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Chronobiological analysis and mass spectrometric characterization of pigment-dispersing factor in the cockroach Leucophaea maderae

Hamasaka, Yasutaka; Mohrherr, Carl J; Predel, Reinhard; Wegener, Christian
Fonte: University of Arizona Library Publicador: University of Arizona Library
Tipo: Artigo de Revista Científica
Publicado em 22/12/2005 Português
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Pigment-dispersing factor (PDF) is a neuropeptide that plays a prominent role in the circadian clock of several insects. The cockroach Leucophaea maderae was the first animal where the site of a biological clock could be located, and still is a focal point of circadian research. Although detailed studies on the action of pigment-dispersing factor and the distribution of PDF-like immunoreactivity in the L. maderae brain exist, a native pigment-dispersing factor of this species has not been characterized so far. The authentic Lem-PDF was isolated from L. maderae by a combination of high performance liquid chromatography, crab pigment-dispersion bioassay and an immunosorbent assay. Mass spectrometric characterization and the conserved sequence of pigment-dispersing factor in orthopteromorphan insects suggest that Lem-PDF has the sequence NSEXINSLLGLPKVLNDAa (where X= I or L). Lem-PDF is thus identical to either Periplaneta americana PDF or Acheta domesticus PDF. Detailed analysis of PDF-like immunofluorescence in different regions of the brain suggests that there are no drastic daily changes in the amount of pigment-dispersing factor as occur in Drosophila melanogaster, which might be explained by a lack of circadian pigment-dispersing factor release and production...

Pigment Dispersing Factor-Dependent and -Independent Circadian Locomotor Behavioral Rhythms

Sheeba, Vasu; Sharma, Vijay K.; Gu, Huaiyu; Chou, Yu-Ting; O’Dowd, Diane K.; Holmes, Todd C.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 02/01/2008 Português
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Circadian pacemaker circuits consist of ensembles of neurons, each expressing molecular oscillations, but how circuit-wide coordination of multiple oscillators regulates rhythmic physiological and behavioral outputs remains an open question. To investigate the relationship between the pattern of oscillator phase throughout the circadian pacemaker circuit and locomotor activity rhythms in Drosophila, we perturbed the electrical activity and pigment dispersing factor (PDF) levels of the lateral ventral neurons (LNv) and assayed their combinatorial effect on molecular oscillations in different parts of the circuit and on locomotor activity behavior. Altered electrical activity of PDF-expressing LNv causes initial behavioral arrhythmicity followed by gradual long-term emergence of two concurrent short- and long-period circadian behavioral activity bouts in ~60% of flies. Initial desynchrony of circuit-wide molecular oscillations is followed by the emergence of a novel pattern of period (PER) synchrony whereby two subgroups of dorsal neurons (DN1 and DN2) exhibit PER oscillation peaks coinciding with two activity bouts, whereas other neuronal subgroups exhibit a single PER peak coinciding with one of the two activity bouts. The emergence of this novel pattern of circuit-wide oscillator synchrony is not accompanied by concurrent change in the electrical activity of the LNv. In PDF-null flies...

Altered LARK Expression Perturbs Development and Physiology of the Drosophila PDF Clock Neurons

Huang, Yanmei; Howlett, Eric; Stern, Michael; Jackson, F. Rob
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
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58.96082%
The LARK RNA-binding protein (RBP) has well documented roles in the circadian systems of Drosophila and mammals. Recent studies have demonstrated that the Drosophila LARK RBP is associated with many mRNA targets, in vivo, including those that regulate either neurophysiology or development of the nervous system. In the present study, we have employed conditional expression techniques to distinguish developmental and physiological functions of LARK for a defined class of neurons: the Pigment Dispersing Factor (PDF)-containing LNv clock neurons. We found that increased LARK expression during development dramatically alters the small LNv class of neurons with no obvious effects on the large LNv cells. Conversely, conditional expression of LARK at the adult stage results in altered clock protein rhythms and circadian locomotor activity, even though neural morphology is normal in such animals. Electrophysiological analyses at the larval neuromuscular junction indicate a role for LARK in regulating neuronal excitability. Altogether, our results demonstrate that LARK activity is critical for neuronal development and physiology.

