• Login
    View Item 
    •   UMB Digital Archive
    • School, Graduate
    • Theses and Dissertations All Schools
    • View Item
    •   UMB Digital Archive
    • School, Graduate
    • Theses and Dissertations All Schools
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of UMB Digital ArchiveCommunitiesPublication DateAuthorsTitlesSubjectsThis CollectionPublication DateAuthorsTitlesSubjects

    My Account

    LoginRegister

    Statistics

    Display statistics

    Effect of cocaine exposure on estimates of reward value and neurobiological correlates

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    Lucantonio_umaryland_0373D_104 ...
    Size:
    1.360Mb
    Format:
    PDF
    Download
    Author
    Lucantonio, Federica
    Advisor
    Schoenbaum, Geoffrey
    Date
    2013
    Type
    dissertation
    
    Metadata
    Show full item record
    Abstract
    Drug addiction is characterized by an inability to correctly adapt behavior in a changing environment. The orbitofrontal cortex (OFC) is implicated in such adaptive responding by signaling information about expected outcomes. Several studies have shown that this function may be disrupted by drug-induced neuroadaptations in OFC. A recent study has demonstrated that the OFC is also crucial for integrating information to imagine novel outcomes. This ability to signal an outcome never before received is fundamental for interpreting reality and make adaptive decisions in the present, but also for learning when those imagined outcomes are not received to improve decision-making in the future. Here, I explored whether cocaine exposure may alter this function. To address this question, I trained animals to self-administer cocaine, and then tested their performance in a Pavlovian over-expectation task. This task consists of three phases: conditioning, compound training, and extinction testing. In conditioning, rats are trained that several cues predict reward. Subsequently, in compound training, two of the cues are presented together, still followed by the same reward. Typically, this results in increased responding to the compound cue. Subsequent test trials with the cues by themselves reveal a reduction in conditioned responding to the compounded cues. I found that prior cocaine self-administration impaired both the ability of imaging new likely outcomes and learning when those outcomes turned out to be incorrect. These data are consistent with a drug-induced disruption of OFC's role in outcome signaling but might also be explained in other ways. To test the hypothesis more directly, I recorded single unit activity in the OFC of cocaine-experienced rats. Consistent with the hypothesis, OFC signaling in cocaine-exposed animals did not reflect a real-time integration of the cue-evoked expectations for reward, necessary to generate novel estimates about future outcomes. These results are consistent with proposals that cocaine disrupts the normal ability of networks in OFC to signal estimates about future outcomes, normally used for both adjusting current behavior and driving learning. Such deficit results in inflexible behavior and impaired learning and it may account for the complex pattern of maladaptive behaviors associated with drug abuse.
    Description
    University of Maryland, Baltimore. Neuroscience. Ph.D. 2013
    Keyword
    Cocaine
    Decision Making
    Prefrontal Cortex
    Identifier to cite or link to this item
    http://hdl.handle.net/10713/2981
    Collections
    Theses and Dissertations All Schools
    Theses and Dissertations School of Medicine

    entitlement

     
    DSpace software (copyright © 2002 - 2023)  DuraSpace
    Quick Guide | Policies | Contact Us | UMB Health Sciences & Human Services Library
    Open Repository is a service operated by 
    Atmire NV
     

    Export search results

    The export option will allow you to export the current search results of the entered query to a file. Different formats are available for download. To export the items, click on the button corresponding with the preferred download format.

    By default, clicking on the export buttons will result in a download of the allowed maximum amount of items.

    To select a subset of the search results, click "Selective Export" button and make a selection of the items you want to export. The amount of items that can be exported at once is similarly restricted as the full export.

    After making a selection, click one of the export format buttons. The amount of items that will be exported is indicated in the bubble next to export format.