan, Y; Chatterjee, D; Gerlai, R

    2012-12-05

    The zebrafish is becoming increasingly popular in behavior genetics because it may allow one to conduct large scale mutation and drug screens facilitating the discovery of mechanisms of complex traits. Strain differences in adult zebrafish behavior have already been reported, which may have important implications in neurobehavioral genetics. For example, we have found the AB and SF strains to differ in their behavioral responses to both acute and chronic alcohol exposure. In the current study, we further characterize these strains using semi-quantitative RT-PCR to measure the expression of ten selected genes and HPLC to measure the levels of nine neurochemicals. We chose the target genes and neurochemicals based upon their potential involvement in alcohol and other drugs of abuse related mechanisms. We quantified the expression of the genes encoding D1-R, D2a-R, D4a-R dopamine receptors, GABA(A)-R, GABA(B)-R1, GAD1, MAO, NMDA-R (NR2D subunit), 5HT-R1bd and SLC6 a4a. We found the gene encoding D1 dopamine receptor over-expressed and the genes encoding GABA(B1) receptor and solute family carrier protein 6 (SLC6) 4a under-expressed in SF compared to AB. We also found the level of all (dopamine, DOPAC, Serotonin, GABA, Glutamate, Glycine, Aspartate, Taurine) but one (5HIAA) neurochemicals tested decreased in SF as compared to AB. These results, combined with previously identified behavioral differences between the AB and SF strains, demonstrate the importance of strain characterization in zebrafish. They now also allow formulation of working hypotheses about possible mechanisms underlying the differential effects of acute and chronic alcohol treatment on these two zebrafish strains.

  11. Molecular characterization and functions of zebrafish ABCC2 in cellular efflux of heavy metals.

    PubMed

    Long, Yong; Li, Qing; Zhong, Shan; Wang, Youhui; Cui, Zongbin

    2011-05-01

    Multidrug-resistance associated protein 2 (MRP2/ABCC2) plays crucial roles in bile formation and detoxification by transporting a wide variety of endogenous compounds and xenobiotics, but its functions in zebrafish (Danio rerio) remain to be characterized. In this study, we obtained the full-length cDNA of zebrafish abcc2, analyzed its expression in developing embryos and adult tissues, investigated its transcriptional response to heavy metals, and evaluated its roles in efflux of heavy metals including cadmium, mercury and lead. Zebrafish abcc2 gene is located on chromosome 13 and composed of 32 exons. The deduced polypeptide of zebrafish ABCC2 consists of 1567 amino acids and possesses most of functional domains and critical residues defined in human ABCC2. Zebrafish abcc2 gene is not maternally expressed and its earliest expression was detected in embryos at 72hpf. In larval zebrafish, abcc2 gene was found to be exclusively expressed in liver, intestine and pronephric tubules. In adult zebrafish, the highest expression of abcc2 gene was found in intestine followed by those in liver and kidney, while relative low expression was detected in brain and muscle. Expression of abcc2 in excretory organs including kidney, liver and intestine of zebrafish larvae was induced by exposure to 0.5μM mercury or 5μM lead. Moreover, exposure to 0.125-1μM of mercury or lead also significantly induced abcc2 expression in these excretory organs of adult zebrafish. Furthermore, overexpression of zebrafish ABCC2 in ZF4 cells and zebrafish embryos decreased the cellular accumulation of heavy metals including cadmium, mercury and lead as determined by MRE (metal responsive element)- or EPRE (electrophile response element)-driven luciferase reporters and atomic absorption spectrometry. These results suggest that zebrafish ABCC2/MRP2 is capable of effluxing heavy metals from cells and may play important roles in the detoxification of toxic metals.

  12. Adult human brain cell culture for neuroscience research.

    PubMed

    Gibbons, Hannah M; Dragunow, Mike

    2010-06-01

    Studies of the brain have progressed enormously through the use of in vivo and in vitro non-human models. However, it is unlikely such studies alone will unravel the complexities of the human brain and so far no neuroprotective treatment developed in animals has worked in humans. In this review we discuss the use of adult human brain cell culture methods in brain research to unravel the biology of the normal and diseased human brain. The advantages of using adult human brain cells as tools to study human brain function from both historical and future perspectives are discussed. In particular, studies using dissociated cultures of adult human microglia, astrocytes, oligodendrocytes and neurons are described and the applications of these types of study are evaluated. Alternative sources of human brain cells such as adult neural stem cells, induced pluripotent stem cells and slice cultures of adult human brain tissue are also reviewed. These adult human brain cell culture methods could benefit basic research and more importantly, facilitate the translation of basic neuroscience research to the clinic for the treatment of brain disorders.

  13. Adult zebrafish intestine resection: a novel model of short bowel syndrome, adaptation, and intestinal stem cell regeneration

    PubMed Central

    Schall, K. A.; Holoyda, K. A.; Grant, C. N.; Levin, D. E.; Torres, E. R.; Maxwell, A.; Pollack, H. A.; Moats, R. A.; Frey, M. R.; Darehzereshki, A.; Al Alam, D.; Lien, C.

    2015-01-01

    Loss of significant intestinal length from congenital anomaly or disease may lead to short bowel syndrome (SBS); intestinal failure may be partially offset by a gain in epithelial surface area, termed adaptation. Current in vivo models of SBS are costly and technically challenging. Operative times and survival rates have slowed extension to transgenic models. We created a new reproducible in vivo model of SBS in zebrafish, a tractable vertebrate model, to facilitate investigation of the mechanisms of intestinal adaptation. Proximal intestinal diversion at segment 1 (S1, equivalent to jejunum) was performed in adult male zebrafish. SBS fish emptied distal intestinal contents via stoma as in the human disease. After 2 wk, S1 was dilated compared with controls and villus ridges had increased complexity, contributing to greater villus epithelial perimeter. The number of intervillus pockets, the intestinal stem cell zone of the zebrafish increased and contained a higher number of bromodeoxyuridine (BrdU)-labeled cells after 2 wk of SBS. Egf receptor and a subset of its ligands, also drivers of adaptation, were upregulated in SBS fish. Igf has been reported as a driver of intestinal adaptation in other animal models, and SBS fish exposed to a pharmacological inhibitor of the Igf receptor failed to demonstrate signs of intestinal adaptation, such as increased inner epithelial perimeter and BrdU incorporation. We describe a technically feasible model of human SBS in the zebrafish, a faster and less expensive tool to investigate intestinal stem cell plasticity as well as the mechanisms that drive intestinal adaptation. PMID:26089336

  14. Social Plasticity Relies on Different Neuroplasticity Mechanisms across the Brain Social Decision-Making Network in Zebrafish.

    PubMed

    Teles, Magda C; Cardoso, Sara D; Oliveira, Rui F

    2016-01-01

    Social living animals need to adjust the expression of their behavior to their status within the group and to changes in social context and this ability (social plasticity) has an impact on their Darwinian fitness. At the proximate level social plasticity must rely on neuroplasticity in the brain social decision-making network (SDMN) that underlies the expression of social behavior, such that the same neural circuit may underlie the expression of different behaviors depending on social context. Here we tested this hypothesis in zebrafish by characterizing the gene expression response in the SDMN to changes in social status of a set of genes involved in different types of neural plasticity: bdnf, involved in changes in synaptic strength; npas4, involved in contextual learning and dependent establishment of GABAergic synapses; neuroligins (nlgn1 and nlgn2) as synaptogenesis markers; and genes involved in adult neurogenesis (wnt3 and neurod). Four social phenotypes were experimentally induced: Winners and Losers of a real-opponent interaction; Mirror-fighters, that fight their own image in a mirror and thus do not experience a change in social status despite the expression of aggressive behavior; and non-interacting fish, which were used as a reference group. Our results show that each social phenotype (i.e., Winners, Losers, and Mirror-fighters) present specific patterns of gene expression across the SDMN, and that different neuroplasticity genes are differentially expressed in different nodes of the network (e.g., BDNF in the dorsolateral telencephalon, which is a putative teleost homolog of the mammalian hippocampus). Winners expressed unique patterns of gene co-expression across the SDMN, whereas in Losers and Mirror-fighters the co-expression patterns were similar in the dorsal regions of the telencephalon and in the supracommissural nucleus of the ventral telencephalic area, but differents in the remaining regions of the ventral telencephalon. These results

  15. Social Plasticity Relies on Different Neuroplasticity Mechanisms across the Brain Social Decision-Making Network in Zebrafish

    PubMed Central

    Teles, Magda C.; Cardoso, Sara D.; Oliveira, Rui F.

    2016-01-01

    Social living animals need to adjust the expression of their behavior to their status within the group and to changes in social context and this ability (social plasticity) has an impact on their Darwinian fitness. At the proximate level social plasticity must rely on neuroplasticity in the brain social decision-making network (SDMN) that underlies the expression of social behavior, such that the same neural circuit may underlie the expression of different behaviors depending on social context. Here we tested this hypothesis in zebrafish by characterizing the gene expression response in the SDMN to changes in social status of a set of genes involved in different types of neural plasticity: bdnf, involved in changes in synaptic strength; npas4, involved in contextual learning and dependent establishment of GABAergic synapses; neuroligins (nlgn1 and nlgn2) as synaptogenesis markers; and genes involved in adult neurogenesis (wnt3 and neurod). Four social phenotypes were experimentally induced: Winners and Losers of a real-opponent interaction; Mirror-fighters, that fight their own image in a mirror and thus do not experience a change in social status despite the expression of aggressive behavior; and non-interacting fish, which were used as a reference group. Our results show that each social phenotype (i.e., Winners, Losers, and Mirror-fighters) present specific patterns of gene expression across the SDMN, and that different neuroplasticity genes are differentially expressed in different nodes of the network (e.g., BDNF in the dorsolateral telencephalon, which is a putative teleost homolog of the mammalian hippocampus). Winners expressed unique patterns of gene co-expression across the SDMN, whereas in Losers and Mirror-fighters the co-expression patterns were similar in the dorsal regions of the telencephalon and in the supracommissural nucleus of the ventral telencephalic area, but differents in the remaining regions of the ventral telencephalon. These results

  16. Adult neurogenesis and its role in neuropsychiatric disease, brain repair and normal brain function.

    PubMed

    Braun, S M G; Jessberger, S

    2014-02-01

    Neural stem/progenitor cells (NSPCs) in the mammalian brain retain the ability to generate new neurones throughout life in discrete brain regions, through a process called adult neurogenesis. Adult neurogenesis, a dramatic form of adult brain circuitry plasticity, has been implicated in physiological brain function and appears to be of pivotal importance for certain forms of learning and memory. In addition, failing or altered neurogenesis has been associated with a variety of brain diseases such as major depression, epilepsy and age-related cognitive decline. Here we review recent advances in our understanding of the basic biology underlying the neurogenic process in the adult brain, focusing on mechanisms that regulate quiescence, proliferation and differentiation of NSPCs. In addition, we discuss how neurogenesis influences normal brain function, and in particular its role in memory formation, as well as its contribution to neuropsychiatric diseases. Finally, we evaluate the potential of targeting endogenous NSPCs for brain repair.

  17. Stem Cell-Mediated Regeneration of the Adult Brain

    PubMed Central

    Jessberger, Sebastian

    2016-01-01

    Acute or chronic injury of the adult mammalian brain is often associated with persistent functional deficits as its potential for regeneration and capacity to rebuild lost neural structures is limited. However, the discovery that neural stem cells (NSCs) persist throughout life in discrete regions of the brain, novel approaches to induce the formation of neuronal and glial cells, and recently developed strategies to generate tissue for exogenous cell replacement strategies opened novel perspectives how to regenerate the adult brain. Here, we will review recently developed approaches for brain repair and discuss future perspectives that may eventually allow for developing novel treatment strategies in acute and chronic brain injury. PMID:27781019

  18. Experience-Dependent Neural Plasticity in the Adult Damaged Brain

    ERIC Educational Resources Information Center

    Kerr, Abigail L.; Cheng, Shao-Ying; Jones, Theresa A.

    2011-01-01

    Behavioral experience is at work modifying the structure and function of the brain throughout the lifespan, but it has a particularly dramatic influence after brain injury. This review summarizes recent findings on the role of experience in reorganizing the adult damaged brain, with a focus on findings from rodent stroke models of chronic upper…

  19. Efficient Cargo Delivery into Adult Brain Tissue Using Short Cell-Penetrating Peptides.

    PubMed

    Kizil, Caghan; Iltzsche, Anne; Thomas, Alvin Kuriakose; Bhattarai, Prabesh; Zhang, Yixin; Brand, Michael

    2015-01-01

    Zebrafish brains can regenerate lost neurons upon neurogenic activity of the radial glial progenitor cells (RGCs) that reside at the ventricular region. Understanding the molecular events underlying this ability is of great interest for translational studies of regenerative medicine. Therefore, functional analyses of gene function in RGCs and neurons are essential. Using cerebroventricular microinjection (CVMI), RGCs can be targeted efficiently but the penetration capacity of the injected molecules reduces dramatically in deeper parts of the brain tissue, such as the parenchymal regions that contain the neurons. In this report, we tested the penetration efficiency of five known cell-penetrating peptides (CPPs) and identified two- polyR and Trans - that efficiently penetrate the brain tissue without overt toxicity in a dose-dependent manner as determined by TUNEL staining and L-Plastin immunohistochemistry. We also found that polyR peptide can help carry plasmid DNA several cell diameters into the brain tissue after a series of coupling reactions using DBCO-PEG4-maleimide-based Michael's addition and azide-mediated copper-free click reaction. Combined with the advantages of CVMI, such as rapidness, reproducibility, and ability to be used in adult animals, CPPs improve the applicability of the CVMI technique to deeper parts of the central nervous system tissues.

  20. Efficient Cargo Delivery into Adult Brain Tissue Using Short Cell-Penetrating Peptides

    PubMed Central

    Thomas, Alvin Kuriakose; Bhattarai, Prabesh; Zhang, Yixin; Brand, Michael

    2015-01-01

    Zebrafish brains can regenerate lost neurons upon neurogenic activity of the radial glial progenitor cells (RGCs) that reside at the ventricular region. Understanding the molecular events underlying this ability is of great interest for translational studies of regenerative medicine. Therefore, functional analyses of gene function in RGCs and neurons are essential. Using cerebroventricular microinjection (CVMI), RGCs can be targeted efficiently but the penetration capacity of the injected molecules reduces dramatically in deeper parts of the brain tissue, such as the parenchymal regions that contain the neurons. In this report, we tested the penetration efficiency of five known cell-penetrating peptides (CPPs) and identified two– polyR and Trans – that efficiently penetrate the brain tissue without overt toxicity in a dose-dependent manner as determined by TUNEL staining and L-Plastin immunohistochemistry. We also found that polyR peptide can help carry plasmid DNA several cell diameters into the brain tissue after a series of coupling reactions using DBCO-PEG4-maleimide-based Michael’s addition and azide-mediated copper-free click reaction. Combined with the advantages of CVMI, such as rapidness, reproducibility, and ability to be used in adult animals, CPPs improve the applicability of the CVMI technique to deeper parts of the central nervous system tissues. PMID:25894337

  1. Reproductive toxicity of inorganic mercury exposure in adult zebrafish: Histological damage, oxidative stress, and alterations of sex hormone and gene expression in the hypothalamic-pituitary-gonadal axis.

    PubMed

    Zhang, Qun-Fang; Li, Ying-Wen; Liu, Zhi-Hao; Chen, Qi-Liang

    2016-08-01

    Mercury (Hg) is a prominent environmental contaminant that causes a variety of adverse effects on aquatic organisms. However, the mechanisms underlying inorganic Hg-induced reproductive impairment in fish remains largely unknown. In this study, adult zebrafish were exposed to 0 (control), 15 and 30μg Hg/l (added as mercuric chloride, HgCl2) for 30days, and the effects on histological structure, antioxidant status and sex hormone levels in the ovary and testis, as well as the mRNA expression of genes involved in the hypothalamic-pituitary-gonadal (HPG) axis were analyzed. Exposure to Hg caused pathological lesions in zebrafish gonads, and changed the activities and mRNA levels of antioxidant enzymes (catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx)) as well as the content of glutathione (GSH) and malondialdehyde (MDA). In females, although ovarian 17β-estradiol (E2) content remained relatively stable, significant down-regulation of lhβ, gnrh2, gnrh3, lhr and erα were observed. In males, testosterone (T) levels in the testis significantly decreased after Hg exposure, accompanied by down-regulated expression of gnrh2, gnrh3, fshβ and lhβ in the brain as well as fshr, lhr, ar, cyp17 and cyp11b in the testis. Thus, our study indicated that waterborne inorganic Hg exposure caused histological damage and oxidative stress in the gonads of zebrafish, and altered sex hormone levels by disrupting the transcription of related HPG-axis genes, which could subsequently impair the reproduction of fish. Different response of the antioxidant defense system, sex hormone and HPG-axis genes between females and males exposed to inorganic Hg indicated the gender-specific regulatory effect by Hg. To our knowledge, this is the first time to explore the effects and mechanisms of inorganic Hg exposure on reproduction at the histological, enzymatic and molecular levels, which will greatly extend our understanding on the mechanisms underlying of reproductive

  2. Correlating Whole Brain Neural Activity with Behavior in Head-Fixed Larval Zebrafish.

    PubMed

    Orger, Michael B; Portugues, Ruben

    2016-01-01

    We present a protocol to combine behavioral recording and imaging using 2-photon laser-scanning microscopy in head-fixed larval zebrafish that express a genetically encoded calcium indicator. The steps involve restraining the larva in agarose, setting up optics that allow projection of a visual stimulus and infrared illumination to monitor behavior, and analysis of the neuronal and behavioral data.

  3. Actin-Cytoskeleton- and Rock-Mediated INM Are Required for Photoreceptor Regeneration in the Adult Zebrafish Retina

    PubMed Central

    Lahne, Manuela; Li, Jingling; Marton, Rebecca M.

    2015-01-01

    Loss of retinal neurons in adult zebrafish (Danio rerio) induces a robust regenerative response mediated by the reentry of the resident Müller glia into the cell cycle. Upon initiating Müller glia proliferation, their nuclei migrate along the apicobasal axis of the retina in phase with the cell cycle in a process termed interkinetic nuclear migration (INM). We examined the mechanisms governing this cellular process and explored its function in regenerating the adult zebrafish retina. Live-cell imaging revealed that the majority of Müller glia nuclei migrated to the outer nuclear layer (ONL) to divide. These Müller glia formed prominent actin filaments at the rear of nuclei that had migrated to the ONL. Inhibiting actin filament formation or Rho-associated coiled-coil kinase (Rock) activity, which is necessary for phosphorylation of myosin light chain and actin myosin-mediated contraction, disrupted INM with increased numbers of mitotic nuclei remaining in the basal inner nuclear layer, the region where Müller glia typically reside. Double knockdown of Rho-associated coiled-coil kinase 2a (Rock2a) and Rho-associated coiled-coil kinase 2b (Rock2b) similarly disrupted INM and reduced Müller glial cell cycle reentry. In contrast, Rock inhibition immediately before the onset of INM did not affect Müller glia proliferation, but subsequently reduced neuronal progenitor cell proliferation due to early cell cycle exit. Long-term, Rock inhibition increased the generation of mislocalized ganglion/amacrine cells at the expense of rod and cone photoreceptors. In summary, INM is driven by an actin-myosin-mediated process controlled by Rock2a and Rock2b activity, which is required for sufficient proliferation and regeneration of photoreceptors after light damage. SIGNIFICANCE STATEMENT The human retina does not replace lost or damaged neurons, ultimately causing vision impairment. In contrast, zebrafish are capable of regenerating lost neurons. Understanding the mechanisms

  4. Localization of genes encoding metallothionein-like protein (mt2 and smtb) in the brain of zebrafish.

    PubMed

    Teoh, Seong Lin; Ogawa, Satoshi; Parhar, Ishwar S

    2015-12-01

    Metallothionein (MT) is a small cysteine-rich heavy metal-binding protein involved in metal homeostasis, detoxification and free radical-scavenging. MT is ubiquitously expressed in several tissues, but its role in the central nervous system is not well understood. In this study, we identified two MT homologous genes (mt2 and smtb) in the zebrafish. Digoxigenin-in situ hybridization showed the expression of mt2 and smtb genes in the ventricular layers in the telencephalon, diencephalon, mesencephalon and rhombencephalon, most of which are cell proliferating regions in the brain of zebrafish. Cellular characteristics of MT genes expressing cells were examined by double-labelling with markers for neurons (HuC/D) and astrocytes (glial fibrillary acidic protein, GFAP and S100 protein) and cell proliferation marker (PCNA). mt2 and smtb mRNAs are expressed in neurons and not in astrocytes, and they were co-localized with PCNA. These results suggest that mt2 and smtb may play an important role in neurogenesis and neuroprotection.

  5. Estrogen-Responsive Transient Expression Assay Using a Brain Aromatase-Based Reporter Gene in Zebrafish (Danio rerio)

    PubMed Central

    Kim, Dong-Jae; Seok, Seung-Hyeok; Baek, Min-Won; Lee, Hui-Young; Na, Yi-Rang; Park, Sung-Hoon; Lee, Hyun-Kyoung; Dutta, Noton Kumar; Kawakami, Koichi; Park, Jae-Hak

    2009-01-01

    Whereas endogenous estrogens play an important role in the development, maintenance, and function of female and male reproductive organs, xenoestrogens present in the environment disrupt normal endocrine function in humans and wildlife. Various in vivo and in vitro assays have been developed to screen these xenoestrogens. However, traditional in vivo assays are laborious and unsuitable for large-scale screening, and in vitro assays do not necessarily replicate in vivo functioning. To overcome these limitations, we developed a transient expression assay in zebrafish, into which a brain aromatase (cyp19a1b)-based estrogen-responsive reporter gene was introduced. In response to 17β-estradiol (10−6 M) and heptachlor (10−6 M), zebrafish embryos carrying the reporter construct expressed enhanced green fluorescent protein in the olfactory bulb, telencephalon, preoptic area, and mediobasal hypothalamus. This system will serve to model the in vivo conversion and breakdown of estrogenic compounds and thus provide a rapid preliminary screening method to estimate their estrogenicity. PMID:19887024

  6. Role of eosinophils and apoptosis in PDIMs/PGLs deficient mycobacterium elimination in adult zebrafish.

    PubMed

    Huang, Xinhua; Wang, Hui; Meng, Lu; Wang, Qinglan; Yu, Jia; Gao, Qian; Wang, Decheng

    2016-06-01

    The cell wall lipids phthiocerol dimycocerosates (PDIMs) and its structurally-related compound, phenolic glycolipids (PGLs) are major virulence factors of mycobacterium, as shown by the reduced growth of PDIMs/PGLs deficient mutants in various animal models. PDIMs/PGLs play active roles in modulating host immune responses. However, the cellular and molecular mechanisms of how PDIMs/PGLs deficient mutant was eliminated in vivo are still elusive. Our aim was to investigate what host immune responses have effect on mycobacterium elimination in vivo. Using microarray, we find PDIMs/PGLs modulate divergent host responses, including chemotaxis and focal adhesion's downstream pathway and apoptosis. We examine these two host responses by Diff-Quik stain, coupled with transmission electron microscopy and TUNEL stain respectively. The ultrastructure observation showed that eosinophils appeared in WT-infected zebrafish at day 1, however eosinophils arrived was delayed to day 7 in PDIMs/PGLs-deficient mutant-infected animals. More intriguingly, apoptosis was markedly increased in PDIMs/PGLs-mutant infected zebrafish at day 1 after infection, compared to WT-infected fishes at this time. However, apoptosis trend was fully reversed by day 7, with increased apoptosis were detected in WT-infected zebrafish compared with the PDIMs/PGLs-deficient mutant, especially more apoptosis within the granuloma. This study shows that the anti-apoptotic effects of PDIMs/PGLs and the recruitment of eosinophils in tissue during the early infection in zebrafish might promote bacterium growth in vivo.

  7. Mechanisms of neuronal migration in the adult brain.

    PubMed

    Kaneko, Naoko; Sawada, Masato; Sawamoto, Kazunobu

    2017-03-02

    Adult neurogenesis was first observed nearly 60 years ago, and it has since grown into an important neurochemistry research field. Much recent research has focused on the treatment of brain diseases through neuronal regeneration with endogenously generated neurons. In the adult brain, immature neurons called neuroblasts are continuously generated in the ventricular-subventricular zone (V-SVZ). These neuroblasts migrate rapidly through the rostral migratory stream to the olfactory bulb, where they mature and are integrated into the neuronal circuitry. After brain insult, some of the neuroblasts in the V-SVZ migrate toward the lesion to repopulate the injured tissue. This notable migratory capacity of V-SVZ-derived neuroblasts is important for efficiently regenerating neurons in remote areas of the brain. As these neurons migrate for long distances through adult brain tissue, they are supported by various guidance cues and structures that act as scaffolds. Some of these mechanisms are unique to neuroblast migration in the adult brain, and are not involved in migration in the developing brain. Here, we review the latest findings on the mechanisms of neuroblast migration in the adult brain under physiological and pathological conditions, and discuss various issues that still need to be resolved. This article is protected by copyright. All rights reserved.

  8. In vivo spectroscopic photoacoustic tomography imaging of a far red fluorescent protein expressed in the exocrine pancreas of adult zebrafish

    NASA Astrophysics Data System (ADS)

    Liu, Mengyang; Schmitner, Nicole; Sandrian, Michelle G.; Zabihian, Behrooz; Hermann, Boris; Salvenmoser, Willi; Meyer, Dirk; Drexler, Wolfgang

    2014-03-01

    Fluorescent proteins brought a revolution in life sciences and biological research in that they make a powerful tool for researchers to study not only the structural and morphological information, but also dynamic and functional information in living cells and organisms. While green fluorescent proteins (GFP) have become a common labeling tool, red-shifted or even near infrared fluorescent proteins are becoming the research focus due to the fact that longer excitation wavelengths are more suitable for deep tissue imaging. In this study, E2-Crimson, a far red fluorescent protein whose excitation wavelength is 611 nm, was genetically expressed in the exocrine pancreas of adult zebrafish. Using spectroscopic all optical detection photoacoustic tomography, we mapped the distribution of E2-Crimson in 3D after imaging the transgenic zebrafish in vivo using two different wavelengths. With complementary morphological information provided by imaging the same fish using a spectral domain optical coherence tomography system, the E2-Crimson distribution acquired from spectroscopic photoacoustic tomography was confirmed in 2D by epifluorescence microscopy and in 3D by histology. To the authors' knowledge, this is the first time a far red fluorescent protein is imaged in vivo by spectroscopic photoacoustic tomography. Due to the regeneration feature of zebrafish pancreas, this work preludes the longitudinal studies of animal models of diseases such as pancreatitis by spectroscopic photoacoustic tomography. Since the effective penetration depth of photoacoustic tomography is beyond the transport mean free path length, other E2-Crimson labeled inner organs will also be able to be studied dynamically using spectroscopic photoacoustic tomography.

  9. Nicotinic involvement in memory function in zebrafish.

    PubMed

    Levin, Edward D; Chen, Elaine

    2004-01-01

    Zebrafish are an emerging model for the study of the molecular mechanisms of brain function. To conduct studies of the neural bases of behavior in zebrafish, we must understand the behavioral function of zebrafish and how it is altered by perturbations of brain function. This study determined nicotine actions on memory function in zebrafish. With the methods that we have developed to assess memory in zebrafish using delayed spatial alternation (DSA), we determined the dose effect function of acute nicotine on memory function in zebrafish. As in rodents and primates, low nicotine doses improve memory in zebrafish, while high nicotine doses have diminished effect and can impair memory. This study shows that nicotine affects memory function in zebrafish much like in rats, mice, monkeys and humans. Now, zebrafish can be used to help understand the molecular mechanisms crucial to nicotine effects on memory.

  10. Additive effects of levonorgestrel and ethinylestradiol on brain aromatase (cyp19a1b) in zebrafish specific in vitro and in vivo bioassays.

    PubMed

    Hinfray, N; Tebby, C; Garoche, C; Piccini, B; Bourgine, G; Aït-Aïssa, S; Kah, O; Pakdel, F; Brion, F

    2016-09-15

    Estrogens and progestins are widely used in combination in human medicine and both are present in aquatic environment. Despite the joint exposure of aquatic wildlife to estrogens and progestins, very little information is available on their combined effects. In the present study we investigated the effect of ethinylestradiol (EE2) and Levonorgestrel (LNG), alone and in mixtures, on the expression of the brain specific ER-regulated cyp19a1b gene. For that purpose, recently established zebrafish-derived tools were used: (i) an in vitro transient reporter gene assay in a human glial cell line (U251-MG) co-transfected with zebrafish estrogen receptors (zfERs) and the luciferase gene under the control of the zebrafish cyp19a1b gene promoter and (ii) an in vivo bioassay using a transgenic zebrafish expressing GFP under the control of the zebrafish cyp19a1b gene promoter (cyp19a1b-GFP). Concentration-response relationships for single chemicals were modeled and used to design the mixture experiments following a ray design. The results from mixture experiments were analyzed to predict joint effects according to concentration addition and statistical approaches were used to characterize the potential interactions between the components of the mixtures (synergism/antagonism). We confirmed that some progestins could elicit estrogenic effects in fish brain. In mixtures, EE2 and LNG exerted additive estrogenic effects both in vitro and in vivo, suggesting that some environmental progestin could exert effects that will add to those of environmental (xeno-)estrogens. Moreover, our zebrafish specific assays are valuable tools that could be used in risk assessment for both single chemicals and their mixtures.

  11. Conjugated Polymer Nanoparticles for Fluorescence Imaging and Sensing of Neurotransmitter Dopamine in Living Cells and the Brains of Zebrafish Larvae.

    PubMed

    Qian, Cheng-Gen; Zhu, Sha; Feng, Pei-Jian; Chen, Yu-Lei; Yu, Ji-Cheng; Tang, Xin; Liu, Yun; Shen, Qun-Dong

    2015-08-26

    Nanoscale materials are now attracting a great deal of attention for biomedical applications. Conjugated polymer nanoparticles have remarkable photophysical properties that make them highly advantageous for biological fluorescence imaging. We report on conjugated polymer nanoparticles with phenylboronic acid tags on the surface for fluorescence detection of neurotransmitter dopamine in both living PC12 cells and brain of zebrafish larvae. The selective enrichment of dopamine and fluorescence signal amplification characteristics of the nanoparticles show rapid and high-sensitive probing such neurotransmitter with the detection limit of 38.8 nM, and minimum interference from other endogenous molecules. It demonstrates the potential of nanomaterials as a multifunctional nanoplatform for targeting, diagnosis, and therapy of dopamine-relative disease.

  12. Programming effects of high-carbohydrate feeding of larvae on adult glucose metabolism in zebrafish, Danio rerio.

    PubMed

    Fang, Liu; Liang, Xu-Fang; Zhou, Yi; Guo, Xiao-Ze; He, Yan; Yi, Ti-Lin; Liu, Li-Wei; Yuan, Xiao-Chen; Tao, Ya-Xiong

    2014-03-14

    The aim of the present study was to determine the potential long-term metabolic effects of early nutritional programming on carbohydrate utilisation in adult zebrafish (Danio rerio). High-carbohydrate diets were fed to fish during four ontogenetic stages: from the first-feeding stage to the end of the yolk-sac larval stage; from the first-feeding stage to 2 d after yolk-sac exhaustion; after yolk-sac exhaustion for 3 or 5 d. The carbohydrate stimuli significantly increased the body weight of the first-feeding groups in the short term. The expression of genes was differentially regulated by the early dietary intervention. The high-carbohydrate diets resulted in decreased plasma glucose levels in the adult fish. The mRNA levels and enzyme activities of glucokinase, pyruvate kinase, α-amylase and sodium-dependent glucose co-transporter 1 were up-regulated in the first-feeding groups. There was no significant change in the mRNA levels of glucose-6-phosphatase (G6Pase) in any experimental group, and the activity of G6Pase enzyme in the FF-5 (first feeding to 2 d after yolk-sac exhaustion) group was significantly different from that of the other groups. The expression of phosphoenolpyruvate carboxykinase gene in all the groups was significantly decreased. In the examined early programming range, growth performance was not affected. Taken together, data reported herein indicate that the period ranging from the polyculture to the external feeding stage is an important window for potential modification of the long-term physiological functions. In conclusion, the present study demonstrates that it is possible to permanently modify carbohydrate digestion, transport and metabolism of adult zebrafish through early nutritional programming.

  13. A New Anaesthetic Protocol for Adult Zebrafish (Danio rerio): Propofol Combined with Lidocaine

    PubMed Central

    Valentim, Ana M.; Félix, Luís M.; Carvalho, Leonor; Diniz, Enoque; Antunes, Luís M.

    2016-01-01

    Background The increasing use of zebrafish model has not been accompanied by the evolution of proper anaesthesia for this species in research. The most used anaesthetic in fishes, MS222, may induce aversion, reduction of heart rate, and consequently high mortality, especially during long exposures. Therefore, we aim to explore new anaesthetic protocols to be used in zebrafish by studying the quality of anaesthesia and recovery induced by different concentrations of propofol alone and in combination with different concentrations of lidocaine. Material and Methods In experiment A, eighty-three AB zebrafish were randomly assigned to 7 different groups: control, 2.5 (2.5P), 5 (5P) or 7.5 μg/ml (7.5P) of propofol; and 2.5 μg/ml of propofol combined with 50, (P/50L), 100 (P/100L) or 150 μg/ml (P/150L) of lidocaine. Zebrafish were placed in an anaesthetic water bath and time to lose the equilibrium, reflex to touch, reflex to a tail pinch, and respiratory rate were measured. Time to gain equilibrium was also assessed in a clean tank. Five and 24 hours after anaesthesia recovery, zebrafish were evaluated concerning activity and reactivity. Afterwards, in a second phase of experiments (experiment B), the best protocol of the experiment A was compared with a new group of 8 fishes treated with 100 mg/L of MS222 (100M). Results In experiment A, only different concentrations of propofol/lidocaine combination induced full anaesthesia in all animals. Thus only these groups were compared with a standard dose of MS222 in experiment B. Propofol/lidocaine induced a quicker loss of equilibrium, and loss of response to light and painful stimuli compared with MS222. However zebrafish treated with MS222 recovered quickly than the ones treated with propofol/lidocaine. Conclusion In conclusion, propofol/lidocaine combination and MS222 have advantages in different situations. MS222 is ideal for minor procedures when a quick recovery is important, while propofol/lidocaine is best to

  14. The effects of temperature reduction on gene expression and oxidative stress in skeletal muscle from adult zebrafish.

    PubMed

    Malek, Renae L; Sajadi, Hedieh; Abraham, Joseph; Grundy, Martin A; Gerhard, Glenn S

    2004-07-01

    Longevity is inversely proportional to ambient temperature in ectothermic organisms such as fish. However, the mechanism by which reducing temperature over a physiological range increases life span is not known and available data are derived primarily from invertebrates. With a rodent-like longevity and abundant biological resources, the zebrafish is an ideal vertebrate ectothermic model in which to investigate this phenomenon. As an initial approach, the effects of a year-long 10 degrees C reduction in water temperature on global gene expression in tail skeletal muscle from adult zebrafish were determined using an oligonucleotide microarray representing 15,512 genes. Expression levels for approximately 600 genes were up-regulated by 1.7-fold or greater by the reduction in temperature, while a similar number of transcripts were down regulated by more than 1.7-fold. Using gene ontology (GO) classifications for molecular function, two functional groups, "oxygen and reactive oxygen species metabolism" and "response to oxidative stress," were found to be overrepresented among up-regulated genes. Transcripts levels for the genes in these two categories were increased by temperature reduction (TR). However, temperature reduction did not suppress lipid peroxidation potential, protein carbonyl content, or 8-oxoguanine level. Additional studies will be required to further delineate the role of altered gene expression and oxidative stress on the longevity-promoting effects of temperature reduction.

  15. Memory and Brain Volume in Adults Prenatally Exposed to Alcohol

    ERIC Educational Resources Information Center

    Coles, Claire D.; Goldstein, Felicia C.; Lynch, Mary Ellen; Chen, Xiangchuan; Kable, Julie A.; Johnson, Katrina C.; Hu, Xiaoping

    2011-01-01

    The impact of prenatal alcohol exposure on memory and brain development was investigated in 92 African-American, young adults who were first identified in the prenatal period. Three groups (Control, n = 26; Alcohol-related Neurodevelopmental Disorder, n = 36; and Dysmorphic, n = 30) were imaged using structural MRI with brain volume calculated for…

  16. Function of Sox2 in ependymal cells of lesioned spinal cords in adult zebrafish.

    PubMed

    Ogai, Kazuhiro; Nakatani, Kumi; Hisano, Suguru; Sugitani, Kayo; Koriyama, Yoshiki; Kato, Satoru

    2014-11-01

    The sex-determining region Y-box 2 (Sox2) is related not only to pluripotency, but also to cell proliferation. Zebrafish can regain their motor function after spinal cord injury (SCI). Following SCI, new motor neurons are produced from proliferating ependymal cells. Here, we investigated the expression and function of Sox2 after SCI in zebrafish. Sox2 was upregulated as early as 1 day post-lesion (dpl) in ependymal cells, which was followed by cell proliferation. Sox2 knockdown significantly decreased the number of proliferating cells at 5dpl. The results of this study suggest a role of Sox2 as one of the proliferation initiators in ependymal cells after SCI.

  17. Childhood Onset Schizophrenia: Cortical Brain Abnormalities as Young Adults

    ERIC Educational Resources Information Center

    Greenstein, Deanna; Lerch, Jason; Shaw, Philip; Clasen, Liv; Giedd, Jay; Gochman, Peter; Rapoport, Judith; Gogtay, Nitin

    2006-01-01

    Background: Childhood onset schizophrenia (COS) is a rare but severe form of the adult onset disorder. While structural brain imaging studies show robust, widespread, and progressive gray matter loss in COS during adolescence, there have been no longitudinal studies of sufficient duration to examine comparability with the more common adult onset…

  18. Atomoxetine reduces anticipatory responding in a 5-choice serial reaction time task for adult zebrafish

    PubMed Central

    Parker, Matthew O.; Brock, Alistair J.; Sudwarts, Ari; Brennan, Caroline H.

    2014-01-01

    Deficits in impulse control are related to a number of psychiatric diagnoses, including attention deficit hyperactivity disorder, addiction, and pathological gambling. Despite increases in our knowledge about the underlying neurochemical and neuroanatomical correlates, understanding of the molecular and cellular mechanisms is less well established. Understanding these mechanisms is essential in order to move towards individualized treatment programs and increase efficacy of interventions. Zebrafish are a very useful vertebrate model for exploring molecular processes underlying disease owing to their small size and genetic tractability. Their utility in terms of behavioral neuroscience, however, hinges on the validation and publication of reliable assays with adequate translational relevance. Here, we report an initial pharmacological validation of a fully automated zebrafish version of the commonly used five-choice serial reaction time task using a variable interval pre-stimulus interval. We found that atomoxetine reduced anticipatory responses (0.6 mg/kg), whereas a high-dose (4 mg/kg) methylphenidate increased anticipatory responses and the number of trials completed in a session. On the basis of these results, we argue that similar neurochemical processes in fish as in mammals may control impulsivity, as operationally defined by anticipatory responses on a continuous performance task such as this, making zebrafish potentially a good model for exploring the molecular basis of impulse control disorders and for first-round drug screening. PMID:24481568

  19. Zebrafish as a model for investigating developmental lead (Pb) neurotoxicity as a risk factor in adult neurodegenerative disease: a mini-review.