The CRYPTOCHROME Photoreceptor Gates PDF Neuropeptide Signaling to Set Circadian Network Hierarchy in Drosophila

Zhang, Luoying; Lear, Bridget C.; Seluzicki, Adam; Allada, Ravi
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
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59.44324%
Circadian clocks in the brain are organized as coupled oscillators that integrate seasonal cues to time daily behaviors. In Drosophila, the PIGMENT DISPERSING FACTOR (PDF) neuropeptide expressing morning (M) and non-PDF evening (E) cells are coupled cell groups important for morning and evening behavior, respectively. Depending on day length, either M- (short days) or E-cells (long days) dictate both morning and evening phase, a phenomenon we term network hierarchy. To examine the role of PDF in light-dark conditions, we examined flies lacking both the PDF receptor (PDFR) and the circadian photoreceptor CRYPTOCHROME (CRY). We found that subsets of E-cells exhibit molecular oscillations antiphase to those of wild-type flies, single cry mutants, or single Pdfr mutants, demonstrating a potent role for PDF in light-mediated entrainment specifically in the absence of CRY. Moreover, evening behavioral phase is more strongly reset by PDF(+) M-cells in the absence of CRY. Based on our findings, we propose that CRY can gate PDF signaling to determine behavioral phase and network hierarchy.

PDF Receptor Expression Reveals Direct Interactions between Circadian Oscillators in Drosophila

Im, Seol Hee; Taghert, Paul H.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 01/06/2010 Português
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59.44324%
Daily rhythms of behavior are controlled by a circuit of circadian pacemaking neurons. In Drosophila, 150 pacemakers participate in this network, and recent observations suggest the network is divisible into M and E oscillators which normally interact and synchronize. Sixteen oscillator neurons (the small and large LNvs) express a neuropeptide called pigment dispersing factor (PDF) whose signaling is often equated with M oscillator output. Given the significance of PDF signaling to numerous aspects of behavioral and molecular rhythms, determining precisely where and how signaling via the PDF receptor (PDFR) occurs is now a central question in the field. Here we show that GAL4-mediated rescue of pdfr phenotypes using a UAS-PDFR transgene is insufficient to provide complete behavioral rescue. In contrast, we describe a ~70 kB PDF receptor (pdfr) transgene which does rescue the entire pdfr circadian behavioral phenotype. The transgene is widely but heterogeneously expressed among pacemakers, and also among a limited number of non-pacemakers. Our results support an important hypothesis: the small LNv cells directly target a subset of the other crucial pacemaker neurons cells. Furthermore, expression of the transgene confirms an autocrine feedback signaling by PDF back to PDF-expressing cells. Finally...

Functional Characterization of Three G Protein-coupled Receptors for Pigment Dispersing Factors in Caenorhabditis elegans*S⃞

Janssen, Tom; Husson, Steven J.; Lindemans, Marleen; Mertens, Inge; Rademakers, Suzanne; Donck, Kris Ver; Geysen, Johan; Jansen, Gert; Schoofs, Liliane
Fonte: American Society for Biochemistry and Molecular Biology Publicador: American Society for Biochemistry and Molecular Biology
Tipo: Artigo de Revista Científica
Publicado em 30/05/2008 Português
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Here, we report the identification, cloning, and functional characterization of three Caenorhabditis elegans G protein-coupled pigment dispersing factor (PDF) receptors, which we designated as Ce_PDFR-1a, -b, and -c. They represent three splice isoforms of the same gene (C13B9.4), which share a high degree of similarity with the Drosophila PDF receptor and are distantly related to the mammalian vasoactive intestinal peptide receptors (VPAC2) and calcitonin receptors. In a reverse pharmacological screen, three bioactive C. elegans neuropeptides, which were recently identified as the Drosophila PDF orthologues, were able to activate these receptors in a dose-dependent manner with nanomolar potency (isoforms a and b). Integrated green fluorescent protein reporter constructs reveal the expression of these PDF receptors in all body wall muscle cells and many head and tail neurons involved in the integration of environmental stimuli and the control of locomotion. Using a custom data analysis system, we demonstrate the involvement of this newly discovered neuropeptide signaling system in the regulation of locomotor behavior. Overexpression of PDF-2 phenocopies the locomotor defects of a PDF-1 null mutant, suggesting that they elicit opposite effects on locomotion through the identified PDF receptors. Our findings strengthen the hypothesis that the PDF signaling system...

