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Shelley A Adamo
The classic biomedical view is that stress hormone effects on the immune system are largely pathological, especially if the stress is chronic. However, more recent interpretations have focused on the potential adaptive function of these effects. This paper examines stress response-immune system interactions from a physiological network perspective, using insects because of their simpler physiology. For example, stress hormones can reduce disease resistance, yet activating an immune response results in the release of stress hormones in both vertebrates and invertebrates...
October 13, 2016: Hormones and Behavior
Emily E LeDue, Kevin Mann, Ellen Koch, Bonnie Chu, Roslyn Dakin, Michael D Gordon
Nutrient deprivation can lead to dramatic changes in feeding behavior, including acceptance of foods that are normally rejected. In flies, this behavioral shift depends in part on reciprocal sensitization and desensitization of sweet and bitter taste, respectively. However, the mechanisms for bitter taste modulation remain unclear. Here, we identify a set of octopaminergic/tyraminergic neurons, named OA-VLs, that directly modulate bitter sensory neuron output in response to starvation. OA-VLs are in close proximity to bitter sensory neuron axon terminals and show reduced tonic firing following starvation...
October 1, 2016: Current Biology: CB
L Xu, L Li, P Yang, Z Ma
The migratory locust (Locusta migratoria) shows aggregative traits in nymph marching bands and swarm formations through mutual olfactory attraction of conspecifics. However, olfactory preference in different nymph stages in gregarious locusts is not sufficiently explored. In this study, we found that the nymph olfactory preference for gregarious volatiles exhibited obvious variations at different developmental stages. The gregarious locusts show attractive response to conspecific volatiles from the third stadium...
October 7, 2016: Insect Molecular Biology
Hui-Min Li, Hong-Bo Jiang, Shun-Hua Gui, Xiao-Qiang Liu, Hong Liu, Xue-Ping Lu, Guy Smagghe, Jin-Jun Wang
The biogenic amine octopamine plays a critical role in the regulation of many physiological processes in insects. Octopamine transmits its action through a set of specific G-protein coupled receptors (GPCRs), namely octopamine receptors. Here, we report on a β-adrenergic-like octopamine receptor gene (BdOctβR1) from the oriental fruit fly, Bactrocera dorsalis (Hendel), a destructive agricultural pest that occurs in North America and the Asia-Pacific region. As indicated by RT-qPCR, BdOctβR1 was highly expressed in the central nervous system (CNS) and Malpighian tubules (MT) in the adult flies, suggesting it may undertake important roles in neural signaling in the CNS as well as physiological functions in the MT of this fly...
2016: International Journal of Molecular Sciences
Thiago Carrazoni, Marines de Avila Heberle, Ana Paula Artusi Perin, Ana Paula Zanatta, Polyana Veloso Rodrigues, Fabiola Duarte Machado Dos Santos, Carlos Gabriel Moreira de Almeida, Ricardo Vaz Breda, Douglas Silva Dos Santos, Paulo Marcos Pinto, Jaderson Costa da Costa, Celia Regina Carlini, Cháriston André Dal Belo
BACKGROUND: Ureases of Canavalia ensiformis are natural insecticides with a still elusive entomotoxic mode of action. We have investigated the mechanisms involved in the neurotoxicity induced by Jack Bean Urease (JBU) in Nauphoeta cinerea (Olivier). METHODS: To carry out this study we have employed biochemical and neurophysiological analysis of different cockroach organ systems. RESULTS AND CONCLUSIONS: The injection of the insects with JBU (0...
August 10, 2016: Toxicology
Yue Yu, Rui Huang, Jie Ye, Vivian Zhang, Chao Wu, Guo Cheng, Junling Jia, Liming Wang
Starvation induces sustained increase in locomotion, which facilitates food localization and acquisition and hence composes an important aspect of food-seeking behavior. We investigated how nutritional states modulated starvation-induced hyperactivity in adult Drosophila. The receptor of the adipokinetic hormone (AKHR), the insect analog of glucagon, was required for starvation-induced hyperactivity. AKHR was expressed in a small group of octopaminergic neurons in the brain. Silencing AKHR(+) neurons and blocking octopamine signaling in these neurons eliminated starvation-induced hyperactivity, whereas activation of these neurons accelerated the onset of hyperactivity upon starvation...
September 9, 2016: ELife
Leonardo Rodríguez-Sosa, Gabina Calderón-Rosete, Aída Ortega-Cambranis, Francisco F De-Miguel
The biogenic amine octopamine (OA) modulates invertebrate behavior by changing neuronal responses from sensory inputs to motor outputs. However, the OA modulation of visual sensitivity and its possible coupling to diurnal cycles remains unexplored. Here we studied the diurnal variations in the OA levels in the hemolymph of the crayfish Procambarus clarkii, its release from the structures in the eyestalk and its modulation of the retinal light sensitivity. The hemolymph concentration of OA and its amino acid precursor tyrosine was measured by high-resolution liquid chromatography; OA varied along the 24-hcycle...