    PubMed

    Lee, Jinyoung; Freeman, Jennifer L

    2014-07-01

    Lead (Pb) exposure has long been recognized to cause neurological alterations in both adults and children. While most of the studies in adults are related to higher dose exposure, epidemiological studies indicate cognitive decline and neurobehavioral alterations in children associated with lower dose environmental Pb exposure (a blood Pb level of 10μg/dL and below). Recent animal studies also now report that an early-life Pb exposure results in pathological hallmarks of Alzheimer's disease later in life. While previous studies evaluating higher Pb exposures in adult animal models and higher occupational Pb exposures in humans have suggested a link between higher dose Pb exposure during adulthood and neurodegenerative disease, these newer studies now indicate a link between an early-life Pb exposure and adult neurodegenerative disease. These studies are supporting the "fetal/developmental origin of adult disease" hypothesis and present a new challenge in our understanding of Pb neurotoxicity. There is a need to expand research in this area and additional model systems are needed. The zebrafish presents as a complementary vertebrate model system with numerous strengths including high genetic homology. Several zebrafish genes orthologous to human genes associated with neurodegenerative diseases including Alzheimer's and Parkinson's diseases are identified and this model is starting to be applied in neurodegenerative disease research. Moreover, the zebrafish is being used in developmental Pb neurotoxicity studies to define genetic mechanisms of toxicity and associated neurobehavioral alterations. While these studies are in their infancy, the genetic and functional conservation of genes associated with neurodegenerative diseases and application in developmental Pb neurotoxicity studies supports the potential for this in vivo model to further investigate the link between developmental Pb exposure and adult neurodegenerative disease pathogenesis. In this review, the

  20. Diet-sourced carbon-based nanoparticles induce lipid alterations in tissues of zebrafish (Danio rerio) with genomic hypermethylation changes in brain

    PubMed Central

    Gorrochategui, Eva; Li, Junyi; Fullwood, Nigel J.; Ying, Guang-Guo; Tian, Meiping; Cui, Li; Shen, Heqing; Lacorte, Sílvia; Tauler, Romà; Martin, Francis L.

    2017-01-01

    With rising environmental levels of carbon-based nanoparticles (CBNs), there is an urgent need to develop an understanding of their biological effects in order to generate appropriate risk assessment strategies. Herein, we exposed zebrafish via their diet to one of four different CBNs: C60 fullerene (C60), single-walled carbon nanotubes (SWCNT), short multi-walled carbon nanotubes (MWCNTs) or long MWCNTs. Lipid alterations in male and female zebrafish were explored post-exposure in three target tissues (brain, gonads and gastrointestinal tract) using ‘omic’ procedures based in liquid chromatography coupled with mass spectrometry (LC-MS) data files. These tissues were chosen as they are often target tissues following environmental exposure. Marked alterations in lipid species are noted in all three tissues. To further explore CBN-induced brain alterations, Raman microspectroscopy analysis of lipid extracts was conducted. Marked lipid alterations are observed with males responding differently to females; in addition, there also appears to be consistent elevations in global genomic methylation. This latter observation is most profound in female zebrafish brain tissues post-exposure to short MWCNTs or SWCNTs (P < 0.05). This study demonstrates that even at low levels, CBNs are capable of inducing significant cellular and genomic modifications in a range of tissues. Such alterations could result in modified susceptibility to other influences such as environmental exposures, pathology and, in the case of brain, developmental alterations. PMID:27798195

  1. Effects of chronic dietary selenomethionine exposure on repeat swimming performance, aerobic metabolism and methionine catabolism in adult zebrafish (Danio rerio).

    PubMed

    Thomas, Jith K; Wiseman, Steve; Giesy, John P; Janz, David M

    2013-04-15

    In a previous study we reported impaired swimming performance and greater stored energy in adult zebrafish (Danio rerio) after chronic dietary exposure to selenomethionine (SeMet). The goal of the present study was to further investigate effects of chronic exposure to dietary SeMet on repeat swimming performance, oxygen consumption (MO2), metabolic capacities (standard metabolic rate [SMR], active metabolic rate [AMR], factorial aerobic scope [F-AS] and cost of transport [COT]) and gene expression of energy metabolism and methionine catabolism enzymes in adult zebrafish. Fish were fed SeMet at measured concentrations of 1.3, 3.4, 9.8 or 27.5 μg Se/g dry mass (d.m.) for 90 d. At the end of the exposure period, fish from each treatment group were divided into three subgroups: (a) no swim, (b) swim, and (c) repeat swim. Fish from the no swim group were euthanized immediately at 90 d and whole body triglycerides, glycogen and lactate, and gene expression of energy metabolism and methionine catabolism enzymes were determined. Individual fish from the swim group were placed in a swim tunnel respirometer and swimming performance was assessed by determining the critical swimming speed (U(crit)). After both Ucrit and MO2 analyses, fish were euthanized and whole body energy stores and lactate were determined. Similarly, individual fish from the repeat swim group were subjected to two U(crit) tests (U(crit-1) and U(crit-2)) performed with a 60 min recovery period between tests, followed by determination of energy stores and lactate. Impaired swim performance was observed in fish fed SeMet at concentrations greater than 3 μg Se/g in the diet. However, within each dietary Se treatment group, no significant differences between single and repeat U(crits) were observed. Oxygen consumption, SMR and COT were significantly greater, and F-AS was significantly lesser, in fish fed SeMet. Whole body triglycerides were proportional to the concentration of SeMet in the diet. While

  2. Brain stem auditory evoked responses in human infants and adults

    NASA Technical Reports Server (NTRS)

    Hecox, K.; Galambos, R.

    1974-01-01

    Brain stem evoked potentials were recorded by conventional scalp electrodes in infants (3 weeks to 3 years of age) and adults. The latency of one of the major response components (wave V) is shown to be a function both of click intensity and the age of the subject; this latency at a given signal strength shortens postnatally to reach the adult value (about 6 msec) by 12 to 18 months of age. The demonstrated reliability and limited variability of these brain stem electrophysiological responses provide the basis for an optimistic estimate of their usefulness as an objective method for assessing hearing in infants and adults.

  3. Definition of three somatic adult cell nuclear transplant methods in zebrafish (Danio rerio): before, during and after egg activation by sperm fertilization.

    PubMed

    Pérez-Camps, M; Cardona-Costa, J; Francisco-Simao, M; García-Ximénez, F

    2010-02-01

    Zebrafish somatic nuclear transplant has only been attempted using preactivated eggs. In this work, three methods to carry out the nuclear transplant using adult cells before, during and after the egg activation/fertilization were developed in zebrafish with the aim to be used in reprogramming studies. The donor nucleus from somatic adult cells was inserted: (method A) in the central region of the egg and subsequently fertilized; (method B) in the incipient animal pole at the same time that the egg was fertilized; and (method C) in the completely defined animal pole after fertilization. Larval and adult specimens were obtained using the three methods. Technical aspects related to temperature conditions, media required, egg activation/fertilization, post-ovulatory time of the transplant, egg aging, place of the donor nucleus injection in each methodology are presented. In conclusion, the technical approach developed in this work can be used in reprogramming studies.

  4. Organ-Specific and Size-Dependent Ag Nanoparticle Toxicity in Gills and Intestines of Adult Zebrafish.

    PubMed

    Osborne, Olivia J; Lin, Sijie; Chang, Chong Hyun; Ji, Zhaoxia; Yu, Xuechen; Wang, Xiang; Lin, Shuo; Xia, Tian; Nel, André E

    2015-10-27

    We studied adult zebrafish to determine whether the size of 20 and 110 nm citrate-coated silver nanoparticles (AgC NPs) differentially impact the gills and intestines, known target organs for Ag toxicity in fish. Following exposure for 4 h, 4 days, or 4 days plus a 7 day depuration period, we obtained different toxicokinetic profiles for different particle sizes, as determined by Ag content of the tissues. Ionic AgNO3 served as a positive control. The gills showed a significantly higher Ag content for the 20 nm particles at 4 h and 4 days than the 110 nm particles, while the values were more similar in the intestines. Both particle types were retained in the intestines even after depuration. These toxicokinetics were accompanied by striking size-dependent differences in the ultrastructural features and histopathology in the target organs in response to the particulates. Ag staining of the gills and intestines confirmed prominent Ag deposition in the basolateral membranes for the 20 nm but not for the 110 nm particles. Furthermore, it was possible to link the site of tissue deposition to disruption of the Na(+)/K(+) ion channel, which is also localized to the basolateral membrane. This was confirmed by a reduction in ATPase activity and immunohistochemical detection of the α subunit of this channel in both target organs, with the 20 nm particles causing significantly higher inhibition and disruption than the larger size particles or AgNO3. These results demonstrate the importance of particle size in determining the hazardous impact of AgNPs in the gills and intestines of adult zebrafish.

  5. Characterization of Light Lesion Paradigms and Optical Coherence Tomography as Tools to Study Adult Retina Regeneration in Zebrafish

    PubMed Central

    Weber, Anke; Hochmann, Sarah; Cimalla, Peter; Gärtner, Maria; Kuscha, Veronika; Hans, Stefan; Geffarth, Michaela; Kaslin, Jan; Koch, Edmund; Brand, Michael

    2013-01-01

    Light-induced lesions are a powerful tool to study the amazing ability of photoreceptors to regenerate in the adult zebrafish retina. However, the specificity of the lesion towards photoreceptors or regional differences within the retina are still incompletely understood. We therefore characterized the process of degeneration and regeneration in an established paradigm, using intense white light from a fluorescence lamp on swimming fish (diffuse light lesion). We also designed a new light lesion paradigm where light is focused through a microscope onto the retina of an immobilized fish (focused light lesion). Focused light lesion has the advantage of creating a locally restricted area of damage, with the additional benefit of an untreated control eye in the same animal. In both paradigms, cell death is observed as an immediate early response, and proliferation is initiated around 2 days post lesion (dpl), peaking at 3 dpl. We furthermore find that two photoreceptor subtypes (UV and blue sensitive cones) are more susceptible towards intense white light than red/green double cones and rods. We also observed specific differences within light lesioned areas with respect to the process of photoreceptor degeneration: UV cone debris is removed later than any other type of photoreceptor in light lesions. Unspecific damage to retinal neurons occurs at the center of a focused light lesion territory, but not in the diffuse light lesion areas. We simulated the fish eye optical properties using software simulation, and show that the optical properties may explain the light lesion patterns that we observe. Furthermore, as a new tool to study retinal degeneration and regeneration in individual fish in vivo, we use spectral domain optical coherence tomography. Collectively, the light lesion and imaging assays described here represent powerful tools for studying degeneration and regeneration processes in the adult zebrafish retina. PMID:24303018

  6. New Nerve Cells for the Adult Brain.

    ERIC Educational Resources Information Center

    Kempermann, Gerd; Gage, Fred H.

    1999-01-01

    Contrary to dogma, the human brain does produce new nerve cells in adulthood. The mature human brain spawns neurons routinely in the hippocampus, an area important to memory and learning. This research can make it possible to ease any number of disorders involving neurological damage and death. (CCM)

  7. Short-term exposure to low concentrations of the synthetic androgen methyltestosterone affects vitellogenin and steroid levels in adult male zebrafish (Danio rerio).

    PubMed

    Andersen, Lene; Goto-Kazeto, Rie; Trant, John M; Nash, Jon P; Korsgaard, Bodil; Bjerregaard, Poul

    2006-03-10

    Short-term effects of methyltestosterone (MT) on the endocrine system of adult male zebrafish (Danio rerio) were examined. Males were exposed to 0, 4.5, 6.6, 8.5, 19.8, 35.9, 62.3 ng MT/l and ethinylestradiol (EE2) (26.4 ng/l) for 7 days. Several physiological endpoints that may be affected by endocrine disrupters were analysed, specifically vitellogenin (VTG) concentration, estradiol (E2), testosterone (T), and 11-ketotestosterone (KT) content, brain aromatase activity and gene expression of CYP19A1 and CYP19A2 in the testis. Exposure to the lowest MT concentration (4.5 ng MT/l), and the EE2 increased the concentration of VTG significantly compared to solvent control group. Exposure to higher concentrations of MT did not increase VTG levels. Endogenous KT and T levels decreased significantly in a concentration-dependent manner in response to the MT exposure and the lowest effective concentrations were 6.4 and 8.5 ng MT/l, respectively. The levels of KT and T were also significantly suppressed by EE2 when compared to the solvent control group. Significant decreases in endogenous E2 levels were found in some MT groups but it was not possible to distinguish a simple concentration-response relationship. No effects of MT or EE2 on the brain aromatase activity or on testicular gene expression of CYP19A1 and CYP19A2 were detected. The results show that androgens such as MT can act as endocrine disrupters even at very low concentrations.

  8. Zebrafish and medaka: model organisms for a comparative developmental approach of brain asymmetry

    PubMed Central

    Signore, Iskra A.; Guerrero, Néstor; Loosli, Felix; Colombo, Alicia; Villalón, Aldo; Wittbrodt, Joachim; Concha, Miguel L.

    2008-01-01

    Comparison between related species is a successful approach to uncover conserved and divergent principles of development. Here, we studied the pattern of epithalamic asymmetry in zebrafish (Danio rerio) and medaka (Oryzias latipes), two related teleost species with 115–200 Myr of independent evolution. We found that these species share a strikingly conserved overall pattern of asymmetry in the parapineal–habenular–interpeduncular system. Nodal signalling exhibits comparable spatial and temporal asymmetric expressions in the presumptive epithalamus preceding the development of morphological asymmetries. Neuroanatomical asymmetries consist of left-sided asymmetric positioning and connectivity of the parapineal organ, enlargement of neuropil in the left habenula compared with the right habenula and segregation of left–right habenular efferents along the dorsoventral axis of the interpeduncular nucleus. Despite the overall conservation of asymmetry, we observed heterotopic changes in the topology of parapineal efferent connectivity, heterochronic shifts in the timing of developmental events underlying the establishment of asymmetry and divergent degrees of canalization of embryo laterality. We offer new tools for developmental time comparison among species and propose, for each of these transformations, novel hypotheses of ontogenic mechanisms that explain interspecies variations that can be tested experimentally. Together, these findings highlight the usefulness of zebrafish and medaka as comparative models to study the developmental mechanisms of epithalamic asymmetry in vertebrates. PMID:19064351

  9. Zebrafish and medaka: model organisms for a comparative developmental approach of brain asymmetry.

    PubMed

    Signore, Iskra A; Guerrero, Néstor; Loosli, Felix; Colombo, Alicia; Villalón, Aldo; Wittbrodt, Joachim; Concha, Miguel L

    2009-04-12

    Comparison between related species is a successful approach to uncover conserved and divergent principles of development. Here, we studied the pattern of epithalamic asymmetry in zebrafish (Danio rerio) and medaka (Oryzias latipes), two related teleost species with 115-200 Myr of independent evolution. We found that these species share a strikingly conserved overall pattern of asymmetry in the parapineal-habenular-interpeduncular system. Nodal signalling exhibits comparable spatial and temporal asymmetric expressions in the presumptive epithalamus preceding the development of morphological asymmetries. Neuroanatomical asymmetries consist of left-sided asymmetric positioning and connectivity of the parapineal organ, enlargement of neuropil in the left habenula compared with the right habenula and segregation of left-right habenular efferents along the dorsoventral axis of the interpeduncular nucleus. Despite the overall conservation of asymmetry, we observed heterotopic changes in the topology of parapineal efferent connectivity, heterochronic shifts in the timing of developmental events underlying the establishment of asymmetry and divergent degrees of canalization of embryo laterality. We offer new tools for developmental time comparison among species and propose, for each of these transformations, novel hypotheses of ontogenic mechanisms that explain interspecies variations that can be tested experimentally. Together, these findings highlight the usefulness of zebrafish and medaka as comparative models to study the developmental mechanisms of epithalamic asymmetry in vertebrates.

  10. Effects of bisphenol A and triclocarban on brain-specific expression of aromatase in early zebrafish embryos

    PubMed Central

    Chung, Eunah; Genco, Maria C.; Megrelis, Laura; Ruderman, Joan V.

    2011-01-01

    Estrogen regulates numerous developmental and physiological processes. Most effects are mediated by estrogen receptors (ERs), which function as ligand-regulated transcription factors. Estrogen also regulates the activity of GPR30, a membrane-associated G protein-coupled receptor. Many different types of environmental contaminants can activate ERs; some can bind GPR30 as well. There is growing concern that exposure to some of these compounds, termed xenoestrogens, is interfering with the behavior and reproductive potential of numerous wildlife species, as well as affecting human health. Here, we investigated how two common, environmentally pervasive chemicals affect the in vivo expression of a known estrogen target gene in the brain of developing zebrafish embryos, aromatase AroB, which converts androgens to estrogens. We confirm that, like estrogen, the well-studied xenoestrogen bisphenol A (BPA, a plastics monomer), induces strong brain-specific overexpression of aromatase. Experiments using ER- and GPR30-selective modulators argue that this induction is largely through nuclear ERs. BPA induces dramatic overexpression of AroB RNA in the same subregions of the developing brain as estrogen. The antibacterial triclocarban (TCC) by itself stimulates AroB expression only slightly, but TCC strongly enhances the overexpression of AroB that is induced by exogenous estrogen. Thus, both BPA and TCC have the potential to elevate levels of aromatase and, thereby, levels of endogenous estrogens in the developing brain. In contrast to estrogen, BPA-induced AroB overexpression was suppressed by TCC. These results indicate that exposures to combinations of certain hormonally active pollutants can have outcomes that are not easily predicted from their individual effects. PMID:22006313

  11. In vivo assessment of the permeability of the blood-brain barrier and blood-retinal barrier to fluorescent indoline derivatives in zebrafish

    PubMed Central

    2012-01-01

    Background Successful delivery of compounds to the brain and retina is a challenge in the development of therapeutic drugs and imaging agents. This challenge arises because internalization of compounds into the brain and retina is restricted by the blood–brain barrier (BBB) and blood-retinal barrier (BRB), respectively. Simple and reliable in vivo assays are necessary to identify compounds that can easily cross the BBB and BRB. Methods We developed six fluorescent indoline derivatives (IDs) and examined their ability to cross the BBB and BRB in zebrafish by in vivo fluorescence imaging. These fluorescent IDs were administered to live zebrafish by immersing the zebrafish larvae at 7-8 days post fertilization in medium containing the ID, or by intracardiac injection. We also examined the effect of multidrug resistance proteins (MRPs) on the permeability of the BBB and BRB to the ID using MK571, a selective inhibitor of MRPs. Results The permeability of these barriers to fluorescent IDs administered by simple immersion was comparable to when administered by intracardiac injection. Thus, this finding supports the validity of drug administration by simple immersion for the assessment of BBB and BRB permeability to fluorescent IDs. Using this zebrafish model, we demonstrated that the length of the methylene chain in these fluorescent IDs significantly affected their ability to cross the BBB and BRB via MRPs. Conclusions We demonstrated that in vivo assessment of the permeability of the BBB and BRB to fluorescent IDs could be simply and reliably performed using zebrafish. The structure of fluorescent IDs can be flexibly modified and, thus, the permeability of the BBB and BRB to a large number of IDs can be assessed using this zebrafish-based assay. The large amount of data acquired might be useful for in silico analysis to elucidate the precise mechanisms underlying the interactions between chemical structure and the efflux transporters at the BBB and BRB. In turn

  12. Changes in Brain Monoamines Underlie Behavioural Disruptions after Zebrafish Diet Exposure to Polycyclic Aromatic Hydrocarbons Environmental Mixtures

    PubMed Central

    Vignet, Caroline; Trenkel, Verena M.; Vouillarmet, Annick; Bricca, Giampiero; Bégout, Marie-Laure; Cousin, Xavier

    2017-01-01

    Zebrafish were exposed through diet to two environmentally relevant polycyclic aromatic hydrocarbons (PAHs) mixtures of contrasted compositions, one of pyrolytic (PY) origin and one from light crude oil (LO). Monoamine concentrations were quantified in the brains of the fish after six month of exposure. A significant decrease in noradrenaline (NA) was observed in fish exposed to both mixtures, while a decrease in serotonin (5HT) and dopamine (DA) was observed only in LO-exposed fish. A decrease in metabolites of 5HT and DA was observed in fish exposed to both mixtures. Several behavioural disruptions were observed that depended on mixtures, and parallels were made with changes in monoamine concentrations. Indeed, we observed an increase in anxiety in fish exposed to both mixtures, which could be related to the decrease in 5HT and/or NA, while disruptions of daily activity rhythms were observed in LO fish, which could be related to the decrease in DA. Taken together, these results showed that (i) chronic exposures to PAHs mixtures disrupted brain monoamine contents, which could underlie behavioural disruptions, and that (ii) the biological responses depended on mixture compositions. PMID:28273853

  13. Changes in Brain Monoamines Underlie Behavioural Disruptions after Zebrafish Diet Exposure to Polycyclic Aromatic Hydrocarbons Environmental Mixtures.

    PubMed

    Vignet, Caroline; Trenkel, Verena M; Vouillarmet, Annick; Bricca, Giampiero; Bégout, Marie-Laure; Cousin, Xavier

    2017-03-04

    Zebrafish were exposed through diet to two environmentally relevant polycyclic aromatic hydrocarbons (PAHs) mixtures of contrasted compositions, one of pyrolytic (PY) origin and one from light crude oil (LO). Monoamine concentrations were quantified in the brains of the fish after six month of exposure. A significant decrease in noradrenaline (NA) was observed in fish exposed to both mixtures, while a decrease in serotonin (5HT) and dopamine (DA) was observed only in LO-exposed fish. A decrease in metabolites of 5HT and DA was observed in fish exposed to both mixtures. Several behavioural disruptions were observed that depended on mixtures, and parallels were made with changes in monoamine concentrations. Indeed, we observed an increase in anxiety in fish exposed to both mixtures, which could be related to the decrease in 5HT and/or NA, while disruptions of daily activity rhythms were observed in LO fish, which could be related to the decrease in DA. Taken together, these results showed that (i) chronic exposures to PAHs mixtures disrupted brain monoamine contents, which could underlie behavioural disruptions, and that (ii) the biological responses depended on mixture compositions.

  14. Effects of environmental tobacco smoke on adult rat brain biochemistry.

    PubMed

    Fuller, Brian F; Gold, Mark S; Wang, Kevin K W; Ottens, Andrew K

    2010-05-01

    Environmental tobacco smoke (ETS) has been linked to deleterious health effects, particularly pulmonary and cardiac disease; yet, the general public considers ETS benign to brain function in adults. In contrast, epidemiological data have suggested that ETS impacts the brain and potentially modulates neurodegenerative disease. The present study begins to examine yet unknown biochemical effects of ETS on the adult mammalian brain. In the developed animal model, adult male rats were exposed to ETS 3 h a day for 3 weeks. Biochemical data showed altered glial fibrillary acid protein levels as a main treatment effect of ETS, suggestive of reactive astrogliosis. Yet, markers of oxidative and cell stress were unaffected by ETS exposure in the brain regions examined. Increased proteolytic degradation of alphaII-spectrin by caspase-3 and the dephosphorylation of serine(116) on PEA-15 indicated greater apoptotic cell death modulated by the extrinsic pathway in the brains of ETS-exposed animals. Further, beta-synuclein was upregulated by ETS, a neuroprotective protein previously reported to exhibit anti-apoptotic and anti-fibrillogenic properties. These findings demonstrate that ETS exposure alters the neuroproteome of the adult rat brain, and suggest modulation of inflammatory and cell death processes.

  15. The effects of vitamin D on brain development and adult brain function.

    PubMed

    Kesby, James P; Eyles, Darryl W; Burne, Thomas H J; McGrath, John J

    2011-12-05

    A role for vitamin D in brain development and function has been gaining support over the last decade. Multiple lines of evidence suggest that this vitamin is actually a neuroactive steroid that acts on brain development, leading to alterations in brain neurochemistry and adult brain function. Early deficiencies have been linked with neuropsychiatric disorders, such as schizophrenia, and adult deficiencies have been associated with a host of adverse brain outcomes, including Parkinson's disease, Alzheimer's disease, depression and cognitive decline. This review summarises the current state of research on the actions of vitamin D in the brain and the consequences of deficiencies in this vitamin. Furthermore, we discuss specific implications of vitamin D status on the neurotransmitter, dopamine.

  16. Caffeine protects against memory loss induced by high and non-anxiolytic dose of cannabidiol in adult zebrafish (Danio rerio).

    PubMed

    Nazario, Luiza Reali; Antonioli, Régis; Capiotti, Katiucia Marques; Hallak, Jaime Eduardo Cecílio; Zuardi, Antonio Waldo; Crippa, José Alexandre S; Bonan, Carla Denise; da Silva, Rosane Souza

    2015-08-01

    Cannabidiol (CBD) has been investigated in a wide spectrum of clinical approaches due to its psychopharmacological properties. CBD has low affinity for cannabinoid neuroreceptors and agonistic properties to 5-HT receptors. An interaction between cannabinoid and purinergic receptor systems has been proposed. The purpose of this study is to evaluate CBD properties on memory behavioral and locomotor parameters and the effects of pre-treatment of adenosine receptor blockers on CBD impacts on memory using adult zebrafish. CBD (0.1, 0.5, 5, and 10mg/kg) was tested in the avoidance inhibitory paradigm and anxiety task. We analyzed the effect of a long-term caffeine pre-treatment (~20mg/L - four months). Also, acute block of adenosine receptors was performed in co-administration with CBD exposure in the memory assessment. CBD promoted an inverted U-shaped dose-response curve in the anxiety task; in the memory assessment, CBD in the dose of 5mg/Kg promoted the strongest effects without interfering with social and aggressive behavior. Caffeine treatment was able to prevent CBD (5mg/kg) effects on memory when CBD was given after the training session. CBD effects on memory were partially prevented by co-treatment with a specific A2A adenosine receptor antagonist when given prior to or after the training session, while CBD effects after the training session were fully prevented by adenosine A1 receptor antagonist. These results indicated that zebrafish have responses to CBD anxiolytic properties that are comparable to other animal models, and high doses changed memory retention in a way dependent on adenosine.

  17. Effects of embryonic ethanol exposure at low doses on neuronal development, voluntary ethanol consumption and related behaviors in larval and adult zebrafish: Role of hypothalamic orexigenic peptides.

    PubMed

    Sterling, M E; Chang, G-Q; Karatayev, O; Chang, S Y; Leibowitz, S F

    2016-05-01

    Embryonic exposure to ethanol is known to affect neurochemical systems in rodents and increase alcohol drinking and related behaviors in humans and rodents. With zebrafish emerging as a powerful tool for uncovering neural mechanisms of numerous diseases and exhibiting similarities to rodents, the present report building on our rat studies examined in zebrafish the effects of embryonic ethanol exposure on hypothalamic neurogenesis, expression of orexigenic neuropeptides, and voluntary ethanol consumption and locomotor behaviors in larval and adult zebrafish, and also effects of central neuropeptide injections on these behaviors affected by ethanol. At 24h post-fertilization, zebrafish embryos were exposed for 2h to ethanol, at low concentrations of 0.25% and 0.5%, in the tank water. Embryonic ethanol compared to control dose-dependently increased hypothalamic neurogenesis and the proliferation and expression of the orexigenic peptides, galanin (GAL) and orexin (OX), in the anterior hypothalamus. These changes in hypothalamic peptide neurons were accompanied by an increase in voluntary consumption of 10% ethanol-gelatin and in novelty-induced locomotor and exploratory behavior in adult zebrafish and locomotor activity in larvae. After intracerebroventricular injection, these peptides compared to vehicle had specific effects on these behaviors altered by ethanol, with GAL stimulating consumption of 10% ethanol-gelatin more than plain gelatin food and OX stimulating novelty-induced locomotor behavior while increasing intake of food and ethanol equally. These results, similar to those obtained in rats, suggest that the ethanol-induced increase in genesis and expression of these hypothalamic peptide neurons contribute to the behavioral changes induced by embryonic exposure to ethanol.

  18. Life-cycle exposure to BDE-47 results in thyroid endocrine disruption to adults and offsprings of zebrafish (Danio rerio).

    PubMed

    Zhao, Xuesong; Ren, Xin; Ren, Baixiang; Luo, Zhouying; Zhu, Rong

    2016-12-01

    2,2,4',4'-Tetrabromodi-phenyl ether (BDE-47) is predominantly concentrated in humans and wildlife and disturbs thyroid hormone homeostasis. The purpose of this study was to characterize the thyroid endocrine disruption induced by life-cycle exposure to BDE-47 in adults and offspring of zebrafish (Danio rerio). We exposed zebrafish embryos at the blastula stage to different concentrations of BDE-47 (1, 5, and 10μg/L). Exposure duration was 180days until fish reached adulthood. In F0 larvae, exposure decreased survival and increased malformations at 4 dpf. Thyroid hormone concentrations did not differ significantly between the F0 larvae and controls. All exposures significantly up-regulated expression of tshß, pa8, ugt1 and tg and down-regulated ttr. Significant up-regulation of dio2 and crh was observed in the 10μg/L BDE-47 group. There was no significant difference in the growth and somatic index between F0 adults and controls. BDE-47 (10μg/L) significantly decreased whole-body content of thyroxine (T4) but significantly increased triiodothyronine (T3) in both sexes. All exposures up-regulated expression of crh, tshß, pa8, ugt1 and tg and down-regulated ttr. Exposure to 10μg/L BDE-47 significantly up-regulated dio2 and ugt1 in both sexes. BDE-47 exposure (5 and 10μg/L) significantly increased the activity of pethoxy-resorufin-O-deethylase and UDP-glucuronosyl transferase. BDE-47 (10μg/L) significantly increased activity of ethoxy- and methoxy-resorufin-O-deethylase. In F1 offspring without continued BDE-47 (10μg/L) treatment, T4 significantly decreased and T3 increased. T4 was further decreased and T3 was further increased with continued BDE-47 treatment. Continued BDE-47 exposure decreased hatching and increased malformation compared with those without BDE-47 exposure. Expression of crh, tshß, dio2, pa8, ugt1 and tg was significantly up-regulated without BDE-47 exposure and with continued exposure. With continued BDE-47 exposure, dio1 was significantly

  19. Differential protein profile in zebrafish (Danio rerio) brain under the joint exposure of methyl parathion and cadmium.

    PubMed

    Ling, Xue-Ping; Lu, Ying-Hua; Huang, He-Qing

    2012-11-01

    As different chemicals, methyl parathion (MP) and cadmium (Cd) can induce neurotoxicity on the brain of aquatic ecosystems. This study aims to explore the differential expression proteins in the brain induced by their joint stress and their joint effects, which are poorly reported, and devotes finding novel biomarkers for monitoring their contamination in water and assessing their neurological effects. The bioaccumulation of MP and Cd in tissues after 96 h of exposure was first analyzed by GC and inductively coupled plasma-MS to provide insights into the interaction. Protein profile changes in the brains of the zebrafish (Danio rerio) exposed to MP and Cd were further investigated using the proteomic approach. The correlation of gene expression on the transcription level of mRNA and the translation level of protein was examined by real-time quantitative PCR and Western blotting analysis. It showed that Cd and MP have an interaction on their bioaccumulation, which suggests that their joint effect over 96 h might be antagonistic. Proteomics revealed that 22 protein spots changed their expression levels under stress, of which 16 proteins were identified using MS. These proteins were involved in oxidation/reduction, metabolism, energy production, receptor activity, and cytoskeleton assembly. Among them, five proteins with a remarkable abundance change are significantly suggested to play important roles in the joint effect. This work demonstrates that there exists an interaction between MP and Cd toxicities, which may aid in our understanding of the mechanism of neurotoxicity induced by joint stress. The results may also provide the possibility of the establishment of candidate biomarkers for monitoring MP and Cd contamination in water.

  20. Suppression of the endoplasmic reticulum calcium pump during zebrafish gastrulation affects left-right asymmetry of the heart and brain.

    PubMed

    Kreiling, Jill A; Balantac, Zaneta L; Crawford, Andrew R; Ren, Yuexin; Toure, Jamal; Zchut, Sigalit; Kochilas, Lazaros; Creton, Robbert

    2008-01-01

    Vertebrate embryos generate striking Ca(2+) patterns, which are unique regulators of dynamic developmental events. In the present study, we used zebrafish embryos as a model system to examine the developmental roles of Ca(2+) during gastrulation. We found that gastrula stage embryos maintain a distinct pattern of cytosolic Ca(2+) along the dorsal-ventral axis, with higher Ca(2+) concentrations in the ventral margin and lower Ca(2+) concentrations in the dorsal margin and dorsal forerunner cells. Suppression of the endoplasmic reticulum Ca(2+) pump with 0.5 microM thapsigargin elevates cytosolic Ca(2+) in all embryonic regions and induces a randomization of laterality in the heart and brain. Affected hearts, visualized in living embryos by a subtractive imaging technique, displayed either a reversal or loss of left-right asymmetry. Brain defects include a left-right reversal of pitx2 expression in the dorsal diencephalon and a left-right reversal of the prominent habenular nucleus in the brain. Embryos are sensitive to inhibition of the endoplasmic reticulum Ca(2+) pump during early and mid gastrulation and lose their sensitivity during late gastrulation and early segmentation. Suppression of the endoplasmic reticulum Ca(2+) pump during gastrulation inhibits expression of no tail (ntl) and left-right dynein related (lrdr) in the dorsal forerunner cells and affects development of Kupffer's vesicle, a ciliated organ that generates a counter-clockwise flow of fluid. Previous studies have shown that Ca(2+) plays a role in Kupffer's vesicle function, influencing ciliary motility and translating the vesicle's counter-clockwise flow into asymmetric patterns of gene expression. The present results suggest that Ca(2+) plays an additional role in the formation of Kupffer's vesicle.

  1. Expansion of Multipotent Stem Cells from the Adult Human Brain

    PubMed Central

    Murrell, Wayne; Palmero, Emily; Bianco, John; Stangeland, Biljana; Joel, Mrinal; Paulson, Linda; Thiede, Bernd; Grieg, Zanina; Ramsnes, Ingunn; Skjellegrind, Håvard K.; Nygård, Ståle; Brandal, Petter; Sandberg, Cecilie; Vik-Mo, Einar; Palmero, Sheryl; Langmoen, Iver A.

    2013-01-01

    The discovery of stem cells in the adult human brain has revealed new possible scenarios for treatment of the sick or injured brain. Both clinical use of and preclinical research on human adult neural stem cells have, however, been seriously hampered by the fact that it has been impossible to passage these cells more than a very few times and with little expansion of cell numbers. Having explored a number of alternative culturing conditions we here present an efficient method for the establishment and propagation of human brain stem cells from whatever brain tissue samples we have tried. We describe virtually unlimited expansion of an authentic stem cell phenotype. Pluripotency proteins Sox2 and Oct4 are expressed without artificial induction. For the first time multipotency of adult human brain-derived stem cells is demonstrated beyond tissue boundaries. We characterize these cells in detail in vitro including microarray and proteomic approaches. Whilst clarification of these cells’ behavior is ongoing, results so far portend well for the future repair of tissues by transplantation of an adult patient’s own-derived stem cells. PMID:23967194

  2. Calcium-activated potassium channel SK1 is widely expressed in the peripheral nervous system and sensory organs of adult zebrafish.

    PubMed

    Cabo, R; Zichichi, R; Viña, E; Guerrera, M C; Vázquez, G; García-Suárez, O; Vega, J A; Germanà, A

    2013-10-25

    Sensory cells contain ion channels involved in the organ-specific transduction mechanisms that convert different types of stimuli into electric energy. Here we focus on small-conductance calcium-activated potassium channel 1 (SK1) which plays an important role in all excitable cells acting as feedback regulators in after-hyperpolarization. This study was undertaken to analyze the pattern of expression of SK1 in the zebrafish peripheral nervous system and sensory organs using RT-PRC, Westernblot and immunohistochemistry. Expression of SK1 mRNA was observed at all developmental stages analyzed (from 10 to 100 days post fertilization, dpf), and the antibody used identified a protein with a molecular weight of 70kDa, at 100dpf (regarded to be adult). Cell expressing SK1 in adult animals were neurons of dorsal root and cranial nerve sensory ganglia, sympathetic neurons, sensory cells in neuromasts of the lateral line system and taste buds, crypt olfactory neurons and photoreceptors. Present results report for the first time the expression and the distribution of SK1 in the peripheral nervous system and sensory organs of adult zebrafish, and may contribute to set zebrafish as an interesting experimental model for calcium-activated potassium channels research. Moreover these findings are of potential interest because the potential role of SK as targets for the treatment of neurological diseases and sensory disorders.

  3. Induction of Female-to-Male Sex Change in Adult Zebrafish by Aromatase Inhibitor Treatment

    NASA Astrophysics Data System (ADS)

    Takatsu, Kanae; Miyaoku, Kaori; Roy, Shimi Rani; Murono, Yuki; Sago, Tomohiro; Itagaki, Hideyuki; Nakamura, Masaru; Tokumoto, Toshinobu

    2013-12-01

    This study investigated whether undifferentiated germ and/or somatic stem cells remain in the differentiated ovary of a species that does not undergo sex changes under natural conditions and retain their sexual plasticity. The effect of aromatase inhibitor (AI)-treatment on sexually mature female zebrafish was examined. A 5-month AI treatment caused retraction of the ovaries after which testes-like organs appeared, and cyst structures filled with spermatozoa-like cells were observed in sections of these tissues. Electron microscopic observations revealed that these cells appeared as large sperm heads without tails. Sperm formation was re-examined after changing the diet to an AI-free food. A large number of normal sperm were obtained after eight weeks, and no formation of ovarian tissue was observed. Artificial fertilization using sperm from the sex-changed females was successful. These results demonstrated that sex plasticity remains in the mature ovaries of this species.

  4. Induction of female-to-male sex change in adult zebrafish by aromatase inhibitor treatment.

    PubMed

    Takatsu, Kanae; Miyaoku, Kaori; Roy, Shimi Rani; Murono, Yuki; Sago, Tomohiro; Itagaki, Hideyuki; Nakamura, Masaru; Tokumoto, Toshinobu

    2013-12-02

    This study investigated whether undifferentiated germ and/or somatic stem cells remain in the differentiated ovary of a species that does not undergo sex changes under natural conditions and retain their sexual plasticity. The effect of aromatase inhibitor (AI)-treatment on sexually mature female zebrafish was examined. A 5-month AI treatment caused retraction of the ovaries after which testes-like organs appeared, and cyst structures filled with spermatozoa-like cells were observed in sections of these tissues. Electron microscopic observations revealed that these cells appeared as large sperm heads without tails. Sperm formation was re-examined after changing the diet to an AI-free food. A large number of normal sperm were obtained after eight weeks, and no formation of ovarian tissue was observed. Artificial fertilization using sperm from the sex-changed females was successful. These results demonstrated that sex plasticity remains in the mature ovaries of this species.

  5. Brain abscess caused by Citrobacter koseri infection in an adult.

    PubMed

    Liu, Heng-Wei; Chang, Chih-Ju; Hsieh, Cheng-Ta

    2015-04-01

    Citrobacter koseri is a gram-negative bacillus that causes mostly meningitis and brain abscesses in neonates and infants. However, brain abscess caused by Citrobacter koseri infection in an adult is extremely rare, and only 2 cases have been described. Here, we reported a 73-year-old male presenting with a 3-week headache. A history of diabetes mellitus was noted. The images revealed a brain abscess in the left frontal lobe and pus culture confirmed the growth of Citrobacter koseri. The clinical symptoms improved completely postoperatively.

