721 research outputs found

    Characterization of voltage-gated ionic currents in a peripheral sensory neuron in larval Drosophila.

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    BACKGROUND: The development, morphology and genetics of sensory neurons have been extensively studied in Drosophila. Sensory neurons in the body wall of larval Drosophila in particular have been the subject of numerous anatomical studies, however, little is known about the intrinsic electrical properties of larval sensory cells. FINDINGS: We performed whole cell patch recordings from an identified peripheral sensory cell, the dorsal bipolar sensory neuron (dbd) and measured voltage-gated ionic currents in 1st instar larvae. Voltage clamp analysis revealed that dbds have a TEA sensitive, non-inactivating IK type potassium current as well as a 4-AP sensitive, inactivating IA type potassium current. dbds also show a voltage-gated calcium current (ICa) and a voltage-gated sodium current (INa). CONCLUSIONS: This work provides a first characterization of voltage-activated ionic currents in an identified body-wall sensory neuron in larval Drosophila. Overall, we establish baseline physiology data for future studies aimed at understanding the ionic and genetic basis of sensory neuron function in fruit flies and other model organisms.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

    Localization of muscarinic acetylcholine receptor dependent rhythm generating modules in the Drosophila larval locomotor network

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    This work was supported by the Wellcome Trust through an ISSF award (105621/Z/14/Z) to the University of St Andrews. It was also supported by a Biotechnology and Biological Sciences Research Council (BBSRC) project grant (BB/M021793) awarded to SRP, a CASE studentship awarded to J. M. (BB/M010996/1) and a donation from Kaunas Industrial Water Supply (Kauno Pramoninis Vandentiekis, Kaunas, Lithuania) in support of J. J.Mechanisms of rhythm generation h­­ave been extensively studied in motor systems that control locomotion over terrain in limbed animals; however, much less is known about rhythm generation in soft-bodied terrestrial animals. Here we explored how muscarinic acetylcholine receptor (mAChR) modulated rhythm generating networks are distributed in the central nervous system (CNS) of soft-bodied Drosophila larvae. We measured fictive motor patterns in isolated CNS preparations using a combination of Ca2+ imaging and electrophysiology while manipulating mAChR signalling pharmacologically. Bath application of the mAChR agonist oxotremorine potentiated bilaterally asymmetric activity in anterior thoracic regions and promoted bursting in posterior abdominal regions. Application of the mAChR antagonist scopolamine suppressed rhythm generation in these regions and blocked the effects of oxotremorine. Oxotremorine triggered fictive forward crawling in preparations without brain lobes. Oxotremorine also potentiated rhythmic activity in isolated posterior abdominal CNS segments as well as isolated anterior brain and thoracic regions, but it did not induce rhythmic activity in isolated anterior abdominal segments. Bath application of scopolamine to reduced preparations lowered baseline Ca2+ levels and abolished rhythmic activity. Overall, these results suggest that mAChR signalling plays a role in enabling rhythm generation at multiple sites in the larval CNS. This work furthers our understanding of motor control in soft-bodied locomotion and provides a foundation for study of rhythm generating networks in an emerging genetically tractable locomotor system.Publisher PDFPeer reviewe

    Transplant techniques for sapling mangrove trees, Rhizophora mangle, Laguncularia racemosa, Avicennia germinans, in Florida

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    Channelrhodopsin2 Mediated Stimulation of Synaptic Potentials at Drosophila Neuromuscular Junctions

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    The Drosophila larval neuromuscular preparation has proven to be a useful tool for studying synaptic physiology1,2,3. Currently, the only means available to evoke excitatory junctional potentials (EJPs) in this preparation involves the use of suction electrodes. In both research and teaching labs, students often have difficulty maneuvering and manipulating this type of stimulating electrode. In the present work, we show how to remotely stimulate synaptic potentials at the larval NMJ without the use of suction electrodes. By expressing channelrhodopsin2 (ChR2) 4,5,6 in Drosophila motor neurons using the GAL4-UAS system 7, and making minor changes to a basic electrophysiology rig, we were able to reliably evoke EJPs with pulses of blue light. This technique could be of particular use in neurophysiology teaching labs where student rig practice time and resources are limited