September 1, 2016: Comparative Biochemistry and Physiology. Part A, Molecular & Integrative Physiology
A F C Greenslade, J L Ward, J L Martin, D I Corol, S J Clark, L E Smart, G I Aradottir
Crop protection is an integral part of establishing food security, by protecting the yield potential of crops. Cereal aphids cause yield losses by direct damage and transmission of viruses. Some wild relatives of wheat show resistance to aphids but the mechanisms remain unresolved. In order to elucidate the location of the partial resistance to the bird cherry-oat aphid, Rhopalosiphum padi, in diploid wheat lines of Triticum monococcum, we conducted aphid performance studies using developmental bioassays and electrical penetration graphs, as well as metabolic profiling of partially resistant and susceptible lines...
May 2016: Annals of Applied Biology
H H Caline Koh-Tan, Erin Strachan, Katherine Cooper, Lesley Bell-Sakyi, Nicholas N Jonsson
BACKGROUND: The cattle tick Rhipicephalus (Boophilus) microplus is an economically important parasite of livestock. Effective control of ticks using acaricides is threatened by the emergence of resistance to many existing compounds. Several continuous R. microplus cell lines have been established and provide an under-utilised resource for studies into acaricide targets and potential genetic mutations associated with resistance. As a first step to genetic studies using these resources, this study aimed to determine the presence or absence of two genes and their transcripts that have been linked with acaricide function in cattle ticks: β-adrenergic octopamine receptor (βAOR, associated with amitraz resistance) and ATP-binding cassette B10 (ABCB10, associated with macrocyclic lactone resistance) in six R...
2016: Parasites & Vectors
Tomo Kita, Takeshi Hayashi, Tomohiro Ohtani, Haruka Takao, Hiroshi Takasu, Genyan Liu, Hiroto Ohta, Fumiyo Ozoe, Yoshihisa Ozoe
BACKGROUND: Amitraz is a formamidine acaricide and insecticide used to control ticks, mites and fleas. N(2) -(2,4-Dimethylphenyl)-N(1) -methyformamidine (DPMF), a metabolite of amitraz, is thought to be an active agent that exerts acaricidal and insecticidal effects by acting as an agonist on octopamine receptors. The emergence of cattle ticks resistant to amitraz is a serious problem that requires urgent attention. The objective of this research was to determine which type of octopamine receptor is the primary target of amitraz and thereby understand the molecular mechanisms of action and resistance to amitraz...
August 3, 2016: Pest Management Science
Marta Andrés, Marvin Seifert, Christian Spalthoff, Ben Warren, Lukas Weiss, Diego Giraldo, Margret Winkler, Stephanie Pauls, Martin C Göpfert
The performance of vertebrate ears is controlled by auditory efferents that originate in the brain and innervate the ear, synapsing onto hair cell somata and auditory afferent fibers [1-3]. Efferent activity can provide protection from noise and facilitate the detection and discrimination of sound by modulating mechanical amplification by hair cells and transmitter release as well as auditory afferent action potential firing [1-3]. Insect auditory organs are thought to lack efferent control [4-7], but when we inspected mosquito ears, we obtained evidence for its existence...
August 8, 2016: Current Biology: CB
Muhammad Zahid Khan, Waqas Nawaz
Human trace amines (TAs) are endogenous compounds, previously almost ignored in human pathology for many reasons (difficulty of their measurement in biological fluids, unknown receptors for elusive amines), are now considered to play a significant role in synaptic transmission within the central nervous system (CNS) acting as neuromodulators. The recent discovery of a novel family of G-protein-coupled receptors (GPCRs) that includes individual members that are highly specific for TAs indicates a potential role for TAs as vertebrate neurotransmitters or neuromodulators, although the majority of these GPCRs so far have not been demonstrated to be activated by TAs...
July 14, 2016: Biomedicine & Pharmacotherapy, Biomédecine & Pharmacothérapie
Hiroko Awata, Ryo Wakuda, Yoshiyasu Ishimaru, Yuji Matsuoka, Kanta Terao, Satomi Katata, Yukihisa Matsumoto, Yoshitaka Hamanaka, Sumihare Noji, Taro Mito, Makoto Mizunami
Revealing reinforcing mechanisms in associative learning is important for elucidation of brain mechanisms of behavior. In mammals, dopamine neurons are thought to mediate both appetitive and aversive reinforcement signals. Studies using transgenic fruit-flies suggested that dopamine neurons mediate both appetitive and aversive reinforcements, through the Dop1 dopamine receptor, but our studies using octopamine and dopamine receptor antagonists and using Dop1 knockout crickets suggested that octopamine neurons mediate appetitive reinforcement and dopamine neurons mediate aversive reinforcement in associative learning in crickets...