  6. Inflammation is detrimental for neurogenesis in adult brain

    NASA Astrophysics Data System (ADS)

    Ekdahl, Christine T.; Claasen, Jan-Hendrik; Bonde, Sara; Kokaia, Zaal; Lindvall, Olle

    2003-11-01

    New hippocampal neurons are continuously generated in the adult brain. Here, we demonstrate that lipopolysaccharide-induced inflammation, which gives rise to microglia activation in the area where the new neurons are born, strongly impairs basal hippocampal neurogenesis in rats. The increased neurogenesis triggered by a brain insult is also attenuated if it is associated with microglia activation caused by tissue damage or lipopolysaccharide infusion. The impaired neurogenesis in inflammation is restored by systemic administration of minocycline, which inhibits microglia activation. Our data raise the possibility that suppression of hippocampal neurogenesis by activated microglia contributes to cognitive dysfunction in aging, dementia, epilepsy, and other conditions leading to brain inflammation.

  7. FACS purification of immunolabeled cell types from adult rat brain.

    PubMed

    Guez-Barber, Danielle; Fanous, Sanya; Harvey, Brandon K; Zhang, Yongqing; Lehrmann, Elin; Becker, Kevin G; Picciotto, Marina R; Hope, Bruce T

    2012-01-15

    Molecular analysis of brain tissue is greatly complicated by having many different classes of neurons and glia interspersed throughout the brain. Fluorescence-activated cell sorting (FACS) has been used to purify selected cell types from brain tissue. However, its use has been limited to brain tissue from embryos or transgenic mice with promoter-driven reporter genes. To overcome these limitations, we developed a FACS procedure for dissociating intact cell bodies from adult wild-type rat brains and sorting them using commercially available antibodies against intracellular and extracellular proteins. As an example, we isolated neurons using a NeuN antibody and confirmed their identity using microarray and real time PCR of mRNA from the sorted cells. Our FACS procedure allows rapid, high-throughput, quantitative assays of molecular alterations in identified cell types with widespread applications in neuroscience.

  8. Effects of learning on mTOR pathway gene expression in the brain of zebrafish (Danio rerio) of different ages.

    PubMed

    Peixoto, Carolina da Silva; Parfitt, Gustavo Morrone; Bruch, Gisele Eva; Cordeiro, Marcos Freitas; Almeida, Daniela Volcan; Marins, Luis Fernando Fernandes; Barros, Daniela Martí

    2017-03-01

    Target of rapamycin (TOR) is a protein kinase involved in the modulation of mRNA translation and, therefore, in the regulation of protein synthesis. In neurons, the role of TOR is particularly important in the consolidation of long-term memory (LTM). One of the modulators of TOR is brain-derived neurotrophic factor (BDNF), which activates the TOR signaling pathway to promote protein synthesis, synapse strengthening, and the creation of new neural networks. We investigated the gene expression pattern of this pathway during memory consolidation in zebrafish of different ages. Our findings demonstrate that TOR activation in old animals occurs in the early phase of consolidation, and follows a pattern identical to that of BDNF expression. In younger animals, this increase in activation did not occur, and changes in BDNF expression were also not so remarkable. Furthermore, the expression of the main proteins regulated by the synthesis of TOR (i.e., 4EBP and p70S6K) remained identical to that of TOR in all age groups.

  9. Bilateral Brain Regions Associated with Naming in Older Adults

    ERIC Educational Resources Information Center

    Obler, Loraine K.; Rykhlevskaia, Elena; Schnyer, David; Clark-Cotton, Manuella R.; Spiro, Avron, III; Hyun, JungMoon; Kim, Dae-Shik; Goral, Mira; Albert, Martin L.

    2010-01-01

    To determine structural brain correlates of naming abilities in older adults, we tested 24 individuals aged 56-79 on two confrontation-naming tests (the Boston Naming Test (BNT) and the Action Naming Test (ANT)), then collected from these individuals structural Magnetic-Resonance Imaging (MRI) and Diffusion Tensor Imaging (DTI) data. Overall,…

  10. Differences in inhibitory avoidance, cortisol and brain gene expression in TL and AB zebrafish.

    PubMed

    Gorissen, M; Manuel, R; Pelgrim, T N M; Mes, W; de Wolf, M J S; Zethof, J; Flik, G; van den Bos, R

    2015-06-01

    Recently, we established an inhibitory avoidance paradigm in Tupfel Long-Fin (TL) zebrafish. Here, we compared task performance of TL fish and fish from the AB strain; another widely used strain and shown to differ genetically and behaviourally from TL fish. Whole-body cortisol and telencephalic gene expression related to stress, anxiety and fear were measured before and 2 h post-task. Inhibitory avoidance was assessed in a 3-day paradigm: fish learn to avoid swimming from a white to a black compartment where a 3V-shock is given: day 1 (first shock), day 2 (second shock) and day 3 (no shock, sampling). Tupfel Long-Fin fish rapidly learned to avoid the black compartment and showed an increase in avoidance-related spatial behaviour in the white compartment across days. In contrast, AB fish showed no inhibitory avoidance learning. AB fish had higher basal cortisol levels and expression levels of stress-axis related genes than TL fish. Tupfel Long-Fin fish showed post-task learning-related changes in cortisol and gene expression levels, but these responses were not seen in AB fish. We conclude that AB fish show higher cortisol levels and no inhibitory avoidance than TL fish. The differential learning responses of these Danio strains may unmask genetically defined risks for stress-related disorders.

  11. Pedophilic brain potential responses to adult erotic stimuli.

    PubMed

    Knott, Verner; Impey, Danielle; Fisher, Derek; Delpero, Emily; Fedoroff, Paul

    2016-02-01

    Cognitive mechanisms associated with the relative lack of sexual interest in adults by pedophiles are poorly understood and may benefit from investigations examining how the brain processes adult erotic stimuli. The current study used event-related brain potentials (ERP) to investigate the time course of the explicit processing of erotic, emotional, and neutral pictures in 22 pedophilic patients and 22 healthy controls. Consistent with previous studies, early latency anterior ERP components were highly selective for erotic pictures. Although the ERPs elicited by emotional stimuli were similar in patients and controls, an early frontal positive (P2) component starting as early as 185 ms was significantly attenuated and slow to onset in pedophilia, and correlated with a clinical measure of cognitive distortions. Failure of rapid attentional capture by erotic stimuli suggests a relative reduction in early processing in pedophilic patients which may be associated with relatively diminished sexual interest in adults.

  12. Experience-dependent neural plasticity in the adult damaged brain

    PubMed Central

    Kerr, Abigail L.; Cheng, Shao-Ying; Jones, Theresa A.

    2011-01-01

    Behavioral experience is at work modifying the structure and function of the brain throughout the lifespan, but it has a particularly dramatic influence after brain injury. This review summarizes recent findings on the role of experience in reorganizing the adult damaged brain, with a focus on findings from rodent stroke models of chronic upper extremity (hand and arm) impairments. A prolonged and widespread process of repair and reorganization of surviving neural circuits is instigated by injury to the adult brain. When experience impacts these same neural circuits, it interacts with degenerative and regenerative cascades to shape neural reorganization and functional outcome. This is evident in the cortical plasticity resulting from compensatory reliance on the “good” forelimb in rats with unilateral sensorimotor cortical infarcts. Behavioral interventions (e.g., rehabilitative training) can drive functionally beneficial neural reorganization in the injured hemisphere. However, experience can have both behaviorally beneficial and detrimental effects. The interactions between experience-dependent and injury-induced neural plasticity are complex, time-dependent, and varied with age and other factors. A better understanding of these interactions is needed to understand how to optimize brain remodeling and functional outcome. Learning outcomes Readers will be able to describe (a) experience effects that are maladaptive for behavioral outcome after brain damage, (b) manipulations of experience that drive functionally beneficial neural plasticity, and (c) reasons why rehabilitative training effects can be expected to vary with age, training duration and timing. PMID:21620413

  13. Morphological differences in adipose tissue and changes in BDNF/Trkb expression in brain and gut of a diet induced obese zebrafish model.

    PubMed

    Montalbano, Giuseppe; Mania, Manuela; Guerrera, Maria Cristina; Abbate, Francesco; Laurà, Rosaria; Navarra, Michele; Vega, Jose A; Ciriaco, Emilia; Germanà, Antonino

    2016-03-01

    Obesity is a multifactorial disease generated by an alteration in balance between energy intake and expenditure, also dependent on genetic and non-genetic factors. Moreover, various nuclei of the hypothalamus receive and process peripheral stimuli from the gastrointestinal tract, controlling food intake and therefore energy balance. Among anorexigenic molecules, brain-derived neurotrophic factor (BDNF) acts through the tyrosine-kinase receptor TrkB. Numerous data demonstrate that the BDNF/TrkB system has a fundamental role in the control of food intake and body weight. Quantitative PCR and immunohistochemistry for both BDNF and TrkB were used to determine changes in levels in the brain and gastro-intestinal tract of an experimental zebrafish model of diet-induced obesity. Overfed animals showed increased weight and body mass index as well as accumulation of adipose tissue in the visceral, subcutaneous and hepatic areas. These changes were concomitant with decreased levels of BDNF mRNA in the gastro-intestinal tract and increased expression of TrkB mRNA in the brain. Overfeeding did not change the density of cells displaying immunoreactivity for BDNF or TrkB in the brain although both were significantly diminished in the gastro-intestinal tract. These results suggest an involvement of the BDNF/TrkB system in the regulation of food intake and energy balance in zebrafish, as in mammals.

  14. Notch regulates blastema proliferation and prevents differentiation during adult zebrafish fin regeneration.

    PubMed

    Münch, Juliane; González-Rajal, Alvaro; de la Pompa, José Luis

    2013-04-01

    Zebrafish have the capacity to regenerate several organs, including the heart and fins. Fin regeneration is epimorphic, involving the formation at the amputation plane of a mass of undifferentiated, proliferating mesenchymal progenitor-like cells, called blastema. This tissue provides all the cell types that form the fin, so that after damage or amputation the fin pattern and structure are fully restored. How blastema cells remain in this progenitor-like state is poorly understood. Here, we show that the Notch pathway plays an essential role during fin regeneration. Notch signalling is activated during blastema formation and remains active throughout the regeneration process. Chemical inhibition or morpholino-mediated knockdown of Notch signalling impairs fin regeneration via decreased proliferation accompanied by reduced expression of Notch target genes in the blastema. Conversely, overexpression of a constitutively active form of the Notch1 receptor (N1ICD) in the regenerating fin leads to increased proliferation and to the expansion of the blastema cell markers msxe and msxb, as well as increased expression of the proliferation regulator aldh1a2. This blastema expansion prevents regenerative fin outgrowth, as indicated by the reduction in differentiating osteoblasts and the inhibition of bone regeneration. We conclude that Notch signalling maintains blastema cells in a plastic, undifferentiated and proliferative state, an essential requirement for fin regeneration.

  15. Innervation is required for sense organ development in the lateral line system of adult zebrafish.

    PubMed

    Wada, Hironori; Dambly-Chaudière, Christine; Kawakami, Koichi; Ghysen, Alain

    2013-04-02

    Superficial mechanosensory organs (neuromasts) distributed over the head and body of fishes and amphibians form the "lateral line" system. During zebrafish adulthood, each neuromast of the body (posterior lateral line system, or PLL) produces "accessory" neuromasts that remain tightly clustered, thereby increasing the total number of PLL neuromasts by a factor of more than 10. This expansion is achieved by a budding process and is accompanied by branches of the afferent nerve that innervates the founder neuromast. Here we show that innervation is essential for the budding process, in complete contrast with the development of the embryonic PLL, where innervation is entirely dispensable. To obtain insight into the molecular mechanisms that underlie the budding process, we focused on the terminal system that develops at the posterior tip of the body and on the caudal fin. In this subset of PLL neuromasts, bud neuromasts form in a reproducible sequence over a few days, much faster than for other PLL neuromasts. We show that wingless/int (Wnt) signaling takes place during, and is required for, the budding process. We also show that the Wnt activator R-spondin is expressed by the axons that innervate budding neuromasts. We propose that the axon triggers Wnt signaling, which itself is involved in the proliferative phase that leads to bud formation. Finally, we show that innervation is required not only for budding, but also for long-term maintenance of all PLL neuromasts.

  16. Acute Exposure to Microcystin-Producing Cyanobacterium Microcystis aeruginosa Alters Adult Zebrafish (Danio rerio) Swimming Performance Parameters.

    PubMed

    Kist, Luiza Wilges; Piato, Angelo Luis; da Rosa, João Gabriel Santos; Koakoski, Gessi; Barcellos, Leonardo José Gil; Yunes, João Sarkis; Bonan, Carla Denise; Bogo, Maurício Reis

    2011-01-01

    Microcystins (MCs) are toxins produced by cyanobacteria (blue-green algae), primarily Microcystis aeruginosa, forming water blooms worldwide. When an organism is exposed to environmental perturbations, alterations in normal behavioral patterns occur. Behavioral repertoire represents the consequence of a diversity of physiological and biochemical alterations. In this study, we assessed behavioral patterns and whole-body cortisol levels of adult zebrafish (Danio rerio) exposed to cell culture of the microcystin-producing cyanobacterium M. aeruginosa (MC-LR, strain RST9501). MC-LR exposure (100 μg/L) decreased by 63% the distance traveled and increased threefold the immobility time when compared to the control group. Interestingly, no significant alterations in the number of line crossings were found at the same MC-LR concentration and time of exposure. When animals were exposed to 50 and 100 μg/L, MC-LR promoted a significant increase (around 93%) in the time spent in the bottom portion of the tank, suggesting an anxiogenic effect. The results also showed that none of the MC-LR concentrations tested promoted significant alterations in absolute turn angle, path efficiency, social behavior, or whole-body cortisol level. These findings indicate that behavior is susceptible to MC-LR exposure and provide evidence for a better understanding of the ecological consequences of toxic algal blooms.

  17. An embryonic atrazine exposure results in reproductive dysfunction in adult zebrafish and morphological alterations in their offspring

    PubMed Central

    Wirbisky, Sara E.; Weber, Gregory J.; Sepúlveda, Maria S.; Lin, Tsang-Long; Jannasch, Amber S.; Freeman, Jennifer L.

    2016-01-01

    The herbicide atrazine, a suspected endocrine disrupting chemical (EDC), frequently contaminates potable water supplies. Studies suggest alterations in the neuroendocrine system along the hypothalamus-pituitary-gonadal axis; however, most studies address either developmental, pubertal, or adulthood exposures, with few investigations regarding a developmental origins hypothesis. In this study, zebrafish were exposed to 0, 0.3, 3, or 30 parts per billion (ppb) atrazine through embryogenesis and then allowed to mature with no additional chemical exposure. Reproductive function, histopathology, hormone levels, offspring morphology, and the ovarian transcriptome were assessed. Embryonic atrazine exposure resulted in a significant increase in progesterone levels in the 3 and 30 ppb groups. A significant decrease in spawning and a significant increase in follicular atresia in the 30 ppb group were observed. In offspring, a decrease in the head length to body ratio in the 30 ppb group, along with a significant increase in head width to body ratio in the 0.3 and 3 ppb groups occurred. Transcriptomic alterations involved genes associated with endocrine system development and function, tissue development, and behavior. This study provides evidence to support atrazine as an EDC causing reproductive dysfunction and molecular alterations in adults exposed only during embryogenesis and morphological alterations in their offspring. PMID:26891955

  18. Relationships between gene expression and brain wiring in the adult rodent brain.

    PubMed

    French, Leon; Pavlidis, Paul

    2011-01-06

    We studied the global relationship between gene expression and neuroanatomical connectivity in the adult rodent brain. We utilized a large data set of the rat brain "connectome" from the Brain Architecture Management System (942 brain regions and over 5000 connections) and used statistical approaches to relate the data to the gene expression signatures of 17,530 genes in 142 anatomical regions from the Allen Brain Atlas. Our analysis shows that adult gene expression signatures have a statistically significant relationship to connectivity. In particular, brain regions that have similar expression profiles tend to have similar connectivity profiles, and this effect is not entirely attributable to spatial correlations. In addition, brain regions which are connected have more similar expression patterns. Using a simple optimization approach, we identified a set of genes most correlated with neuroanatomical connectivity, and find that this set is enriched for genes involved in neuronal development and axon guidance. A number of the genes have been implicated in neurodevelopmental disorders such as autistic spectrum disorder. Our results have the potential to shed light on the role of gene expression patterns in influencing neuronal activity and connectivity, with potential applications to our understanding of brain disorders. Supplementary data are available at http://www.chibi.ubc.ca/ABAMS.

  19. Pericytes control key neurovascular functions and neuronal phenotype in the adult brain and during brain aging

    PubMed Central

    Bell, Robert D.; Winkler, Ethan A.; Sagare, Abhay P.; Singh, Itender; LaRue, Barb; Deane, Rashid; Zlokovic, Berislav V.

    2010-01-01

    SUMMARY Pericytes play a key role in the development of cerebral microcirculation. The exact role of pericytes in the neurovascular unit in the adult brain and during brain aging remains, however, elusive. Using adult viable pericyte-deficient mice, we show that pericyte loss leads to brain vascular damage by two parallel pathways: (1) reduction in brain microcirculation causing diminished brain capillary perfusion, cerebral blood flow and cerebral blood flow responses to brain activation which ultimately mediates chronic perfusion stress and hypoxia, and (2) blood-brain barrier breakdown associated with brain accumulation of serum proteins and several vasculotoxic and/or neurotoxic macromolecules ultimately leading to secondary neuronal degenerative changes. We show that age-dependent vascular damage in pericyte-deficient mice precedes neuronal degenerative changes, learning and memory impairment and the neuroinflammatory response. Thus, pericytes control key neurovascular functions that are necessary for proper neuronal structure and function, and pericytes loss results in a progressive age-dependent vascular-mediated neurodegeneration. PMID:21040844

  20. Life Satisfaction in Adult Survivors of Childhood Brain Tumors

    PubMed Central

    Crom, Deborah B.; Li, Zhenghong; Brinkman, Tara M.; Hudson, Melissa M.; Armstrong, Gregory T.; Neglia, Joseph; Ness, Kirsten K.

    2014-01-01

    Adult survivors of childhood brain tumors experience multiple, significant, life-long deficits as a consequence of their malignancy and therapy. Current survivorship literature documents the substantial impact such impairments have on survivors’ physical health and quality of life. Psychosocial reports detail educational, cognitive, and emotional limitations characterizing survivors as especially fragile, often incompetent, and unreliable in evaluating their circumstances. Anecdotal data suggests some survivors report life experiences similar to those of healthy controls. The aim of our investigation was to determine whether life satisfaction in adult survivors of childhood brain tumors differs from that of healthy controls and to identify potential predictors of life satisfaction in survivors. This cross-sectional study compared 78 brain tumor survivors with population–based matched controls. Chi-square tests, t-tests, and linear regression models were used to investigate patterns of life satisfaction and identify potential correlates. Results indicated life satisfaction of adult survivors of childhood brain tumors was similar to that of healthy controls. Survivors’ general health expectations emerged as the primary correlate of life satisfaction. Understanding life satisfaction as an important variable will optimize the design of strategies to enhance participation in follow-up care, reduce suffering, and optimize quality of life in this vulnerable population. PMID:25027187

  1. Life satisfaction in adult survivors of childhood brain tumors.

    PubMed

    Crom, Deborah B; Li, Zhenghong; Brinkman, Tara M; Hudson, Melissa M; Armstrong, Gregory T; Neglia, Joseph; Ness, Kirsten K

    2014-01-01

    Adult survivors of childhood brain tumors experience multiple, significant, lifelong deficits as a consequence of their malignancy and therapy. Current survivorship literature documents the substantial impact such impairments have on survivors' physical health and quality of life. Psychosocial reports detail educational, cognitive, and emotional limitations characterizing survivors as especially fragile, often incompetent, and unreliable in evaluating their circumstances. Anecdotal data suggest some survivors report life experiences similar to those of healthy controls. The aim of our investigation was to determine whether life satisfaction in adult survivors of childhood brain tumors differs from that of healthy controls and to identify potential predictors of life satisfaction in survivors. This cross-sectional study compared 78 brain tumor survivors with population-based matched controls. Chi-square tests, t tests, and linear regression models were used to investigate patterns of life satisfaction and identify potential correlates. Results indicated that life satisfaction of adult survivors of childhood brain tumors was similar to that of healthy controls. Survivors' general health expectations emerged as the primary correlate of life satisfaction. Understanding life satisfaction as an important variable will optimize the design of strategies to enhance participation in follow-up care, reduce suffering, and optimize quality of life in this vulnerable population.

  2. Developmental exposure of zebrafish (Danio rerio) to bisphenol-S impairs subsequent reproduction potential and hormonal balance in adults.

    PubMed

    Naderi, Mohammad; Wong, Marian Y L; Gholami, Fatemeh

    2014-03-01

    In the recent years, there has been a growing concern about the production and use of bisphenol-A substitute, namely bisphenol-S (BPS). Due to its novel nature, there have been few studies addressing the ability of BPS to disrupt the endocrine system of animals. In the present study, zebrafish (Danio rerio) embryos were exposed to and reared in various concentrations of BPS (0, 0.1, 1, 10 and 100 μg/l) for 75 days. Then adult males and females were paired in spawning tanks for 7 days in clean water and the consequent effects on fish development, reproduction, plasma vitellogenin (VTG), sex steroids and thyroid hormone levels were investigated as endpoints. After 75 days of exposure, there was a skewed sex ratio in favor of females. The results also showed that body length and weight significantly decreased in males exposed to 100 μg/l of BPS. Gonadosomatic index was significantly reduced in fish at ≥ 10 μg/l. Hepatosomatic index exhibited a significant increase in both male and female fish. At ≥ 1 μg/l of BPS, plasma 17β-estradiol levels were significantly increased in both males and females. However, plasma testosterone showed a significant reduction in males exposed to 10 and 100 μg/l of BPS. A significant induction in plasma VTG level was observed in both males and females at ≥ 10 μg/l of BPS. Plasma thyroxine and triiodothyronine levels were significantly decreased at 10 and 100 μg/l of BPS in males, and at 100 μg/l in females. Egg production and sperm count were also significantly decreased in groups received 10 and 100 μg/l of BPS. Moreover, once time to hatching and hatching rates were calculated for fertilized eggs the postponed and decreased rates of hatching were observed. Taken together, these results suggest that developmental exposure to low concentrations of BPS has adverse effects on different parts of the endocrine system in zebrafish.

  3. Short-term memory in zebrafish (Danio rerio).

    PubMed

    Jia, Jason; Fernandes, Yohaan; Gerlai, Robert

    2014-08-15

    Learning and memory represent perhaps the most complex behavioral phenomena. Although their underlying mechanisms have been extensively analyzed, only a fraction of the potential molecular components have been identified. The zebrafish has been proposed as a screening tool with which mechanisms of complex brain functions may be systematically uncovered. However, as a relative newcomer in behavioral neuroscience, the zebrafish has not been well characterized for its cognitive and mnemonic features, thus learning and/or memory screens with adults have not been feasible. Here we study short-term memory of adult zebrafish. We show animated images of conspecifics (the stimulus) to the experimental subject during 1 min intervals on ten occasions separated by different (2, 4, 8 or 16 min long) inter-stimulus intervals (ISI), a between subject experimental design. We quantify the distance of the subject from the image presentation screen during each stimulus presentation interval, during each of the 1-min post-stimulus intervals immediately following the stimulus presentations and during each of the 1-min intervals furthest away from the last stimulus presentation interval and just before the next interval (pre-stimulus interval), respectively. Our results demonstrate significant retention of short-term memory even in the longest ISI group but suggest no acquisition of reference memory. Because in the employed paradigm both stimulus presentation and behavioral response quantification is computer automated, we argue that high-throughput screening for drugs or mutations that alter short-term memory performance of adult zebrafish is now becoming feasible.

  4. Retinoic acid signaling controls the formation, proliferation and survival of the blastema during adult zebrafish fin regeneration.

    PubMed

    Blum, Nicola; Begemann, Gerrit

    2012-01-01

    Adult teleosts rebuild amputated fins through a proliferation-dependent process called epimorphic regeneration, in which a blastema of cycling progenitor cells replaces the lost fin tissue. The genetic networks that control formation of blastema cells from formerly quiescent stump tissue and subsequent blastema function are still poorly understood. Here, we investigated the cellular and molecular consequences of genetically interfering with retinoic acid (RA) signaling for the formation of the zebrafish blastema. We show that RA signaling is upregulated within the first few hours after fin amputation in the stump mesenchyme, where it controls Fgf, Wnt/β-catenin and Igf signaling. Genetic inhibition of the RA pathway at this stage blocks blastema formation by inhibiting cell cycle entry of stump cells and impairs the formation of the basal epidermal layer, a signaling center in the wound epidermis. In the established blastema, RA signaling remains active to ensure the survival of the highly proliferative blastemal population by controlling expression of the anti-apoptotic factor bcl2. In addition, RA signaling maintains blastema proliferation through the activation of growth-stimulatory signals mediated by Fgf and Wnt/β-catenin signaling, as well as by reducing signaling through the growth-inhibitory non-canonical Wnt pathway. The endogenous roles of RA in adult vertebrate appendage regeneration are uncovered here for the first time. They provide a mechanistic framework to understand previous observations in salamanders that link endogenous sources of RA to the regeneration process itself and support the hypothesis that the RA signaling pathway is an essential component of vertebrate tissue regeneration.

  5. Experimental selection for body size at age modifies early life-history traits and muscle gene expression in adult zebrafish.

    PubMed

    Amaral, Ian P G; Johnston, Ian A

    2012-11-15

    The short generation time of the zebrafish (Danio rerio) was exploited to investigate the effects of selection for body size at age on early life-history traits and on the transcriptional response to a growth stimulus in skeletal muscle of adult fish. Replicate populations were either unselected (U-lineage) or subjected to four generations of experimental selection for small (S-lineage) or large (L-lineage) body size at 90 days post-fertilization. Body mass was on average 16.3% and 41.0% higher in the L- than in the U- and S-lineages, respectively. Egg diameter was 6.4% lower with 13% less yolk in the S-lineage compared with the other lineages. Maternal transcripts for igf2r, bmpr1aa, igf1ar, igf2a, igfbp5a, ghra and igfbp3 in 2-4 cell stage embryos were higher in the L- than in the S-lineage. Larvae from the L-lineage were significantly larger, but survivorship at the end of the first month was similar between lineages. Gene expression was measured in the fast muscle of adult fish fasted for 7 days and then re-fed to satiation for 48 h. The expression of 11 insulin-like growth factor pathway genes and 12 other nutritionally responsive genes was similar for the S- and L-lineages as was gut fullness with feeding. Transcript abundance for four genes (igf1a, igf2r, igfbp1a and igfbp1b) showed either regulated or constitutive differences between the S- and L-lineages. For example, igf2 receptor transcript abundance was higher and igbp1a/b transcript abundance was lower in the L- than in the S-lineage, consistent with an effect of selection on insulin-like growth factor signalling.

  6. Decreased segregation of brain systems across the healthy adult lifespan

    PubMed Central

    Chan, Micaela Y.; Park, Denise C.; Savalia, Neil K.; Petersen, Steven E.; Wig, Gagan S.

    2014-01-01

    Healthy aging has been associated with decreased specialization in brain function. This characterization has focused largely on describing age-accompanied differences in specialization at the level of neurons and brain areas. We expand this work to describe systems-level differences in specialization in a healthy adult lifespan sample (n = 210; 20–89 y). A graph-theoretic framework is used to guide analysis of functional MRI resting-state data and describe systems-level differences in connectivity of individual brain networks. Young adults’ brain systems exhibit a balance of within- and between-system correlations that is characteristic of segregated and specialized organization. Increasing age is accompanied by decreasing segregation of brain systems. Compared with systems involved in the processing of sensory input and motor output, systems mediating “associative” operations exhibit a distinct pattern of reductions in segregation across the adult lifespan. Of particular importance, the magnitude of association system segregation is predictive of long-term memory function, independent of an individual’s age. PMID:25368199

  7. Prenatal ethanol exposure increases brain cholesterol content in adult rats.

    PubMed

    Barceló-Coblijn, Gwendolyn; Wold, Loren E; Ren, Jun; Murphy, Eric J

    2013-11-01

    Fetal alcohol syndrome is the most severe expression of the fetal alcohol spectrum disorders (FASD). Although alterations in fetal and neonate brain fatty acid composition and cholesterol content are known to occur in animal models of FASD, the persistence of these alterations into adulthood is unknown. To address this question, we determined the effect of prenatal ethanol exposure on individual phospholipid class fatty acid composition, individual phospholipid class mass, and cholesterol mass in brains from 25-week-old rats that were exposed to ethanol during gestation beginning at gestational day 2. While total phospholipid mass was unaffected, phosphatidylinositol and cardiolipin mass was decreased 14 and 43 %, respectively. Exposure to prenatal ethanol modestly altered brain phospholipid fatty acid composition, and the most consistent change was a significant 1.1-fold increase in total polyunsaturated fatty acids (PUFA), in the n-3/n-6 ratio, and in the 22:6n-3 content in ethanolamine glycerophospholipids and in phosphatidylserine. In contrast, prenatal ethanol consumption significantly increased brain cholesterol mass 1.4-fold and the phospholipid to cholesterol ratio was significantly increased 1.3-fold. These results indicate that brain cholesterol mass was significantly increased in adult rats exposed prenatally to ethanol, but changes in phospholipid mass and phospholipid fatty acid composition were extremely limited. Importantly, suppression of postnatal ethanol consumption was not sufficient to reverse the large increase in cholesterol observed in the adult rats.

  8. Deep Brain Photoreceptor (val-opsin) Gene Knockout Using CRISPR/Cas Affects Chorion Formation and Embryonic Hatching in the Zebrafish

    PubMed Central

    Hang, Chong Yee; Moriya, Shogo; Ogawa, Satoshi; Parhar, Ishwar S.

    2016-01-01

    Non-rod non-cone photopigments in the eyes and the brain can directly mediate non-visual functions of light in non-mammals. This was supported by our recent findings on vertebrate ancient long (VAL)-opsin photopigments encoded by the val-opsinA (valopa) and val-opsinB (valopb) genes in zebrafish. However, the physiological functions of valop isoforms remain unknown. Here, we generated valop-mutant zebrafish using CRISPR/Cas genome editing, and examined the phenotypes of loss-of-function mutants. F0 mosaic mutations and germline transmission were confirmed via targeted insertions and/or deletions in the valopa or valopb gene in F1 mutants. Based on in silico analysis, frameshift mutations converted VAL-opsin proteins to non-functional truncated forms with pre-mature stop codons. Most F1 eggs or embryos from F0 female valopa/b mutants showed either no or only partial chorion elevation, and the eggs or embryos died within 26 hour-post-fertilization. However, most F1 embryos from F0 male valopa mutant developed but hatched late compared to wild-type embryos, which hatched at 4 day-post-fertilization. Late-hatched F1 offspring included wild-type and mutants, indicating the parental effects of valop knockout. This study shows valop gene knockout affects chorion formation and embryonic hatching in the zebrafish. PMID:27792783

  9. Clinical review: Brain-body temperature differences in adults with severe traumatic brain injury.

    PubMed

    Childs, Charmaine; Lunn, Kueh Wern

    2013-04-22

    Surrogate or 'proxy' measures of brain temperature are used in the routine management of patients with brain damage. The prevailing view is that the brain is 'hotter' than the body. The polarity and magnitude of temperature differences between brain and body, however, remains unclear after severe traumatic brain injury (TBI). The focus of this systematic review is on the adult patient admitted to intensive/neurocritical care with a diagnosis of severe TBI (Glasgow Coma Scale score of less than 8). The review considered studies that measured brain temperature and core body temperature. Articles published in English from the years 1980 to 2012 were searched in databases, CINAHL, PubMed, Scopus, Web of Science, Science Direct, Ovid SP, Mednar and ProQuest Dissertations & Theses Database. For the review, publications of randomised controlled trials, non-randomised controlled trials, before and after studies, cohort studies, case-control studies and descriptive studies were considered for inclusion. Of 2,391 records identified via the search strategies, 37 were retrieved for detailed examination (including two via hand searching). Fifteen were reviewed and assessed for methodological quality. Eleven studies were included in the systematic review providing 15 brain-core body temperature comparisons. The direction of mean brain-body temperature differences was positive (brain higher than body temperature) and negative (brain lower than body temperature). Hypothermia is associated with large brain-body temperature differences. Brain temperature cannot be predicted reliably from core body temperature. Concurrent monitoring of brain and body temperature is recommended in patients where risk of temperature-related neuronal damage is a cause for clinical concern and when deliberate induction of below-normal body temperature is instituted.

  10. A meal preparation treatment protocol for adults with brain injury.

    PubMed

    Neistadt, M E

    1994-05-01

    Adults with acquired brain injury often demonstrate dysfunction in meal preparation due to deficits in component cognitive-perceptual skills. Although occupational therapy for these clients routinely includes meal preparation training, there are no protocols in the occupational therapy literature to help structure that activity to address clients' cognitive-perceptual deficits. This paper describes a meal preparation treatment protocol based on cognitive-perceptual information processing theory that has been pilot tested in a treatment outcome study with adult men with traumatic or anoxic acquired brain injury. In that study, the group of 23 subjects treated with this meal preparation protocol showed significant improvement in their meal preparation skill, as measured by the Rabideau Kitchen Evaluation-Revised (RKE-R), a test of meal preparation skill, and in their cognitive-perceptual skill, as measured by the WAIS-R Block Design Test. The treatment protocol includes descriptions of the structure, grading, and cuing methods for light meal preparation activities.

  11. Comprehensive cellular‐resolution atlas of the adult human brain

    PubMed Central

    Royall, Joshua J.; Sunkin, Susan M.; Ng, Lydia; Facer, Benjamin A.C.; Lesnar, Phil; Guillozet‐Bongaarts, Angie; McMurray, Bergen; Szafer, Aaron; Dolbeare, Tim A.; Stevens, Allison; Tirrell, Lee; Benner, Thomas; Caldejon, Shiella; Dalley, Rachel A.; Dee, Nick; Lau, Christopher; Nyhus, Julie; Reding, Melissa; Riley, Zackery L.; Sandman, David; Shen, Elaine; van der Kouwe, Andre; Varjabedian, Ani; Write, Michelle; Zollei, Lilla; Dang, Chinh; Knowles, James A.; Koch, Christof; Phillips, John W.; Sestan, Nenad; Wohnoutka, Paul; Zielke, H. Ronald; Hohmann, John G.; Jones, Allan R.; Bernard, Amy; Hawrylycz, Michael J.; Hof, Patrick R.; Fischl, Bruce

    2016-01-01

    ABSTRACT Detailed anatomical understanding of the human brain is essential for unraveling its functional architecture, yet current reference atlases have major limitations such as lack of whole‐brain coverage, relatively low image resolution, and sparse structural annotation. We present the first digital human brain atlas to incorporate neuroimaging, high‐resolution histology, and chemoarchitecture across a complete adult female brain, consisting of magnetic resonance imaging (MRI), diffusion‐weighted imaging (DWI), and 1,356 large‐format cellular resolution (1 µm/pixel) Nissl and immunohistochemistry anatomical plates. The atlas is comprehensively annotated for 862 structures, including 117 white matter tracts and several novel cyto‐ and chemoarchitecturally defined structures, and these annotations were transferred onto the matching MRI dataset. Neocortical delineations were done for sulci, gyri, and modified Brodmann areas to link macroscopic anatomical and microscopic cytoarchitectural parcellations. Correlated neuroimaging and histological structural delineation allowed fine feature identification in MRI data and subsequent structural identification in MRI data from other brains. This interactive online digital atlas is integrated with existing Allen Institute for Brain Science gene expression atlases and is publicly accessible as a resource for the neuroscience community. J. Comp. Neurol. 524:3127–3481, 2016. © 2016 The Authors The Journal of Comparative Neurology Published by Wiley Periodicals, Inc. PMID:27418273

  12. Ketone-body utilization by homogenates of adult rat brain

    SciTech Connect

    Lopes-Cardozo, M.; Klein, W.

    1982-06-01

    The regulation of ketone-body metabolism and the quantitative importance of ketone bodies as lipid precursors in adult rat brain has been studied in vitro. Utilization of ketone bodies and of pyruvate by homogenates of adult rat brain was measured and the distribution of /sup 14/C from (3-/sup 14/C)ketone bodies among the metabolic products was analysed. The rate of ketone-body utilization was maximal in the presence of added Krebs-cycle intermediates and uncouplers of oxidative phosphorylation. The consumption of acetoacetate was faster than that of D-3-hydroxybutyrate, whereas, pyruvate produced twice as much acetyl-CoA as acetoacetate under optimal conditions. Millimolar concentrations of ATP in the presence of uncoupler lowered the consumption of ketone bodies but not of pyruvate. Indirect evidence is presented suggesting that ATP interferes specifically with the mitochondrial uptake of ketone bodies. Interconversion of ketone bodies and the accumulation of acid-soluble intermediates (mainly citrate and glutamate) accounted for the major part of ketone-body utilization, whereas only a small part was oxidized to CO/sub 2/. Ketone bodies were not incorporated into lipids or protein. We conclude that adult rat-brain homogenates use ketone bodies exclusively for oxidative purposes.

  13. A novel brain tumour model in zebrafish reveals the role of YAP activation in MAPK- and PI3K-induced malignant growth

    PubMed Central

    Mayrhofer, Marie; Gourain, Victor; Reischl, Markus; Affaticati, Pierre; Jenett, Arnim; Joly, Jean-Stephane; Benelli, Matteo; Demichelis, Francesca; Poliani, Pietro Luigi; Sieger, Dirk

    2017-01-01

    ABSTRACT Somatic mutations activating MAPK and PI3K signalling play a pivotal role in both tumours and brain developmental disorders. We developed a zebrafish model of brain tumours based on somatic expression of oncogenes that activate MAPK and PI3K signalling in neural progenitor cells and found that HRASV12 was the most effective in inducing both heterotopia and invasive tumours. Tumours, but not heterotopias, require persistent activation of phospho (p)-ERK and express a gene signature similar to the mesenchymal glioblastoma subtype, with a strong YAP component. Application of an eight-gene signature to human brain tumours establishes that YAP activation distinguishes between mesenchymal glioblastoma and low grade glioma in a wide The Cancer Genome Atlas (TCGA) sample set including gliomas and glioblastomas (GBMs). This suggests that the activation of YAP might be an important event in brain tumour development, promoting malignant versus benign brain lesions. Indeed, co-expression of dominant-active YAP (YAPS5A) and HRASV12 abolishes the development of heterotopias and leads to the sole development of aggressive tumours. Thus, we have developed a model proving that neurodevelopmental disorders and brain tumours might originate from the same activation of oncogenes through somatic mutations, and established that YAP activation is a hallmark of malignant brain tumours. PMID:27935819

  14. Brain network activity in monolingual and bilingual older adults.

    PubMed

    Grady, Cheryl L; Luk, Gigi; Craik, Fergus I M; Bialystok, Ellen

    2015-01-01

    Bilingual older adults typically have better performance on tasks of executive control (EC) than do their monolingual peers, but differences in brain activity due to language experience are not well understood. Based on studies showing a relation between the dynamic range of brain network activity and performance on EC tasks, we hypothesized that life-long bilingual older adults would show increased functional connectivity relative to monolinguals in networks related to EC. We assessed intrinsic functional connectivity and modulation of activity in task vs. fixation periods in two brain networks that are active when EC is engaged, the frontoparietal control network (FPC) and the salience network (SLN). We also examined the default mode network (DMN), which influences behavior through reduced activity during tasks. We found stronger intrinsic functional connectivity in the FPC and DMN in bilinguals than in monolinguals. Although there were no group differences in the modulation of activity across tasks and fixation, bilinguals showed stronger correlations than monolinguals between intrinsic connectivity in the FPC and task-related increases of activity in prefrontal and parietal regions. This bilingual difference in network connectivity suggests that language experience begun in childhood and continued throughout adulthood influences brain networks in ways that may provide benefits in later life.

