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Author (up) Adachi, R.; Wakabayashi, T.; Oda, N.; Shingai, R. file  url
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  Title Modulation of Caenorhabditis elegans chemotaxis by cultivation and assay temperatures Type Journal Article
  Year 2008 Publication Neuroscience Research Abbreviated Journal Neurosci Res  
  Volume 60 Issue 3 Pages 300-306  
  Keywords Ammonium Chloride; Animals; Behavior, Animal/*physiology; Caenorhabditis elegans/*physiology; Chemoreceptor Cells/physiology; Chemotaxis/*physiology; Neurons, Afferent/*physiology; Sodium Acetate; Stimulation, Chemical; *Temperature  
  Abstract The chemotaxis behaviors of the nematode Caenorhabditis elegans cultivated at various temperatures (15 degrees C, 20 degrees C and 25 degrees C) were examined at various temperatures (10 degrees C, 15 degrees C, 20 degrees C and 25 degrees C) to determine the multi-sensory integration of physical (thermal) and chemical sensory information within its nervous system. Chemotaxis behavior toward sodium acetate and ammonium chloride were differently affected by both assay and cultivation temperatures, suggesting that the temperature effect on chemotaxis is not general, but rather distinctive for each chemosensory pathway. Since thermosensory cues are likely encountered constantly in C. elegans, we supposed that the chemotaxis behaviors of worms are achieved by the integration of chemo- and thermosensory information. To verify the possible contribution of thermosensory function in chemotaxis, we examined the chemotaxis behaviors of ttx-1(p767) mutant worms with defective AFD thermosensory neurons. The chemotaxis behaviors toward sodium acetate or ammonium chloride of mutant worms cultivated at 20 degrees C and 25 degrees C were reduced relative to those of wild-type worms. These results indicate the important role of multi-sensory integration of chemosensory and thermosensory information in chemotaxis behavior of the C. elegans.  
  Call Number Serial 1025  
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Author (up) Anderson, J.L.; Albergotti, L.; Proulx, S.; Peden, C.; Huey, R.B.; Phillips, P.C. file  url
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  Title Thermal preference of Caenorhabditis elegans: a null model and empirical tests Type Journal Article
  Year 2007 Publication The Journal of Experimental Biology Abbreviated Journal J Exp Biol  
  Volume 210 Issue Pt 17 Pages 3107-3116  
  Keywords Acclimatization; Animals; Behavior, Animal; Body Temperature Regulation; Caenorhabditis elegans--physiology; Escherichia coli--growth & development; Models, Biological; Temperature  
  Abstract The preferred body temperature of ectotherms is typically inferred from the observed distribution of body temperatures in a laboratory thermal gradient. For very small organisms, however, that observed distribution might misrepresent true thermal preferences. Tiny ectotherms have limited thermal inertia, and so their body temperature and speed of movement will vary with their position along the gradient. In order to separate the direct effects of body temperature on movement from actual preference behaviour on a thermal gradient, we generate a null model (i.e. of non-thermoregulating individuals) of the spatial distribution of ectotherms on a thermal gradient and test the model using parameter values estimated from the movement of nematodes (Caenorhabditis elegans) at fixed temperatures and on a thermal gradient. We show that the standard lab strain N2, which is widely used in thermal gradient studies, avoids high temperature but otherwise does not exhibit a clear thermal preference, whereas the Hawaiian natural isolate CB4856 shows a clear preference for cool temperatures ( approximately 17 degrees C). These differences are not influenced substantially by changes in the starting position of worms in the gradient, the natal temperature of individuals or the presence and physiological state of bacterial food. These results demonstrate the value of an explicit null model of thermal effects and highlight problems in the standard model of C. elegans thermotaxis, showing the value of using natural isolates for tests of complex natural behaviours.  
  Call Number Serial 260  
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Author (up) Ardiel, E.L.; Rankin, C.H. file  url
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  Title C. elegans: social interactions in a “nonsocial” animal Type Journal Article
  Year 2009 Publication Advances in Genetics Abbreviated Journal Adv Genet  
  Volume 68 Issue Pages 1-22  
  Keywords Animals; Behavior, Animal; Caenorhabditis elegans/genetics/*physiology; Caenorhabditis elegans Proteins/genetics; Ecosystem; Female; Genetics, Behavioral; Male; Pheromones/physiology; Social Behavior  
  Abstract As self-fertilizing nematodes, Caenorhabditis elegans do not normally come to mind when one thinks of social animals. However, their reproductive mode is optimized for rapid population growth, and although they do not form structured societies, conspecifics are an important source of sensory input. A pheromone signal underlies multiple complex behaviors, including diapause, male-mating, and aggregation. The use of C. elegans in sociogenetics research allows for the analysis of social interactions at the level of genes, circuits, and behaviors. This chapter describes natural polymorphisms in mab-23, plg-1, npr-1, and glb-5 as they relate to two C. elegans social behaviors: male-mating and aggregation.  