    Inexpensive methods for live imaging of central pattern generator activity in the Drosophila larval locomotor system

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    This work was supported by EPSRC Doctoral Training grant EP/L505079/1) and a European Research Council Grant to MCG (640012) It was also supported by a British Council GREAT Scholarship (to VS) as well as grants from the St Andrews Learning and Teaching Initiative and the McCall-McBain Foundation to SRP. This work was also supported by the open source DIY communities as described throughout the paper.Central pattern generators (CPGs) are neural networks that produce rhythmic motor activity in the absence of sensory input. CPGs produce ‘fictive’ behaviours in vitro which parallel activity seen in intact animals. CPG networks have been identified in a wide variety of model organisms and have been shown to be critical for generating rhythmic behaviours such as swimming, walking, chewing and breathing. Work with CPG preparations has led to fundamental advances in neuroscience; however, most CPG preparations involve intensive dissections and require sophisticated electrophysiology equipment, making export to teaching laboratories problematic. Here we present an integrated approach for bringing the study of locomotor CPGs in Drosophila larvae into teaching laboratories. First, we present freely available genetic constructs that enable educators to express genetically encoded calcium indicators in cells of interest in the larval central nervous system. Next, we describe how to isolate the larval central nervous system and prepare it for live imaging. We then show how to modify standard compound microscopes to enable fluorescent imaging using 3D printed materials and inexpensive optical components. Finally, we show how to use the free image analysis programme ImageJ and freely available features in the signal analysis programme DataView to analyse rhythmic CPG activity in the larval CNS. Comparison of results to those obtained on research equipment shows that signal-to-noise levels are comparable and core features of larval CPG activity can be observed. Overall, this work shows the viability of exporting live imaging experiments to low cost environments and paves the way for new teaching laboratory exercises revolving around optical imaging of CPG activity.Publisher PDFPeer reviewe

    In Vitro and In Vivo Toxicometabolomics of the Synthetic Cathinone PCYP Studied by Means of LC-HRMS/MS

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    Synthetic cathinones are one important group amongst new psychoactive substances (NPS) and limited information is available regarding their toxicokinetics and -dynamics. Over the past few years, nontargeted toxicometabolomics has been increasingly used to study compound-related effects of NPS to identify important exogenous and endogenous biomarkers. In this study, the effects of the synthetic cathinone PCYP (2-cyclohexyl-1-phenyl-2-(1-pyrrolidinyl)-ethanone) on in vitro and in vivo metabolomes were investigated. Pooled human-liver microsomes and blood and urine of male Wistar rats were used to generate in vitro and in vivo data, respectively. Samples were analyzed by liquid chromatography and high-resolution mass spectrometry using an untargeted metabolomics workflow. Statistical evaluation was performed using univariate and multivariate statistics. In total, sixteen phase I and one phase II metabolite of PCYP could be identified as exogenous biomarkers. Five endogenous biomarkers (e.g., adenosine and metabolites of tryptophan metabolism) related to PCYP intake could be identified in rat samples. The present data on the exogenous biomarker of PCYP are crucial for setting up analytical screening procedures. The data on the endogenous biomarker are important for further studies to better understand the physiological changes associated with cathinone abuse but may also serve in the future as additional markers for an intake

    Indigenous Health – Australia, Canada, New Zealand and the United States - Laying Claim to a Future that Embraces Health for Us All.

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    Improving the health of all peoples has been a call across the globe for many decades and unfortunately remains relevant today, particularly given the large disparities in health status of peoples found around the world. Rather than differences in health, or health inequalities, we use a different term, health inequities. This is so as mere differences in health (or inequalities ) can be common in societies and do not necessarily reflect unfair social policies or practices. For example, natural ageing implies older people are more prone to illness. Yet, when differences are systematic, socially produced and unfair, these are considered health inequities. Certainly making judgments on what is systematic, socially produced and unfair, reflects value judgments and merit open debate. We are making explicit in this paper what our judgments are, and the basis for these judgment
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