Daily rhythms in locomotor circuits in Drosophila involve PDF

Pírez, Nicolás; Christmann, Bethany L.; Griffith, Leslie C.
Fonte: American Physiological Society Publicador: American Physiological Society
Tipo: Artigo de Revista Científica
Português
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The neuropeptide pigment-dispersing factor (PDF) has been studied extensively in Drosophila, and its role in circadian time-keeping has been firmly established. The role of PDF outside of the clock circuit, however, is poorly understood. A recent study suggested that PDF may act on the ellipsoid body (EB) to link the clock and sleep/activity circuits. We performed whole brain optical imaging with the fluorescence resonance energy transfer (FRET)-based cAMP sensor Epac1-camps expressed under control of the pdfR promoter to address how the clock and sleep deprivation affect the physiology of these cells. Basal cAMP levels in EB were regulated both by PDF and synaptic inputs that are controlled by the circadian clock. Acute application of PDF to the brain caused a significant, and PDF-receptor-dependent, increase in cAMP in EB cells. Application of TTX to block circuit-mediated effects of PDF increased the morning response but not the response at night, implying the existence of a temporally regulated, PDF-stimulated input that blocks cAMP generation. ACh produced both direct (TTX-insensitive) and indirect (TTX-sensitive) increases in cAMP during the day but was totally TTX-insensitive at night, indicating that ACh-stimulated inputs to the EB are suppressed at night. Sleep deprivation did not affect the cAMP responses of these cells to either PDF or ACh. These results suggest a novel role for PDF as a modulator of activity outside of the clock circuit. By elucidating the mechanisms by which the neuropeptide PDF act on its target cells...

A PDF/NPF neuropeptide signaling circuitry of male Drosophila melanogaster controls rival-induced prolonged mating

Kim, Woo Jae; Jan, Lily Yeh; Jan, Yuh Nung
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 04/12/2013 Português
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A primary function of males for many species involves mating with females for reproduction. Drosophila melanogaster males respond to the presence of other males by prolonging mating duration to increase the chance of passing on their genes. To understand the basis of such complex behaviors, we examine the genetic network and neural circuits that regulate rival-induced longer mating duration (LMD). Here we identify a small subset of clock neurons in the male brain that regulate LMD via neuropeptide signaling. LMD requires the function of pigment-dispersing factor (PDF) in four s-LNv neurons and its receptor PDFR in two LNd neurons per hemisphere, as well as the function of neuropeptide F (NPF) in two neurons within the sexually dimorphic LNd region and its receptor NPFR1 in four s-LNv neurons per hemisphere. Moreover, rival exposure modifies the neuronal activities of a subset of clock neurons involved in neuropeptide signaling for LMD.

Serotonin and the Neuropeptide PDF Initiate and Extend Opposing Behavioral States in C. elegans

Flavell, Steven W.; Pokala, Navin; Macosko, Evan Z.; Albrecht, Dirk R.; Larsch, Johannes; Bargmann, Cornelia I.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
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Foraging animals have distinct exploration and exploitation behaviors that are organized into discrete behavioral states. Here we characterize a neuromodulatory circuit that generates long-lasting roaming and dwelling states in Caenorhabditis elegans. We find that two opposing neuromodulators, serotonin and the neuropeptide pigment dispersing factor (PDF), each initiate and extend one behavioral state. Serotonin promotes dwelling states through the MOD-1 serotonin-gated chloride channel. The spontaneous activity of serotonergic neurons correlates with dwelling behavior, and optogenetic modulation of the critical MOD-1-expressing targets induces prolonged dwelling states. PDF promotes roaming states through a Gαs-coupled PDF receptor; optogenetic activation of cAMP production in PDF receptor-expressing cells induces prolonged roaming states. The neurons that produce and respond to each neuromodulator form a distributed circuit orthogonal to the classical wiring diagram, with several essential neurons that express each molecule. The slow temporal dynamics of this neuromodulatory circuit supplement fast motor circuits to organize long-lasting behavioral states.