  Call Number Serial 1074  
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Author (up) Bencan, Z.; Sledge, D.; Levin, E.D. file  url
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  Title Buspirone, chlordiazepoxide and diazepam effects in a zebrafish model of anxiety Type Journal Article
  Year 2009 Publication Pharmacology, Biochemistry, and Behavior Abbreviated Journal Pharmacol Biochem Behav  
  Volume 94 Issue 1 Pages 75-80  
  Keywords Animals; Anti-Anxiety Agents/*therapeutic use; Anxiety/*drug therapy; Behavior, Animal/drug effects; Benzodiazepines/administration & dosage/therapeutic use; Buspirone/administration & dosage/*therapeutic use; Chlordiazepoxide/administration & dosage/*therapeutic use; Cholinergic Agents/administration & dosage/therapeutic use; Diazepam/administration & dosage/*therapeutic use; *Disease Models, Animal; Diving; Dose-Response Relationship, Drug; Exploratory Behavior/drug effects; Imaging, Three-Dimensional/methods; Serotonin Agents/administration & dosage/therapeutic use; Stress, Psychological; Time Factors; *Zebrafish  
  Abstract Zebrafish are becoming more widely used to study neurobehavioral pharmacology. We have developed a method to assess novel environment diving behavior of zebrafish as a model of stress response and anxiolytic drug effects. In a novel tank, zebrafish dwell in the bottom of the tank initially and then increase their swimming exploration to higher levels over time. We previously found that nicotine, which has anxiolytic effects in rodents and humans, significantly lessens the novel tank diving response in zebrafish. The specificity of the diving effect was validated with a novel vs. non-novel test tank. The novel tank diving response of zebrafish was tested when given three anxiolytic drugs from two different chemical and pharmacological classes: buspirone, chlordiazepoxide and diazepam. When the test tank was novel the diving response was clearly seen whereas it was significantly reduced when the test tank was not novel. Buspirone, a serotonergic (5HT(1A) receptor agonist) anxiolytic drug with some D(2) dopaminergic effect, had a pronounced anxiolytic-like effect in the zebrafish diving model at doses that did not have sedative effects. In contrast, chlordiazepoxide, a benzodiazepine anxiolytic drug, which is an effective agonist at GABA-A receptors, did not produce signs of anxiolysis in zebrafish over a broad dose range up to those that caused sedation. Diazepam another benzodiazepine anxiolytic drug did produce an anxiolytic effect at doses that did not cause sedation. The zebrafish novel tank diving task can be useful in discriminating anxiolytic drugs of several classes (serotonergic, benzodiazepines and nicotinic).  
  Call Number Serial 209  
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Author (up) Biron, D.; Shibuya, M.; Gabel, C.; Wasserman, S.M.; Clark, D.A.; Brown, A.; Sengupta, P.; Samuel, A.D.T. file  url
openurl 
  Title A diacylglycerol kinase modulates long-term thermotactic behavioral plasticity in C. elegans Type Journal Article
  Year 2006 Publication Nature Neuroscience Abbreviated Journal Nat Neurosci  
  Volume 9 Issue 12 Pages 1499-1505  
  Keywords Animals; Association Learning/physiology; Behavior, Animal/*physiology; Body Temperature Regulation/physiology; Caenorhabditis elegans/*enzymology/genetics; Caenorhabditis elegans Proteins/genetics/*metabolism; Diacylglycerol Kinase/genetics/*metabolism; Gene Expression Profiling; Mutation; Neurons/enzymology; Thermosensing/*physiology  
  Abstract A memory of prior thermal experience governs Caenorhabditis elegans thermotactic behavior. On a spatial thermal gradient, C. elegans tracks isotherms near a remembered temperature we call the thermotactic set-point (T(S)). The T(S) corresponds to the previous cultivation temperature and can be reset by sustained exposure to a new temperature. The mechanisms underlying this behavioral plasticity are unknown, partly because sensory and experience-dependent components of thermotactic behavior have been difficult to separate. Using newly developed quantitative behavioral analyses, we demonstrate that the T(S) represents a weighted average of a worm's temperature history. We identify the DGK-3 diacylglycerol kinase as a thermal memory molecule that regulates the rate of T(S) resetting by modulating the temperature range of synaptic output, but not temperature sensitivity, of the AFD thermosensory neurons. These results provide the first mechanistic insight into the basis of experience-dependent plasticity in this complex behavior.  
  Call Number Serial 1679  
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