  15. Brain Network Activity in Monolingual and Bilingual Older Adults

    PubMed Central

    Grady, Cheryl L.; Luk, Gigi; Craik, Fergus I.M.; Bialystok, Ellen

    2016-01-01

    Bilingual older adults typically have better performance on tasks of executive control (EC) than do their monolingual peers, but differences in brain activity due to language experience are not well understood. Based on studies showing a relation between the dynamic range of brain network activity and performance on EC tasks, we hypothesized that life-long bilingual older adults would show increased functional connectivity relative to monolinguals in networks related to EC. We assessed intrinsic functional connectivity and modulation of activity in task vs. fixation periods in two brain networks that are active when EC is engaged, the frontoparietal control network (FPC) and the salience network (SLN). We also examined the default mode network (DMN), which influences behavior through reduced activity during tasks. We found stronger intrinsic functional connectivity in the FPC and DMN in bilinguals than in monolinguals. Although there were no group differences in the modulation of activity across tasks and fixation, bilinguals showed stronger correlations than monolinguals between intrinsic connectivity in the FPC and task-related increases of activity in prefrontal and parietal regions. This bilingual difference in network connectivity suggests that language experience begun in childhood and continued throughout adulthood influences brain networks in ways that may provide benefits in later life. PMID:25445783

  16. Time Spent Caregiving and Help Received by Spouses and Adult Children of Brain-Impaired Adults.

    ERIC Educational Resources Information Center

    Enright, Robert B., Jr.

    1991-01-01

    Surveyed 233 family caregivers for brain-impaired adults. Spousal caregivers (both husbands and wives) devoted much time to caregiving. Most caregivers received little assistance from other family members and friends, but husbands received more than others. Employed spouses received more paid help than unemployed spouses; employment did not affect…

  17. Epigenetic choreographers of neurogenesis in the adult mammalian brain

    PubMed Central

    Ma, Dengke K; Marchetto, Maria Carolina; Guo, Junjie U; Ming, Guo-li; Gage, Fred H; Song, Hongjun

    2012-01-01

    Epigenetic mechanisms regulate cell differentiation during embryonic development and also serve as important interfaces between genes and the environment in adulthood. Neurogenesis in adults, which generates functional neural cell types from adult neural stem cells, is dynamically regulated by both intrinsic state-specific cell differentiation cues and extrinsic neural niche signals. Epigenetic regulation by DNA and histone modifiers, non-coding RNAs and other self-sustained mechanisms can lead to relatively long-lasting biological effects and maintain functional neurogenesis throughout life in discrete regions of the mammalian brain. Here, we review recent evidence that epigenetic mechanisms carry out diverse roles in regulating specific aspects of adult neurogenesis and highlight the implications of such epigenetic regulation for neural plasticity and disorders. PMID:20975758

  18. Preference for ethanol in zebrafish following a single exposure.

    PubMed

    Mathur, Priya; Berberoglu, Michael A; Guo, Su

    2011-02-02

    Ethanol is one of the most widely abused drugs in the world. Its addictive property is believed to primarily stem from its ability to influence the brain reinforcement pathway evolved for mediating natural rewards. Although dopamine is a known component of the reinforcement pathway, clear molecular and cellular compositions of this pathway and its sensitivity to ethanol remain not well understood. Zebrafish has been increasingly used to model and understand human disease states, due to its genetic tractability and ease of maintenance. In this study, we determine whether adult zebrafish develop ethanol preference after a single exposure using a conditioned place preference (CPP) paradigm. Moreover, we establish a procedure that can be carried out in an automated and relatively high-throughput fashion. We find that zebrafish of the AB strain display significantly increased preference for the compartment where they received ethanol during a single 20-min exposure. The largest increase in preference is in response to a 1.5% ethanol administered in the tank water. The results demonstrate robust ethanol preference in zebrafish. Such a relatively high-throughput assay with automated tracking and response to a single ethanol exposure provides a potential means for a large-scale screening aimed at understanding the brain reinforcement pathway and its sensitivity to ethanol in this genetically tractable vertebrate.

  19. Caffeine neuroprotects against dexamethasone-induced anxiety-like behaviour in the Zebrafish (Danio rerio).

    PubMed

    Khor, Yee Min; Soga, Tomoko; Parhar, Ishwar S

    2013-01-15

    The early-life stress has critical impact on brain development which can lead to long-term effects on brain functions during adulthood. It has been reported that caffeine possesses a protective effect in neurodegenerative diseases. Thus, this study investigates the potential of caffeine to protect brain functions from adverse effects due to stress exposure during early-life development in the male zebrafish. In the first part of this study, synthetic glucocorticoid, dexamethasone (DEX) (2-200 mg/L for 24 h) was used to induce stress effects in the zebrafish larvae from 4 to 5 days post-fertilisation (dpf) and the effect of DEX administration on zebrafish larvae on anxiety-like behaviour during adulthood in novel tank test was investigated. Next, the possible protective effect of caffeine pre-treatment (5-50 mg/L for 24 h from 3 to 4dpf) before DEX administration was studied. DEX-treated adult male zebrafish showed higher anxiety levels in behavioural tests, as seen in longer latency to enter the top part of the tank, lower transition numbers between the top and bottom parts with more time spent at the bottom and lesser time spent at the top and lower distance travelled at top part. The effect of DEX on anxiety-like behaviour was dose-dependent. Importantly, adult male zebrafish pre-treated with caffeine before DEX treatment did not show any anxiety-like behaviour. These results show that exposure to stress during early-life leads to anxiety-like behaviour in the adult male zebrafish but pre-treatment with caffeine protects from stress-induced anxiety.

  20. The Mammalian “Obesogen” Tributyltin Targets Hepatic Triglyceride Accumulation and the Transcriptional Regulation of Lipid Metabolism in the Liver and Brain of Zebrafish

    PubMed Central

    Lyssimachou, Angeliki; Santos, Joana G.; André, Ana; Soares, Joana; Lima, Daniela; Guimarães, Laura; Almeida, C. Marisa R.; Teixeira, Catarina; Castro, L. Filipe C.; Santos, Miguel M.

    2015-01-01

    Recent findings indicate that different Endocrine Disrupting Chemicals (EDCs) interfere with lipid metabolic pathways in mammals and promote fat accumulation, a previously unknown site of action for these compounds. The antifoulant and environmental pollutant tributyltin (TBT), which causes imposex in gastropod snails, induces an “obesogenic” phenotype in mammals, through the activation of the nuclear receptors retinoid X receptor (RXR) and peroxisome proliferator-activated receptor gamma (PPARγ). In teleosts, the effects of TBT on the lipid metabolism are poorly understood, particularly following exposure to low, environmental concentrations. In this context, the present work shows that exposure of zebrafish to 10 and 50 ng/L of TBT (as Sn) from pre-hatch to 9 months of age alters the body weight, condition factor, hepatosomatic index and hepatic triglycerides in a gender and dose related manner. Furthermore, TBT modulated the transcription of key lipid regulating factors and enzymes involved in adipogenesis, lipogenesis, glucocorticoid metabolism, growth and development in the brain and liver of exposed fish, revealing sexual dimorphic effects in the latter. Overall, the present study shows that the model mammalian obesogen TBT interferes with triglyceride accumulation and the transcriptional regulation of lipid metabolism in zebrafish and indentifies the brain lipogenic transcription profile of fish as a new target of this compound. PMID:26633012

  1. The Mammalian "Obesogen" Tributyltin Targets Hepatic Triglyceride Accumulation and the Transcriptional Regulation of Lipid Metabolism in the Liver and Brain of Zebrafish.

    PubMed

    Lyssimachou, Angeliki; Santos, Joana G; André, Ana; Soares, Joana; Lima, Daniela; Guimarães, Laura; Almeida, C Marisa R; Teixeira, Catarina; Castro, L Filipe C; Santos, Miguel M

    2015-01-01

    Recent findings indicate that different Endocrine Disrupting Chemicals (EDCs) interfere with lipid metabolic pathways in mammals and promote fat accumulation, a previously unknown site of action for these compounds. The antifoulant and environmental pollutant tributyltin (TBT), which causes imposex in gastropod snails, induces an "obesogenic" phenotype in mammals, through the activation of the nuclear receptors retinoid X receptor (RXR) and peroxisome proliferator-activated receptor gamma (PPARγ). In teleosts, the effects of TBT on the lipid metabolism are poorly understood, particularly following exposure to low, environmental concentrations. In this context, the present work shows that exposure of zebrafish to 10 and 50 ng/L of TBT (as Sn) from pre-hatch to 9 months of age alters the body weight, condition factor, hepatosomatic index and hepatic triglycerides in a gender and dose related manner. Furthermore, TBT modulated the transcription of key lipid regulating factors and enzymes involved in adipogenesis, lipogenesis, glucocorticoid metabolism, growth and development in the brain and liver of exposed fish, revealing sexual dimorphic effects in the latter. Overall, the present study shows that the model mammalian obesogen TBT interferes with triglyceride accumulation and the transcriptional regulation of lipid metabolism in zebrafish and indentifies the brain lipogenic transcription profile of fish as a new target of this compound.

  2. Identification of estrogen target genes during zebrafish embryonic development through transcriptomic analysis.

    PubMed

    Hao, Ruixin; Bondesson, Maria; Singh, Amar V; Riu, Anne; McCollum, Catherine W; Knudsen, Thomas B; Gorelick, Daniel A; Gustafsson, Jan-Åke

    2013-01-01

    Estrogen signaling is important for vertebrate embryonic development. Here we have used zebrafish (Danio rerio) as a vertebrate model to analyze estrogen signaling during development. Zebrafish embryos were exposed to 1 µM 17β-estradiol (E2) or vehicle from 3 hours to 4 days post fertilization (dpf), harvested at 1, 2, 3 and 4 dpf, and subjected to RNA extraction for transcriptome analysis using microarrays. Differentially expressed genes by E2-treatment were analyzed with hierarchical clustering followed by biological process and tissue enrichment analysis. Markedly distinct sets of genes were up and down-regulated by E2 at the four different time points. Among these genes, only the well-known estrogenic marker vtg1 was co-regulated at all time points. Despite this, the biological functional categories targeted by E2 were relatively similar throughout zebrafish development. According to knowledge-based tissue enrichment, estrogen responsive genes were clustered mainly in the liver, pancreas and brain. This was in line with the developmental dynamics of estrogen-target tissues that were visualized using transgenic zebrafish containing estrogen responsive elements driving the expression of GFP (Tg(5xERE:GFP)). Finally, the identified embryonic estrogen-responsive genes were compared to already published estrogen-responsive genes identified in male adult zebrafish (Gene Expression Omnibus database). The expressions of a few genes were co-regulated by E2 in both embryonic and adult zebrafish. These could potentially be used as estrogenic biomarkers for exposure to estrogens or estrogenic endocrine disruptors in zebrafish. In conclusion, our data suggests that estrogen effects on early embryonic zebrafish development are stage- and tissue- specific.

  3. Identification of Estrogen Target Genes during Zebrafish Embryonic Development through Transcriptomic Analysis

    PubMed Central

    Hao, Ruixin; Bondesson, Maria; Singh, Amar V.; Riu, Anne; McCollum, Catherine W.; Knudsen, Thomas B.; Gorelick, Daniel A.; Gustafsson, Jan-Åke

    2013-01-01

    Estrogen signaling is important for vertebrate embryonic development. Here we have used zebrafish (Danio rerio) as a vertebrate model to analyze estrogen signaling during development. Zebrafish embryos were exposed to 1 µM 17β-estradiol (E2) or vehicle from 3 hours to 4 days post fertilization (dpf), harvested at 1, 2, 3 and 4 dpf, and subjected to RNA extraction for transcriptome analysis using microarrays. Differentially expressed genes by E2-treatment were analyzed with hierarchical clustering followed by biological process and tissue enrichment analysis. Markedly distinct sets of genes were up and down-regulated by E2 at the four different time points. Among these genes, only the well-known estrogenic marker vtg1 was co-regulated at all time points. Despite this, the biological functional categories targeted by E2 were relatively similar throughout zebrafish development. According to knowledge-based tissue enrichment, estrogen responsive genes were clustered mainly in the liver, pancreas and brain. This was in line with the developmental dynamics of estrogen-target tissues that were visualized using transgenic zebrafish containing estrogen responsive elements driving the expression of GFP (Tg(5xERE:GFP)). Finally, the identified embryonic estrogen-responsive genes were compared to already published estrogen-responsive genes identified in male adult zebrafish (Gene Expression Omnibus database). The expressions of a few genes were co-regulated by E2 in both embryonic and adult zebrafish. These could potentially be used as estrogenic biomarkers for exposure to estrogens or estrogenic endocrine disruptors in zebrafish. In conclusion, our data suggests that estrogen effects on early embryonic zebrafish development are stage- and tissue- specific. PMID:24223173

  4. Acute moderate exercise enhances compensatory brain activation in older adults.

    PubMed

    Hyodo, Kazuki; Dan, Ippeita; Suwabe, Kazuya; Kyutoku, Yasushi; Yamada, Yuhki; Akahori, Mitsuya; Byun, Kyeongho; Kato, Morimasa; Soya, Hideaki

    2012-11-01

    A growing number of reports state that regular exercise enhances brain function in older adults. Recently a functional near-infrared spectroscopy (fNIRS) study revealed that an acute bout of moderate exercise enhanced activation of the left dorsolateral prefrontal cortex (L-DLPFC) associated with Stroop interference in young adults. Whether this acute effect is also applicable to older adults was examined. Sixteen older adults performed a color-word matching Stroop task before and after 10 minutes of exercise on a cycle ergometer at a moderate intensity. Cortical hemodynamics of the prefrontal area was monitored with a fNIRS during the Stroop task. We analyzed Stroop interference (incongruent-neutral) as Stroop performance. Though activation for Stroop interference was found in the bilateral prefrontal area before the acute bout of exercise, activation of the right frontopolar area (R-FPA) was enhanced after exercise. In the majority of participants, this coincided with improved performance reflected in Stroop interference results. Thus, an acute bout of moderate exercise improved Stroop performance in older adults, and this was associated with contralateral compensatory activation.

  5. Analyzing the structure and function of neuronal circuits in zebrafish

    PubMed Central

    Friedrich, Rainer W.; Genoud, Christel; Wanner, Adrian A.

    2013-01-01

    The clever choice of animal models has been instrumental for many breakthrough discoveries in life sciences. One of the outstanding challenges in neuroscience is the in-depth analysis of neuronal circuits to understand how interactions between large numbers of neurons give rise to the computational power of the brain. A promising model organism to address this challenge is the zebrafish, not only because it is cheap, transparent and accessible to sophisticated genetic manipulations but also because it offers unique advantages for quantitative analyses of circuit structure and function. One of the most important advantages of zebrafish is its small brain size, both at larval and adult stages. Small brains enable exhaustive measurements of neuronal activity patterns by optical imaging and facilitate large-scale reconstructions of wiring diagrams by electron microscopic approaches. Such information is important, and probably essential, to obtain mechanistic insights into neuronal computations underlying higher brain functions and dysfunctions. This review provides a brief overview over current methods and motivations for dense reconstructions of neuronal activity and connectivity patterns. It then discusses selective advantages of zebrafish and provides examples how these advantages are exploited to study neuronal computations in the olfactory bulb. PMID:23630467

  6. Neuroimaging in adult penetrating brain injury: a guide for radiographers

    PubMed Central

    Temple, Nikki; Donald, Cortny; Skora, Amanda; Reed, Warren

    2015-01-01

    Penetrating brain injuries (PBI) are a medical emergency, often resulting in complex damage and high mortality rates. Neuroimaging is essential to evaluate the location and extent of injuries, and to manage them accordingly. Currently, a myriad of imaging modalities are included in the diagnostic workup for adult PBI, including skull radiography, computed tomography (CT), magnetic resonance imaging (MRI) and angiography, with each modality providing their own particular benefits. This literature review explores the current modalities available for investigating PBI and aims to assist in decision making for the appropriate use of diagnostic imaging when presented with an adult PBI. Based on the current literature, the authors have developed an imaging pathway for adult penetrating brain injury that functions as both a learning tool and reference guide for radiographers and other health professionals. Currently, CT is recommended as the imaging modality of choice for the initial assessment of PBI patients, while MRI is important in the sub-acute setting where it aids prognosis prediction and rehabilitation planning, Additional follow-up imaging, such as angiography, should be dependent upon clinical findings. PMID:26229677

  7. Neuroimaging in adult penetrating brain injury: a guide for radiographers.

    PubMed

    Temple, Nikki; Donald, Cortny; Skora, Amanda; Reed, Warren

    2015-06-01

    Penetrating brain injuries (PBI) are a medical emergency, often resulting in complex damage and high mortality rates. Neuroimaging is essential to evaluate the location and extent of injuries, and to manage them accordingly. Currently, a myriad of imaging modalities are included in the diagnostic workup for adult PBI, including skull radiography, computed tomography (CT), magnetic resonance imaging (MRI) and angiography, with each modality providing their own particular benefits. This literature review explores the current modalities available for investigating PBI and aims to assist in decision making for the appropriate use of diagnostic imaging when presented with an adult PBI. Based on the current literature, the authors have developed an imaging pathway for adult penetrating brain injury that functions as both a learning tool and reference guide for radiographers and other health professionals. Currently, CT is recommended as the imaging modality of choice for the initial assessment of PBI patients, while MRI is important in the sub-acute setting where it aids prognosis prediction and rehabilitation planning, Additional follow-up imaging, such as angiography, should be dependent upon clinical findings.

  8. Neuroimaging in adult penetrating brain injury: a guide for radiographers

    SciTech Connect

    Temple, Nikki; Donald, Cortny; Skora, Amanda; Reed, Warren

    2015-06-15

    Penetrating brain injuries (PBI) are a medical emergency, often resulting in complex damage and high mortality rates. Neuroimaging is essential to evaluate the location and extent of injuries, and to manage them accordingly. Currently, a myriad of imaging modalities are included in the diagnostic workup for adult PBI, including skull radiography, computed tomography (CT), magnetic resonance imaging (MRI) and angiography, with each modality providing their own particular benefits. This literature review explores the current modalities available for investigating PBI and aims to assist in decision making for the appropriate use of diagnostic imaging when presented with an adult PBI. Based on the current literature, the authors have developed an imaging pathway for adult penetrating brain injury that functions as both a learning tool and reference guide for radiographers and other health professionals. Currently, CT is recommended as the imaging modality of choice for the initial assessment of PBI patients, while MRI is important in the sub-acute setting where it aids prognosis prediction and rehabilitation planning, Additional follow-up imaging, such as angiography, should be dependent upon clinical findings.

  9. Testosterone affects language areas of the adult human brain

    PubMed Central

    Hahn, Andreas; Kranz, Georg S.; Sladky, Ronald; Kaufmann, Ulrike; Ganger, Sebastian; Hummer, Allan; Seiger, Rene; Spies, Marie; Vanicek, Thomas; Winkler, Dietmar; Kasper, Siegfried; Windischberger, Christian; Swaab, Dick F.

    2016-01-01

    Abstract Although the sex steroid hormone testosterone is integrally involved in the development of language processing, ethical considerations mostly limit investigations to single hormone administrations. To circumvent this issue we assessed the influence of continuous high‐dose hormone application in adult female‐to‐male transsexuals. Subjects underwent magnetic resonance imaging before and after 4 weeks of testosterone treatment, with each scan including structural, diffusion weighted and functional imaging. Voxel‐based morphometry analysis showed decreased gray matter volume with increasing levels of bioavailable testosterone exclusively in Broca's and Wernicke's areas. Particularly, this may link known sex differences in language performance to the influence of testosterone on relevant brain regions. Using probabilistic tractography, we further observed that longitudinal changes in testosterone negatively predicted changes in mean diffusivity of the corresponding structural connection passing through the extreme capsule. Considering a related increase in myelin staining in rodents, this potentially reflects a strengthening of the fiber tract particularly involved in language comprehension. Finally, functional images at resting‐state were evaluated, showing increased functional connectivity between the two brain regions with increasing testosterone levels. These findings suggest testosterone‐dependent neuroplastic adaptations in adulthood within language‐specific brain regions and connections. Importantly, deteriorations in gray matter volume seem to be compensated by enhancement of corresponding structural and functional connectivity. Hum Brain Mapp 37:1738–1748, 2016. © 2016 Wiley Periodicals, Inc. PMID:26876303

  10. Experimental induction of corpora amylacea in adult rat brain.

    PubMed

    Schipper, H M

    1998-10-01

    Corpora amylacea (CA) are glycoproteinaceous inclusions that accumulate in astroglia and other brain cells as a function of advancing age and, to an even greater extent, in several human neurodegenerative conditions. The mechanisms responsible for their biogenesis and their subcellular origin(s) remain unclear. We previously demonstrated that the sulfhydryl agent, cysteamine (CSH), promotes the accumulation of CA-like inclusions in cultured rat astroglia. In the present study, we show that subcutaneous administration of CSH to adult rats (150 mg/kg for 6 weeks followed by a 5-week drug-washout period) elicits the accumulation of CA in many cortical and subcortical brain regions. As in the aging human brain and in CSH-treated rat astrocyte cultures, the inclusions are periodic acid-Schiff -positive and are consistently immunostained with antibodies directed against mitochondrial epitopes and ubiquitin. Our findings support our contention that mitochondria are important structural precursors of CA, and that CSH accelerates aging-like processes in rat astroglia both in vitro and in the intact brain.

  11. Testosterone affects language areas of the adult human brain.

    PubMed

    Hahn, Andreas; Kranz, Georg S; Sladky, Ronald; Kaufmann, Ulrike; Ganger, Sebastian; Hummer, Allan; Seiger, Rene; Spies, Marie; Vanicek, Thomas; Winkler, Dietmar; Kasper, Siegfried; Windischberger, Christian; Swaab, Dick F; Lanzenberger, Rupert

    2016-05-01

    Although the sex steroid hormone testosterone is integrally involved in the development of language processing, ethical considerations mostly limit investigations to single hormone administrations. To circumvent this issue we assessed the influence of continuous high-dose hormone application in adult female-to-male transsexuals. Subjects underwent magnetic resonance imaging before and after 4 weeks of testosterone treatment, with each scan including structural, diffusion weighted and functional imaging. Voxel-based morphometry analysis showed decreased gray matter volume with increasing levels of bioavailable testosterone exclusively in Broca's and Wernicke's areas. Particularly, this may link known sex differences in language performance to the influence of testosterone on relevant brain regions. Using probabilistic tractography, we further observed that longitudinal changes in testosterone negatively predicted changes in mean diffusivity of the corresponding structural connection passing through the extreme capsule. Considering a related increase in myelin staining in rodents, this potentially reflects a strengthening of the fiber tract particularly involved in language comprehension. Finally, functional images at resting-state were evaluated, showing increased functional connectivity between the two brain regions with increasing testosterone levels. These findings suggest testosterone-dependent neuroplastic adaptations in adulthood within language-specific brain regions and connections. Importantly, deteriorations in gray matter volume seem to be compensated by enhancement of corresponding structural and functional connectivity. Hum Brain Mapp 37:1738-1748, 2016. © 2016 Wiley Periodicals, Inc.

  12. Identification and functional characterization of zebrafish solute carrier Slc16a2 (Mct8) as a thyroid hormone membrane transporter.

    PubMed

    Arjona, Francisco J; de Vrieze, Erik; Visser, Theo J; Flik, Gert; Klaren, Peter H M

    2011-12-01

    Most components of the thyroid system in bony fish have been described and characterized, with the notable exception of thyroid hormone membrane transporters. We have cloned, sequenced, and expressed the zebrafish solute carrier Slc16a2 (also named monocarboxylate transporter Mct8) cDNA and established its role as a thyroid hormone transport protein. The cloned cDNA shares 56-57% homology with its mammalian orthologs. The 526-amino-acid sequence contains 12 predicted transmembrane domains. An intracellular N-terminal PEST domain, thought to be involved in proteolytic processing of the protein, is present in the zebrafish sequence. Measured at initial rate and at the body/rearing temperature of zebrafish (26 C), T(3) uptake by zebrafish Slc16a2 is a saturable process with a calculated Michaelis-Menten constant of 0.8 μM T(3). The rate of T(3) uptake is temperature dependent and Na(+) independent. Interestingly, at 26 C, zebrafish Slc16a2 does not transport T(4). This implies that at a normal body temperature in zebrafish, Slc16a2 protein is predominantly involved in T(3) uptake. When measured at 37 C, zebrafish Slc16a2 transports T(4) in a Na(+)-independent manner. In adult zebrafish, the Slc16a2 gene is highly expressed in brain, gills, pancreas, liver, pituitary, heart, kidney, and gut. Beginning from the midblastula stage, Slc16a2 is also expressed during zebrafish early development, the highest expression levels occurring 48 h after fertilization. This is the first direct evidence for thyroid hormone membrane transporters in fish. We suggest that Slc16a2 plays a key role in the local availability of T(3) in adult tissues as well as during the completion of morphogenesis of primary organ systems.

  13. Development of social behavior in young zebrafish

    PubMed Central

    Dreosti, Elena; Lopes, Gonçalo; Kampff, Adam R.; Wilson, Stephen W.

    2015-01-01

    Adult zebrafish are robustly social animals whereas larva is not. We designed an assay to determine at what stage of development zebrafish begin to interact with and prefer other fish. One week old zebrafish do not show significant social preference whereas most 3 weeks old zebrafish strongly prefer to remain in a compartment where they can view conspecifics. However, for some individuals, the presence of conspecifics drives avoidance instead of attraction. Social preference is dependent on vision and requires viewing fish of a similar age/size. In addition, over the same 1–3 weeks period larval zebrafish increasingly tend to coordinate their movements, a simple form of social interaction. Finally, social preference and coupled interactions are differentially modified by an NMDAR antagonist and acute exposure to ethanol, both of which are known to alter social behavior in adult zebrafish. PMID:26347614

  14. Roles for oestrogen receptor β in adult brain function.

    PubMed

    Handa, R J; Ogawa, S; Wang, J M; Herbison, A E

    2012-01-01

    Oestradiol exerts a profound influence upon multiple brain circuits. For the most part, these effects are mediated by oestrogen receptor (ER)α. We review here the roles of ERβ, the other ER isoform, in mediating rodent oestradiol-regulated anxiety, aggressive and sexual behaviours, the control of gonadotrophin secretion, and adult neurogenesis. Evidence exists for: (i) ERβ located in the paraventricular nucleus underpinning the suppressive influence of oestradiol on the stress axis and anxiety-like behaviour; (ii) ERβ expressed in gonadotrophin-releasing hormone neurones contributing to oestrogen negative-feedback control of gonadotrophin secretion; (iii) ERβ controlling the offset of lordosis behaviour; (iv) ERβ suppressing aggressive behaviour in males; (v) ERβ modulating responses to social stimuli; and (vi) ERβ in controlling adult neurogenesis. This review highlights two major themes; first, ERβ and ERα are usually tightly inter-related in the oestradiol-dependent control of a particular brain function. For example, even though oestradiol feedback to control reproduction occurs principally through ERα-dependent mechanisms, modulatory roles for ERβ also exist. Second, the roles of ERα and ERβ within a particular neural network may be synergistic or antagonistic. Examples of the latter include the role of ERα to enhance, and ERβ to suppress, anxiety-like and aggressive behaviours. Splice variants such as ERβ2, acting as dominant negative receptors, are of further particular interest because their expression levels may reflect preceeding oestradiol exposure of relevance to oestradiol replacement therapy. Together, this review highlights the predominant modulatory, but nonetheless important, roles of ERβ in mediating the many effects of oestradiol upon adult brain function.

  15. Biological Uptake, Distribution, and Depuration of Radio-Labeled Graphene in Adult Zebrafish: Effects of Graphene Size and Natural Organic Matter.

    PubMed

    Lu, Kun; Dong, Shipeng; Petersen, Elijah J; Niu, Junfeng; Chang, Xiaofeng; Wang, Peng; Lin, Sijie; Gao, Shixiang; Mao, Liang

    2017-03-28

    The exciting commercial application potential of graphene materials may inevitably lead to their increasing release into the environment where they may pose ecological risks. This study focused on using carbon-14-labeled few-layer graphene (FLG) to determine whether the size of graphene plays a role in its uptake, depuration, and biodistribution in adult zebrafish. After 48 h exposure to larger FLG (L-FLG) at 250 μg/L, the amount of graphene in the organism was close to 48 mg/kg fish dry mass, which was more than 170-fold greater than the body burden of those exposed to the same concentration of smaller FLG (S-FLG). The amount of uptake for both L-FLG and S-FLG increased by a factor of 2.5 and 16, respectively, when natural organic matter (NOM) was added in the exposure suspension. While the L-FLG mainly accumulated in the gut of adult zebrafish, the S-FLG was found in both the gut and liver after exposure with or without NOM. Strikingly, the S-FLG was able to pass through the intestinal wall and enter the intestinal epithelial cells and blood. The presence of NOM increased the quantity of S-FLG in these cells. Exposure to L-FLG or S-FLG also had a significantly different impact on the intestinal microbial community structure.

  16. Sterol O-Acyltransferase 2 Contributes to the Yolk Cholesterol Trafficking during Zebrafish Embryogenesis

    PubMed Central

    Lee, Yen-Hua; HuangFu, Wei-Chun

    2016-01-01

    To elucidate whether Sterol O-acyltransferase (Soat) mediates the absorption and transportation of yolk lipids to the developing embryo, zebrafish soat1 and soat2 were cloned and studied. In the adult zebrafish, soat1 was detected ubiquitously while soat2 mRNA was detected specifically in the liver, intestine, brain and testis. Whole mount in situ hybridization demonstrated that both soat1 and soat2 expressed in the yolk syncytial layer, hatching gland and developing cardiovascular as well as digestive systems, suggesting that Soats may play important roles in the lipid trafficking and utilization during embryonic development. The enzymatic activity of zebrafish Soat2 was confirmed by Oil Red O staining in the HEK293 cells overexpressing this gene, and could be quenched by Soat2 inhibitor Pyripyropene A (PPPA). The zebrafish embryos injected with PPPA or morpholino oligo against soat2 in the yolk showed significantly larger yolk when compared with wild-type embryos, especially at 72 hpf, indicating a slower rate of yolk consumption. Our result indicated that zebrafish Soat2 is catalytically active in synthesizing cholesteryl esters and contributes to the yolk cholesterol trafficking during zebrafish embryogenesis. PMID:27936201

  17. Increased radial glia quiescence, decreased reactivation upon injury and unaltered neuroblast behavior underlie decreased neurogenesis in the aging zebrafish telencephalon.

    PubMed

    Edelmann, Kathrin; Glashauser, Lena; Sprungala, Susanne; Hesl, Birgit; Fritschle, Maike; Ninkovic, Jovica; Godinho, Leanne; Chapouton, Prisca

    2013-09-01

    The zebrafish has recently become a source of new data on the mechanisms of neural stem cell (NSC) maintenance and ongoing neurogenesis in adult brains. In this vertebrate, neurogenesis occurs at high levels in all ventricular regions of the brain, and brain injuries recover successfully, owing to the recruitment of radial glia, which function as NSCs. This new vertebrate model of adult neurogenesis is thus advancing our knowledge of the molecular cues in use for the activation of NSCs and fate of their progeny. Because the regenerative potential of somatic stem cells generally weakens with increasing age, it is important to assess the extent to which zebrafish NSC potential decreases or remains unaltered with age. We found that neurogenesis in the ventricular zone, in the olfactory bulb, and in a newly identified parenchymal zone of the telencephalon indeed declines as the fish ages and that oligodendrogenesis also declines. In the ventricular zone, the radial glial cell population remains largely unaltered morphologically but enters less frequently into the cell cycle and hence produces fewer neuroblasts. The neuroblasts themselves do not change their behavior with age and produce the same number of postmitotic neurons. Thus, decreased neurogenesis in the physiologically aging zebrafish brain is correlated with an increasing quiescence of radial glia. After injuries, radial glia in aged brains are reactivated, and the percentage of cell cycle entry is increased in the radial glia population. However, this reaction is far less pronounced than in younger animals, pointing to irreversible changes in aging zebrafish radial glia.

  18. Hour-Long Nap May Boost Brain Function in Older Adults

    MedlinePlus

    ... fullstory_162923.html Hour-Long Nap May Boost Brain Function in Older Adults Linked to improved memory and ... during the day had any effects on their brain function. Nearly 60 percent of the people regularly napped ...

  19. Evaluation of an automatic brain segmentation method developed for neonates on adult MR brain images

    NASA Astrophysics Data System (ADS)

    Moeskops, Pim; Viergever, Max A.; Benders, Manon J. N. L.; Išgum, Ivana

    2015-03-01

    Automatic brain tissue segmentation is of clinical relevance in images acquired at all ages. The literature presents a clear distinction between methods developed for MR images of infants, and methods developed for images of adults. The aim of this work is to evaluate a method developed for neonatal images in the segmentation of adult images. The evaluated method employs supervised voxel classification in subsequent stages, exploiting spatial and intensity information. Evaluation was performed using images available within the MRBrainS13 challenge. The obtained average Dice coefficients were 85.77% for grey matter, 88.66% for white matter, 81.08% for cerebrospinal fluid, 95.65% for cerebrum, and 96.92% for intracranial cavity, currently resulting in the best overall ranking. The possibility of applying the same method to neonatal as well as adult images can be of great value in cross-sectional studies that include a wide age range.

  20. Doublecortin in Oligodendrocyte Precursor Cells in the Adult Mouse Brain

    PubMed Central

    Boulanger, Jenna J.; Messier, Claude

    2017-01-01

    Key Points Oligodendrocyte precursor cells express doublecortin, a microtubule-associated protein.Oligodendrocyte precursor cells express doublecortin, but at a lower level of expression than in neuronal precursor.Doublecortin is not associated with a potential immature neuronal phenotype in Oligodendrocyte precursor cells. Oligodendrocyte precursor cells (OPC) are glial cells that differentiate into myelinating oligodendrocytes during embryogenesis and early stages of post-natal life. OPCs continue to divide throughout adulthood and some eventually differentiate into oligodendrocytes in response to demyelinating lesions. There is growing evidence that OPCs are also involved in activity-driven de novo myelination of previously unmyelinated axons and myelin remodeling in adulthood. Considering these roles in the adult brain, OPCs are likely mobile cells that can migrate on some distances before they differentiate into myelinating oligodendrocytes. A number of studies have noted that OPCs express doublecortin (DCX), a microtubule-associated protein expressed in neural precursor cells and in migrating immature neurons. Here we describe the distribution of DCX in OPCs. We found that almost all OPCs express DCX, but the level of expression appears to be much lower than what is found in neural precursor. We found that DCX is downregulated when OPCs start expressing mature oligodendrocyte markers and is absent in myelinating oligodendrocytes. DCX does not appear to signal an immature neuronal phenotype in OPCs in the adult mouse brain. Rather, it could be involved either in cell migration, or as a marker of an immature oligodendroglial cell phenotype.

  1. Noncanonical Sites of Adult Neurogenesis in the Mammalian Brain.

    PubMed

    Feliciano, David M; Bordey, Angélique; Bonfanti, Luca

    2015-09-18

    Two decades after the discovery that neural stem cells (NSCs) populate some regions of the mammalian central nervous system (CNS), deep knowledge has been accumulated on their capacity to generate new neurons in the adult brain. This constitutive adult neurogenesis occurs throughout life primarily within remnants of the embryonic germinal layers known as "neurogenic sites." Nevertheless, some processes of neurogliogenesis also occur in the CNS parenchyma commonly considered as "nonneurogenic." This "noncanonical" cell genesis has been the object of many claims, some of which turned out to be not true. Indeed, it is often an "incomplete" process as to its final outcome, heterogeneous by several measures, including regional location, progenitor identity, and fate of the progeny. These aspects also strictly depend on the animal species, suggesting that persistent neurogenic processes have uniquely adapted to the brain anatomy of different mammals. Whereas some examples of noncanonical neurogenesis are strictly parenchymal, others also show stem cell niche-like features and a strong link with the ventricular cavities. This work will review results obtained in a research field that expanded from classic neurogenesis studies involving a variety of areas of the CNS outside of the subventricular zone (SVZ) and subgranular zone (SGZ). It will be highlighted how knowledge concerning noncanonical neurogenic areas is still incomplete owing to its regional and species-specific heterogeneity, and to objective difficulties still hampering its full identification and characterization.

  2. Assessment of Xenoestrogens Using Three Distinct Estrogen Receptors and the Zebrafish Brain Aromatase Gene in a Highly Responsive Glial Cell System

    PubMed Central

    Le Page, Yann; Scholze, Martin; Kah, Olivier; Pakdel, Farzad

    2006-01-01

    The brain cytochrome P450 aromatase (Aro-B) in zebrafish is expressed in radial glial cells and is strongly stimulated by estrogens (E2); thus, it can be used in vivo as a biomarker of xenoestrogen effects on the central nervous system. By quantitative real-time polymerase chain reaction, we first confirmed that the expression of Aro-B gene is robustly stimulated in juvenile zebrafish exposed to several xenoestrogens. To investigate the impact of environmental estrogenic chemicals on distinct estrogen receptor (ER) activity, we developed a glial cell-based assay using Aro-B as the target gene. To this end, the ER-negative glial cell line U251-MG was transfected with the three zebrafish ER subtypes and the Aro-B promoter linked to a luciferase reporter gene. E2 treatment of U251-MG glial cells cotransfected with zebrafish ER-α and the Aro-B promoter–luciferase reporter resulted in a 60- to 80-fold stimulation of luciferase activity. The detection limit was < 0.05 nM, and the EC50 (median effective concentration) was 1.4 nM. Interestingly, in this glial cell context, maximal induction achieved with the Aro-B reporter was three times greater than that observed with a classical estrogen-response-element reporter gene (ERE-tk-Luc). Dose–response analyses with ethynylestradiol (EE2), estrone (E1), α-zeralenol, and genistein showed that estrogenic potency of these agents markedly differed depending on the ER subtype in the assay. Moreover, the combination of these agents showed an additive effect according to the concept of concentration addition. This confirmed that the combined additive effect of the xenoestrogens leads to an enhancement of the estrogenic potency, even when each single agent might be present at low effect concentrations. In conclusion, we demonstrate that our bioassay provides a fast, reliable, sensitive, and efficient test for evaluating estrogenic potency of endocrine disruptors on ER subtypes in a glial context. PMID:16675432

  3. Duplicated gelsolin family genes in zebrafish: a novel scinderin-like gene (scinla) encodes the major corneal crystallin.

    PubMed

    Jia, Sujuan; Omelchenko, Marina; Garland, Donita; Vasiliou, Vasilis; Kanungo, Jyotshnabala; Spencer, Michael; Wolf, Yuri; Koonin, Eugene; Piatigorsky, Joram

    2007-10-01

    We have previously identified a gelsolin-like protein (C/L-gelsolin) as a corneal crystallin in zebrafish. Here we show by phylogenetic analysis that there are at least six genes encoding gelsolin-like proteins based on their gelsolin domains in zebrafish: gsna and gsnb group with the vertebrate gelsolin gene, scina and scinb group with the scinderin (adseverin) gene, and scinla (C/L-gelsolin) and scinlb are novel scinderin-like genes. RT-PCR showed that scinla, scinlb, and gsnb are preferentially expressed in the adult cornea whereas gsna is expressed to a similar extent in cornea, lens, brain, and heart; scina and scinb expression were detectable only in whole zebrafish and not in these adult tissues. Quantitative RT-PCR and 2-dimensional polyacrylamide gel electrophoresis followed by MALDI/TOF mass spectroscopy confirmed high expression of beta-actin and scinla, moderate expression of scinlb, and very low expression of gsna and gsnb in the cornea. Finally, transgenic zebrafish carrying a green fluorescent protein reporter transgene driven by a 4 kb scinla promoter fragment showed expression in the cornea, snout, dorsal fin, and tail fin of 3-day-old zebrafish larvae. Our data suggest that scinla and scinlb are diverged paralogs of the vertebrate scinderin gene and show that scinla encodes the zebrafish corneal crystallin previously called C/L-gelsolin.

