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dc.contributor.advisorRoitman, Mitchell F.en_US
dc.contributor.advisorRagozzino, Michael E.en_US
dc.contributor.authorBrown, Holden D.en_US
dc.date.accessioned2012-12-07T11:45:26Z
dc.date.available2014-04-15T09:30:38Z
dc.date.created2011-08en_US
dc.date.issued2012-12-07
dc.date.submitted2011-08en_US
dc.identifier.urihttp://hdl.handle.net/10027/8914
dc.description.abstractLearning about stimuli that signal the attainment of food and other rewards is critical for survival. Evidence suggests that the midbrain dopamine system plays a critical role in reward learning and goal-directed behavior. Recordings of midbrain dopamine neurons in awake and behaving subjects suggest that phasic dopamine signals are uniformly broadcast throughout terminal regions in response to unpredicted reward or environmental stimuli that predict reward. However, studies sampling dopamine release from the nucleus accumbens during unpredicted reward or predictive stimuli show that phasic dopamine signaling may occur in a more regionally-selective manner. However, there has not been a systematic examination of whether phasic dopamine release from dorsal and ventral striatal subregions occurs uniformly throughout the striatum or in a regional-selective manner. To address this, I measured phasic dopamine release, using fast-scan cyclic voltammetry, in four striatal regions (nucleus accumbens shell and core, dorsomedial and dorsolateral striatum) during electrical stimulation of the ventral midbrain, unpredicted food reward or during a discriminative stimulus paradigm. The results from all experiments indicate that dopamine signaling occurs in a regional-specific manner. Electrical stimulation of the SNpc/VTA evoked dopamine release in all striatal regions but the rate of reuptake was fastest in the dorsolateral striatum and slowest in the nucleus accumbens shell. Unpredicted food reward only evoked phasic dopamine release in the nucleus accumbens core. In the discriminative stimulus task, a cue predictive of reward evoked a phasic dopamine signal in the nucleus accumbens core and dorsomedial striatum. Following performance of the discriminative stimulus task, unpredicted food reward increased phasic dopamine release in both the nucleus accumbens core and the dorsomedial striatum. No condition evoked phasic dopamine release in the nucleus accumbens shell or dorsolateral striatum. These findings provide the first demonstration that phasic stimulation, reward stimuli and reward predictive cues evoke highly compartmentalized changes in phasic dopamine release across multiple striatal regions. This incongruence with electrophysiological recordings may be due to several factors including prior task experience, selection criterion for dopamine neuronal recording, or presynaptic modification of dopamine release. Together, these results suggest distinct roles of phasic dopamine release across striatal subregions.en_US
dc.language.isoenen_US
dc.rightsen_US
dc.rightsCopyright 2011 Holden D. Brownen_US
dc.subjectdopamineen_US
dc.subjectstriatumen_US
dc.subjectnucleus accumbensen_US
dc.subjectrewarden_US
dc.subjectvoltammetryen_US
dc.titleAn examination of phasic dopamine release in distinct striatal subregions during reward-directed behavioren_US
thesis.degree.departmentNeuroscienceen_US
thesis.degree.disciplineNeuroscienceen_US
thesis.degree.grantorUniversity of Illinois at Chicagoen_US
thesis.degree.levelDoctoralen_US
thesis.degree.namePhD, Doctor of Philosophyen_US
dc.type.genrethesisen_US
dc.contributor.committeeMemberRagozzino, Michael E.en_US
dc.contributor.committeeMemberWirtshafter, R. Daviden_US
dc.contributor.committeeMemberCorcos, Daniel M.en_US
dc.contributor.committeeMemberMarinelli, Michaelaen_US
dc.type.materialtexten_US


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