The Drosophila neuropeptides PDF and sNPF have opposing electrophysiological and molecular effects on central neurons

Vecsey, Christopher G.; Pírez, Nicolás; Griffith, Leslie C.
Fonte: American Physiological Society Publicador: American Physiological Society
Tipo: Artigo de Revista Científica
Português
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59.318745%
Neuropeptides have widespread effects on behavior, but how these molecules alter the activity of their target cells is poorly understood. We employed a new model system in Drosophila melanogaster to assess the electrophysiological and molecular effects of neuropeptides, recording in situ from larval motor neurons, which transgenically express a receptor of choice. We focused on two neuropeptides, pigment-dispersing factor (PDF) and small neuropeptide F (sNPF), which play important roles in sleep/rhythms and feeding/metabolism. PDF treatment depolarized motor neurons expressing the PDF receptor (PDFR), increasing excitability. sNPF treatment had the opposite effect, hyperpolarizing neurons expressing the sNPF receptor (sNPFR). Live optical imaging using a genetically encoded fluorescence resonance energy transfer (FRET)-based sensor for cyclic AMP (cAMP) showed that PDF induced a large increase in cAMP, whereas sNPF caused a small but significant decrease in cAMP. Coexpression of pertussis toxin or RNAi interference to disrupt the G-protein Gαo blocked the electrophysiological responses to sNPF, showing that sNPFR acts via Gαo signaling. Using a fluorescent sensor for intracellular calcium, we observed that sNPF-induced hyperpolarization blocked spontaneous waves of activity propagating along the ventral nerve cord...

Pigment-Dispersing Factor Modulates Pheromone Production in Clock Cells that Influence Mating in Drosophila

Krupp, Joshua J.; Billeter, Jean-Christophe; Wong, Amy; Choi, Charles; Nitabach, Michael N.; Levine, Joel D.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 10/07/2013 Português
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Social cues contribute to the circadian entrainment of physiological and behavioral rhythms. These cues supplement the influence of daily and seasonal cycles in light and temperature. In Drosophila, the social environment modulates circadian mechanisms that regulate sex pheromone production and mating behavior. Here we demonstrate that a neuroendocrine pathway, defined by the neuropeptide Pigment-Dispersing Factor (PDF), couples the central nervous system (CNS) to the physiological output of peripheral clock cells that produce pheromones, the oenocytes. PDF signaling from the CNS modulates the phase of the oenocyte clock. Despite its requirement for sustaining free-running locomoter activity rhythms, PDF is not necessary to sustain molecular rhythms in the oenocytes. Interestingly, disruption of the PDF signaling pathway reduces male sex pheromones and results in sex-specific differences in mating behavior. Our findings highlight the role of neuropeptide signaling and the circadian system in synchronizing the physiological and behavioral processes which govern social interactions.

Dual PDF Signaling Pathways Reset Clocks Via TIMELESS and Acutely Excite Target Neurons to Control Circadian Behavior

Seluzicki, Adam; Flourakis, Matthieu; Kula-Eversole, Elzbieta; Zhang, Luoying; Kilman, Valerie; Allada, Ravi
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 18/03/2014 Português
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Molecular circadian clocks are interconnected via neural networks. In Drosophila, PIGMENT-DISPERSING FACTOR (PDF) acts as a master network regulator with dual functions in synchronizing molecular oscillations between disparate PDF(+) and PDF(−) circadian pacemaker neurons and controlling pacemaker neuron output. Yet the mechanisms by which PDF functions are not clear. We demonstrate that genetic inhibition of protein kinase A (PKA) in PDF(−) clock neurons can phenocopy PDF mutants while activated PKA can partially rescue PDF receptor mutants. PKA subunit transcripts are also under clock control in non-PDF DN1p neurons. To address the core clock target of PDF, we rescued per in PDF neurons of arrhythmic per01 mutants. PDF neuron rescue induced high amplitude rhythms in the clock component TIMELESS (TIM) in per-less DN1p neurons. Complete loss of PDF or PKA inhibition also results in reduced TIM levels in non-PDF neurons of per01 flies. To address how PDF impacts pacemaker neuron output, we focally applied PDF to DN1p neurons and found that it acutely depolarizes and increases firing rates of DN1p neurons. Surprisingly, these effects are reduced in the presence of an adenylate cyclase inhibitor, yet persist in the presence of PKA inhibition. We have provided evidence for a signaling mechanism (PKA) and a molecular target (TIM) by which PDF resets and synchronizes clocks and demonstrates an acute direct excitatory effect of PDF on target neurons to control neuronal output. The identification of TIM as a target of PDF signaling suggests it is a multimodal integrator of cell autonomous clock...