  4. Traumatic Brain Injury Severity Affects Neurogenesis in Adult Mouse Hippocampus.

    PubMed

    Wang, Xiaoting; Gao, Xiang; Michalski, Stephanie; Zhao, Shu; Chen, Jinhui

    2016-04-15

    Traumatic brain injury (TBI) has been proven to enhance neural stem cell (NSC) proliferation in the hippocampal dentate gyrus. However, various groups have reported contradictory results on whether TBI increases neurogenesis, partially due to a wide range in the severities of injuries seen with different TBI models. To address whether the severity of TBI affects neurogenesis in the injured brain, we assessed neurogenesis in mouse brains receiving different severities of controlled cortical impact (CCI) with the same injury device. The mice were subjected to mild, moderate, or severe TBI by a CCI device. The effects of TBI severity on neurogenesis were evaluated at three stages: NSC proliferation, immature neurons, and newly-generated mature neurons. The results showed that mild TBI did not affect neurogenesis at any of the three stages. Moderate TBI promoted NSC proliferation without increasing neurogenesis. Severe TBI increased neurogenesis at all three stages. Our data suggest that the severity of injury affects adult neurogenesis in the hippocampus, and thus it may partially explain the inconsistent results of different groups regarding neurogenesis following TBI. Further understanding the mechanism of TBI-induced neurogenesis may provide a potential approach for using endogenous NSCs to protect against neuronal loss after trauma.

  5. Combinatorial analysis of calcium-binding proteins in larval and adult zebrafish primary olfactory system identifies differential olfactory bulb glomerular projection fields.

    PubMed

    Kress, Sigrid; Biechl, Daniela; Wullimann, Mario F

    2015-07-01

    In the zebrafish (Danio rerio) olfactory epithelium, the calcium-binding proteins (CBPs) calretinin and S100/S100-like protein are mainly expressed in ciliated or crypt olfactory sensory neurons (OSNs), respectively. In contrast parvalbumin and calbindin1 have not been investigated. We present a combinatorial immunohistological analysis of all four CBPs, including their expression in OSNs and their axonal projections to the olfactory bulb in larval and adult zebrafish. A major expression of calretinin and S100 in ciliated and crypt cells, respectively, with some expression of S100 in microvillous cells is confirmed. Parvalbumin and calbindin1 are strongly expressed in ciliated and microvillous cells, but not in crypt cells. Moreover, detailed combinatorial double-label experiments indicate that there are eight subpopulations of zebrafish OSNs: S100-positive crypt cells (negative for all other three CBPs), parvalbumin only, S100 and parvalbumin, parvalbumin and calbindin1, and parvalbumin and calbindin1 and calretinin-positive microvillous OSNs, as well as a major parvalbumin and calbindin1 and calretinin, and minor parvalbumin and calbindin1 and calretinin-only-positive ciliated OSN populations. CBP-positive projections to olfactory bulb are consistent with previous reports of ciliated OSNs projecting to dorsal and ventromedial glomerular fields and microvillous OSNs to ventrolateral glomerular fields. We newly describe parvalbumin-positive fibers to the mediodorsal field which is calretinin free, with its anterior part showing additionally calbindin1-positive fibers, but absence thereof in the posterior part, indicating an origin from microvillous OSNs in both parts. One singular glomerulus (mdG2) exhibits S100 and parvalbumin-positive fibers, apparently originating from all crypt cells plus some microvillous OSNs. Arguments for various olfactory labeled lines are discussed.

  6. Mechanism of TiO2 nanoparticle-induced neurotoxicity in zebrafish (Danio rerio).

    PubMed

    Sheng, Lei; Wang, Ling; Su, Mingyu; Zhao, Xiaoyang; Hu, Renping; Yu, Xiaohong; Hong, Jie; Liu, Dong; Xu, Bingqing; Zhu, Yunting; Wang, Han; Hong, Fashui

    2016-02-01

    Zebrafish (Danio rerio) has been used historically for evaluating the toxicity of environmental and aqueous toxicants, and there is an emerging literature reporting toxic effects of manufactured nanoparticles (NPs) in zebrafish embryos. Few researches, however, are focused on the neurotoxicity on adult zebrafish after subchronic exposure to TiO2 NPs. This study was designed to evaluate the morphological changes, alterations of neurochemical contents, and expressions of memory behavior-related genes in zebrafish brains caused by exposures to 5, 10, 20, and 40 μg/L TiO2 NPs for 45 consecutive days. Our data indicated that spatial recognition memory and levels of norepinephrine, dopamine, and 5-hydroxytryptamine were significantly decreased and NO levels were markedly elevated, and over proliferation of glial cells, neuron apoptosis, and TiO2 NP aggregation were observed after low dose exposures of TiO2 NPs. Furthermore, the low dose exposures of TiO2 NPs significantly activated expressions of C-fos, C-jun, and BDNF genes, and suppressed expressions of p38, NGF, CREB, NR1, NR2ab, and GluR2 genes. These findings imply that low dose exposures of TiO2 NPs may result in the brain damages in zebrafish, provide a developmental basis for evaluating the neurotoxicity of subchronic exposure, and raise the caution of aquatic application of TiO2 NPs.

  7. Electrophysiological Properties of Subventricular Zone Cells in Adult Mouse Brain

    PubMed Central

    Lai, Bin; Mao, Xiao Ou; Xie, Lin; Chang, Su-Youne; Xiong, Zhi-Gang; Jin, Kunlin; Greenberg, David A.

    2010-01-01

    The subventricular zone (SVZ) is a principal site of adult neurogenesis and appears to participate in the brain’s response to injury. Thus, measures that enhance SVZ neurogenesis may have a role in treatment of neurological disease. To better characterize SVZ cells and identify potential targets for therapeutic intervention, we studied electrophysiological properties of SVZ cells in adult mouse brain slices using patch-clamp techniques. Electrophysiology was correlated with immunohistochemical phenotype by injecting cells with lucifer yellow and by studying transgenic mice carrying green fluorescent protein under control of the doublecortin (DCX) or glial fibrillary acidic protein (GFAP) promoter. We identified five types of cells in the adult mouse SVZ: type 1 cells, with 4-aminopyridine (4-AP)/tetraethylammonium (TEA)-sensitive and CdCl2-sensitive inward currents; type 2 cells, with Ca2+-sensitive K+ and both 4-AP/TEA-sensitive and -insensitive currents; type 3 cells, with 4-AP/TEA-sensitive and -insensitive and small Na+ currents; type 4 cells, with slowly activating, large linear outward current and sustained outward current without fast-inactivating component; and type 5 cells, with a large outward rectifying current with a fast inactivating component. Type 2 and 3 cells expressed DCX, types 4 and 5 cells expressed GFAP, and type 1 cells expressed neither. We propose that SVZ neurogenesis involves a progression of electrophysiological cell phenotypes from types 4 and 5 cells (astrocytes) to type 1 cells (neuronal progenitors) to types 2 and 3 cells (nascent neurons), and that drugs acting on. ion channels expressed during neurogenesis might promote therapeutic neurogenesis in the injured brain. PMID:20434436

  8. Doublecortin expression in the normal and epileptic adult human brain.

    PubMed

    Liu, Y W J; Curtis, M A; Gibbons, H M; Mee, E W; Bergin, P S; Teoh, H H; Connor, B; Dragunow, M; Faull, R L M

    2008-12-01

    Mesial temporal lobe epilepsy (MTLE) is a neurological disorder associated with spontaneous recurrent complex partial seizures and hippocampal sclerosis. Although increased hippocampal neurogenesis has been reported in animal models of MTLE, increased neurogenesis has not been reported in the hippocampus of adult human MTLE cases. Here we showed that cells expressing doublecortin (Dcx), a microtubule-associated protein expressed in migrating neuroblasts, were present in the hippocampus and temporal cortex of the normal and MTLE adult human brain. In particular, increased numbers of Dcx-positive cells were observed in the epileptic compared with the normal temporal cortex. Importantly, 56% of Dcx-expressing cells in the epileptic temporal cortex coexpressed both the proliferative cell marker, proliferating cell nuclear antigen and early neuronal marker, TuJ1, suggesting that they may be newly generated neurons. A subpopulation of Dcx-positive cells in the epileptic temporal cortex also coexpressed the mature neuronal marker, NeuN, suggesting that epilepsy may promote the generation of new neurons in the temporal cortex. This study has identified, for the first time, a novel population of Dcx-positive cells in the adult human temporal cortex that can be upregulated by epilepsy and thus, raises the possibility that these cells may have functional significance in the pathophysiology of epilepsy.

  9. Automated Processing of Zebrafish Imaging Data: A Survey

    PubMed Central

    Dickmeis, Thomas; Driever, Wolfgang; Geurts, Pierre; Hamprecht, Fred A.; Kausler, Bernhard X.; Ledesma-Carbayo, María J.; Marée, Raphaël; Mikula, Karol; Pantazis, Periklis; Ronneberger, Olaf; Santos, Andres; Stotzka, Rainer; Strähle, Uwe; Peyriéras, Nadine

    2013-01-01

    Abstract Due to the relative transparency of its embryos and larvae, the zebrafish is an ideal model organism for bioimaging approaches in vertebrates. Novel microscope technologies allow the imaging of developmental processes in unprecedented detail, and they enable the use of complex image-based read-outs for high-throughput/high-content screening. Such applications can easily generate Terabytes of image data, the handling and analysis of which becomes a major bottleneck in extracting the targeted information. Here, we describe the current state of the art in computational image analysis in the zebrafish system. We discuss the challenges encountered when handling high-content image data, especially with regard to data quality, annotation, and storage. We survey methods for preprocessing image data for further analysis, and describe selected examples of automated image analysis, including the tracking of cells during embryogenesis, heartbeat detection, identification of dead embryos, recognition of tissues and anatomical landmarks, and quantification of behavioral patterns of adult fish. We review recent examples for applications using such methods, such as the comprehensive analysis of cell lineages during early development, the generation of a three-dimensional brain atlas of zebrafish larvae, and high-throughput drug screens based on movement patterns. Finally, we identify future challenges for the zebrafish image analysis community, notably those concerning the compatibility of algorithms and data formats for the assembly of modular analysis pipelines. PMID:23758125

  10. Mitragynine attenuates withdrawal syndrome in morphine-withdrawn zebrafish.

    PubMed

    Khor, Beng-Siang; Jamil, Mohd Fadzly Amar; Adenan, Mohamad Ilham; Shu-Chien, Alexander Chong

    2011-01-01

    A major obstacle in treating drug addiction is the severity of opiate withdrawal syndrome, which can lead to unwanted relapse. Mitragynine is the major alkaloid compound found in leaves of Mitragyna speciosa, a plant widely used by opiate addicts to mitigate the harshness of drug withdrawal. A series of experiments was conducted to investigate the effect of mitragynine on anxiety behavior, cortisol level and expression of stress pathway related genes in zebrafish undergoing morphine withdrawal phase. Adult zebrafish were subjected to two weeks chronic morphine exposure at 1.5 mg/L, followed by withdrawal for 24 hours prior to tests. Using the novel tank diving tests, we first showed that morphine-withdrawn zebrafish display anxiety-related swimming behaviors such as decreased exploratory behavior and increased erratic movement. Morphine withdrawal also elevated whole-body cortisol levels, which confirms the phenotypic stress-like behaviors. Exposing morphine-withdrawn fish to mitragynine however attenuates majority of the stress-related swimming behaviors and concomitantly lower whole-body cortisol level. Using real-time PCR gene expression analysis, we also showed that mitragynine reduces the mRNA expression of corticotropin releasing factor receptors and prodynorphin in zebrafish brain during morphine withdrawal phase, revealing for the first time a possible link between mitragynine's ability to attenuate anxiety during opiate withdrawal with the stress-related corticotropin pathway.

  11. Expression of neuropeptides and anoctamin 1 in the embryonic and adult zebrafish intestine, revealing neuronal subpopulations and ICC-like cells.

    PubMed

    Uyttebroek, Leen; Shepherd, Iain T; Hubens, Guy; Timmermans, Jean-Pierre; Van Nassauw, Luc

    2013-11-01

    This immunohistochemical study in zebrafish aims to extend the neurochemical characterization of enteric neuronal subpopulations and to validate a marker for identification of interstitial cells of Cajal (ICC). The expression of neuropeptides and anoctamin 1 (Ano1), a selective ICC marker in mammals, was analyzed in both embryonic and adult intestine. Neuropeptides were present from 3 days postfertilization (dpf). At 3 dpf, galanin-positive nerve fibers were found in the proximal intestine, while calcitonin gene-related peptide (CGRP)- and substance P-expressing fibers appeared in the distal intestine. At 5 dpf, immunoreactive fibers were present along the entire intestinal length, indicating a well-developed peptidergic innervation at the onset of feeding. In the adult intestine, vasoactive intestinal peptide (VIP), pituitary adenylate cyclase-activating peptide (PACAP), galanin, CGRP and substance P were detected in nerve fibers. Colchicine pretreatment enhanced only VIP and PACAP immunoreactivity. VIP and PACAP were coexpressed in enteric neurons. Colocalization stainings revealed three neuronal subpopulations expressing VIP and PACAP: a nitrergic noncholinergic subpopulation, a serotonergic subpopulation and a subpopulation expressing no other markers. Ano1-immunostaining revealed a 3-dimensional network in the adult intestine containing multipolar cells at the myenteric plexus and bipolar cells interspersed between circular smooth muscle cells. Ano1 immunoreactivity first appeared at 3 dpf, indicative of the onset of proliferation of ICC-like cells. It is shown that the Ano1 antiserum is a selective marker of ICC-like cells in the zebrafish intestine. Finally, it is hypothesized that ICC-like cells mediate the spontaneous regular activity of the embryonic intestine.

  12. Brain self-protection: the role of endogenous neural progenitor cells in adult brain after cerebral cortical ischemia.

    PubMed

    Li, Bin; Piao, Chun-Shu; Liu, Xiao-Yun; Guo, Wen-Ping; Xue, Yue-Qiang; Duan, Wei-Ming; Gonzalez-Toledo, Maria E; Zhao, Li-Ru

    2010-04-23

    Convincing evidence has shown that brain ischemia causes the proliferation of neural stem cells/neural progenitor cells (NSCs/NPCs) in both the subventricular zone (SVZ) and the subgranular zone (SGZ) of adult brain. The role of brain ischemia-induced NSC/NPC proliferation, however, has remained unclear. Here we have determined whether brain ischemia-induced amplification of the NSCs/NPCs in adult brain is required for brain self-protection. The approach of intracerebroventricular (ICV) infusion of cytosine arabinoside (Ara-C), an inhibitor for cell proliferation, for the first 7days after brain ischemia was used to block ischemia-induced NSC/NPC proliferation. We observed that ICV infusion of Ara-C caused a complete blockade of NSC/NPC proliferation in the SVZ and a dramatic reduction of NSC/NPC proliferation in the SGZ. Additionally, as a result of the inhibition of ischemia-induced NSC/NPC pool amplification, the number of neurons in the hippocampal CA1 and CA3 was significantly reduced, the infarction size was significantly enlarged, and neurological deficits were significantly worsened after focal brain ischemia. We also found that an NSC/NPC-conditioned medium showed neuroprotective effects in vitro and that adult NSC/NPC-released brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF) are required for NSC/NPC-conditioned medium-induced neuroprotection. These data suggest that NSC/NPC-generated trophic factors are neuroprotective and that brain ischemia-triggered NSC/NPC proliferation is crucial for brain protection. This study provides insights into the contribution of endogenous NSCs/NPCs to brain self-protection in adult brain after ischemia injury.

  13. CILIA FORMATION IN THE ADULT CAT BRAIN AFTER PARGYLINE TREATMENT

    PubMed Central

    Milhaud, Monique; Pappas, George D.

    1968-01-01

    The brains of four adult cats treated with pargyline (a nonhydrazide monoaminoxidase inhibitor) were examined at both the light and electron microscopic levels. Formation of typical mature cilia with the 9 + 2 pattern was observed in neural cells in the following areas: habenula nuclei, interpeduncular nuclei, hippocampus, mammillary bodies, thalamus, and caudate nucleus. The most marked ciliation occurs in the habenula nuclei. In general, glial cells greatly predominate in the formation of cilia. It is not clear whether ciliation in the central nervous system is the direct result of pargyline or if it occurs indirectly as a result of inhibition of monoaminoxidase. These findings are compared with the serotonin effect on ciliation in the embryogenesis of lower forms. It is suggested that pharmacological stimulation of centriolar reproduction without subsequent mitosis may lead to ciliary formation. PMID:11905194

  14. A model for genomic imprinting in the social brain: adults.

    PubMed

    Ubeda, Francisco; Gardner, Andy

    2011-02-01

    Genomic imprinting refers to genes that are silenced when inherited via sperm or via egg. The silencing of genes conditional upon their parental origin requires an evolutionary explanation. The most widely accepted theory for the evolution of genomic imprinting-the kinship theory-argues that conflict between maternally inherited and paternally inherited genes over phenotypes with asymmetric effects on matrilineal and patrilineal kin results in self-imposed silencing of one of the copies. This theory has been applied to imprinting of genes expressed in the placenta, and infant brain determining the allocation of parental resources being the source of conflict parental promiscuity. However, there is growing evidence that imprinted genes are expressed in the postinfant brain where parental promiscuity per se is no longer a source of conflict. Here, we advance the kinship theory by developing an evolutionary model of genomic imprinting in adults, driven by intragenomic conflict over allocation to parental versus communal care. We consider the role of sex differences in dispersal and variance in reproductive success as sources of conflict. We predict that, in hominids and birds, parental care will be expressed by maternally inherited genes. In nonhominid mammals, we predict more diversity, with some mammals showing the same pattern and other showing the reverse. We use the model to interpret experimental data on imprinted genes in the house mouse: specifically, paternally expressed Peg1 and Peg3 genes, underlying maternal care, and maternally expressed Gnas and paternally expressed Gnasxl genes, underlying communal care. We also use the model to relate ancestral demography to contemporary imprinting disorders of adults, in humans and other taxa.

  15. Wnts in adult brain: from synaptic plasticity to cognitive deficiencies

    PubMed Central

    Oliva, Carolina A.; Vargas, Jessica Y.; Inestrosa, Nibaldo C.

    2013-01-01

    During development of the central nervous system the Wnt signaling pathway has been implicated in a wide spectrum of physiological processes, including neuronal connectivity and synapse formation. Wnt proteins and components of the Wnt pathway are expressed in the brain since early development to the adult life, however, little is known about its role in mature synapses. Here, we review evidences indicating that Wnt proteins participate in the remodeling of pre- and post-synaptic regions, thus modulating synaptic function. We include the most recent data in the literature showing that Wnts are constantly released in the brain to maintain the basal neural activity. Also, we review the evidences that involve components of the Wnt pathway in the development of neurological and mental disorders, including a special emphasis on in vivo studies that relate behavioral abnormalities to deficiencies in Wnt signaling. Finally, we include the evidences that support a neuroprotective role of Wnt proteins in Alzheimer’s disease. We postulate that deregulation in Wnt signaling might have a fundamental role in the origin of neurological diseases, by altering the synaptic function at stages where the phenotype is not yet established but when the cognitive decline starts. PMID:24348327

  16. Wnts in adult brain: from synaptic plasticity to cognitive deficiencies.

    PubMed

    Oliva, Carolina A; Vargas, Jessica Y; Inestrosa, Nibaldo C

    2013-12-03

    During development of the central nervous system the Wnt signaling pathway has been implicated in a wide spectrum of physiological processes, including neuronal connectivity and synapse formation. Wnt proteins and components of the Wnt pathway are expressed in the brain since early development to the adult life, however, little is known about its role in mature synapses. Here, we review evidences indicating that Wnt proteins participate in the remodeling of pre- and post-synaptic regions, thus modulating synaptic function. We include the most recent data in the literature showing that Wnts are constantly released in the brain to maintain the basal neural activity. Also, we review the evidences that involve components of the Wnt pathway in the development of neurological and mental disorders, including a special emphasis on in vivo studies that relate behavioral abnormalities to deficiencies in Wnt signaling. Finally, we include the evidences that support a neuroprotective role of Wnt proteins in Alzheimer's disease. We postulate that deregulation in Wnt signaling might have a fundamental role in the origin of neurological diseases, by altering the synaptic function at stages where the phenotype is not yet established but when the cognitive decline starts.

  17. Functional aging and gradual senescence in zebrafish.

    PubMed

    Kishi, Shuji

    2004-06-01

    Zebrafish (Danio rerio) has been recognized as a powerful model for genetic studies in developmental biology. Recently, the zebrafish system also has given insights into several human diseases such as neurodegenerative, hematopoietic, and cardiovascular disease, and cancer. Because aging processes affect these and various other human disorders, it is important to compare zebrafish and mammalian senescence. However, the aging process of zebrafish remains largely unexplored, and little is known about functional aging and senescence in zebrafish. In our initial studies to assess aging phenotypes in zebrafish, we have identified several potential aging biomarkers in an ongoing search for suitable ones on zebrafish aging. In aging zebrafish, we detected senescence-associated beta-galactosidase activity in skin and oxidized protein accumulation in muscle. On the other hand, we did not observe lipofuscin granules (aging pigments), which accumulate in postmitotic cells, in muscle of zebrafish with advancing age. Consistently, there were continuously proliferating myocytes that incorporated BrdU in muscle tissues of the aged fish. Moreover, we demonstrated that zebrafish have constitutively abundant telomerase activity in adult somatic tissues implicating unlimited replicative ability of cells throughout their lives. Although some stress-associated markers are upregulated and minor histological changes are observed during the aging process of zebrafish, our studies together with other evidence of remarkable reproductive and regenerative abilities suggest that zebrafish show very gradual senescence. By using those biological and biochemical aging markers already characterized in normal zebrafish, transgenic fish analyses and genetic mutant fish screens can be readily performed. These efforts will help to elucidate the role and molecular mechanisms of common or different pathways of aging among vertebrates from fish to humans and also will contribute to the discovery of

  18. Emotions and motivated behavior converge on an amygdala-like structure in the zebrafish.

    PubMed

    von Trotha, Jakob William; Vernier, Philippe; Bally-Cuif, Laure

    2014-11-01

    The brain reward circuitry plays a key role in emotional and motivational behaviors, and its dysfunction underlies neuropsychiatric disorders such as schizophrenia, depression and drug addiction. Here, we characterized the neuronal activity pattern induced by acute amphetamine administration and during drug-seeking behavior in the zebrafish, and demonstrate the existence of conserved underlying brain circuitry. Combining quantitative analyses of cfos expression with neuronal subtype-specific markers at single-cell resolution, we show that acute d-amphetamine administration leads to both increased neuronal activation and the recruitment of neurons in the medial (Dm) and the lateral (Dl) domains of the adult zebrafish pallium, which contain homologous structures to the mammalian amygdala and hippocampus, respectively. Calbindin-positive and glutamatergic neurons are recruited in Dm, and glutamatergic and γ-aminobutyric acid (GABAergic) neurons in Dl. The drug-activated neurons in Dm and Dl are born at juvenile stage rather than in the embryo or during adulthood. Furthermore, the same territory in Dm is activated during both drug-seeking approach and light avoidance behavior, while these behaviors do not elicit activation in Dl. These data identify the pallial territories involved in acute psychostimulant response and reward formation in the adult zebrafish. They further suggest an evolutionarily conserved function of amygdala-like structures in positive emotions and motivated behavior in zebrafish and mammals.

  19. Emotions and motivated behavior converge on an amygdala-like structure in the zebrafish

    PubMed Central

    von Trotha, Jakob William; Vernier, Philippe; Bally-Cuif, Laure

    2014-01-01

    The brain reward circuitry plays a key role in emotional and motivational behaviors, and its dysfunction underlies neuropsychiatric disorders such as schizophrenia, depression and drug addiction. Here, we characterized the neuronal activity pattern induced by acute amphetamine administration and during drug-seeking behavior in the zebrafish, and demonstrate the existence of conserved underlying brain circuitry. Combining quantitative analyses of cfos expression with neuronal subtype-specific markers at single-cell resolution, we show that acute d-amphetamine administration leads to both increased neuronal activation and the recruitment of neurons in the medial (Dm) and the lateral (Dl) domains of the adult zebrafish pallium, which contain homologous structures to the mammalian amygdala and hippocampus, respectively. Calbindin-positive and glutamatergic neurons are recruited in Dm, and glutamatergic and γ-aminobutyric acid (GABAergic) neurons in Dl. The drug-activated neurons in Dm and Dl are born at juvenile stage rather than in the embryo or during adulthood. Furthermore, the same territory in Dm is activated during both drug-seeking approach and light avoidance behavior, while these behaviors do not elicit activation in Dl. These data identify the pallial territories involved in acute psychostimulant response and reward formation in the adult zebrafish. They further suggest an evolutionarily conserved function of amygdala-like structures in positive emotions and motivated behavior in zebrafish and mammals. PMID:25145867

  20. The effect of titanium dioxide on the biochemical constituents of the brain of Zebrafish ( Danio rerio): An FT-IR study

    NASA Astrophysics Data System (ADS)

    Palaniappan, PL. RM.; Pramod, K. S.

    2011-06-01

    During recent years, the use of nanoparticles (NPs) in commercial products and industrial applications has increased greatly. One of the most widely used nanoparticles is titanium dioxide ( nTiO 2). It is a very versatile compound that has many uses, depending on its particle size. In the present paper an attempt is made to study the effect of TiO 2 nanoparticles and its bulk material on the biochemical constituents of the brain of Zebrafish ( Danio rerio) by using FT-IR technique. FT-IR spectra reveals significant differences in absorbance intensities between the control and TiO 2 exposed brain tissues, reflecting alterations on the major biochemical constituents such as proteins, lipids and nucleic acids in the brain tissues of D. rerio due to TiO 2 exposure. The results further reveal that TiO 2 nanoparticles are more toxic than their bulk counterparts. The higher ratio of integrated area of carbonyl-to-CH 2 peaks (1743 cm -1:1458 cm -1) observed in the present study in the nTiO 2 exposed brain tissues suggests that lipids are being oxidized. Since oxidation can cause an increase in carbonyls and a degradation of lipids, both of these changes could be contributed to the elevated ratio. Further, the observed decreasing ratio of integrated areas of both 1458 cm -1:1542 cm -1 and 1743 cm -1:1542 cm -1 in the TiO 2 exposed tissues suggests that lipid degradation predominates over carbonyl formation. The observed changes in the biochemical constituents in the brain tissues of D. rerio could be due to the overproduction of ROS.

  1. Distribution of carnosine-like peptides in the nervous system of developing and adult zebrafish (Danio rerio) and embryonic effects of chronic carnosine exposure

    PubMed Central

    Azher, Seema; Margolis, Frank L.; Patel, Kamakshi; Mousa, Ahmad; Majid, Arshad

    2013-01-01

    Carnosine-like peptides (carnosine-LP) are a family of histidine derivatives that are present in the nervous system of various species and that exhibit antioxidant, anti-matrix-metalloproteinase, anti-excitotoxic, and free-radical scavenging properties. They are also neuroprotective in animal models of cerebral ischemia. Although the function of carnosine-LP is largely unknown, the hypothesis has been advanced that they play a role in the developing nervous system. Since the zebrafish is an excellent vertebrate model for studying development and disease, we have examined the distribution pattern of carnosine-LP in the adult and developing zebrafish. In the adult, immunoreactivity for carnosine-LP is specifically concentrated in sensory neurons and non-sensory cells of the olfactory epithelium, the olfactory nerve, and the olfactory bulb. Robust staining has also been observed in the retinal outer nuclear layer and the corneal epithelium. Developmental studies have revealed immunostaining for carnosine-LP as early as 18 h, 24 h, and 7 days post-fertilization in, respectively, the olfactory, corneal, and retinal primordia. These data suggest that carnosine-LP are involved in olfactory and visual function. We have also investigated the effects of chronic (7 days) exposure to carnosine on embryonic development and show that 0.01 μM to 10 mM concentrations of carnosine do not elicit significant deleterious effects. Conversely, treatment with 100 mM carnosine results in developmental delay and compromised larval survival. These results indicate that, at lower concentrations, exogenously administered carnosine can be used to explore the role of carnosine in development and developmental disorders of the nervous system. PMID:19440736

  2. Inactivation of ca10a and ca10b Genes Leads to Abnormal Embryonic Development and Alters Movement Pattern in Zebrafish

    PubMed Central

    Aspatwar, Ashok; Barker, Harlan R.; Saralahti, Anni K.; Bäuerlein, Carina A.; Ortutay, Csaba; Pan, Peiwen; Kuuslahti, Marianne; Parikka, Mataleena; Rämet, Mika; Parkkila, Seppo

    2015-01-01

    Carbonic anhydrase related proteins (CARPs) X and XI are highly conserved across species and are predominantly expressed in neural tissues. The biological role of these proteins is still an enigma. Ray-finned fish have lost the CA11 gene, but instead possess two co-orthologs of CA10. We analyzed the expression pattern of zebrafish ca10a and ca10b genes during embryonic development and in different adult tissues, and studied 61 CARP X/XI-like sequences to evaluate their phylogenetic relationship. Sequence analysis of zebrafish ca10a and ca10b reveals strongly predicted signal peptides, N-glycosylation sites, and a potential disulfide, all of which are conserved, suggesting that all of CARP X and XI are secretory proteins and potentially dimeric. RT-qPCR showed that zebrafish ca10a and ca10b genes are expressed in the brain and several other tissues throughout the development of zebrafish. Antisense morpholino mediated knockdown of ca10a and ca10b showed developmental delay with a high rate of mortality in larvae. Zebrafish morphants showed curved body, pericardial edema, and abnormalities in the head and eye, and there was increased apoptotic cell death in the brain region. Swim pattern showed abnormal movement in morphant zebrafish larvae compared to the wild type larvae. The developmental phenotypes of the ca10a and ca10b morphants were confirmed by inactivating these genes with the CRISPR/Cas9 system. In conclusion, we introduce a novel zebrafish model to investigate the mechanisms of CARP Xa and CARP Xb functions. Our data indicate that CARP Xa and CARP Xb have important roles in zebrafish development and suppression of ca10a and ca10b expression in zebrafish larvae leads to a movement disorder. PMID:26218428

  3. Generation of Parabiotic Zebrafish Embryos by Surgical Fusion of Developing Blastulae

    PubMed Central

    Hagedorn, Elliott J.; Cillis, Jennifer L.; Curley, Caitlyn R.; Patch, Taylor C.; Li, Brian; Blaser, Bradley W.; Riquelme, Raquel; Zon, Leonard I.; Shah, Dhvanit I.

    2016-01-01

    Surgical parabiosis of two animals of different genetic backgrounds creates a unique scenario to study cell-intrinsic versus cell-extrinsic roles for candidate genes of interest, migratory behaviors of cells, and secreted signals in distinct genetic settings. Because parabiotic animals share a common circulation, any blood or blood-borne factor from one animal will be exchanged with its partner and vice versa. Thus, cells and molecular factors derived from one genetic background can be studied in the context of a second genetic background. Parabiosis of adult mice has been used extensively to research aging, cancer, diabetes, obesity, and brain development. More recently, parabiosis of zebrafish embryos has been used to study the developmental biology of hematopoiesis. In contrast to mice, the transparent nature of zebrafish embryos permits the direct visualization of cells in the parabiotic context, making it a uniquely powerful method for investigating fundamental cellular and molecular mechanisms. The utility of this technique, however, is limited by a steep learning curve for generating the parabiotic zebrafish embryos. This protocol provides a step-by-step method on how to surgically fuse the blastulae of two zebrafish embryos of different genetic backgrounds to investigate the role of candidate genes of interest. In addition, the parabiotic zebrafish embryos are tolerant to heat shock, making temporal control of gene expression possible. This method does not require a sophisticated set-up and has broad applications for studying cell migration, fate specification, and differentiation in vivo during embryonic development. PMID:27341538

  4. Generation of Parabiotic Zebrafish Embryos by Surgical Fusion of Developing Blastulae.

    PubMed

    Hagedorn, Elliott J; Cillis, Jennifer L; Curley, Caitlyn R; Patch, Taylor C; Li, Brian; Blaser, Bradley W; Riquelme, Raquel; Zon, Leonard I; Shah, Dhvanit I

    2016-06-11

    Surgical parabiosis of two animals of different genetic backgrounds creates a unique scenario to study cell-intrinsic versus cell-extrinsic roles for candidate genes of interest, migratory behaviors of cells, and secreted signals in distinct genetic settings. Because parabiotic animals share a common circulation, any blood or blood-borne factor from one animal will be exchanged with its partner and vice versa. Thus, cells and molecular factors derived from one genetic background can be studied in the context of a second genetic background. Parabiosis of adult mice has been  used extensively to research aging, cancer, diabetes, obesity, and brain development. More recently, parabiosis of zebrafish embryos has been used to study the developmental biology of hematopoiesis. In contrast to mice, the transparent nature of zebrafish embryos permits the direct visualization of cells in the parabiotic context, making it a uniquely powerful method for investigating fundamental cellular and molecular mechanisms. The utility of this technique, however, is limited by a steep learning curve for generating the parabiotic zebrafish embryos. This protocol provides a step-by-step method on how to surgically fuse the blastulae of two zebrafish embryos of different genetic backgrounds to investigate the role of candidate genes of interest. In addition, the parabiotic zebrafish embryos are tolerant to heat shock, making temporal control of gene expression possible. This method does not require a sophisticated set-up and has broad applications for studying cell migration, fate specification, and differentiation in vivo during embryonic development.

  5. Investigation of genes important in neurodevelopment disorders in adult human brain.

    PubMed

    Maussion, Gilles; Diallo, Alpha B; Gigek, Carolina O; Chen, Elizabeth S; Crapper, Liam; Théroux, Jean-Francois; Chen, Gary G; Vasuta, Cristina; Ernst, Carl

    2015-10-01

    Several neurodevelopmental disorders (NDDs) are caused by mutations in genes expressed in fetal brain, but little is known about these same genes in adult human brain. Here, we test the hypothesis that genes associated with NDDs continue to have a role in adult human brain to explore the idea that NDD symptoms may be partially a result of their adult function rather than just their neurodevelopmental function. To demonstrate adult brain function, we performed expression analyses and ChIPseq in human neural stem cell(NSC) lines at different developmental stages and adult human brain, targeting two genes associated with NDDs, SATB2 and EHMT1, and the WNT signaling gene TCF7L2, which has not been associated with NDDs. Analysis of DNA interaction sites in neural stem cells reveals high (40-50 %) overlap between proliferating and differentiating cells for each gene in temporal space. Studies in adult brain demonstrate that consensus sites are similar to NSCs but occur at different genomic locations. We also performed expression analyses using BrainSpan data for NDD-associated genes SATB2, EHMT1, FMR1, MECP2, MBD5, CTNND2, RAI1, CHD8, GRIN2A, GRIN2B, TCF4, SCN2A, and DYRK1A and find high expression of these genes in adult brain, at least comparable to developing human brain, confirming that genes associated with NDDs likely have a role in adult tissue. Adult function of genes associated with NDDs might be important in clinical disease presentation and may be suitable targets for therapeutic intervention.

  6. Sex-dependent effects of microcystin-LR on hypothalamic-pituitary-gonad axis and gametogenesis of adult zebrafish

    PubMed Central

    Liu, Wanjing; Chen, Chuanyue; Chen, Liang; Wang, Li; Li, Jian; Chen, Yuanyuan; Jin, Jienan; Kawan, Atufa; Zhang, Xuezhen

    2016-01-01

    While microcystins (MCs) have been reported to exert reproductive toxicity on fish with a sex-dependent effect, the underlying mechanism has been rarely investigated. In the present study, zebrafish were exposed to 1, 5 and 20 μg/L MC-LR for 30 d. The gonad-somatic index declined in all treated males. 17β-estradiol (E2), testosterone (T), 11-keto testosterone (11-KT) and follicle-stimulating hormone (FSH) levels increased in serum from all treated females, while T, FSH and luteinizing hormone (LH) levels changed in all treated males. Histomorphological observation showed that MC-LR exposure evidently retarded oogenesis and spermatogenesis. Transcriptional changes of 22 genes of the hypothalamic-pituitary-gonad (HPG) axis exhibited sex-specific responses, and the relationship between gene transcriptions and gametogenesis was evaluated by principle component analysis (PCA). Major contributors to PC1 (gnrh2, gnrhr3, ar, lhr, hmgra, hmgrb and cyp19a) were positively correlated with the number of post-vitellogenic oocytes, while PC1 (gnrh2, lhβ, erβ, fshr, cyp11a and 17βhsd) were positively correlated with the number of spermatozoa. The protein levels of 17βHSD and CYP19a were affected in both females and males. In conclusion, this study first investigated the sex-dependent effects of microcystins on fish reproduction and revealed some important molecular biomarkers related to gametogenesis in zebrafish suffered from MC-LR. PMID:26960901

  7. Sex-dependent effects of microcystin-LR on hypothalamic-pituitary-gonad axis and gametogenesis of adult zebrafish

    NASA Astrophysics Data System (ADS)

    Liu, Wanjing; Chen, Chuanyue; Chen, Liang; Wang, Li; Li, Jian; Chen, Yuanyuan; Jin, Jienan; Kawan, Atufa; Zhang, Xuezhen

    2016-03-01

    While microcystins (MCs) have been reported to exert reproductive toxicity on fish with a sex-dependent effect, the underlying mechanism has been rarely investigated. In the present study, zebrafish were exposed to 1, 5 and 20 μg/L MC-LR for 30 d. The gonad-somatic index declined in all treated males. 17β-estradiol (E2), testosterone (T), 11-keto testosterone (11-KT) and follicle-stimulating hormone (FSH) levels increased in serum from all treated females, while T, FSH and luteinizing hormone (LH) levels changed in all treated males. Histomorphological observation showed that MC-LR exposure evidently retarded oogenesis and spermatogenesis. Transcriptional changes of 22 genes of the hypothalamic-pituitary-gonad (HPG) axis exhibited sex-specific responses, and the relationship between gene transcriptions and gametogenesis was evaluated by principle component analysis (PCA). Major contributors to PC1 (gnrh2, gnrhr3, ar, lhr, hmgra, hmgrb and cyp19a) were positively correlated with the number of post-vitellogenic oocytes, while PC1 (gnrh2, lhβ, erβ, fshr, cyp11a and 17βhsd) were positively correlated with the number of spermatozoa. The protein levels of 17βHSD and CYP19a were affected in both females and males. In conclusion, this study first investigated the sex-dependent effects of microcystins on fish reproduction and revealed some important molecular biomarkers related to gametogenesis in zebrafish suffered from MC-LR.

  8. Comparative effects of nodularin and microcystin-LR in zebrafish: 2. Uptake and molecular effects in eleuthero-embryos and adult liver with focus on endoplasmic reticulum stress.

    PubMed

    Faltermann, Susanne; Grundler, Verena; Gademann, Karl; Pernthaler, Jakob; Fent, Karl

    2016-02-01

    . In contrast to adult liver, MC-LR and nodularin did not result in detectable changes of mRNA levels of selected target genes involved in ER-stress in zebrafish eleuthero-embryos, nor was the abundance of transcripts belonging to the MAPK and pro-apoptosis pathways altered. In conclusion, our data indicate that MC-LR and nodularin have similar transcriptional effects. They lead to changes in mRNA levels of genes that suggest induction of ER-stress, and furthermore, lead to increased level of tnfα mRNA in the adult liver, which suggests a novel (transcriptional) mode of action in fish. However, although taken up by eleuthero-embryos, no transcriptional changes induced by these cyanobacterial toxins were detected. This is probably due to action to specific organs such as liver and kidneys that could not be identified by whole-embryo sampling.