2016: Scientific Reports
Neetha N Vellichirammal, Nandakumar Madayiputhiya, Jennifer A Brisson
Phenotypic plasticity is a key life history strategy used by many plants and animals living in heterogeneous environments. A multitude of studies have investigated the costs and limits of plasticity, as well as the conditions under which it evolves. Much less well understood are the molecular genetic mechanisms that enable an organism to sense its environment and respond in a plastic manner. The pea aphid wing polyphenism is a compelling laboratory model to study these mechanisms. In this polyphenism, environmental stressors like high density cause asexual, viviparous adult female aphids to change the development of their embryos from wingless to winged morphs...
September 2016: Molecular Ecology
Jun Tao, Yi-Cheng Ma, Zhong-Shan Yang, Cheng-Gang Zou, Ke-Qin Zhang
Starvation is probably the most common stressful situation in nature. In vertebrates, elevation of the biogenic amine norepinephrine levels is common during starvation. However, the precise role of norepinephrine in nutrient deprivation remains largely unknown. We report that in the free-living nematode Caenorhabditis elegans, up-regulation of the biosynthesis of octopamine, the invertebrate counterpart of norepinephrine, serves as a mechanism to adapt to starvation. During nutrient deprivation, the nuclear receptor DAF-12, known to sense nutritional cues, up-regulates the expression of tbh-1 that encodes tyramine β-hydroxylase, a key enzyme for octopamine biosynthesis, in the RIC neurons...
May 2016: Science Advances
Md Nazmul Hasan, Mohammad Jakir Hosen, Prasoon Kumar Thakur, Ruhshan Ahmed Abir, Abdullah Zubaer, Guo Renkai, Mayumi Yoshida, Hiroto Ohta, Jae Man Lee, Takahiro Kusakabe, Akinori Hirashima
Biogenic amines are common biologically active substances extended within the whole animal kingdom where they play vital roles as signal transducer as well as regulator of cell functions. One of these biogenic amines called octopamine (OA) is synthesized from tyramine (TA) by the catalysis of tyramine-β-hydroxylase (TβH) originated in the insect nervous system. Both TA and OA act as neurotransmitters, neurohormones and neuromodulators in the arthropod nervous system. Herein, the inhibitory activity of 1-arylimidazole-2(3H)-thiones (AITs) was tested on cloned Drosophila tyramine-β-hydroxylase (DmTβH) expressed in Bombyx mori strain...
June 26, 2016: International Journal of Biological Macromolecules
Heike Sprenger, Christina Kurowsky, Renate Horn, Alexander Erban, Sylvia Seddig, Katharina Rudack, Axel Fischer, Dirk Walther, Ellen Zuther, Karin Köhl, Dirk K Hincha, Joachim Kopka
Systems responses to drought stress of four potato reference cultivars with differential drought tolerance (Solanum tuberosum L.) were investigated by metabolome profiling and RNA-Sequencing. Systems analysis was based on independent field and greenhouse trials. Robust differential drought responses across all cultivars under both conditions comprised changes proline, raffinose, galactinol, arabitol, arabinonic acid, chlorogenic acid, and 102 transcript levels. The encoded genes contained a high proportion of heat shock proteins and proteins with signaling or regulatory functions, e...
June 24, 2016: Plant, Cell & Environment
Carola Städele, Wolfgang Stein
UNLABELLED: Essential to understanding the process of neuronal signal integration is the knowledge of where within a neuron action potentials (APs) are generated. Recent studies support the idea that the precise location where APs are initiated and the properties of spike initiation zones define the cell's information processing capabilities. Notably, the location of spike initiation can be modified homeostatically within neurons to adjust neuronal activity. Here we show that this potential mechanism for neuronal plasticity can also be exploited in a rapid and dynamic fashion...
June 22, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Poojan Pyakurel, Eve Privman Champaloux, B Jill Venton
Octopamine is an endogenous biogenic amine neurotransmitter, neurohormone, and neuromodulator in invertebrates and has functional analogy with norepinephrine in vertebrates. Fast-scan cyclic voltammetry (FSCV) can detect rapid changes in neurotransmitters, but FSCV has not been optimized for octopamine detection in situ. The goal of this study was to characterize octopamine release in the ventral nerve cord of Drosophila larvae for the first time. A FSCV waveform was optimized so that the potential for octopamine oxidation would not be near the switching potential where interferences can occur...
August 17, 2016: ACS Chemical Neuroscience
Kevin W Kastner, Jesús A Izaguirre
Octopamine receptors (OARs) perform key biological functions in invertebrates, making this class of G-protein coupled receptors (GPCRs) worth considering for insecticide development. However, no crystal structures and very little research exists for OARs. Furthermore, GPCRs are large proteins, are suspended in a lipid bilayer, and are activated on the millisecond timescale, all of which make conventional molecular dynamics (MD) simulations infeasible, even if run on large supercomputers. However, accelerated Molecular Dynamics (aMD) simulations can reduce this timescale to even hundreds of nanoseconds, while running the simulations on graphics processing units (GPUs) would enable even small clusters of GPUs to have processing power equivalent to hundreds of CPUs...
October 2016: Proteins
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