Pigment Dispersing Factor Regulates Ecdysone Biosynthesis via Bombyx Neuropeptide G Protein Coupled Receptor-B2 in the Prothoracic Glands of Bombyx mori

Iga, Masatoshi; Nakaoka, Takayoshi; Suzuki, Yutaka; Kataoka, Hiroshi
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 29/07/2014 Português
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Ecdysone is the key hormone regulating insect growth and development. Ecdysone synthesis occurs in the prothoracic glands (PGs) and is regulated by several neuropeptides. Four prothoracicotropic and three prothoracicostatic factors have been identified to date, suggesting that ecdysone biosynthesis is intricately regulated. Here, we demonstrate that the neuropeptide pigment dispersing factor (PDF) stimulates ecdysone biosynthesis and that this novel signaling pathway partially overlaps with the prothoracicotropic hormone (PTTH) signaling pathway. We performed transcriptome analysis and focused on receptors predominantly expressed in the PGs. From this screen, we identified a candidate orphan G protein coupled receptor (GPCR), Bombyx neuropeptide GPCR-B2 (BNGR-B2). BNGR-B2 was predominantly expressed in ecdysteroidogenic tissues, and the expression pattern in the PGs corresponded to the ecdysteroid titer in the hemolymph. Furthermore, we identified PDF as a ligand for BNGR-B2. PDF stimulated ecdysone biosynthesis in the PGs, but the stimulation was only observed in the PGs during a specific larval stage. PDF did not affect the transcript level of known ecdysone biosynthetic enzymes, and inhibiting transcription did not suppress ecdysone biosynthesis...

Mmp1 Processing of the PDF Neuropeptide Regulates Circadian Structural Plasticity of Pacemaker Neurons

Depetris-Chauvin, Ana; Fernández-Gamba, Ágata; Gorostiza, E. Axel; Herrero, Anastasia; Castaño, Eduardo M.; Ceriani, M. Fernanda
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 30/10/2014 Português
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In the Drosophila brain, the neuropeptide PIGMENT DISPERSING FACTOR (PDF) is expressed in the small and large Lateral ventral neurons (LNvs) and regulates circadian locomotor behavior. Interestingly, PDF immunoreactivity at the dorsal terminals changes across the day as synaptic contacts do as a result of a remarkable remodeling of sLNv projections. Despite the relevance of this phenomenon to circuit plasticity and behavior, the underlying mechanisms remain poorly understood. In this work we provide evidence that PDF along with matrix metalloproteinases (Mmp1 and 2) are key in the control of circadian structural remodeling. Adult-specific downregulation of PDF levels per se hampers circadian axonal remodeling, as it does altering Mmp1 or Mmp2 levels within PDF neurons post-developmentally. However, only Mmp1 affects PDF immunoreactivity at the dorsal terminals and exerts a clear effect on overt behavior. In vitro analysis demonstrated that PDF is hydrolyzed by Mmp1, thereby suggesting that Mmp1 could directly terminate its biological activity. These data demonstrate that Mmp1 modulates PDF processing, which leads to daily structural remodeling and circadian behavior.

Remote control of renal physiology by the intestinal neuropeptide pigment-dispersing factor in Drosophila

Talsma, Aaron D.; Christov, Christo P.; Terriente-Felix, Ana; Linneweber, Gerit A.; Perea, Daniel; Wayland, Matthew; Shafer, Orie T.; Miguel-Aliaga, Irene
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
Português
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The role of the central neuropeptide pigment-dispersing factor (PDF) in circadian timekeeping in Drosophila is remarkably similar to that of vasoactive intestinal peptide (VIP) in mammals. Like VIP, PDF is expressed outside the circadian network by neurons innervating the gut, but the function and mode of action of this PDF have not been characterized. Here we investigate the visceral roles of PDF by adapting cellular and physiological methods to the study of visceral responses to PDF signaling in wild-type and mutant genetic backgrounds. We find that intestinal PDF acts at a distance on the renal system, where it regulates ureter contractions. We show that PdfR, PDF's established receptor, is expressed by the muscles of the excretory system, and present evidence that PdfR-induced cAMP increases underlie the myotropic effects of PDF. These findings extend the similarities between PDF and VIP beyond their shared central role as circadian regulators, and uncover an unexpected endocrine mode of myotropic action for an intestinal neuropeptide on the renal system.