  9. Molecular analysis and heavy metal detoxification of ABCC1/MRP1 in zebrafish.

    PubMed

    Long, Yong; Li, Qing; Cui, Zongbin

    2011-03-01

    ABCC1/MRP1 belongs to the ATP-binding cassette superfamily and its elevated expression is closely associated with the multidrug resistance of various tumor cells. In normal tissues, ABCC1 confers resistance to a wide variety of xenobiotics and toxicants, demonstrating its important roles in tissue defense. Here, we report the cloning and functional characterization of abcc1 gene in zebrafish. This gene is localized on zebrafish chromosome 3 and contains a 4,557 bp open-reading frame. The deduced polypeptide is composed of 1,518 amino acids, which shares 70% identity with human ABCC1. Phylogenetic analysis revealed that ABCC1 proteins from thirteen vertebrate species are highly conserved during evolution. Transcriptional expression of zebrafish abcc1 gene in developing embryos was examined by whole-mount in situ hybridization and real-time PCR. Transcripts of zebrafish abcc1 gene were detectable in four-cell stage embryos, indicating that this gene is maternally expressed. ABCC1 mRNAs were ubiquitously distributed in embryos before 12 h post-fertilization (hpf) and mainly localized in eyes and brain from 24 to 72 hpf, and in gills from 96 to 120 hpf. In addition, zebrafish abcc1 gene was highly expressed in 1-hpf embryos and detected in all adult tissues examined, with highest expression in testis and lowest in heart and liver. Exposure of ZF4 cells and embryos to CdCl(2)·2.5H(2)O, HgCl(2), Pb(NO(3))(2), or Na(3)AsO(4)·12H(2)O significantly induced transcriptional expression of abcc1 gene. Furthermore, overexpression of abcc1 improved the survival rates of embryos exposed to Cd, Hg or As, while overexpression of a abcc1 mutant (ABCC1-G1420D) sensitized zebrafish embryos to toxic metals. These data indicate that zebrafish ABCC1 has crucial roles in heavy metals detoxification.

  10. GABA regulates synaptic integration of newly generated neurons in the adult brain

    NASA Astrophysics Data System (ADS)

    Ge, Shaoyu; Goh, Eyleen L. K.; Sailor, Kurt A.; Kitabatake, Yasuji; Ming, Guo-Li; Song, Hongjun

    2006-02-01

    Adult neurogenesis, the birth and integration of new neurons from adult neural stem cells, is a striking form of structural plasticity and highlights the regenerative capacity of the adult mammalian brain. Accumulating evidence suggests that neuronal activity regulates adult neurogenesis and that new neurons contribute to specific brain functions. The mechanism that regulates the integration of newly generated neurons into the pre-existing functional circuitry in the adult brain is unknown. Here we show that newborn granule cells in the dentate gyrus of the adult hippocampus are tonically activated by ambient GABA (γ-aminobutyric acid) before being sequentially innervated by GABA- and glutamate-mediated synaptic inputs. GABA, the major inhibitory neurotransmitter in the adult brain, initially exerts an excitatory action on newborn neurons owing to their high cytoplasmic chloride ion content. Conversion of GABA-induced depolarization (excitation) into hyperpolarization (inhibition) in newborn neurons leads to marked defects in their synapse formation and dendritic development in vivo. Our study identifies an essential role for GABA in the synaptic integration of newly generated neurons in the adult brain, and suggests an unexpected mechanism for activity-dependent regulation of adult neurogenesis, in which newborn neurons may sense neuronal network activity through tonic and phasic GABA activation.

  11. Reprint of "Caffeine protects against memory loss induced by high and non-anxiolytic dose of cannabidiol in adult zebrafish (Danio rerio)".

    PubMed

    Nazario, Luiza Reali; Antonioli, Régis Junior; Capiotti, Katiucia Marques; Hallak, Jaime Eduardo Cecílio; Zuardi, Antonio Waldo; Crippa, José Alexandre S; Bonan, Carla Denise; da Silva, Rosane Souza

    2015-12-01

    Cannabidiol (CBD) has been investigated in a wide spectrum of clinical approaches due to its psychopharmacological properties. CBD has low affinity for cannabinoid neuroreceptors and agonistic properties to 5-HT receptors. An interaction between cannabinoid and purinergic receptor systems has been proposed. The purpose of this study is to evaluate CBD properties on memory behavioral and locomotor parameters and the effects of pre-treatment of adenosine receptor blockers on CBD impacts on memory using adult zebrafish. CBD (0.1, 0.5, 5, and 10mg/kg) was tested in the avoidance inhibitory paradigm and anxiety task. We analyzed the effect of a long-term caffeine pre-treatment (~20mg/L - four months). Also, acute block of adenosine receptors was performed in co-administration with CBD exposure in the memory assessment. CBD promoted an inverted U-shaped dose-response curve in the anxiety task; in the memory assessment, CBD in the dose of 5mg/Kg promoted the strongest effects without interfering with social and aggressive behavior. Caffeine treatment was able to prevent CBD (5mg/kg) effects on memory when CBD was given after the training session. CBD effects on memory were partially prevented by co-treatment with a specific A2A adenosine receptor antagonist when given prior to or after the training session, while CBD effects after the training session were fully prevented by adenosine A1 receptor antagonist. These results indicated that zebrafish have responses to CBD anxiolytic properties that are comparable to other animal models, and high doses changed memory retention in a way dependent on adenosine.

  12. Short-term treatment of adult male zebrafish (Danio Rerio) with 17α-ethinyl estradiol affects the transcription of genes involved in development and male sex differentiation.

    PubMed

    Reyhanian Caspillo, Nasim; Volkova, Kristina; Hallgren, Stefan; Olsson, Per-Erik; Porsch-Hällström, Inger

    2014-08-01

    The synthetic estrogen 17α-ethinyl estradiol (EE2) disturbs reproduction and causes gonadal malformation in fish. Effects on the transcription of genes involved in gonad development and function that could serve as sensitive biomarkers of reproductive effects in the field is, however, not well known. We have studied mRNA expression in testes and liver of adult zebrafish (Danio rerio) males treated with 0, 5 or 25 ng/L EE2for 14 days. qPCR analysis showed that the mRNA expression of four genes linked to zebrafish male sex determination and differentiation, Anti-Mullerian Hormone, Double sex and mab-related protein, Sry-related HMG box-9a and Nuclear receptor subfamily 5 group number 1b were significantly decreased by 25 ng/L, but not 5 ng/L EE2 compared with the levels in untreated fish. The decreased transcription was correlated with a previously shown spawning failure in these males (Reyhanian et al., 2011. Aquat Toxicol 105, 41-48), suggesting that decreased mRNA expression of genes regulating male sexual function could be involved in the functional sterility. The mRNA level of Cytochrome P-45019a, involved in female reproductive development, was unaffected by hormone treatment. The transcription of the female-specific Vitellogenin was significantly induced in testes. While testicular Androgen Receptor and the Estrogen Receptor-alpha mRNA levels were unchanged, Estrogen receptor-beta was significantly decreased by 25 ng/L EE2. Hepatic Estrogen Receptor-alpha mRNA was significantly increased by both exposure concentrations, while Estrogen Receptor-beta transcription was unaltered. The decreased transcription of male-predominant genes supports a demasculinization of testes by EE2 and might reflect reproductive disturbances in the environment.

  13. Cytochrome P450 20A1 in zebrafish: Cloning, regulation and potential involvement in hyperactivity disorders

    PubMed Central

    Kubota, Akira; O'Meara, Conor M.; Lamb, David C.; Tanguay, Robert L.; Goldstone, Jared V.

    2016-01-01

    Cytochrome P450 (CYP) enzymes for which there is no functional information are considered “orphan” CYPs. Previous studies showed that CYP20A1, an orphan, is expressed in human hippocampus and substantia nigra, and in zebrafish (Danio rerio) CYP20A1 maternal transcript occurs in eggs, suggesting involvement in brain and in early development. Moreover, hyperactivity is reported in humans with chromosome 2 microdeletions including CYP20A1. We examined CYP20A1 in zebrafish, including impacts of chemical exposure on expression. Zebrafish CYP20A1 cDNA was cloned, sequenced, and aligned with cloned human CYP20A1 and predicted vertebrate orthologs. CYP20A1s share a highly conserved N-terminal region and unusual sequences in the I-helix and the heme-binding CYP signature motifs. CYP20A1 mRNA expression was observed in adult zebrafish organs including liver, heart, gonads, spleen and brain, as well as eye and optic nerve. Putative binding sites in proximal promoter regions of CYP20A1s, and response of zebrafish CYP20A1 to selected nuclear and xenobiotic receptor agonists, point to up-regulation by agents involved in steroid hormone response, cholesterol and lipid metabolism. There also was a dose-dependent reduction of CYP20A1 expression in embryos exposed to environmentally relevant levels of methylmercury. Morpholino knockdown of CYP20A1 in developing zebrafish resulted in behavioral effects, including hyperactivity and a slowing of the optomotor response in larvae. The results suggest that altered expression of CYP20A1 might be part of a mechanism linking methylmercury exposure to neurobehavioral deficits. The expanded information on CYP20A1 brings us closer to “deorphanization”, that is, identifying CYP20A1 functions and its roles in health and disease. PMID:26853319

  14. Encoding of mechanical nociception differs in the adult and infant brain

    PubMed Central

    Fabrizi, Lorenzo; Verriotis, Madeleine; Williams, Gemma; Lee, Amy; Meek, Judith; Olhede, Sofia; Fitzgerald, Maria

    2016-01-01

    Newborn human infants display robust pain behaviour and specific cortical activity following noxious skin stimulation, but it is not known whether brain processing of nociceptive information differs in infants and adults. Imaging studies have emphasised the overlap between infant and adult brain connectome architecture, but electrophysiological analysis of infant brain nociceptive networks can provide further understanding of the functional postnatal development of pain perception. Here we hypothesise that the human infant brain encodes noxious information with different neuronal patterns compared to adults. To test this we compared EEG responses to the same time-locked noxious skin lance in infants aged 0–19 days (n = 18, clinically required) and adults aged 23–48 years (n = 21). Time-frequency analysis revealed that while some features of adult nociceptive network activity are present in infants at longer latencies, including beta-gamma oscillations, infants display a distinct, long latency, noxious evoked 18-fold energy increase in the fast delta band (2–4 Hz) that is absent in adults. The differences in activity between infants and adults have a widespread topographic distribution across the brain. These data support our hypothesis and indicate important postnatal changes in the encoding of mechanical pain in the human brain. PMID:27345331

  15. Behavioral and magnetoencephalographic correlates of plasticity in the adult human brain

    PubMed Central

    Ramachandran, V. S.

    1993-01-01

    Recent behavioral and physiological evidence suggests that even brief sensory deprivation can lead to the rapid emergence of new and functionally effective neural connections in the adult human brain. Images Fig. 2 PMID:8248123

  16. The Zebrafish Brain in Research and Teaching: A Simple in Vivo and in Vitro Model for the Study of Spontaneous Neural Activity

    ERIC Educational Resources Information Center

    Vargas, R.; Johannesdottir, I. P.; Sigurgeirsson, B.; Porsteinsson, H.; Karlsson, K. AE.

    2011-01-01

    Recently, the zebrafish ("Danio rerio") has been established as a key animal model in neuroscience. Behavioral, genetic, and immunohistochemical techniques have been used to describe the connectivity of diverse neural circuits. However, few studies have used zebrafish to understand the function of cerebral structures or to study neural circuits.…

  17. Quantifying Aggressive Behavior in Zebrafish.

    PubMed

    Teles, Magda C; Oliveira, Rui F

    2016-01-01

    Aggression is a complex behavior that influences social relationships and can be seen as adaptive or maladaptive depending on the context and intensity of expression. A model organism suitable for genetic dissection of the underlying neural mechanisms of aggressive behavior is still needed. Zebrafish has already proven to be a powerful vertebrate model organism for the study of normal and pathological brain function. Despite the fact that zebrafish is a gregarious species that forms shoals, when allowed to interact in pairs, both males and females express aggressive behavior and establish dominance hierarchies. Here, we describe two protocols that can be used to quantify aggressive behavior in zebrafish, using two different paradigms: (1) staged fights between real opponents and (2) mirror-elicited fights. We also discuss the methodology for the behavior analysis, the expected results for both paradigms, and the advantages and disadvantages of each paradigm in face of the specific goals of the study.

  18. Molecular Mechanism of Adult Neurogenesis and its Association with Human Brain Diseases

    PubMed Central

    Liu, He; Song, Ni

    2016-01-01

    Recent advances in neuroscience challenge the old dogma that neurogenesis occurs only during embryonic development. Mounting evidence suggests that functional neurogenesis occurs throughout adulthood. This review article discusses molecular factors that affect adult neurogenesis, including morphogens, growth factors, neurotransmitters, transcription factors, and epigenetic factors. Furthermore, we summarize and compare current evidence of associations between adult neurogenesis and human brain diseases such as Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, and brain tumors. PMID:27375363

  19. Brain-specific ablation of Efr3a promotes adult hippocampal neurogenesis via the brain-derived neurotrophic factor pathway.

    PubMed

    Qian, Qi; Liu, Qiuji; Zhou, Dongming; Pan, Hongyu; Liu, Zhiwei; He, Fangping; Ji, Suying; Wang, Dongpi; Bao, Wangxiao; Liu, Xinyi; Liu, Zhaoling; Zhang, Heng; Zhang, Xiaoqin; Zhang, Ling; Wang, Mingkai; Xu, Ying; Huang, Fude; Luo, Benyan; Sun, Binggui

    2017-02-13

    Efr3 is a newly identified plasma membrane protein and plays an important role in the phosphoinositide metabolism on the plasma membrane. However, although it is highly expressed in the brain, the functional significance of Efr3 in the brain is not clear. In the present study, we generated Efr3a(f/f) mice and then crossed them with Nestin-Cre mice to delete Efr3a, one of the Efr3 isoforms, specifically in the brain. We found that brain-specific ablation of Efr3a promoted adult hippocampal neurogenesis by increasing survival and maturation of newborn neurons without affecting their dendritic tree morphology. Moreover, the brain-derived neurotrophic factor (BDNF)-tropomyosin-related kinase B (TrkB) signaling pathway was significantly enhanced in the hippocampus of Efr3a-deficient mice, as reflected by increased expression of BDNF, TrkB, and the downstream molecules, including phospho-MAPK and phospho-Akt. Furthermore, the number of TUNEL(+) cells was decreased in the subgranular zone of dentate gyrus in Efr3a-deficient mice compared with that of control mice. Our data suggest that brain-specific deletion of Efr3a could promote adult hippocampal neurogenesis, presumably by upregulating the expression of BDNF and its receptor, TrkB, and therefore provide new insight into the roles of Efr3 in the brain.-Qian, Q., Liu, Q., Zhou, D., Pan, H., Liu, Z., He, F., Ji, S., Wang, D., Bao, W., Liu, X., Liu, Z., Zhang, H., Zhang, X., Zhang, L., Wang, M., Xu, Y., Huang, F., Luo, B., Sun B. Brain-specific ablation of Efr3a promotes adult hippocampal neurogenesis via the brain-derived neurotrophic factor pathway.

  20. Health Problems Precede Traumatic Brain Injury in Older Adults

    PubMed Central

    Dams-O’Connor, Kristen; Gibbons, Laura E; Landau, Alexandra; Larson, Eric B; Crane, Paul K.

    2016-01-01

    Objectives To evaluate whether indices of pre-injury health and functioning were associated with risk for incident traumatic brain injury (TBI) with loss of consciousness (LOC), and evaluated health-related factors associated with mortality among those with an incident TBI. Design Prospective community cohort study. Setting Group Health, Seattle Washington. Participants 3,363 individuals aged 65 and older with no self-reported prior TBI with LOC were enrolled and followed every 2 years for an average of 7.5 years (range 0–18 years). Measurements We used Weibull survival models to evaluate baseline and time-varying predictors of incident TBI with LOC, including measures of depression, activities of daily living, cerebrovascular disease, and disease comorbidity. Results In an adjusted multivariate model, baseline depression symptoms as measured by CES-D score (hazard ratio (HR) and 95% confidence interval (CI) for 4 points = 1.34 (1.13, 1.58); p<0.05) and baseline impairment in activities of daily living (ADL; HR (95% CI) = 2.37 (1.24, 4.53); p<0.01) were associated with incident TBI. In a model that included time-dependent covariates, cerebrovascular disease at the previous visit (HR (95% CI) = 2.28 (1.37, 3.78); p<0.01), CES-D score the previous visit (HR for 4 points (95% CI) = 1.23 (1.02, 1.49); p<0.05) and baseline impairment in ADL (HR (95% CI) 2.14 (1.11, 4.13); p<0.05) predicted incident TBI. Of factors considered, cerebrovascular disease and ADL impairment were associated with earlier mortality among those with an incident TBI with LOC. Conclusion Indices of health, mood, and functional status predict incident TBI with LOC in older adults. These findings may have implications for injury prevention and post-injury clinical management. PMID:26925541

  1. Monte Carlo simulation of light propagation in the adult brain

    NASA Astrophysics Data System (ADS)

    Mudra, Regina M.; Nadler, Andreas; Keller, Emanuella; Niederer, Peter

    2004-06-01

    When near infrared spectroscopy (NIRS) is applied noninvasively to the adult head for brain monitoring, extra-cerebral bone and surface tissue exert a substantial influence on the cerebral signal. Most attempts to subtract extra-cerebral contamination involve spatially resolved spectroscopy (SRS). However, inter-individual variability of anatomy restrict the reliability of SRS. We simulated the light propagation with Monte Carlo techniques on the basis of anatomical structures determined from 3D-magnetic resonance imaging (MRI) exhibiting a voxel resolution of 0.8 x 0.8 x 0.8 mm3 for three different pairs of T1/T2 values each. The MRI data were used to define the material light absorption and dispersion coefficient for each voxel. The resulting spatial matrix was applied in the Monte Carlo Simulation to determine the light propagation in the cerebral cortex and overlaying structures. The accuracy of the Monte Carlo Simulation was furthermore increased by using a constant optical path length for the photons which was less than the median optical path length of the different materials. Based on our simulations we found a differential pathlength factor (DPF) of 6.15 which is close to with the value of 5.9 found in the literature for a distance of 4.5cm between the external sensors. Furthermore, we weighted the spatial probability distribution of the photons within the different tissues with the probabilities of the relative blood volume within the tissue. The results show that 50% of the NIRS signal is determined by the grey matter of the cerebral cortex which allows us to conclude that NIRS can produce meaningful cerebral blood flow measurements providing that the necessary corrections for extracerebral contamination are included.

  2. Inhibiting effects of rhynchophylline on zebrafish methamphetamine dependence are associated with amelioration of neurotransmitters content and down-regulation of TH and NR2B expression.

    PubMed

    Jiang, Mingjin; Chen, Yifei; Li, Chan; Peng, Qiuxian; Fang, Miao; Liu, Wei; Kang, Qunzhao; Lin, Yingbo; Yung, Ken Kin Lam; Mo, Zhixian

    2016-07-04

    Others and we have reported that rhynchophylline reverses amphetamine-induced conditioned place preference (CPP) effect which may be partly mediated by amelioration of central neurotransmitters and N-methyl-d-aspartate receptor 2B (NR2B) levels in the rat brains. The current study investigated the inhibiting effects of rhynchophylline on methamphetamine-induced (METH-induced) CPP in adult zebrafish and METH-induced locomotor activity in tyrosine hydroxylase-green fluorescent protein (TH-GFP) transgenic zebrafish larvae and attempted to confirm the hypothesis that these effects were mediated via regulation of neurotransmitters and dopaminergic and glutamatergic systems. After baseline preference test (on days 1-3), zebrafish were injected intraperitoneally METH (on days 4, 6 and 8) or the same volume of fish physiological saline (on days 5 and 7) and were immediately conditioned. Rhynchophylline was administered at 12h after injection of METH. On day 9, zebrafish were tested for METH-induced CPP. Results revealed that rhynchophylline (100mg/kg) significantly inhibited the acquisition of METH-induced CPP, reduced the content of dopamine and glutamate and down-regulated the expression of TH and NR2B in the CPP zebrafish brains. Furthermore, the influence of rhynchophylline on METH-induced locomotor activity was also observed in TH-GFP transgenic zebrafish larvae. Results showed that rhynchophylline (50mg/L) treatment led to a significant reduction on the locomotor activity and TH expression in TH-GFP transgenic zebrafish larvae. Taken together, these data indicate that the inhibition of the formation of METH dependence by rhynchophylline in zebrafish is associated with amelioration of the neurotransmitters dopamine and glutamate content and down-regulation of TH and NR2B expression.

  3. Treatment Efficacy: Cognitive-Communicative Disorders Resulting from Traumatic Brain Injury in Adults.

    ERIC Educational Resources Information Center

    Coelho, Carl A.; And Others

    1996-01-01

    This article discusses adults with brain injuries and resulting cognitive communicative disorders. The incidence of brain injuries, the effects of cognitive-communication disorders, the role of the speech-language pathologist, the benefits of treatment, and the effects of different treatments are discussed. Charts are included that summarize…

  4. Future Concerns of Adult Siblings of Persons with Traumatic Brain Injury

    ERIC Educational Resources Information Center

    Degeneffe, Charles Edmund; Olney, Marjorie F.

    2008-01-01

    This study examined future concerns conveyed by adult siblings who provided regular caregiving support to their brothers and sisters with traumatic brain injury (TBI). The authors surveyed a national sample of 280 adult siblings of persons with TBI. Using a constant comparative approach to text analysis, the authors analyzed responses to the…

  5. Correlates of Depression in Adult Siblings of Persons with Traumatic Brain Injury

    ERIC Educational Resources Information Center

    Degeneffe, Charles Edmund; Lynch, Ruth Torkelson

    2006-01-01

    Using Pearlin's stress process model, this study examined correlates of depression in 170 adult siblings of persons with traumatic brain injury (TBI). Approximately 39% of adult sibling participants evinced "Center for Epidemiologic Studies-Depression" (CES-D; Radloff, 1977) scores indicating clinically significant depressive symptoms. Background…

  6. Development of a Conceptual Model to Predict Physical Activity Participation in Adults with Brain Injuries

    ERIC Educational Resources Information Center

    Driver, Simon

    2008-01-01

    The purpose was to examine psychosocial factors that influence the physical activity behaviors of adults with brain injuries. Two differing models, based on Harter's model of self-worth, were proposed to examine the relationship between perceived competence, social support, physical self-worth, affect, and motivation. Adults numbering 384 with…

  7. Zebrafish Sensitivity to Botulinum Neurotoxins

    PubMed Central

    Chatla, Kamalakar; Gaunt, Patricia S.; Petrie-Hanson, Lora; Ford, Lorelei; Hanson, Larry A.

    2016-01-01

    Botulinum neurotoxins (BoNT) are the most potent known toxins. The mouse LD50 assay is the gold standard for testing BoNT potency, but is not sensitive enough to detect the extremely low levels of neurotoxin that may be present in the serum of sensitive animal species that are showing the effects of BoNT toxicity, such as channel catfish affected by visceral toxicosis of catfish. Since zebrafish are an important animal model for diverse biomedical and basic research, they are readily available and have defined genetic lines that facilitate reproducibility. This makes them attractive for use as an alternative bioassay organism. The utility of zebrafish as a bioassay model organism for BoNT was investigated. The 96 h median immobilizing doses of BoNT/A, BoNT/C, BoNT/E, and BoNT/F for adult male Tübingen strain zebrafish (0.32 g mean weight) at 25 °C were 16.31, 124.6, 4.7, and 0.61 picograms (pg)/fish, respectively. These findings support the use of the zebrafish-based bioassays for evaluating the presence of BoNT/A, BoNT/E, and BoNT/F. Evaluating the basis of the relatively high resistance of zebrafish to BoNT/C and the extreme sensitivity to BoNT/F may reveal unique functional patterns to the action of these neurotoxins. PMID:27153088

  8. Analysis of nicastrin gene phylogeny and expression in zebrafish.

    PubMed

    Lim, Anne; Moussavi Nik, Seyyed Hani; Ebrahimie, Esmaeil; Lardelli, Michael

    2015-06-01

    NICASTRIN is a component of the aspartyl protease γ-secretase complex which is involved in intramembranous cleavage of type I transmembrane proteins, notably the Notch receptor proteins and the AMYLOID BETA A4 PRECURSOR PROTEIN (APP). This study aimed to characterize the orthologue of the human NICASTRIN (NCSTN) gene in zebrafish, an advantageous model organism for the study of human disease. Zebrafish Nicastrin protein was predicted to possess the conserved glutamate 333 residue and DYIGS motif of human NCSTN that are important for substrate recognition/processing in γ-secretase. Quantitative real-time RT-PCR revealed the profile of relative zebrafish nicastrin (ncstn) transcript levels in embryos at different times during development and in adult tissues. The analysis of synteny conservation revealed local rearrangements of ncstn and another gene, mpz, relative to copa, and pex19. In situ hybridization showed higher relative levels of ncstn transcripts in the developing brain and otic vesicles of embryos at 24 and 48 h post fertilization, respectively. Our observations are consistent with a role for Ncstn protein in Notch signaling within the proliferative ventricular zone of the developing central nervous system.

  9. Visualization of Estrogen Receptor Transcriptional Activation in Zebrafish

    PubMed Central

    Halpern, Marnie E.

    2011-01-01

    Estrogens regulate a diverse range of physiological processes and affect multiple tissues. Estrogen receptors (ERs) regulate transcription by binding to DNA at conserved estrogen response elements, and such elements have been used to report ER activity in cultured cells and in transgenic mice. We generated stable, transgenic zebrafish containing five consecutive elements upstream of a c-fos minimal promoter and green fluorescent protein (GFP) to visualize and quantify transcriptional activation in live larvae. Transgenic larvae show robust, dose-dependent estrogen-dependent fluorescent labeling in the liver, consistent with er gene expression, whereas ER antagonists inhibit GFP expression. The nonestrogenic steroids dexamethasone and progesterone fail to activate GFP, confirming ER selectivity. Natural and synthetic estrogens activated the transgene with varying potency, and two chemicals, genistein and bisphenol A, preferentially induce GFP expression in the heart. In adult fish, fluorescence was observed in estrogenic tissues such as the liver, ovary, pituitary gland, and brain. Individual estrogen-responsive neurons and their projections were visualized in the adult brain, and GFP-positive neurons increased in number after 17β-estradiol exposure. The transgenic estrogen-responsive zebrafish allow ER signaling to be monitored visually and serve as in vivo sentinels for detection of estrogenic compounds. PMID:21540282

  10. The Social Environment and Neurogenesis in the Adult Mammalian Brain

    PubMed Central

    Lieberwirth, Claudia; Wang, Zuoxin

    2012-01-01

    Adult neurogenesis – the formation of new neurons in adulthood – has been shown to be modulated by a variety of endogenous (e.g., trophic factors, neurotransmitters, and hormones) as well as exogenous (e.g., physical activity and environmental complexity) factors. Research on exogenous regulators of adult neurogenesis has focused primarily on the non-social environment. More recently, however, evidence has emerged suggesting that the social environment can also affect adult neurogenesis. The present review details the effects of adult–adult (e.g., mating and chemosensory interactions) and adult–offspring (e.g., gestation, parenthood, and exposure to offspring) interactions on adult neurogenesis. In addition, the effects of a stressful social environment (e.g., lack of social support and dominant–subordinate interactions) on adult neurogenesis are reviewed. The underlying hormonal mechanisms and potential functional significance of adult-generated neurons in mediating social behaviors are also discussed. PMID:22586385

  11. Growth response and expression of muscle growth-related candidate genes in adult zebrafish fed plant and fishmeal protein-based diets.

    PubMed

    Ulloa, Pilar E; Peña, Andrea A; Lizama, Carla D; Araneda, Cristian; Iturra, Patricia; Neira, Roberto; Medrano, Juan F

    2013-03-01

    The main objective of this study was to examine the effects of a plant protein- vs. fishmeal-based diet on growth response in a population of 24 families, as well as expression of growth-related genes in the muscle of adult zebrafish (Danio rerio). Each family was split to create two fish populations with similar genetic backgrounds, and the fish were fed either fishmeal (FM diet) or plant protein (PP diet) as the unique protein source in their diets from 35 to 98 days postfertilization (dpf). To understand the effect of the PP diet on gene expression, individuals from three families, representative of the mean weight in both populations, were selected. To understand the effect of familiar variation on gene expression, the same families were evaluated separately. At 98 dpf, growth-related genes Igf1a, Igf2a, mTOR, Pld1a, Mrf4, Myod, Myogenin, and Myostatin1b were evaluated. In males, Myogenin, Mrf4, and Igf2a showed changes attributable to the PP diet. In females, the effect of the PP diet did not modulate the expression in any of the eight genes studied. The effect of familiar variation on gene expression was observed among families. This study shows that PP diet and family variation have effects on gene expression in fish muscle.

  12. Mutations in zebrafish lrp2 result in adult-onset ocular pathogenesis that models myopia and other risk factors for glaucoma.

    PubMed

    Veth, Kerry N; Willer, Jason R; Collery, Ross F; Gray, Matthew P; Willer, Gregory B; Wagner, Daniel S; Mullins, Mary C; Udvadia, Ava J; Smith, Richard S; John, Simon W M; Gregg, Ronald G; Link, Brian A

    2011-02-01

    The glaucomas comprise a genetically complex group of retinal neuropathies that typically occur late in life and are characterized by progressive pathology of the optic nerve head and degeneration of retinal ganglion cells. In addition to age and family history, other significant risk factors for glaucoma include elevated intraocular pressure (IOP) and myopia. The complexity of glaucoma has made it difficult to model in animals, but also challenging to identify responsible genes. We have used zebrafish to identify a genetically complex, recessive mutant that shows risk factors for glaucoma including adult onset severe myopia, elevated IOP, and progressive retinal ganglion cell pathology. Positional cloning and analysis of a non-complementing allele indicated that non-sense mutations in low density lipoprotein receptor-related protein 2 (lrp2) underlie the mutant phenotype. Lrp2, previously named Megalin, functions as an endocytic receptor for a wide-variety of bioactive molecules including Sonic hedgehog, bone morphogenic protein 4, retinol-binding protein, vitamin D-binding protein, and apolipoprotein E, among others. Detailed phenotype analyses indicated that as lrp2 mutant fish age, many individuals--but not all--develop high IOP and severe myopia with obviously enlarged eye globes. This results in retinal stretch and prolonged stress to retinal ganglion cells, which ultimately show signs of pathogenesis. Our studies implicate altered Lrp2-mediated homeostasis as important for myopia and other risk factors for glaucoma in humans and establish a new genetic model for further study of phenotypes associated with this disease.

  13. Mutations in Zebrafish lrp2 Result in Adult-Onset Ocular Pathogenesis That Models Myopia and Other Risk Factors for Glaucoma

    PubMed Central

    Veth, Kerry N.; Willer, Jason R.; Collery, Ross F.; Gray, Matthew P.; Willer, Gregory B.; Wagner, Daniel S.; Mullins, Mary C.; Udvadia, Ava J.; Smith, Richard S.; John, Simon W. M.; Gregg, Ronald G.; Link, Brian A.

    2011-01-01

    The glaucomas comprise a genetically complex group of retinal neuropathies that typically occur late in life and are characterized by progressive pathology of the optic nerve head and degeneration of retinal ganglion cells. In addition to age and family history, other significant risk factors for glaucoma include elevated intraocular pressure (IOP) and myopia. The complexity of glaucoma has made it difficult to model in animals, but also challenging to identify responsible genes. We have used zebrafish to identify a genetically complex, recessive mutant that shows risk factors for glaucoma including adult onset severe myopia, elevated IOP, and progressive retinal ganglion cell pathology. Positional cloning and analysis of a non-complementing allele indicated that non-sense mutations in low density lipoprotein receptor-related protein 2 (lrp2) underlie the mutant phenotype. Lrp2, previously named Megalin, functions as an endocytic receptor for a wide-variety of bioactive molecules including Sonic hedgehog, Bone morphogenic protein 4, retinol-binding protein, vitamin D-binding protein, and apolipoprotein E, among others. Detailed phenotype analyses indicated that as lrp2 mutant fish age, many individuals—but not all—develop high IOP and severe myopia with obviously enlarged eye globes. This results in retinal stretch and prolonged stress to retinal ganglion cells, which ultimately show signs of pathogenesis. Our studies implicate altered Lrp2-mediated homeostasis as important for myopia and other risk factors for glaucoma in humans and establish a new genetic model for further study of phenotypes associated with this disease. PMID:21379331

  14. An Assessment of the Long-Term Effects of Simulated Microgravity on Cranial Neural Crest Cells in Zebrafish Embryos with a Focus on the Adult Skeleton

    PubMed Central

    Edsall, Sara C.; Franz-Odendaal, Tamara A.

    2014-01-01

    It is becoming increasingly important to address the long-term effects of exposure to simulated microgravity as the potential for space tourism and life in space become prominent topics amongst the World’s governments. There are several studies examining the effects of exposure to simulated microgravity on various developmental systems and in various organisms; however, few examine the effects beyond the juvenile stages. In this study, we expose zebrafish embryos to simulated microgravity starting at key stages associated with cranial neural crest cell migration. We then analyzed the skeletons of adult fish. Gross observations and morphometric analyses show that exposure to simulated microgravity results in stunted growth, reduced ossification and severe distortion of some skeletal elements. Additionally, we investigated the effects on the juvenile skull and body pigmentation. This study determines for the first time the long-term effects of embryonic exposure to simulated microgravity on the developing skull and highlights the importance of studies investigating the effects of altered gravitational forces. PMID:24586670

  15. Specific and Efficient Uptake of Surfactant-Free Poly(Lactic Acid) Nanovaccine Vehicles by Mucosal Dendritic Cells in Adult Zebrafish after Bath Immersion

    PubMed Central

    Rességuier, Julien; Delaune, Emilie; Coolen, Anne-Line; Levraud, Jean-Pierre; Boudinot, Pierre; Le Guellec, Dominique; Verrier, Bernard

    2017-01-01

    Activation of mucosal immunity is a key milestone for next-generation vaccine development. Biocompatible polymer-based nanoparticles (NPs) are promising vectors and adjuvants for mucosal vaccination. However, their in vivo uptake by mucosae and their biodistribution in antigen-presenting cells (APCs) need to be better understood to optimize mucosal nanovaccine designs. Here, we assessed if APCs are efficiently targeted in a spontaneous manner by surfactant-free poly(lactic acid) nanoparticles (PLA-NPs) after mucosal administration. Combining histology and flow imaging approaches, we describe and quantify the mucosal uptake of 200 nm PLA-NPs in adult zebrafish. Following bath administration, PLA-NPs penetrated and crossed epithelial barriers from all exposed mucosae. In mucosae, PLA-NPs accumulated in APCs, which were identified as dendritic cells (DCs), macrophages, and IgZ+ B cells in gills and skin. PLA-NP uptake by phagocytes was specific to these cell types, as PLA-NPs were not detected in neutrophils. Importantly, quantitative analyses in gills revealed that DCs take up PLA-NPs with specifically high efficiency. This study shows that surfactant-free PLA-NPs, which display optimal biocompatibility, can spontaneously target DCs with high efficiency in vivo following mucosal administration, and highlights PLA-NPs as powerful platforms for mucosal vaccine delivery in the medical and veterinary fields, and particularly in aquaculture. PMID:28289416

  16. Efficient regeneration by activation of neurogenesis in homeostatically quiescent regions of the adult vertebrate brain.

    PubMed

    Berg, Daniel A; Kirkham, Matthew; Beljajeva, Anna; Knapp, Dunja; Habermann, Bianca; Ryge, Jesper; Tanaka, Elly M; Simon, András

    2010-12-01

    In contrast to mammals, salamanders and teleost fishes can efficiently repair the adult brain. It has been hypothesised that constitutively active neurogenic niches are a prerequisite for extensive neuronal regeneration capacity. Here, we show that the highly regenerative salamander, the red spotted newt, displays an unexpectedly similar distribution of active germinal niches with mammals under normal physiological conditions. Proliferation zones in the adult newt brain are restricted to the forebrain, whereas all other regions are essentially quiescent. However, ablation of midbrain dopamine neurons in newts induced ependymoglia cells in the normally quiescent midbrain to proliferate and to undertake full dopamine neuron regeneration. Using oligonucleotide microarrays, we have catalogued a set of differentially expressed genes in these activated ependymoglia cells. This strategy identified hedgehog signalling as a key component of adult dopamine neuron regeneration. These data show that brain regeneration can occur by activation of neurogenesis in quiescent brain regions.

  17. Age-Related Differences in the Brain Areas outside the Classical Language Areas among Adults Using Category Decision Task

    ERIC Educational Resources Information Center

    Cho, Yong Won; Song, Hui-Jin; Lee, Jae Jun; Lee, Joo Hwa; Lee, Hui Joong; Yi, Sang Doe; Chang, Hyuk Won; Berl, Madison M.; Gaillard, William D.; Chang, Yongmin

    2012-01-01

    Older adults perform much like younger adults on language. This similar level of performance, however, may come about through different underlying brain processes. In the present study, we evaluated age-related differences in the brain areas outside the typical language areas among adults using a category decision task. Our results showed that…

  18. Control of adult neurogenesis by programmed cell death in the mammalian brain.

    PubMed

    Ryu, Jae Ryun; Hong, Caroline Jeeyeon; Kim, Joo Yeon; Kim, Eun-Kyoung; Sun, Woong; Yu, Seong-Woon

    2016-04-21

    The presence of neural stem cells (NSCs) and the production of new neurons in the adult brain have received great attention from scientists and the public because of implications to brain plasticity and their potential use for treating currently incurable brain diseases. Adult neurogenesis is controlled at multiple levels, including proliferation, differentiation, migration, and programmed cell death (PCD). Among these, PCD is the last and most prominent process for regulating the final number of mature neurons integrated into neural circuits. PCD can be classified into apoptosis, necrosis, and autophagic cell death and emerging evidence suggests that all three may be important modes of cell death in neural stem/progenitor cells. However, the molecular mechanisms that regulate PCD and thereby impact the intricate balance between self-renewal, proliferation, and differentiation during adult neurogenesis are not well understood. In this comprehensive review, we focus on the extent, mechanism, and biological significance of PCD for the control of adult neurogenesis in the mammalian brain. The role of intrinsic and extrinsic factors in the regulation of PCD at the molecular and systems levels is also discussed. Adult neurogenesis is a dynamic process, and the signals for differentiation, proliferation, and death of neural progenitor/stem cells are closely interrelated. A better understanding of how adult neurogenesis is influenced by PCD will help lead to important insights relevant to brain health and diseases.

  19. Adolescent binge ethanol treatment alters adult brain regional volumes, cortical extracellular matrix protein and behavioral flexibility.

    PubMed

    Coleman, Leon Garland; Liu, Wen; Oguz, Ipek; Styner, Martin; Crews, Fulton T

    2014-01-01

    Adolescents binge drink more than any other age group, increasing risk of disrupting the development of the frontal cortex. We hypothesized that adolescent binge drinking would lead to persistent alterations in adulthood. In this study, we modeled adolescent weekend underage binge-drinking, using adolescent mice (post-natal days [P] 28-37). The adolescent intermittent binge ethanol (AIE) treatment includes 6 binge intragastric doses of ethanol in an intermittent pattern across adolescence. Assessments were conducted in adulthood following extended abstinence to determine if there were persistent changes in adults. Reversal learning, open field and other behavioral assessments as well as brain structure using magnetic imaging and immunohistochemistry were determined. We found that AIE did not impact adult Barnes Maze learning. However, AIE did cause reversal learning deficits in adults. AIE also caused structural changes in the adult brain. AIE was associated with adulthood volume enlargements in specific brain regions without changes in total brain volume. Enlarged regions included the orbitofrontal cortex (OFC, 4%), cerebellum (4.5%), thalamus (2%), internal capsule (10%) and genu of the corpus callosum (7%). The enlarged OFC volume in adults after AIE is consistent with previous imaging studies in human adolescents. AIE treatment was associated with significant increases in the expression of several extracellular matrix (ECM) proteins in the adult OFC including WFA (55%), Brevican (32%), Neurocan (105%), Tenacin-C (25%), and HABP (5%). These findings are consistent with AIE causing persistent changes in brain structure that could contribute to a lack of behavioral flexibility.

