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dc.contributor.advisorZars, Troy Danieleng
dc.contributor.authorSitaraman, Divya, 1981-eng
dc.date.issued2010eng
dc.date.submitted2010 Springeng
dc.descriptionTitle from PDF of title page (University of Missouri--Columbia, viewed on October 25, 2010).eng
dc.descriptionThe entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.eng
dc.descriptionDissertation advisor: Dr.Troy Zars.eng
dc.descriptionVita.eng
dc.descriptionIncludes bibliographical references.eng
dc.descriptionPh. D. University of Missouri--Columbia 2010.eng
dc.descriptionDissertations, Academic -- University of Missouri--Columbia -- Biological sciences.eng
dc.description.abstractMemory performance levels can reliably match the intensity / amount/ probability of reinforcement. Interestingly, experience with a reinforcer unpaired from any predictors can enhance or impair later associative learning. We identified and characterized the reinforcement matching and the pre-exposure induced behavior in Drosophila spatial operant learning using high temperature as negative reinforcement. Further we investigated the neural systems influencing matching and pre-exposure effect. Analysis of the white mutant implicates a role for serotonin and dopamine in memory matching. Using genetic and pharmacological manipulations, we found that serotonin but not dopamine plays a critical role in reinforcement matching. The serotonergic system is required for reinforcement processing in the heat box. Our results also show that the serotonergic reinforcement circuit is required for uncertainty bias in the heat box. Furthermore, altering the excitability of serotonergic neurons is sufficient in memory matching and inducing the pre-exposure effect. Another important finding is that the absence of a behavioral predictor is important for the pre-exposure effect and this effect can bias learning in a positive way. Moreover, we also looked at the role of serotonergic signaling in aversive olfactory learning. Unlike the spatial learning where serotonin mediates the aversive reinforcing signal, serotonin enhances the olfactory memory 3 and 6 hrs post training. Finally, serotonin and dopamine seem to have specific functions in two different aversive learning paradigms arguing against common negative reinforcing signals. Octopamine, known to mediate some positive reinforcing signals, seems dispensable for place learning. This either supports the conclusion of the absence of an appetitive component in place learning or the presence of one that is not dependent on octopamine.eng
dc.format.extentviii, 169 pageseng
dc.identifier.oclc727405044eng
dc.identifier.urihttps://hdl.handle.net/10355/10802
dc.identifier.urihttps://doi.org/10.32469/10355/10802eng
dc.languageEnglisheng
dc.publisherUniversity of Missouri--Columbiaeng
dc.relation.ispartofcollectionUniversity of Missouri--Columbia. Graduate School. Theses and Dissertationseng
dc.source.originalSubmitted by University of Missouri--Columbia Graduate School.eng
dc.subject.lcshDrosophilaeng
dc.subject.lcshMemory -- Effect of drugs oneng
dc.subject.lcshMemory -- Physiological aspectseng
dc.subject.lcshLearning -- Effect of drugs oneng
dc.subject.lcshReinforcement learningeng
dc.subject.lcshDopamineeng
dc.subject.lcshSerotonin -- Physiological effecteng
dc.titleReinforcement signaling in Drosophilaeng
dc.typeThesiseng
thesis.degree.disciplineBiological sciences (MU)eng
thesis.degree.grantorUniversity of Missouri--Columbiaeng
thesis.degree.levelDoctoraleng
thesis.degree.namePh. D.eng


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