Comparative Analysis of Pdf-Mediated Circadian Behaviors Between Drosophila melanogaster and D. virilis

Bahn, Jae Hoon; Lee, Gyunghee; Park, Jae H.
Fonte: Genetics Society of America Publicador: Genetics Society of America
Tipo: Artigo de Revista Científica
Publicado em /03/2009 Português
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A group of small ventrolateral neurons (s-LNv's) are the principal pacemaker for circadian locomotor rhythmicity of Drosophila melanogaster, and the pigment-dispersing factor (Pdf) neuropeptide plays an essential role as a clock messenger within these neurons. In our comparative studies on Pdf-associated circadian rhythms, we found that daily locomotor activity patterns of D. virilis were significantly different from those of D. melanogaster. Activities of D. virilis adults were mainly restricted to the photophase under light:dark cycles and subsequently became arrhythmic or weakly rhythmic in constant conditions. Such activity patterns resemble those of Pdf01 mutant of D. melanogaster. Intriguingly, endogenous D. virilis Pdf (DvPdf) expression was not detected in the s-LNv-like neurons in the adult brains, implying that the Pdf01-like behavioral phenotypes of D. virilis are attributed in part to the lack of DvPdf in the s-LNv-like neurons. Heterologous transgenic analysis showed that cis-regulatory elements of the DvPdf transgene are capable of directing their expression in all endogenous Pdf neurons including s-LNv's, as well as in non-Pdf clock neurons (LNd's and fifth s-LNv) in a D. melanogaster host. Together these findings suggest a significant difference in the regulatory mechanisms of Pdf transcription between the two species and such a difference is causally associated with species-specific establishment of daily locomotor activity patterns.

Signaling of Pigment-Dispersing Factor (PDF) in the Madeira Cockroach Rhyparobia maderae

Wei, Hongying; Yasar, Hanzey; Funk, Nico W.; Giese, Maria; Baz, El-Sayed; Stengl, Monika
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 30/09/2014 Português
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The insect neuropeptide pigment-dispersing factor (PDF) is a functional ortholog of vasoactive intestinal polypeptide, the coupling factor of the mammalian circadian pacemaker. Despite of PDF's importance for synchronized circadian locomotor activity rhythms its signaling is not well understood. We studied PDF signaling in primary cell cultures of the accessory medulla, the circadian pacemaker of the Madeira cockroach. In Ca2+ imaging studies four types of PDF-responses were distinguished. In regularly bursting type 1 pacemakers PDF application resulted in dose-dependent long-lasting increases in Ca2+ baseline concentration and frequency of oscillating Ca2+ transients. Adenylyl cyclase antagonists prevented PDF-responses in type 1 cells, indicating that PDF signaled via elevation of intracellular cAMP levels. In contrast, in type 2 pacemakers PDF transiently raised intracellular Ca2+ levels even after blocking adenylyl cyclase activity. In patch clamp experiments the previously characterized types 1–4 could not be identified. Instead, PDF-responses were categorized according to ion channels affected. Application of PDF inhibited outward potassium or inward sodium currents, sometimes in the same neuron. In a comparison of Ca2+ imaging and patch clamp experiments we hypothesized that in type 1 cells PDF-dependent rises in cAMP concentrations block primarily outward K+ currents. Possibly...