  20. Adolescent binge ethanol treatment alters adult brain regional volumes, cortical extracellular matrix protein and behavioral flexibility

    PubMed Central

    Coleman, Leon Garland; Liu, Wen; Oguz, Ipek; Styner, Martin; Crews, Fulton T.

    2014-01-01

    Adolescents binge drink more than any other age group, increasing risk of disrupting the development of the frontal cortex. We hypothesized that adolescent binge drinking would lead to persistent alterations in adulthood. In this study, we modeled adolescent weekend underage binge-drinking, using adolescent mice (post-natal days [P] 28–37). The adolescent intermittent binge ethanol (AIE) treatment includes 6 binge intragastric doses of ethanol in an intermittent pattern across adolescence. Assessments were conducted in adulthood following extended abstinence to determine if there were persistent changes in adults. Reversal learning, open field and other behavioral assessments as well as brain structure using magnetic imaging and immunohistochemistry were determined. We found AIE did not impact adult Barnes Maze learning. However, AIE did cause reversal learning deficits in adults. AIE also caused structural changes in the adult brain. AIE was associated with adulthood volume enlargements in specific brain regions without changes in total brain volume. Enlarged regions included the orbitofrontal cortex (OFC, 4%), cerebellum (4.5%), thalamus (2%), internal capsule (10%) and genu of the corpus callosum (7%). The enlarged OFC volume in adults after AIE is consistent with previous imaging studies in human adolescents. AIE treatment was associated with significant increases in the expression of several extracellular matrix (ECM) proteins in the adult OFC including WFA (55%), Brevican (32%), Neurocan (105%), Tenacin-C (25%), and HABP (5%). These findings are consistent with AIE causing persistent changes in brain structure that could contribute to a lack of behavioral flexibility. PMID:24275185

  1. The toxicity of a new disinfection by-product, 2,2-dichloroacetamide (DCAcAm), on adult zebrafish (Danio rerio) and its occurrence in the chlorinated drinking water.

    PubMed

    Yu, Shilin; Lin, Tao; Chen, Wei; Tao, Hui

    2015-11-01

    The detection method of 2,2-dichloroacetamide (DCAcAm), a new disinfection by-product (DBP) in chlorinated drinking water, was established using a gas chromatograph coupled with a micro-electron capture detector. The chlorinated water samples were taken from ten drinking water treatment plants around Yangtze River or Taihu Lake in China. The concentration of DCAcAm was detected ranging from 0.5 to 1.8μg/L in the waterworks around Yangtze River, and 1.5-2.6μg/L around Taihu Lake. The toxicity of DCAcAm on adult zebrafish was assessed by investigating the metabolism damage with multiple metabolic biomarkers and the accumulation capability with bio-concentration factor. The results showed that DCAcAm could cause the acute metabolism damage and was easily accumulated in zebrafish, and should be extremely cautioned.

  2. Effects of Pro-Tex on zebrafish (Danio rerio) larvae, adult common carp (Cyprinus carpio) and adult yellowtail kingfish (Seriola lalandi).

    PubMed

    Boerrigter, Jeroen G J; van de Vis, Hans W; van den Bos, Ruud; Abbink, Wout; Spanings, Tom; Zethof, Jan; Martinez, Laura Louzao; van Andel, Wouter F M; Lopez-Luna, Javier; Flik, Gert

    2014-08-01

    Aquaculture practices bring several stressful events to fish. Stressors not only activate the hypothalamus-pituitary-interrenal-axis, but also evoke cellular stress responses. Up-regulation of heat shock proteins (HSPs) is among the best studied mechanisms of the cellular stress response. An extract of the prickly pear cactus (Opuntia ficus indica), Pro-Tex, a soluble variant of TEX-OE(®), may induce expression of HSPs and reduce negative effects of cellular stress. Pro-Tex therefore is used to ameliorate conditions during stressful aquaculture-related practices. We tested Pro-Tex in zebrafish (Danio rerio), common carp (Cyprinus carpio L.) and yellowtail kingfish (Seriola lalandi) exposed to aquaculture-relevant stressors (thermal stress, net confinement, transport) and assessed its effects on stress physiology. Heat shock produced a mild increase in hsp70 mRNA expression in 5-day-old zebrafish larvae. Pro-Tex increased basal hsp70 mRNA expression, but decreased heat-shock-induced expression of hsp70 mRNA. In carp, Pro-Tex increased plasma cortisol and glucose levels, while it did not affect the mild stress response (increased plasma cortisol and glucose) to net confinement. In gills, and proximal and distal intestine, stress increased hsp70 mRNA expression; in the distal intestine, an additive enhancement of hsp70 mRNA expression by Pro-Tex was seen under stress. In yellowtail kingfish, Pro-Tex reduced the negative physiological effects of transport more efficiently than when fish were sedated with AQUI-S(®). Overall, our data indicate that Pro-Tex has protective effects under high levels of stress only. As Pro-Tex has potential for use in aquaculture, its functioning and impact on health and welfare of fish should be further studied.

  3. PDYN, a gene implicated in brain/mental disorders, is targeted by REST in the adult human brain.

    PubMed

    Henriksson, Richard; Bäckman, Cristina M; Harvey, Brandon K; Kadyrova, Helena; Bazov, Igor; Shippenberg, Toni S; Bakalkin, Georgy

    2014-11-01

    The dynorphin κ-opioid receptor system is implicated in mental health and brain/mental disorders. However, despite accumulating evidence that PDYN and/or dynorphin peptide expression is altered in the brain of individuals with brain/mental disorders, little is known about transcriptional control of PDYN in humans. In the present study, we show that PDYN is targeted by the transcription factor REST in human neuroblastoma SH-SY5Y cells and that that interfering with REST activity increases PDYN expression in these cells. We also show that REST binding to PDYN is reduced in the adult human brain compared to SH-SY5Y cells, which coincides with higher PDYN expression. This may be related to MIR-9 mediated down-regulation of REST as suggested by a strong inverse correlation between REST and MIR-9 expression. Our results suggest that REST represses PDYN expression in SH-SY5Y cells and the adult human brain and may have implications for mental health and brain/mental disorders.

  4. Not(ch) just development: Notch signalling in the adult brain

    PubMed Central

    Ables, Jessica L.; Breunig, Joshua J.; Eisch, Amelia J.; Rakic, Pasko

    2011-01-01

    The Notch pathway is often regarded as a developmental pathway, but components of Notch signalling are expressed and active in the adult brain. With the advent of more sophisticated genetic manipulations, evidence has emerged that suggests both conserved and novel roles for Notch signalling in the adult brain. Not surprisingly, Notch is a key regulator of adult neural stem cells, but it is increasingly clear that Notch signalling also has roles in the regulation of migration, morphology, synaptic plasticity and survival of immature and mature neurons. Understanding the many functions of Notch signalling in the adult brain, and its dysfunction in neurodegenerative disease and malignancy, is crucial to the development of new therapeutics that are centred around this pathway. PMID:21505516

  5. Developmental role of acetylcholinesterase in impulse control in zebrafish

    PubMed Central

    Parker, Matthew O.; Brock, Alistair J.; Sudwarts, Ari; Teh, Muy-Teck; Combe, Fraser J.; Brennan, Caroline H.

    2015-01-01

    Cellular and molecular processes that mediate individual variability in impulsivity, a key behavioral component of many neuropsychiatric disorders, are poorly understood. Zebrafish heterozygous for a nonsense mutation in ache (achesb55/+) showed lower levels of impulsivity in a 5-choice serial reaction time task (5-CSRTT) than wild type and ache+∕+. Assessment of expression of cholinergic (nAChR), serotonergic (5-HT), and dopamine (DR) receptor mRNA in both adult and larval (9 dpf) achesb55/+ revealed significant downregulation of chrna2, chrna5, and drd2 mRNA in achesb55/+ larvae, but no differences in adults. Acute exposure to cholinergic agonist/antagonists had no effect on impulsivity, supporting the hypothesis that behavioral effects observed in adults were due to lasting impact of developmental alterations in cholinergic and dopaminergic signaling. This shows the cross-species role of cholinergic signaling during brain development in impulsivity, and suggests zebrafish may be a useful model for the role of cholinergic pathways as a target for therapeutic advances in addiction medicine. PMID:26528153

  6. Neuregulin 1 Type II-ErbB Signaling Promotes Cell Divisions Generating Neurons from Neural Progenitor Cells in the Developing Zebrafish Brain.

    PubMed

    Sato, Tomomi; Sato, Fuminori; Kamezaki, Aosa; Sakaguchi, Kazuya; Tanigome, Ryoma; Kawakami, Koichi; Sehara-Fujisawa, Atsuko

    2015-01-01

    Post-mitotic neurons are generated from neural progenitor cells (NPCs) at the expense of their proliferation. Molecular and cellular mechanisms that regulate neuron production temporally and spatially should impact on the size and shape of the brain. While transcription factors such as neurogenin1 (neurog1) and neurod govern progression of neurogenesis as cell-intrinsic mechanisms, recent studies show regulatory roles of several cell-extrinsic or intercellular signaling molecules including Notch, FGF and Wnt in production of neurons/neural progenitor cells from neural stem cells/radial glial cells (NSCs/RGCs) in the ventricular zone (VZ). However, it remains elusive how production of post-mitotic neurons from neural progenitor cells is regulated in the sub-ventricular zone (SVZ). Here we show that newborn neurons accumulate in the basal-to-apical direction in the optic tectum (OT) of zebrafish embryos. While neural progenitor cells are amplified by mitoses in the apical ventricular zone, neurons are exclusively produced through mitoses of neural progenitor cells in the sub-basal zone, later in the sub-ventricular zone, and accumulate apically onto older neurons. This neurogenesis depends on Neuregulin 1 type II (NRG1-II)-ErbB signaling. Treatment with an ErbB inhibitor, AG1478 impairs mitoses in the sub-ventricular zone of the optic tectum. Removal of AG1478 resumes sub-ventricular mitoses without precedent mitoses in the apical ventricular zone prior to basal-to-apical accumulation of neurons, suggesting critical roles of ErbB signaling in mitoses for post-mitotic neuron production. Knockdown of NRG1-II impairs both mitoses in the sub-basal/sub-ventricular zone and the ventricular zone. Injection of soluble human NRG1 into the developing brain ameliorates neurogenesis of NRG1-II-knockdown embryos, suggesting a conserved role of NRG1 as a cell-extrinsic signal. From these results, we propose that NRG1-ErbB signaling stimulates cell divisions generating neurons from

  7. Spinal cord transection in the larval zebrafish.

    PubMed

    Briona, Lisa K; Dorsky, Richard I

    2014-05-21

    Mammals fail in sensory and motor recovery following spinal cord injury due to lack of axonal regrowth below the level of injury as well as an inability to reinitiate spinal neurogenesis. However, some anamniotes including the zebrafish Danio rerio exhibit both sensory and functional recovery even after complete transection of the spinal cord. The adult zebrafish is an established model organism for studying regeneration following spinal cord injury, with sensory and motor recovery by 6 weeks post-injury. To take advantage of in vivo analysis of the regenerative process available in the transparent larval zebrafish as well as genetic tools not accessible in the adult, we use the larval zebrafish to study regeneration after spinal cord transection. Here we demonstrate a method for reproducibly and verifiably transecting the larval spinal cord. After transection, our data shows sensory recovery beginning at 2 days post-injury (dpi), with the C-bend movement detectable by 3 dpi and resumption of free swimming by 5 dpi. Thus we propose the larval zebrafish as a companion tool to the adult zebrafish for the study of recovery after spinal cord injury.

  8. Characterization and Vaccine Potential of Membrane Vesicles Produced by Francisella noatunensis sup. orientalis in an Adult Zebrafish Model.

    PubMed

    Lagos, Leidy; Tandberg, Julia I; Repnik, Urska; Boysen, Preben; Ropstad, Erik; Varkey, Deepa; Paulsen, Ian T; Winther-Larsen, Hanne C

    2017-03-22

    Vaccine development against extracellular bacteria has been important for the sustainability of the aquaculture industry. In contrast, infections with intracellular pathogens remain largely an unresolved problem. Francisella noatunensis subspecies orientalis (Fno) are Gram-negative, facultative intracellular bacteria that cause the disease francisellosis in fish. Francisellosis is commonly characterized as a chronic granulomatous disease with high morbidity and can result in high mortality depending on the host. In this study, we explored the potential of bacterial membrane vesicles (MVs) as a vaccine agent against Fno Bacterial MVs are spherical structures naturally released from the membrane of bacteria and are often enriched with selected bacterial components such as toxins and signaling molecules. In the present work, MVs were isolated from broth-cultured Fno and proteomic analysis by mass spectrometry revealed that MVs contained a variety of immunogenic factors, including the intracellular growth proteins IglC and IglB, known to be part of a Francisella Pathogenicity Island (FPI), as well as outer membrane protein OmpA, chaperonin GroEL and chaperone ClpB. By using flow cytometry and electron microscopy, we observed that Fno mainly infect myelomonocytic cells, both in vivo and in vitro. Immunization with MVs isolated from Fno protect zebrafish from subsequent challenge with a lethal dose of Fno To determine if MVs induce a typical acute inflammatory response, mRNA expression level were assessed by quantitative real-time PCR. The expression of tnfa, il1b, ifng, as well as mhcii, mpeg1.1 and ighm was upregulated, thus confirming the immunogenic properties of Fno derived MVs.

  9. Sex, stress and the brain: interactive actions of hormones on the developing and adult brain.

    PubMed

    McEwen, B S

    2014-12-01

    The brain is a target of steroid hormone actions that affect brain architecture, molecular and neurochemical processes, behavior and neuroprotection via both genomic and non-genomic actions. Estrogens have such effects throughout the brain and this article provides an historical and current view of how this new view has come about and how it has affected the study of sex differences, as well as other areas of neuroscience, including the effects of stress on the brain.

  10. Clonal development and organization of the adult Drosophila central brain

    PubMed Central

    Yu, Hung-Hsiang; Awasaki, Takeshi; Schroeder, Mark David; Long, Fuhui; Yang, Jacob S.; He, Yisheng; Ding, Peng; Kao, Jui-Chun; Wu, Gloria Yueh-Yi; Peng, Hanchuan; Myers, Gene; Lee, Tzumin

    2013-01-01

    Summary Background The insect brain can be divided into neuropils that are formed by neurites of both local and remote origin. The complexity of the interconnections obscures how these neuropils are established and interconnected through development. The Drosophila central brain develops from a fixed number of neuroblasts (NBs) that deposit neurons in regional clusters. Results By determining individual NB clones and pursuing their projections into specific neuropils we unravel the regional development of the brain neural network. Exhaustive clonal analysis revealed 95 stereotyped neuronal lineages with characteristic cell body locations and neurite trajectories. Most clones show complex projection patterns, but despite the complexity, neighboring clones often co-innervate the same local neuropil(s) and further target a restricted set of distant neuropils. Conclusions These observations argue for regional clonal development of both neuropils and neuropil connectivity throughout the Drosophila central brain. PMID:23541733

  11. Streptococcus-Zebrafish Model of Bacterial Pathogenesis

    PubMed Central

    Neely, Melody N.; Pfeifer, John D.; Caparon, Michael

    2002-01-01

    Due to its small size, rapid generation time, powerful genetic systems, and genomic resources, the zebrafish has emerged as an important model of vertebrate development and human disease. Its well-developed adaptive and innate cellular immune systems make the zebrafish an ideal model for the study of infectious diseases. With a natural and important pathogen of fish, Streptococcus iniae, we have established a streptococcus- zebrafish model of bacterial pathogenesis. Following injection into the dorsal muscle, zebrafish developed a lethal infection, with a 50% lethal dose of 103 CFU, and died within 2 to 3 days. The pathogenesis of infection resembled that of S. iniae in farmed fish populations and that of several important human streptococcal diseases and was characterized by an initial focal necrotic lesion that rapidly progressed to invasion of the pathogen into all major organ systems, including the brain. Zebrafish were also susceptible to infection by the human pathogen Streptococcus pyogenes. However, disease was characterized by a marked absence of inflammation, large numbers of extracellular streptococci in the dorsal muscle, and extensive myonecrosis that occurred far in advance of any systemic invasion. The genetic systems available for streptococci, including a novel method of mutagenesis which targets genes whose products are exported, were used to identify several mutants attenuated for virulence in zebrafish. This combination of a genetically amenable pathogen with a well-defined vertebrate host makes the streptococcus-zebrafish model of bacterial pathogenesis a powerful model for analysis of infectious disease. PMID:12065534

  12. Zebrafish Behavior: Opportunities and Challenges.

    PubMed

    Orger, Michael B; de Polavieja, Gonzalo G

    2017-04-03

    A great challenge in neuroscience is understanding how activity in the brain gives rise to behavior. The zebrafish is an ideal vertebrate model to address this challenge, thanks to the capacity, at the larval stage, for precise behavioral measurements, genetic manipulations, and recording and manipulation of neural activity noninvasively and at single-neuron resolution throughout the whole brain. These techniques are being further developed for application in freely moving animals and juvenile stages to study more complex behaviors including learning, decision making, and social interactions. We review some of the approaches that have been used to study the behavior of zebrafish and point to opportunities and challenges that lie ahead. Expected final online publication date for the Annual Review of Neuroscience Volume 40 is July 8, 2017. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

  13. Event-related brain potentials - Comparison between children and adults

    NASA Technical Reports Server (NTRS)

    Courchesne, E.

    1977-01-01

    The reported investigation shows that nontarget stimuli which are infrequently presented and deviate from the background elicit Nc and Pc waves in children. The same stimuli elicit P3 waves in adults. The scalp distribution of P3 waves in adults appears to vary with the ease of stimulus recognition or the degree of stimulus novelty. However, the Nc and Pc distributions in children do not seem to vary with these factors. The differences between children and adults in event-related potentials suggest corresponding differences in the mode of processing employed by each when rare, deviant stimuli are encountered

  14. Morphological brain network assessed using graph theory and network filtration in deaf adults.

    PubMed

    Kim, Eunkyung; Kang, Hyejin; Lee, Hyekyoung; Lee, Hyo-Jeong; Suh, Myung-Whan; Song, Jae-Jin; Oh, Seung-Ha; Lee, Dong Soo

    2014-09-01

    Prolonged deprivation of auditory input can change brain networks in pre- and postlingual deaf adults by brain-wide reorganization. To investigate morphological changes in these brains voxel-based morphometry, voxel-wise correlation with the primary auditory cortex, and whole brain network analyses using morphological covariance were performed in eight prelingual deaf, eleven postlingual deaf, and eleven hearing adults. Network characteristics based on graph theory and network filtration based on persistent homology were examined. Gray matter density in the primary auditor cortex was preserved in prelingual deafness, while it tended to decrease in postlingual deafness. Unlike postlingual, prelingual deafness showed increased bilateral temporal connectivity of the primary auditory cortex compared to the hearing adults. Of the graph theory-based characteristics, clustering coefficient, betweenness centrality, and nodal efficiency all increased in prelingual deafness, while all the parameters of postlingual deafness were similar to the hearing adults. Patterns of connected components changing during network filtration were different between prelingual deafness and hearing adults according to the barcode, dendrogram, and single linkage matrix representations, while these were the same in postlingual deafness. Nodes in fronto-limbic and left temporal components were closely coupled, and nodes in the temporo-parietal component were loosely coupled, in prelingual deafness. Patterns of connected components changing in postlingual deafness were the same as hearing adults. We propose that the preserved density of auditory cortex associated with increased connectivity in prelingual deafness, and closer coupling between certain brain areas, represent distinctive reorganization of auditory and related cortices compared with hearing or postlingual deaf adults. The differential network reorganization in the prelingual deaf adults could be related to the absence of auditory speech

  15. Copper acutely impairs behavioral function and muscle acetylcholinesterase activity in zebrafish (Danio rerio).

    PubMed

    Haverroth, Gabriela M B; Welang, Chariane; Mocelin, Riciéri N; Postay, Daniela; Bertoncello, Kanandra T; Franscescon, Francini; Rosemberg, Denis B; Dal Magro, Jacir; Dalla Corte, Cristiane L

    2015-12-01

    Copper is a heavy metal found at relatively high concentrations in surface waters around the world. Copper is a micronutrient at low concentrations and is essential to several organisms. At higher concentrations copper can become toxic, which reveal the importance of studying the toxic effects of this metal on the aquatic life. Thus, the objective of this study was to evaluate the toxic effects of copper on the behavior and biochemical parameters of zebrafish (Danio rerio). Zebrafish were exposed for 24h at a concentration of 0.006 mg/L Cu. After the exposure period, behavioral profile of animals was recorded through 6 min using two different apparatuses tests: the Novel Tank and the Light-Dark test. After behavioral testing, animals were euthanized with a solution of 250 mg/L of tricaine (MS-222). Brain, muscle, liver and gills were extracted for analysis of parameters related to oxidative stress and accumulation of copper in these tissues. Acetylcholinesterase (AChE) activity was determined in brain and muscle. Results showed acute exposure to copper induces significant changes in behavioral profile of zebrafish by changing locomotion and natural tendency to avoid brightly lit area. On the other hand, there were no significant effects on parameters related to oxidative stress. AChE activity decreased significantly in zebrafish muscle, but there were no significant changes in cerebral AChE activity. Copper levels in tissues did not increase significantly compared to the controls. Taken together, these results indicate that a low concentration of copper can acutely affect behavioral profile of adult zebrafish which could be partially related to an inhibition on muscle AChE activity. These results reinforce the need of additional tests to establishment of safe copper concentrations to aquatic organisms and the importance of behavioral parameters in ecotoxicological studies.

  16. aBEAT: A Toolbox for Consistent Analysis of Longitudinal Adult Brain MRI

    PubMed Central

    Dai, Yakang; Wang, Yaping; Wang, Li; Wu, Guorong; Shi, Feng; Shen, Dinggang

    2013-01-01

    Longitudinal brain image analysis is critical for revealing subtle but complex structural and functional changes of brain during aging or in neurodevelopmental disease. However, even with the rapid increase of clinical research and trials, a software toolbox dedicated for longitudinal image analysis is still lacking publicly. To cater for this increasing need, we have developed a dedicated 4D Adult Brain Extraction and Analysis Toolbox (aBEAT) to provide robust and accurate analysis of the longitudinal adult brain MR images. Specially, a group of image processing tools were integrated into aBEAT, including 4D brain extraction, 4D tissue segmentation, and 4D brain labeling. First, a 4D deformable-surface-based brain extraction algorithm, which can deform serial brain surfaces simultaneously under temporal smoothness constraint, was developed for consistent brain extraction. Second, a level-sets-based 4D tissue segmentation algorithm that incorporates local intensity distribution, spatial cortical-thickness constraint, and temporal cortical-thickness consistency was also included in aBEAT for consistent brain tissue segmentation. Third, a longitudinal groupwise image registration framework was further integrated into aBEAT for consistent ROI labeling by simultaneously warping a pre-labeled brain atlas to the longitudinal brain images. The performance of aBEAT has been extensively evaluated on a large number of longitudinal MR T1 images which include normal and dementia subjects, achieving very promising results. A Linux-based standalone package of aBEAT is now freely available at http://www.nitrc.org/projects/abeat. PMID:23577105

  17. Assessing teratogenic changes in a zebrafish model of fetal alcohol exposure.

    PubMed

    Loucks, Evyn; Ahlgren, Sara

    2012-03-20

    Fetal alcohol syndrome (FAS) is a severe manifestation of embryonic exposure to ethanol. It presents with characteristic defects to the face and organs, including mental retardation due to disordered and damaged brain development. Fetal alcohol spectrum disorder (FASD) is a term used to cover a continuum of birth defects that occur due to maternal alcohol consumption, and occurs in approximately 4% of children born in the United States. With 50% of child-bearing age women reporting consumption of alcohol, and half of all pregnancies being unplanned, unintentional exposure is a continuing issue. In order to best understand the damage produced by ethanol, plus produce a model with which to test potential interventions, we developed a model of developmental ethanol exposure using the zebrafish embryo. Zebrafish are ideal for this kind of teratogen study. Each pair lays hundreds of eggs, which can then be collected without harming the adult fish. The zebrafish embryo is transparent and can be readily imaged with any number of stains. Analysis of these embryos after exposure to ethanol at different doses and times of duration and application shows that the gross developmental defects produced by ethanol are consistent with the human birth defect. Described here are the basic techniques used to study and manipulate the zebrafish FAS model.

  18. Comparison of proteomic profiles in the zebrafish retina during experimental degeneration and regeneration

    PubMed Central

    Eastlake, Karen; Heywood, Wendy E.; Tracey-White, Dhani; Aquino, Erika; Bliss, Emily; Vasta, Gerardo R.; Mills, Kevin; Khaw, Peng T.; Moosajee, Mariya; Limb, G. Astrid

    2017-01-01

    Zebrafish spontaneously regenerate the retina after injury. Although the gene expression profile has been extensively studied in this species during regeneration, this does not reflect protein function. To further understand the regenerative process in the zebrafish, we compared the proteomic profile of the retina during injury and upon regeneration. Using two-dimensional difference gel electrophoresis (2D-DIGE) and label-free quantitative proteomics (quadrupole time of flight LC-MS/MS), we analysed the retina of adult longfin wildtype zebrafish at 0, 3 and 18 days after Ouabain injection. Gene ontology analysis indicates reduced metabolic processing, and increase in fibrin clot formation, with significant upregulation of fibrinogen gamma polypeptide, apolipoproteins A-Ib and A-II, galectin-1, and vitellogenin-6 during degeneration when compared to normal retina. In addition, cytoskeleton and membrane transport proteins were considerably altered during regeneration, with the highest fold upregulation observed for tubulin beta 2 A, histone H2B and brain type fatty acid binding protein. Key proteins identified in this study may play an important role in the regeneration of the zebrafish retina and investigations on the potential regulation of these proteins may lead to the design of protocols to promote endogenous regeneration of the mammalian retina following retinal degenerative disease. PMID:28300160

  19. Dietary resistant starch improves selected brain and behavioral functions in adult and aged rodents.

    PubMed

    Zhou, June; Keenan, Michael J; Fernandez-Kim, Sun Ok; Pistell, Paul J; Ingram, Donald K; Li, Bing; Raggio, Anne M; Shen, Li; Zhang, Hanjie; McCutcheon, Kathleen L; Tulley, Richard T; Blackman, Marc R; Keller, Jeffrey N; Martin, Roy J

    2013-11-01

    Resistant starch (RS) is a dietary fiber that exerts multiple beneficial effects. The current study explored the effects of dietary RS on selected brain and behavioral functions in adult and aged rodents. Because glucokinase (GK) expression in hypothalamic arcuate nucleus and area postrema of the brainstem is important for brain glucose sensing, GK mRNA was measured by brain nuclei microdissection and PCR. Adult RS-fed rats had a higher GK mRNA than controls in both brain nuclei, an indicator of improved brain glucose sensing. Next, we tested whether dietary RS improve selected behaviors in aged mice. RS-fed aged mice exhibited (i) an increased eating responses to fasting, a behavioral indicator of improvement in aged brain glucose sensing; (ii) a longer latency to fall from an accelerating rotarod, a behavioral indicator of improved motor coordination; and (iii) a higher serum active glucagon-like peptide-1 (GLP-1). Then, GLP-1 receptor null (GLP-1RKO) mice were used to test the role of GLP-1 in brain glucose sensing, and they exhibited impaired eating responses to fasting. We conclude that in rodents (i) dietary RS improves two important indicators of brain function: glucose sensing and motor coordination, and (ii) GLP-1 is important in the optimal feeding response to a fast.

  20. Delineating multiple functions of VEGF-A in the adult brain.

    PubMed

    Licht, Tamar; Keshet, Eli

    2013-05-01

    Vascular endothelial growth factor-A (abbreviated throughout this review as VEGF) is mostly known for its angiogenic activity, for its activity as a vascular permeability factor, and for its vascular survival activity [1]. There is a growing body of evidence, however, that VEGF fulfills additional less 'traditional' functions in multiple organs, both during development, as well as homeostatic functions in fully developed organs. This review focuses on the multiple roles of VEGF in the adult brain and is less concerned with the roles played by VEGF during brain development, functions described elsewhere in this review series. Most functions of VEGF that are essential for proper brain development are, in fact, dispensable in the adult brain as was clearly demonstrated using a conditional brain-specific VEGF loss-of-function (LOF) approach. Thus, in contrast to VEGF LOF in the developing brain, a process which is detrimental for the growth and survival of blood vessels and leads to massive neuronal apoptosis [2-4], continued signaling by VEGF in the mature brain is no longer required for maintaining already established cerebral vasculature and its inhibition does not cause appreciable vessel regression, hypoxia or apoptosis [4-7]. Yet, VEGF continues to be expressed in the adult brain in a constitutive manner. Moreover, VEGF is expressed in the adult brain in a region-specific manner and in distinctive spatial patterns incompatible with an angiogenic role (see below), strongly suggesting angiogenesis-independent and possibly also perfusion-independent functions. Here we review current knowledge on some of these 'non-traditional', often unexpected homeostatic VEGF functions, including those unrelated to its effects on the brain vasculature. These effects could be mediated directly (on non-vascular cells expressing cognate VEGF receptors) or indirectly (via the endothelium). Experimental approaches aimed at distinguishing between these possibilities for each particular

  1. Cranial irradiation induces bone marrow-derived microglia in adult mouse brain tissue.

    PubMed

    Okonogi, Noriyuki; Nakamura, Kazuhiro; Suzuki, Yoshiyuki; Suto, Nana; Suzue, Kazutomo; Kaminuma, Takuya; Nakano, Takashi; Hirai, Hirokazu

    2014-07-01

    Postnatal hematopoietic progenitor cells do not contribute to microglial homeostasis in adult mice under normal conditions. However, previous studies using whole-body irradiation and bone marrow (BM) transplantation models have shown that adult BM cells migrate into the brain tissue and differentiate into microglia (BM-derived microglia; BMDM). Here, we investigated whether cranial irradiation alone was sufficient to induce the generation of BMDM in the adult mouse brain. Transgenic mice that express green fluorescent protein (GFP) under the control of a murine stem cell virus (MSCV) promoter (MSCV-GFP mice) were used. MSCV-GFP mice express GFP in BM cells but not in the resident microglia in the brain. Therefore, these mice allowed us to detect BM-derived cells in the brain without BM reconstitution. MSCV-GFP mice, aged 8-12 weeks, received 13.0 Gy irradiation only to the cranium, and BM-derived cells in the brain were quantified at 3 and 8 weeks after irradiation. No BM-derived cells were detected in control non-irradiated MSCV-GFP mouse brains, but numerous GFP-labeled BM-derived cells were present in the brain stem, basal ganglia and cerebral cortex of the irradiated MSCV-GFP mice. These BM-derived cells were positive for Iba1, a marker for microglia, indicating that GFP-positive BM-derived cells were microglial in nature. The population of BMDM was significantly greater at 8 weeks post-irradiation than at 3 weeks post-irradiation in all brain regions examined. Our results clearly show that cranial irradiation alone is sufficient to induce the generation of BMDM in the adult mouse.

  2. Receptor protein tyrosine phosphatase σ binds to neurons in the adult mouse brain

    PubMed Central

    Yi, Jae-Hyuk; Katagiri, Yasuhiro; Yu, Panpan; Lourie, Jacob; Bangayan, Nathanael J.; Symes, Aviva J.; Geller, Herbert M.

    2014-01-01

    The role of type IIA receptor protein tyrosine phosphatases (RPTPs), which includes LAR, RPTPσ and RPTPδ, in the nervous system is becoming increasingly recognized. Evidence supports a significant role for these RPTPs during the development of the nervous system as well as after injury, and mutations in RPTPs are associated with human disease. However, a major open question is the nature of the ligands that interact with type IIA RPTPs in the adult brain. Candidates include several different proteins as well as the glycosaminoglycan chains of proteoglycans. In order to investigate this problem, we used a receptor affinity probe assay with RPTPσ-AP fusion proteins on sections of adult mouse brain and to cultured neurons. Our results demonstrate that the major binding sites for RPTPσ in adult mouse brain are on neurons and are not proteoglycan GAG chains, as RPTPσ binding overlaps with the neuronal marker NeuN and was not significantly altered by treatments which eliminate chondroitin sulfate, heparan sulfate, or both. We also demonstrate no overlap of binding of RPTPσ with perineuronal nets, and a unique modulation of RPTPσ binding to brain by divalent cations. Our data therefore point to neuronal proteins, rather than CSPGs, as being the ligands for RPTPσ in the adult, uninjured brain. PMID:24530640

  3. Functional Assessment of Cardiac Responses of Adult Zebrafish (Danio rerio) to Acute and Chronic Temperature Change Using High-Resolution Echocardiography

    PubMed Central

    Cua, Michelle; Sheng, Xiaoye; Rayani, Kaveh; Beg, Mirza F.; Sarunic, Marinko V.; Tibbits, Glen F.

    2016-01-01

    The zebrafish (Danio rerio) is an important organism as a model for understanding vertebrate cardiovascular development. However, little is known about adult ZF cardiac function and how contractile function changes to cope with fluctuations in ambient temperature. The goals of this study were to: 1) determine if high resolution echocardiography (HRE) in the presence of reduced cardiodepressant anesthetics could be used to accurately investigate the structural and functional properties of the ZF heart and 2) if the effect of ambient temperature changes both acutely and chronically could be determined non-invasively using HRE in vivo. Heart rate (HR) appears to be the critical factor in modifying cardiac output (CO) with ambient temperature fluctuation as it increases from 78 ± 5.9 bpm at 18°C to 162 ± 9.7 bpm at 28°C regardless of acclimation state (cold acclimated CA– 18°C; warm acclimated WA– 28°C). Stroke volume (SV) is highest when the ambient temperature matches the acclimation temperature, though this difference did not constitute a significant effect (CA 1.17 ± 0.15 μL at 18°C vs 1.06 ± 0.14 μl at 28°C; WA 1.10 ± 0.13 μL at 18°C vs 1.12 ± 0.12 μl at 28°C). The isovolumetric contraction time (IVCT) was significantly shorter in CA fish at 18°C. The CA group showed improved systolic function at 18°C in comparison to the WA group with significant increases in both ejection fraction and fractional shortening and decreases in IVCT. The decreased early peak (E) velocity and early peak velocity / atrial peak velocity (E/A) ratio in the CA group are likely associated with increased reliance on atrial contraction for ventricular filling. PMID:26730947

  4. Embryological exposure to valproic acid induces social interaction deficits in zebrafish (Danio rerio): A developmental behavior analysis.

    PubMed

    Zimmermann, Fernanda Francine; Gaspary, Karina Vidarte; Leite, Carlos Eduardo; De Paula Cognato, Giana; Bonan, Carla Denise

    2015-01-01

    Changes in social behavior are associated with brain disorders, including mood disorders, stress, schizophrenia, Alzheimer's disease, and autism spectrum disorders (ASD). Autism is a complex neurodevelopmental disorder characterized by deficits in social interaction, impaired communication, anxiety, hyperactivity, and the presence of restricted interests. Zebrafish is one of the most social vertebrates used as a model in biomedical research, contributing to an understanding of the mechanisms that underlie social behavior. Valproic acid (VPA) is used as an anti-epileptic drug and mood stabilizer; however, prenatal VPA exposure in humans has been associated with an increased incidence of autism and it can also affect fetal brain development. Therefore, we conducted a behavioral screening at different periods of zebrafish development at 6, 30, 70, and 120dpf (days postfertilization) after VPA exposure in the early development stage to investigate social behavior, locomotion, aggression, and anxiety. VPA (48μM) exposure during the first 48hpf (hours postfertilization) did not promote changes on survival, morphology, and hatching rate at 24hpf, 48hpf, and 72hpf. The behavioral patterns suggest that VPA exposure induces changes in locomotor activity and anxiety at different developmental periods in zebrafish. Furthermore, a social interaction deficit is present at 70dpf and 120dpf. VPA exposure did not affect aggression in the adult stage at 70dpf and 120dpf. This is the first study that demonstrated zebrafish exposed to VPA during the first 48h of development exhibit deficits in social interaction, anxiety, and hyperactivity at different developmental periods.

  5. Using network science to evaluate exercise-associated brain changes in older adults.

    PubMed

    Burdette, Jonathan H; Laurienti, Paul J; Espeland, Mark A; Morgan, Ashley; Telesford, Qawi; Vechlekar, Crystal D; Hayasaka, Satoru; Jennings, Janine M; Katula, Jeffrey A; Kraft, Robert A; Rejeski, W Jack

    2010-01-01

    Literature has shown that exercise is beneficial for cognitive function in older adults and that aerobic fitness is associated with increased hippocampal tissue and blood volumes. The current study used novel network science methods to shed light on the neurophysiological implications of exercise-induced changes in the hippocampus of older adults. Participants represented a volunteer subgroup of older adults that were part of either the exercise training (ET) or healthy aging educational control (HAC) treatment arms from the Seniors Health and Activity Research Program Pilot (SHARP-P) trial. Following the 4-month interventions, MRI measures of resting brain blood flow and connectivity were performed. The ET group's hippocampal cerebral blood flow (CBF) exhibited statistically significant increases compared to the HAC group. Novel whole-brain network connectivity analyses showed greater connectivity in the hippocampi of the ET participants compared to HAC. Furthermore, the hippocampus was consistently shown to be within the same network neighborhood (module) as the anterior cingulate cortex only within the ET group. Thus, within the ET group, the hippocampus and anterior cingulate were highly interconnected and localized to the same network neighborhood. This project shows the power of network science to investigate potential mechanisms for exercise-induced benefits to the brain in older adults. We show a link between neurological network features and CBF, and it is possible that this alteration of functional brain networks may lead to the known improvement in cognitive function among older adults following exercise.

  6. Modeling Syndromic Congenital Heart Defects in Zebrafish.

    PubMed

    Grant, Meagan G; Patterson, Victoria L; Grimes, Daniel T; Burdine, Rebecca D

    2017-01-01

    Cardiac development is a dynamic process regulated by spatial and temporal cues that are integrated to effect molecular, cellular, and tissue-level events that form the adult heart. Disruption of these highly orchestrated events can be devastating for cardiac form and function. Aberrations in heart development result in congenital heart defects (CHDs), which affect 1 in 100 infants in the United States each year. Zebrafish have proven informative as a model organism to understand both heart development and the mechanisms associated with CHDs due to the similarities in heart morphogenesis among vertebrates, as well as their genetic tractability and amenability to live imaging. In this review, we discuss the mechanisms of zebrafish heart development and the utility of zebrafish for understanding syndromic CHDs, those cardiac abnormalities that occur in the context of multisystem disorders. We conclude with avenues of zebrafish research that will potentially inform future therapeutic approaches for the treatment of CHDs.

