Reward and Anxiety: From Rodent Post-Traumatic Stress to Human Psychosocial Stress

Persistent Link:
http://hdl.handle.net/10150/222616
Title:
Reward and Anxiety: From Rodent Post-Traumatic Stress to Human Psychosocial Stress
Author:
Corral Frias, Nadia Sarai
Issue Date:
2012
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Posttraumatic stress disorder (PTSD) is a chronic disabling condition that results from exposure to traumatic stress. However, although trauma is fairly common, PTSD will only occur in a small proportion of people. This suggests that resilience is a common response to trauma. The neurobiology underlying this adaptive response is thought to involve reward related areas as well as reward functions. This dissertation proposes that reward and reward-related areas have a role in anxiety disorders such as PTSD. This hypothesis was explored using an animal model of PTSD as well as a human mode of psychosical stress. The hypothesis that the ventral tegmental area (VTA), crucial for reward processing, is part of the neural circuitry involved in the symptomatology of PTSD was explored. To assess the role of VTA in PTSD, cells in this area were reversibly inactivated during a single exposure to inescapable foot-shock in a rodent model. Animals that underwent inactivation of VTA neurons decreased avoidance and lowered long-term anxiety-like behaviors in comparison with control groups. To assess short- and long-term electrophysiological effects of trauma on VTA cells, in vivo extracellular recordings were conducted. Results showed that the firing frequency of VTA cells changed both in the short- and long-term, following shock procedures. A human model of psychosical stress was used to test the hypothesis that the ability to respond appropriately to positive stimuli is important for the preservation of positive emotions following stressful events. The results show a positive correlation between trait resilience and trait reward sensitivity. To investigate the link between resilience and reward sensitivity further, the empirical portion of this study used a Monetary Incentive Delay Task (MID) to measure reward sensitivity before and after exposure to a psychosocial stressor. Moreover, behavioral reward sensitivity (as measured by MID and self-report satisfaction after the reward task) also correlated positively with trait and behaviorally measured resilience. The results shown in this dissertation suggest that the neural circuits involved in reward processing and reward function may be involved in resilient responses to stress.
Type:
text; Electronic Dissertation
Keywords:
Electrophysiolgy; Peripheral psychophysiology; Resilience; Reward; Neuroscience; Anxiety; Dopamine
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Neuroscience
Degree Grantor:
University of Arizona
Advisor:
Fellous, Jean-Marc

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleReward and Anxiety: From Rodent Post-Traumatic Stress to Human Psychosocial Stressen_US
dc.creatorCorral Frias, Nadia Saraien_US
dc.contributor.authorCorral Frias, Nadia Saraien_US
dc.date.issued2012-
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractPosttraumatic stress disorder (PTSD) is a chronic disabling condition that results from exposure to traumatic stress. However, although trauma is fairly common, PTSD will only occur in a small proportion of people. This suggests that resilience is a common response to trauma. The neurobiology underlying this adaptive response is thought to involve reward related areas as well as reward functions. This dissertation proposes that reward and reward-related areas have a role in anxiety disorders such as PTSD. This hypothesis was explored using an animal model of PTSD as well as a human mode of psychosical stress. The hypothesis that the ventral tegmental area (VTA), crucial for reward processing, is part of the neural circuitry involved in the symptomatology of PTSD was explored. To assess the role of VTA in PTSD, cells in this area were reversibly inactivated during a single exposure to inescapable foot-shock in a rodent model. Animals that underwent inactivation of VTA neurons decreased avoidance and lowered long-term anxiety-like behaviors in comparison with control groups. To assess short- and long-term electrophysiological effects of trauma on VTA cells, in vivo extracellular recordings were conducted. Results showed that the firing frequency of VTA cells changed both in the short- and long-term, following shock procedures. A human model of psychosical stress was used to test the hypothesis that the ability to respond appropriately to positive stimuli is important for the preservation of positive emotions following stressful events. The results show a positive correlation between trait resilience and trait reward sensitivity. To investigate the link between resilience and reward sensitivity further, the empirical portion of this study used a Monetary Incentive Delay Task (MID) to measure reward sensitivity before and after exposure to a psychosocial stressor. Moreover, behavioral reward sensitivity (as measured by MID and self-report satisfaction after the reward task) also correlated positively with trait and behaviorally measured resilience. The results shown in this dissertation suggest that the neural circuits involved in reward processing and reward function may be involved in resilient responses to stress.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectElectrophysiolgyen_US
dc.subjectPeripheral psychophysiologyen_US
dc.subjectResilienceen_US
dc.subjectRewarden_US
dc.subjectNeuroscienceen_US
dc.subjectAnxietyen_US
dc.subjectDopamineen_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineNeuroscienceen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorFellous, Jean-Marcen_US
dc.contributor.committeememberFrench, Edward D.en_US
dc.contributor.committeememberJacobs, William J.en_US
dc.contributor.committeememberNadel, Lynnen_US
dc.contributor.committeememberNighorn, Alan J.en_US
dc.contributor.committeememberFellous, Jean-Marcen_US
All Items in UA Campus Repository are protected by copyright, with all rights reserved, unless otherwise indicated.