Optogenetic Inhibition of the mPFC During Delay Discounting

dc.contributor.advisorLapish, Christopher
dc.contributor.authorWhite, Shelby M.
dc.contributor.otherLogrip, Marian
dc.contributor.otherCzachowski, Cristine
dc.date.accessioned2019-04-24T12:09:59Z
dc.date.available2019-04-24T12:09:59Z
dc.date.issued2019-05
dc.degree.date2019en_US
dc.degree.disciplinePsychologyen
dc.degree.grantorPurdue Universityen_US
dc.degree.levelM.S.en_US
dc.descriptionIndiana University-Purdue University Indianapolis (IUPUI)en_US
dc.description.abstractImpulsivity, or the tendency to act prematurely without foresight, has been linked to a diverse range of pathological conditions. Foresight refers to the ability to envision future rewards and events (i.e. prospectively sample) and has been associated with decreased impulsivity. One form of impulsivity is measured by the ability to delay gratification and is often studied in the framework of Delay Discounting (DD). DD provides the means to study impulsivity in a number of pathological conditions. However, whether impulsivity precedes the development of pathological states or results from the pathological state itself is not fully understood. This necessitates an understanding of neurobiological mechanisms contributing to decision making in both non-impulsive as well as impulsive populations of individuals. Animal models allow invasive techniques to be used to dissect the neurocircuitry involved in decision making. Given that the decision-making process is an ongoing process rather than an isolated event, optogenetics provide the temporal and spatial specificity necessary for evaluating brain region specific contributions to decision making in DD. In the present study, optogenetics were used to assess the contribution of the medial Prefrontal Cortex (mPFC), a brain region involved in ‘goal-directed’ behavior, in the planning of future choices (i.e. prospective plans) and subsequent measures of impulsivity in an adjusting amount DD procedure. Optogenetic inhibition of mPFC was conducted in Wistar rats during different epochs of a DD task in order to assess how mPFC affects planning behavior in a population of rat not considered to be highly impulsive. Although no direct effects on planning behavior (e.g. consistency) were observed, inhibiting mPFC after a trial has been initiated and directly before a choice was made (Epoch 2) was observed to increase measures of impulsivity in comparison to days where no optogenetic manipulation occurred in a delay-specific manner. This suggests that mPFC differentially contributes to decision making at different delays. A pattern of associations between choice latency, impulsivity, and consistency began to emerge for inactivation occurring in Epoch 2, suggesting that mPFC contributes to some aspect of planning choices during this epoch. Moreover, these results indicate that mPFC is involved in decision making in Wistar Rats. Understanding the direct role that mPFC plays in promoting choices of delayed rewards provides a neurobiological target for treatment aimed at reducing impulsivity in the clinical population.en_US
dc.identifier.urihttps://hdl.handle.net/1805/18932
dc.identifier.urihttp://dx.doi.org/10.7912/C2/1070
dc.subjectArchTen_US
dc.subjectmPFCen_US
dc.subjectDelay Discountingen_US
dc.subjectImpulsive Choiceen_US
dc.subjectIntertemporal Choiceen_US
dc.subjectWistaren_US
dc.subjectImpulsivityen_US
dc.subjectStrategyen_US
dc.subjectProspectionen_US
dc.subjectEpoch-specificen_US
dc.subjectDecision Makingen_US
dc.subjectOptogeneticsen_US
dc.titleOptogenetic Inhibition of the mPFC During Delay Discountingen_US
dc.typeThesisen
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