  7. Modular Brain Network Organization Predicts Response to Cognitive Training in Older Adults

    PubMed Central

    Gallen, Courtney L.; Baniqued, Pauline L.; Chapman, Sandra B.; Aslan, Sina; Keebler, Molly; Didehbani, Nyaz; D’Esposito, Mark

    2016-01-01

    Cognitive training interventions are a promising approach to mitigate cognitive deficits common in aging and, ultimately, to improve functioning in older adults. Baseline neural factors, such as properties of brain networks, may predict training outcomes and can be used to improve the effectiveness of interventions. Here, we investigated the relationship between baseline brain network modularity, a measure of the segregation of brain sub-networks, and training-related gains in cognition in older adults. We found that older adults with more segregated brain sub-networks (i.e., more modular networks) at baseline exhibited greater training improvements in the ability to synthesize complex information. Further, the relationship between modularity and training-related gains was more pronounced in sub-networks mediating “associative” functions compared with those involved in sensory-motor processing. These results suggest that assessments of brain networks can be used as a biomarker to guide the implementation of cognitive interventions and improve outcomes across individuals. More broadly, these findings also suggest that properties of brain networks may capture individual differences in learning and neuroplasticity. Trail Registration: ClinicalTrials.gov, NCT#00977418 PMID:28006029

  8. Expression and functions of ASIC1 in the zebrafish retina.

    PubMed

    Liu, Sha; Wang, Mei-Xia; Mao, Cheng-Jie; Cheng, Xiao-Yu; Wang, Chen-Tao; Huang, Jian; Zhong, Zhao-Min; Hu, Wei-Dong; Wang, Fen; Hu, Li-Fang; Wang, Han; Liu, Chun-Feng

    2014-12-12

    It has been demonstrated that acid sensing ionic channels (ASICs) are present in the central and peripheral nervous system of mammals, including the retina. However, it remains unclear whether the zebrafish retina also expresses ASICs. In the present study, the expression and distribution of zasic1 were examined in the retina of zebrafish. Both zasic1 mRNA and protein expressions were detected in the adult zebrafish retina. A wide distribution of ASIC1 in zebrafish retina was confirmed using whole mount in situ hybridization and immunohistochemistry study. Acidosis-induced currents in the isolated retinal ganglion cells (RGCs) were also recorded using whole cell patch clamping. Moreover, blockade of ASICs channel significantly reduced the locomotion of larval zebrafish in response to light exposure. In sum, our data demonstrate the presence of ASIC1 and its possible functional relevance in the retina of zebrafish.

  9. Conserved gene regulation during acute inflammation between zebrafish and mammals.

    PubMed

    Forn-Cuní, G; Varela, M; Pereiro, P; Novoa, B; Figueras, A

    2017-02-03

    Zebrafish (Danio rerio), largely used as a model for studying developmental processes, has also emerged as a valuable system for modelling human inflammatory diseases. However, in a context where even mice have been questioned as a valid model for these analysis, a systematic study evaluating the reproducibility of human and mammalian inflammatory diseases in zebrafish is still lacking. In this report, we characterize the transcriptomic regulation to lipopolysaccharide in adult zebrafish kidney, liver, and muscle tissues using microarrays and demonstrate how the zebrafish genomic responses can effectively reproduce the mammalian inflammatory process induced by acute endotoxin stress. We provide evidence that immune signaling pathways and single gene expression is well conserved throughout evolution and that the zebrafish and mammal acute genomic responses after lipopolysaccharide stimulation are highly correlated despite the differential susceptibility between species to that compound. Therefore, we formally confirm that zebrafish inflammatory models are suited to study the basic mechanisms of inflammation in human inflammatory diseases, with great translational impact potential.

  10. Single-Cell Reconstruction of Oxytocinergic Neurons Reveals Separate Hypophysiotropic and Encephalotropic Subtypes in Larval Zebrafish

    PubMed Central

    Gutierrez-Triana, Jose Arturo; Knerr, Boris

    2017-01-01

    Oxytocin regulates a diverse set of processes including stress, analgesia, metabolism, and social behavior. How such diverse functions are mediated by a single hormonal system is not well understood. Different functions of oxytocin could be mediated by distinct cell groups, yet it is currently unknown whether different oxytocinergic cell types exist that specifically mediate peripheral neuroendocrine or various central neuromodulatory processes via dedicated pathways. Using the Brainbow technique to map the morphology and projections of individual oxytocinergic cells in the larval zebrafish brain, we report here the existence of two main types of oxytocinergic cells: those that innervate the pituitary and those that innervate diverse brain regions. Similar to the situation in the adult rat and the adult midshipman, but in contrast to the situation in the adult trout, these two cell types are mutually exclusive and can be distinguished based on morphological and anatomical criteria. Further, our results reveal that complex oxytocinergic innervation patterns are already established in the larval zebrafish brain. PMID:28317020

  11. Brain function differences in language processing in children and adults with autism.

    PubMed

    Williams, Diane L; Cherkassky, Vladimir L; Mason, Robert A; Keller, Timothy A; Minshew, Nancy J; Just, Marcel Adam

    2013-08-01

    Comparison of brain function between children and adults with autism provides an understanding of the effects of the disorder and associated maturational differences on language processing. Functional imaging (functional magnetic resonance imaging) was used to examine brain activation and cortical synchronization during the processing of literal and ironic texts in 15 children with autism, 14 children with typical development, 13 adults with autism, and 12 adult controls. Both the children and adults with autism had lower functional connectivity (synchronization of brain activity among activated areas) than their age and ability comparison group in the left hemisphere language network during irony processing, and neither autism group had an increase in functional connectivity in response to increased task demands. Activation differences for the literal and irony conditions occurred in key language-processing regions (left middle temporal, left pars triangularis, left pars opercularis, left medial frontal, and right middle temporal). The children and adults with autism differed from each other in the use of some brain regions during the irony task, with the adults with autism having activation levels similar to those of the control groups. Overall, the children and adults with autism differed from the adult and child controls in (a) the degree of network coordination, (b) the distribution of the workload among member nodes, and (3) the dynamic recruitment of regions in response to text content. Moreover, the differences between the two autism age groups may be indicative of positive changes in the neural function related to language processing associated with maturation and/or educational experience.

  12. ABAEnrichment: an R package to test for gene set expression enrichment in the adult and developing human brain.

    PubMed

    Grote, Steffi; Prüfer, Kay; Kelso, Janet; Dannemann, Michael

    2016-10-15

    We present ABAEnrichment, an R package that tests for expression enrichment in specific brain regions at different developmental stages using expression information gathered from multiple regions of the adult and developing human brain, together with ontologically organized structural information about the brain, both provided by the Allen Brain Atlas. We validate ABAEnrichment by successfully recovering the origin of gene sets identified in specific brain cell-types and developmental stages.

  13. Novel Genes Critical for Hypoxic Preconditioning in Zebrafish Are Regulators of Insulin and Glucose Metabolism

    PubMed Central

    Manchenkov, Tania; Pasillas, Martina P.; Haddad, Gabriel G.; Imam, Farhad B.

    2015-01-01

    Severe hypoxia is a common cause of major brain, heart, and kidney injury in adults, children, and newborns. However, mild hypoxia can be protective against later, more severe hypoxia exposure via “hypoxic preconditioning,” a phenomenon that is not yet fully understood. Accordingly, we have established and optimized an embryonic zebrafish model to study hypoxic preconditioning. Using a functional genomic approach, we used this zebrafish model to identify and validate five novel hypoxia-protective genes, including irs2, crtc3, and camk2g2, which have been previously implicated in metabolic regulation. These results extend our understanding of the mechanisms of hypoxic preconditioning and affirm the discovery potential of this novel vertebrate hypoxic stress model. PMID:25840431

  14. The effects of sleep deprivation on brain functioning in older adults.

    PubMed

    Almklov, Erin L; Drummond, Sean P A; Orff, Henry; Alhassoon, Omar M

    2015-01-01

    Few studies have examined the effects of total sleep deprivation (TSD) on cognitive performance and brain activation using functional MRI (fMRI) in older adults. The current study examines blood oxygen level-dependent (BOLD) activation in older adults and younger adults during the sustained attention (GO) and response inhibition (NOGO) portions of a GO-NOGO cognitive task following 36 hr of total sleep deprivation. No significant performance differences were observed between the groups on the behavioral outcome measures of total hits and false alarms. Neuroimaging results, however, revealed a significant interaction between age-group and sleep-deprivation status. Specifically, older adults showed greater BOLD activation as compared to younger adults after 36 hours total sleep deprivation in brain regions typically associated with attention and inhibitory processes. These results suggest in order for older adults to perform the GO-NOGO task effectively after sleep deprivation, they rely on compensatory recruitment of brain regions that aide in the maintenance of cognitive performance.

  15. Educating the adult brain: How the neuroscience of learning can inform educational policy

    NASA Astrophysics Data System (ADS)

    Knowland, Victoria C. P.; Thomas, Michael S. C.

    2014-05-01

    The acquisition of new skills in adulthood can positively affect an individual's quality of life, including their earning potential. In some cases, such as the learning of literacy in developing countries, it can provide an avenue to escape from poverty. In developed countries, job retraining in adulthood contributes to the flexibility of labour markets. For all adults, learning opportunities increase participation in society and family life. However, the popular view is that adults are less able to learn for an intrinsic reason: their brains are less plastic than in childhood. This article reviews what is currently known from neuroscientific research about how brain plasticity changes with age, with a particular focus on the ability to acquire new skills in adulthood. Anchoring their review in the examples of the adult acquisition of literacy and new motor skills, the authors address five specific questions: (1) Are sensitive periods in brain development relevant to learning complex educational skills like literacy? (2) Can adults become proficient in a new skill? (3) Can everyone learn equally effectively in adulthood? (4) What is the role of the learning environment? (5) Does adult education cost too much? They identify areas where further research is needed and conclude with a summary of principles for enhancing adult learning now established on a neuroscience foundation.

  16. The effects of acetaldehyde on nicotine-induced transmitter levels in young and adult brain areas.

    PubMed

    Sershen, H; Shearman, E; Fallon, S; Chakraborty, G; Smiley, J; Lajtha, A

    2009-08-14

    The aim of the present study was to examine the effect of acetaldehyde administration on neurotransmitters in the presence of nicotine in brain areas associated with cognition and reward. We assayed these effects via microdialysis in conscious freely moving male Sprague-Dawley rats. It was reported that low doses of acetaldehyde enhance nicotine self-administration in young, but not in adult rats. Since nicotine enhances reward and learning, while acetaldehyde is reported to enhance reward but inhibit learning, acetaldehyde thus would be likely to stimulate reward without stimulating learning. We hoped that examining the effects of acetaldehyde (on nicotine-mediated neurotransmitter changes) would help to distinguish reward mechanisms less influenced by learning mechanisms. To avoid the aversive effect of acetaldehyde, we used a low dose of acetaldehyde (0.16 mg/kg) administered after nicotine (0.3mg/kg). We analyzed six brain regions: nucleus accumbens shell (NAccS), ventral tegmental area (VTA), ventral and dorsal hippocampus (VH and DH), and prefrontal and medial temporal cortex (PFC, MTC), assaying dopamine (DA), norepinephrine (NE) and serotonin (5-HT) and their metabolites in young and adult rats. The effect of acetaldehyde on nicotine-induced transmitter changes was different in young as compared to adult rat brain regions. In the NAccS of the young, DA was not affected while NE and 5-HT were increased. In the adult in this area DA and NE were decreased, while 5-HT was not altered. In other areas also in many cases, the effect of acetaldehyde in the young and in the adult was different. As an example, acetaldehyde administration increased NE in young and decreased NE in adult DH. We found stimulation of nicotine-induced changes by acetaldehyde in seven instances - six of these were observed in areas in young brain, NE in four areas (NAccS, DH, VH, and PFC), and 5-HT in two (NAccS and DH). Only one increase was noted in adult brain (DA in VTA). Inhibition of

  17. Fetal Alcohol Exposure Reduces Adult Brain Plasticity. Science Briefs

    ERIC Educational Resources Information Center

    National Scientific Council on the Developing Child, 2007

    2007-01-01

    "Science Briefs" summarize the findings and implications of a recent study in basic science or clinical research. This Brief summarizes the findings and implications of "Moderate Fetal Alcohol Exposure Impairs the Neurogenic Response to an Enriched Environment in Adult Mice" (I. Y. Choi; A. M. Allan; and L. A. Cunningham). Observations of mice…

  18. Executive control function, brain activation and white matter hyperintensities in older adults

    PubMed Central

    Venkatraman, Vijay K.; Aizenstein, Howard; Guralnik, Jack; Newman, Anne B.; Glynn, Nancy W.; Taylor, Christopher; Studenski, Stephanie; Launer, Lenore; Pahor, Marco; Williamson, Jeff; Rosano, Caterina

    2009-01-01

    Context Older adults responding to executive control function (ECF) tasks show greater brain activation on functional MRI (fMRI). It is not clear whether greater fMRI activation indicates a strategy to compensate for underlying brain structural abnormalities while maintaining higher performance. Objective To identify the patterns of fMRI activation in relationship with ECF performance and with brain structural abnormalities. Design Cross-sectional analysis. Main variables of interest: fMRI activation, accuracy while performing an ECF task (Digit Symbol Substitution Test), volume of white matter hyperintensities and of total brain atrophy. Setting Cohort of community-dwelling older adults. Participants Data were obtained on 25 older adults (20 women, 81 years mean age). Outcome Measure Accuracy (number of correct response / total number of responses) while performing the Digit Symbol Substitution Test. Results Greater accuracy was significantly associated with greater peak fMRI activation, from ECF regions, including left middle frontal gyrus and right posterior parietal cortex. Greater WMH was associated with lower activation within accuracy-related regions. The interaction of accuracy by white matter hyperintensities volume was significant within the left posterior parietal region. Specifically, the correlation of white matter hyperintensities volume with fMRI activation varied as a function of accuracy and it was positive for greater accuracy. Associations with brain atrophy were not significant. Conclusions Recruitment of additional areas and overall greater brain activation in older adults is associated with higher performance. Posterior parietal activation may be particularly important to maintain higher accuracy in the presence of underlying brain connectivity structural abnormalities. PMID:19922803

  19. Neuroanatomical distribution of galectin-3 in the adult rat brain.

    PubMed

    Yoo, Hong-Il; Kim, Eu-Gene; Lee, Eun-Jin; Hong, Sung-Young; Yoon, Chi-Sun; Hong, Min-Ju; Park, Sang-Jin; Woo, Ran-Sook; Baik, Tai-Kyoung; Song, Dae-Yong

    2017-04-01

    Galectin-3 is a member of the lectin subfamily that enables the specific binding of β-galactosides. It is expressed in a broad spectrum of species and organs, and is known to have various functions related to cell adhesion, signal transduction, and proinflammatory responses. Although, expression of galectin-3 in some activated neuroglia under neuroinflammation has been well documented in the central nervous system, little is known about the neuronal expression and distribution of galectin-3 in normal brain. To describe the cellular and neuroanatomical expression map of galectin-3, we performed galectin-3 immunohistochemistry on the entire normal rat brain and subsequently analyzed the neuronal distribution. Galectin-3 expression was observed not only in some neuroglia but also in neurons. Neuronal expression of galectin-3 was observed in many functional parts of the cerebral cortex and various other subcortical nuclei in the hypothalamus and brainstem. Neuroanatomical analysis revealed that robust galectin-3 immuno-signals were present in many hypothalamic nuclei related to a variety of physiological functions responsible for mediating anxiety responses, energy balance, and neuroendocrine regulation. In addition, the regions highly connected with these hypothalamic nuclei also showed intense galectin-3 expression. Moreover, multiple key regions involved in regulating autonomic functions exhibited high levels of galectin-3 expression. In contrast, the subcortical nuclei responsible for the control of voluntary motor functions and limbic system exhibited no galectin-3 immunoreactivity. These observations suggest that galectin-3 expression in the rat brain seems to be regulated by developmental cascades, and that functionally and neuroanatomically related brain nuclei constitutively express galectin-3 in adulthood.

  20. Brain tissue pressure measurements in perinatal and adult rabbits.

    PubMed

    Hornig, G W; Lorenzo, A V; Zavala, L M; Welch, K

    1987-12-01

    Brain tissue pressure (BTP) in pre- and post-natal anesthetized rabbits, held in a stereotactic head holder, was measured with a fluid filled 23 gauge open-ended cannula connected distally to a pressure transducer. By advancing the cannula step wise through a hole in the cranium it was possible to sequentially measure pressure from the cranial subarachnoid space, cortex, ventricle and basal ganglia. Separate cannulas and transducers were used to measure CSFP from the cisterna magna and arterial and/or venous pressure. Pressure recordings obtained when the tip of the BTP cannula was located in the cranial subarachnoid space or ventricle exhibited respiratory and blood pressure pulsations equivalent to and in phase with CSF pulsations recorded from the cisterna magna. When the tip was advanced into brain parenchymal sites such pulsations were suppressed or non-detectable unless communication with a CSF compartment had been established inadvertently. Although CSF pressures in the three spinal fluid compartments were equivalent, in most animals BTP was higher than CSFP. However, after momentary venting of the system BTP equilibrated at a pressure below that of CSFP. We speculate that venting of the low compliance system (1.20 x 10(-5) ml/mmHg) relieves the isometric pressure build-up due to insertion of the cannula into brain parenchyma. Under these conditions, and at all ages examined, BTP in the rabbit is consistently lower than CSFP and, as with CSFP, it increases as the animal matures.

  1. Canonical Genetic Signatures of the Adult Human Brain

    PubMed Central

    Hawrylycz, Michael; Miller, Jeremy A.; Menon, Vilas; Feng, David; Dolbeare, Tim; Guillozet-Bongaarts, Angela L.; Jegga, Anil G.; Aronow, Bruce J.; Lee, Chang-Kyu; Bernard, Amy; Glasser, Matthew F.; Dierker, Donna L.; Menche, Jörge; Szafer, Aaron; Collman, Forrest; Grange, Pascal; Berman, Kenneth A.; Mihalas, Stefan; Yao, Zizhen; Stewart, Lance; Barabási, Albert-László; Schulkin, Jay; Phillips, John; Ng, Lydia; Dang, Chinh; Haynor, David R.; Jones, Allan; Van Essen, David C.; Koch, Christof; Lein, Ed

    2015-01-01

    The structure and function of the human brain are highly stereotyped, implying a conserved molecular program responsible for its development, cellular structure, and function. We applied a correlation-based metric of “differential stability” (DS) to assess reproducibility of gene expression patterning across 132 structures in six individual brains, revealing meso-scale genetic organization. The highest DS genes are highly biologically relevant, with enrichment for brain-related biological annotations, disease associations, drug targets, and literature citations. Using high DS genes we identified 32 anatomically diverse and reproducible gene expression signatures, which represent distinct cell types, intracellular components, and/or associations with neurodevelopmental and neurodegenerative disorders. Genes in neuron-associated compared to non-neuronal networks showed higher preservation between human and mouse; however, many diversely-patterned genes displayed dramatic shifts in regulation between species. Finally, highly consistent transcriptional architecture in neocortex is correlated with resting state functional connectivity, suggesting a link between conserved gene expression and functionally relevant circuitry. PMID:26571460

  2. Waterborne fluoride exposure changed the structure and the expressions of steroidogenic-related genes in gonads of adult zebrafish (Danio rerio).

    PubMed

    Li, MeiYan; Cao, Jinling; Chen, Jianjie; Song, Jie; Zhou, Bingrui; Feng, Cuiping; Wang, Jundong

    2016-02-01

    Excessive fluoride in natural water ecosystem has been demonstrated to have adverse effects on reproductive system in humans and mammals, while the most vulnerable aquatic organisms were ignored. In this study, the effects of waterborne fluoride on growth performance, sex steroid hormone, histological structure, and the transcriptional profiles of sex steroid related genes were examined in both female and male zebrafish exposed to different concentrations of 0.79, 18.60, 36.83 mg L(-1) of fluoride for 30 and 60 d to investigate the effects of fluoride on reproductive system and the underlying toxic mechanisms caused by fluoride. The results showed that the body weight was remarkably decreased, the structure of ovary and testis were serious injured, and the T and E2 levels were significantly reduced in male zebrafish. The transcriptional profiles of steroidogenic related genes displayed phenomenal alterations, the expressions of pgr and cyp19a1a were significantly up-regulated, while the transcriptional levels of er, ar and hsd3β were decreased both in the ovary and testis, and hsd17β8 were down-regulated just in males. Taken together, these results demonstrated that fluoride could significantly inhibit the growth of zebrafish, and notably affect the reproductive system in both sex zebrafish by impairing the structure of ovary and testis, altering steroid hormone levels and steroidogenic genes expression related to the synthesis of sex hormones in zebrafish.

  3. Proliferation zones in the brain of adult fish Austrolebias (Cyprinodontiform: Rivulidae): a comparative study.

    PubMed

    Fernández, A S; Rosillo, J C; Casanova, G; Olivera-Bravo, S

    2011-08-25

    In contrast with mammals, adult fish brains exhibit an enormous potential to produce new cells. Proliferation zones, however, have been described in only a few species, hindering comparisons among genuses and orders. Here we analyzed brain cell proliferation in annual teleostean fishes Austrolebias (Cyprinodontiform: Rivulidae). Immunocytochemistry against 5-bromo-2'-deoxyuridine (BrdU) was quantitated and mapped 24 h after injection in three species with different phylogenetic positions or habitats. All species had similar brain anatomy and total volume, but olfactory bulbs, torus longitudinalis and cerebellum were of different sizes in different species. Cell proliferation was found throughout the brain. Three-D reconstructions provided evidence for contiguity along the rostro-caudal axis and concentration in the vicinity of the ventricles. Brain regions analyzed exhibited high mitotic activity, and the torus longitudinalis had the highest volume-normalized proliferation index. A. affinis exhibited the highest normalized proliferation indexes in visual regions but the lowest in olfactory bulb. A. reicherti showed an inverse pattern, suggesting that these species have a different hierarchy of sensorial modalities that could be related to phylogeny or habitat. Double immunostaining against BrdU and cell-type specific markers was performed to determine the fate of proliferating cells. A widespread gliogenesis was evidenced. Few cells positive for both BrdU and the neuronal marker HuC/D were found in the brain of the three species, demonstrating neurogenesis in the adult Austrolebias brain. Summarizing, adult members of the three species showed similar brain anatomy and cell proliferation patterns. Among species, volume-normalized proliferation indexes varied in regions involved in different sensory modalities. To our knowledge, this is the first report showing proliferating cells with neuronal markers as earlier as 24 h after BrdU injection.

  4. Adding chemo after radiation treatment improves survival for adults with a type of brain tumor

    Cancer.gov

    Adults with low-grade gliomas, a form of brain tumor, who received chemotherapy following completion of radiation therapy lived longer than patients who received radiation therapy alone, according to long-term follow-up results from a NIH-supported random

  5. Humor, Rapport, and Uncomfortable Moments in Interactions with Adults with Traumatic Brain Injury

    ERIC Educational Resources Information Center

    Kovarsky, Dana; Schiemer, Christine; Murray, Allison

    2011-01-01

    We examined uncomfortable moments that damaged rapport during group interactions between college students in training to become speech-language pathologists and adults with traumatic brain injury. The students worked as staff in a community-based program affiliated with a university training program that functioned as a recreational gathering…

  6. Brain Blood Flow Related to Acoustic Laryngeal Reaction Time in Adult Developmental Stutterers.

    ERIC Educational Resources Information Center

    Watson, Ben C.; And Others

    1992-01-01

    This study sought to identify patterns of impaired acoustic laryngeal reaction time as a function of response complexity parallel to metabolic measures of brain function. Findings indicated that the disruption in speech motor control for 16 adult male developmental stutterers was systematically related to metabolic asymmetry in left superior and…

  7. Neural Underpinnings of Working Memory in Adult Survivors of Childhood Brain Tumors.

    PubMed

    King, Tricia Z; Na, Sabrina; Mao, Hui

    2015-08-01

    Adult survivors of childhood brain tumors are at risk for cognitive performance deficits that require the core cognitive skill of working memory. Our goal was to examine the neural mechanisms underlying working memory performance in survivors. We studied the working memory of adult survivors of pediatric posterior fossa brain tumors using a letter n-back paradigm with varying cognitive workload (0-, 1-, 2-, and 3-back) and functional magnetic resonance imaging as well as neuropsychological measures. Survivors of childhood brain tumors evidenced lower working memory performance than demographically matched healthy controls. Whole-brain analyses revealed significantly greater blood-oxygen level dependent (BOLD) activation in the left superior / middle frontal gyri and left parietal lobe during working memory (2-back versus 0-back contrast) in survivors. Left frontal BOLD response negatively correlated with 2- and 3-back working memory performance, Auditory Consonant Trigrams (ACT), and Digit Span Backwards. In contrast, parietal lobe BOLD response negatively correlated with 0-back (vigilance task) and ACT. The results revealed that adult survivors of childhood posterior fossa brain tumors recruited additional cognitive control resources in the prefrontal lobe during increased working memory demands. This increased prefrontal activation is associated with lower working memory performance and is consistent with the allocation of latent resources theory.

  8. Combined Cognitive-Psychological-Physical Intervention Induces Reorganization of Intrinsic Functional Brain Architecture in Older Adults

    PubMed Central

    Zheng, Zhiwei; Zhu, Xinyi; Yin, Shufei; Wang, Baoxi; Niu, Yanan; Huang, Xin; Li, Rui; Li, Juan

    2015-01-01

    Mounting evidence suggests that enriched mental, physical, and socially stimulating activities are beneficial for counteracting age-related decreases in brain function and cognition in older adults. Here, we used functional magnetic resonance imaging (fMRI) to demonstrate the functional plasticity of brain activity in response to a combined cognitive-psychological-physical intervention and investigated the contribution of the intervention-related brain changes to individual performance in healthy older adults. The intervention was composed of a 6-week program of combined activities including cognitive training, Tai Chi exercise, and group counseling. The results showed improved cognitive performance and reorganized regional homogeneity of spontaneous fluctuations in the blood oxygen level-dependent (BOLD) signals in the superior and middle temporal gyri, and the posterior lobe of the cerebellum, in the participants who attended the intervention. Intriguingly, the intervention-induced changes in the coherence of local spontaneous activity correlated with the improvements in individual cognitive performance. Taken together with our previous findings of enhanced resting-state functional connectivity between the medial prefrontal cortex and medial temporal lobe regions following a combined intervention program in older adults, we conclude that the functional plasticity of the aging brain is a rather complex process, and an effective cognitive-psychological-physical intervention is helpful for maintaining a healthy brain and comprehensive cognition during old age. PMID:25810927

  9. A living biosensor model to dynamically trace glucocorticoid transcriptional activity during development and adult life in zebrafish.

    PubMed

    Benato, Francesca; Colletti, Elisa; Skobo, Tatjana; Moro, Enrico; Colombo, Lorenzo; Argenton, Francesco; Dalla Valle, Luisa

    2014-07-05

    Glucocorticoids (GCs) modulate many cellular processes through the binding of the glucocorticoid receptor (GR) to specific responsive elements located upstream of the transcription starting site or within an intron of GC target genes. Here we describe a transgenic fish line harboring a construct with nine GC-responsive elements (GREs) upstream of a reporter (EGFP) coding sequence. Transgenic fish exhibit strong fluorescence in many known GC-responsive organs. Moreover, its enhanced sensitivity allowed the discovery of novel GC-responsive tissue compartments, such as fin, eyes, and otic vesicles. Long-term persistence of transgene expression is seen during adult stages in several organs. Pharmacological and genetic analysis demonstrates that the transgenic line is highly responsive to drug administration and molecular manipulation. Moreover, reporter expression is sensitively and dynamically modulated by the photoperiod, thus proving that these fish are an in vivo valuable platform to explore GC responsiveness to both endogenous and exogenous stimuli.

  10. Traumatic Brain Injury Activation of the Adult Subventricular Zone Neurogenic Niche

    PubMed Central

    Chang, Eun Hyuk; Adorjan, Istvan; Mundim, Mayara V.; Sun, Bin; Dizon, Maria L. V.; Szele, Francis G.

    2016-01-01

    Traumatic brain injury (TBI) is common in both civilian and military life, placing a large burden on survivors and society. However, with the recognition of neural stem cells in adult mammals, including humans, came the possibility to harness these cells for repair of damaged brain, whereas previously this was thought to be impossible. In this review, we focus on the rodent adult subventricular zone (SVZ), an important neurogenic niche within the mature brain in which neural stem cells continue to reside. We review how the SVZ is perturbed following various animal TBI models with regards to cell proliferation, emigration, survival, and differentiation, and we review specific molecules involved in these processes. Together, this information suggests next steps in attempting to translate knowledge from TBI animal models into human therapies for TBI. PMID:27531972

  11. In silico predicted reproductive endocrine transcriptional regulatory networks during zebrafish (Danio rerio) development.

    PubMed

    Hala, D

    2017-03-21

    The interconnected topology of transcriptional regulatory networks (TRNs) readily lends to mathematical (or in silico) representation and analysis as a stoichiometric matrix. Such a matrix can be 'solved' using the mathematical method of extreme pathway (ExPa) analysis, which identifies uniquely activated genes subject to transcription factor (TF) availability. In this manuscript, in silico multi-tissue TRN models of brain, liver and gonad were used to study reproductive endocrine developmental programming in zebrafish (Danio rerio) from 0.25h post fertilization (hpf; zygote) to 90 days post fertilization (dpf; adult life stage). First, properties of TRN models were studied by sequentially activating all genes in multi-tissue models. This analysis showed the brain to exhibit lowest proportion of co-regulated genes (19%) relative to liver (23%) and gonad (32%). This was surprising given that the brain comprised 75% and 25% more TFs than liver and gonad respectively. Such 'hierarchy' of co-regulatory capability (brainbrain, alluding to its role as 'master controller' of endocrine function. Second, TRN models were constrained with varying TF availabilities during zebrafish development. Normalized numbers of genes active during development showed concomitant activations between brain and gonad from 10 to 12 hpf (embryonic life stage) up to 30-90 dpf (adult life stage). This indicated a putative 'syncing' between the brain and gonad, and initiation of an early reproductive endocrine developmental program. Finally, comparison of in vivo active genes with those predicted in silico showed relatively good agreement for brain (49%), liver (27%) and gonad (32%). The multi-tissue TRN models presented can lend diagnostic insights into the effects of changing environmental and/or genetic constraints on reproductive endocrine function.

  12. [Regulation of neurogenesis: factors affecting of new neurons formation in adult mammals brain].

    PubMed

    Respondek, Michalina; Buszman, Ewa

    2015-12-31

    Neurogenesis is a complex and multi-step process of generating completely functional neurons. This process in adult brain is based on pluripotentional neuronal stem cells (NSC), which are able to proliferation and differentiation into mature neurons or glial cells. NSC are located in subgranular zone inside hippocampus and in subventricular zone. The new neurons formation depends on many endo- and exogenous factors which modulate each step of neurogenesis. This article describes the most important regulators of adult neurogenesis, mainly: neurotrophins, growth factors, hormones, neurotransmitters and microenvironment of NSC. Some drugs, especially antipsychotics, antidepressants and normothymics may affect the neurogenic properties of adult brain. Moreover pathological processes such as neuroinflammation, stroke or epilepsy are able to induce proliferation of NSC. The proneurogenic effects of psychotropic drugs and pathological processes are associated with their ability to increase some hormones and neurotrophins level, as well as with rising the expression of antiapoptotic Bcl-2 protein and metalloproteinase MMP-2. Additionaly, some drugs, for example haloperidol, are able to block prolactin and dopaminergic neuroblasts receptors. Down-regulation of adult neurogenesis is associated with alcohol abuse and high stress level. Negative effect of many drugs, such as cytostatics, COX-2 inhibitors and opioides was also observed. The proneurogenic effect of described factors suggest their broad therapeutic potential and gives a new perspective on an effective and modern treatment of many neuropsychiatric disorders. This effect can also help to clarify the pathogenesis of disorders associated with proliferation and degeneration of adult brain cells.

  13. Transcriptional profiling of adult neural stem-like cells from the human brain.

    PubMed

    Sandberg, Cecilie Jonsgar; Vik-Mo, Einar O; Behnan, Jinan; Helseth, Eirik; Langmoen, Iver A

    2014-01-01

    There is a great potential for the development of new cell replacement strategies based on adult human neural stem-like cells. However, little is known about the hierarchy of cells and the unique molecular properties of stem- and progenitor cells of the nervous system. Stem cells from the adult human brain can be propagated and expanded in vitro as free floating neurospheres that are capable of self-renewal and differentiation into all three cell types of the central nervous system. Here we report the first global gene expression study of adult human neural stem-like cells originating from five human subventricular zone biopsies (mean age 42, range 33-60). Compared to adult human brain tissue, we identified 1,189 genes that were significantly up- and down-regulated in adult human neural stem-like cells (1% false discovery rate). We found that adult human neural stem-like cells express stem cell markers and have reduced levels of markers that are typical of the mature cells in the nervous system. We report that the genes being highly expressed in adult human neural stem-like cells are associated with developmental processes and the extracellular region of the cell. The calcium signaling pathway and neuroactive ligand-receptor interactions are enriched among the most differentially regulated genes between adult human neural stem-like cells and adult human brain tissue. We confirmed the expression of 10 of the most up-regulated genes in adult human neural stem-like cells in an additional sample set that included adult human neural stem-like cells (n = 6), foetal human neural stem cells (n = 1) and human brain tissues (n = 12). The NGFR, SLITRK6 and KCNS3 receptors were further investigated by immunofluorescence and shown to be heterogeneously expressed in spheres. These receptors could potentially serve as new markers for the identification and characterisation of neural stem- and progenitor cells or as targets for manipulation of cellular fate.

  14. New neurons clear the path of astrocytic processes for their rapid migration in the adult brain.

    PubMed

    Kaneko, Naoko; Marín, Oscar; Koike, Masato; Hirota, Yuki; Uchiyama, Yasuo; Wu, Jane Y; Lu, Qiang; Tessier-Lavigne, Marc; Alvarez-Buylla, Arturo; Okano, Hideyuki; Rubenstein, John L R; Sawamoto, Kazunobu

    2010-07-29

    In the long-range neuronal migration of adult mammals, young neurons travel from the subventricular zone to the olfactory bulb, a long journey (millimeters to centimeters, depending on the species). How can these neurons migrate through the dense meshwork of neuronal and glial processes of the adult brain parenchyma? Previous studies indicate that young neurons achieve this by migrating in chains through astrocytic tunnels. Here, we report that young migrating neurons actively control the formation and maintenance of their own migration route. New neurons secrete the diffusible protein Slit1, whose receptor, Robo, is expressed on astrocytes. We show that the Slit-Robo pathway is required for morphologic and organizational changes in astrocytes that result in the formation and maintenance of the astrocytic tunnels. Through this neuron-glia interaction, the new neurons regulate the formation of the astrocytic meshwork that is needed to enable their rapid and directional migration in adult brain.

  15. Removing brakes on adult brain plasticity: from molecular to behavioral interventions

    PubMed Central

    Bavelier, D.; Levi, D.M.; Li, R.W.; Dan, Y.; Hensch, T.K.

    2010-01-01

    Adult brain plasticity, although possible, remains more restricted in scope than during development. Here, we address conditions under which circuit rewiring may be facilitated in the mature brain. At a cellular and molecular level, adult plasticity is actively limited. Some of these “brakes” are structural, such as peri-neuronal nets or myelin, which inhibit neurite outgrowth. Others are functional, acting directly upon excitatory-inhibitory balance within local circuits. Plasticity in adulthood can be induced either by lifting these brakes through invasive interventions or by exploiting endogenous permissive factors, such as neuromodulators. Using the amblyopic visual system as a model, we discuss genetic, pharmacological, and environmental removal of brakes to enable recovery of vision in adult rodents. Although these mechanisms remain largely uncharted in the human, we consider how they may provide a biological foundation for the remarkable increase in plasticity after action video game play by amblyopic subjects. PMID:21068299

  16. Lake-front property: a unique germinal niche by the lateral ventricles of the adult brain.

    PubMed

    Ihrie, Rebecca A; Alvarez-Buylla, Arturo

    2011-05-26

    New neurons and glial cells are generated in an extensive germinal niche adjacent to the walls of the lateral ventricles in the adult brain. The primary progenitors (B1 cells) have astroglial characteristics but retain important neuroepithelial properties. Recent work shows how B1 cells contact all major compartments of this niche. They share the "shoreline" on the ventricles with ependymal cells, forming a unique adult ventricular zone (VZ). In the subventricular zone (SVZ), B1 cells contact transit amplifying (type C) cells, chains of young neurons (A cells), and blood vessels. How signals from these compartments influence the behavior of B1 or C cells remains largely unknown, but recent work highlights growth factors, neurotransmitters, morphogens, and the extracellular matrix as key regulators of this niche. The integration of emerging molecular and anatomical clues forecasts an exciting new understanding of how the germ of youth is actively maintained in the adult brain.

  17. Rapid and efficient gene delivery into the adult mouse brain via focal electroporation

    PubMed Central

    Nomura, Tadashi; Nishimura, Yusuke; Gotoh, Hitoshi; Ono, Katsuhiko

    2016-01-01

    In vivo gene delivery is required for studying the cellular and molecular mechanisms of various biological events. Virus-mediated gene transfer or generation of transgenic animals is widely used; however, these methods are time-consuming and expensive. Here we show an improved electroporation technique for acute gene delivery into the adult mouse brain. Using a syringe-based microelectrode, local DNA injection and the application of electric current can be performed simultaneously; this allows rapid and efficient gene transduction of adult non-neuronal cells. Combining this technique with various expression vectors that carry specific promoters resulted in targeted gene expression in astrocytic cells. Our results constitute a powerful strategy for the genetic manipulation of adult brains in a spatio-temporally controlled manner. PMID:27430903

  18. Oxytocin enhances inter-brain synchrony during social coordination in male adults.

    PubMed

    Mu, Yan; Guo, Chunyan; Han, Shihui

    2016-12-01

    Recent brain imaging research has revealed oxytocin (OT) effects on an individual's brain activity during social interaction but tells little about whether and how OT modulates the coherence of inter-brain activity related to two individuals' coordination behavior. We developed a new real-time coordination game that required two individuals of a dyad to synchronize with a partner (coordination task) or with a computer (control task) by counting in mind rhythmically. Electroencephalography (EEG) was recorded simultaneously from a dyad to examine OT effects on inter-brain synchrony of neural activity during interpersonal coordination. Experiment 1 found that dyads showed smaller interpersonal time lags of counting and greater inter-brain synchrony of alpha-band neural oscillations during the coordination (vs control) task and these effects were reliably observed in female but not male dyads. Moreover, the increased alpha-band inter-brain synchrony predicted better interpersonal behavioral synchrony across all participants. Experiment 2, using a double blind, placebo-controlled between-subjects design, revealed that intranasal OT vs placebo administration in male dyads improved interpersonal behavioral synchrony in both the coordination and control tasks but specifically enhanced alpha-band inter-brain neural oscillations during the coordination task. Our findings provide first evidence that OT enhances inter-brain synchrony in male adults to facilitate social coordination.

  19. Altered Gene Expression in the Brain and Ovaries of Zebrafish Exposed to the Aromatase Inhibitor Fadrosole: Microarray Analysis for Hypothesis Generation

    EPA Science Inventory

    A part of an overall program of research aimed at examining system-wide responses of the hypothalamic-pituitary-gonadal axis in fish to endocrine active chemicals acting through a variety of modes of action, we exposed zebrafish (Danio rerio) to the aromatase inhibitor fadrozole ...

  20. Altered Gene Expression in the Brain and Ovaries of Zebrafish Exposed to the Aromatase Inhibitor Fadrozole: Microarray analysis and Hypothesis Generation

    EPA Science Inventory

    As part of a research effort examining system-wide responses of the hypothalamic-pituitary-gonadal (HPG) axis in fish to endocrine active chemicals (EACs) with different modes of action, we exposed zebrafish (Danio rerio) to 25 or 100 ìg/L of the aromatase inhibitor fadrozole for...