Circadian Period Integrates Network Information Through Activation of the BMP Signaling Pathway

Beckwith, Esteban Javier; Gorostiza, Ezequiel Axel; Berni, Jimena; Rezaval, Carolina; Perez-Santangelo, Agustín; Nadra, Alejandro Daniel; Ceriani, Maria Fernanda
Fonte: Public Library Science Publicador: Public Library Science
Tipo: info:ar-repo/semantics/artículo; info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion Formato: application/pdf
Português
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Living organisms use biological clocks to maintain their internal temporal order and anticipate daily environmental changes.
In Drosophila, circadian regulation of locomotor behavior is controlled by ,150 neurons; among them, neurons expressing
the PIGMENT DISPERSING FACTOR (PDF) set the period of locomotor behavior under free-running conditions. To this date it
remains unclear how individual circadian clusters integrate their activity to assemble a distinctive behavioral output. Here
we show that the BONE MORPHOGENETIC PROTEIN (BMP) signaling pathway plays a crucial role in setting the circadian
period in PDF neurons in the adult brain. Acute deregulation of BMP signaling causes period lengthening through
regulation of dClock transcription, providing evidence for a novel function of this pathway in the adult brain. We propose
that coherence in the circadian network arises from integration in PDF neurons of both the pace of the cell-autonomous
molecular clock and information derived from circadian-relevant neurons through release of BMP ligands.

Rol del neuropéptido PDF en la adquisición y el mantenimiento de la estructura del circuito PDF; Role of the PDF neuropeptide in the acquisition and maintenance of the PDF circuit structure

Gorostiza, Ezequiel Axel
Fonte: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires Publicador: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires
Tipo: info:eu-repo/semantics/doctoralThesis; tesis doctoral; info:eu-repo/semantics/publishedVersion Formato: application/pdf
Publicado em //2013 Português
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La ritmicidad comportamental en Drosophila es sostenida por una red neuronal que en el cerebro adulto comprende alrededor de 150 neuronas. Entre éstas, las sLNv han demostrado ser esenciales para el control de la actividad rítmica. Desde el punto de vista circadiano, las sLNv tienen dos características sobresalientes: expresan el neuropéptido PDF, y atraviesan cambios estructurales circadianos en sus terminales axonales, proceso denominado plasticidad estructural. En esta tesis estudiamos qué otros cambios ocurrían concomitantes con la plasticidad estructural. Encontramos que ésta es acompañada por aumentos en el número de sinapsis y disponibilidad de vesículas en momentos de mayor complejidad del árbol axonal, que luego caen durante la fase de menor complejidad. Además demostramos que la plasticidad estructural depende de los niveles de PDF y a raíz de este análisis descubrimos un nuevo rol para PDF durante el desarrollo de las sLNv. La arquitectura adulta de las sLNv necesita que PDF actúe sobre su postsinapsis temprano en el desarrollo larval, proceso que requiere su receptor canónico. Sin embargo, la ausencia de PDF produce defectos presinápticos evidentes luego de la metamorfosis. Comprobamos que previo a la metamorfosis la postsinapsis libera GBB...

Rol del neuropéptido PDF en la adquisición y el mantenimiento de la estructura del circuito PDF; Role of the PDF neuropeptide in the acquisition and maintenance of the PDF circuit structure

Gorostiza, Ezequiel Axel
Fonte: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires Publicador: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires
Tipo: Tesis Doctoral Formato: text; pdf
Publicado em //2013 Português
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La ritmicidad comportamental en Drosophila es sostenida por una red neuronal que en el cerebro adulto comprende alrededor de 150 neuronas. Entre éstas, las sLNv han demostrado ser esenciales para el control de la actividad rítmica. Desde el punto de vista circadiano, las sLNv tienen dos características sobresalientes: expresan el neuropéptido PDF, y atraviesan cambios estructurales circadianos en sus terminales axonales, proceso denominado plasticidad estructural. En esta tesis estudiamos qué otros cambios ocurrían concomitantes con la plasticidad estructural. Encontramos que ésta es acompañada por aumentos en el número de sinapsis y disponibilidad de vesículas en momentos de mayor complejidad del árbol axonal, que luego caen durante la fase de menor complejidad. Además demostramos que la plasticidad estructural depende de los niveles de PDF y a raíz de este análisis descubrimos un nuevo rol para PDF durante el desarrollo de las sLNv. La arquitectura adulta de las sLNv necesita que PDF actúe sobre su postsinapsis temprano en el desarrollo larval, proceso que requiere su receptor canónico. Sin embargo, la ausencia de PDF produce defectos presinápticos evidentes luego de la metamorfosis. Comprobamos que previo a la metamorfosis la postsinapsis libera GBB...