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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
371

Neurobiological Mechanisms of Mating-Induced Stress-Buffering and Anxiolysis

Unknown Date (has links)
Mating is a socially rewarding experience that yields protective benefits to health, confers resistance to stress, and lowers anxiety-related behaviors in a number of mammalian species, including humans and rodents. These beneficial effects may stem from hormonal and neurobiological changes that not only promote and maintain sexual function but also alleviate stress and anxiety. However, the brain sites and biological mechanisms regulating such effects are poorly understood. Sexual activity increases serum testosterone levels and stimulates gamma-aminobutyric acid (GABA) containing cells, both of which can reduce anxiety and attenuate stress responses of the paraventricular nucleus (PVN) and hypothalamic-pituitary-adrenal (HPA) axis. One brain region that potentially mediates these effects is the medial preoptic area (MPOA) of the hypothalamus, a critical site for male sexual behavior, anti-sympathetic function, and testosterone- and GABA-mediated suppression of the PVN. This dissertation investigates whether steroid sensitive cells in the MPOA and PVN afferents are involved in mating-induced anxiolysis and stress reduction. Here, I report that repeated mating lowers anxiety-like behaviors and corticotrophin-releasing hormone (CRH) expression in the PVN. Sexually experienced males also exhibit lower levels of stress-reactive serum corticosterone and less stress-induced c-Fos immunoreactivity (ir) in hypophysiotrophic neurons that contain CRH, compared to sexually naïve males subjected to stress. Together, this suggests that sexual experience buffers behavioral, physiological, and neuronal responses to stress. Additionally, unilateral intra-MPOA administration of an androgen receptor (AR) antagonist prior to each mating session blocked the suppressive effects of mating on stress-induced c-Fos reactivity in ipsilateral PVN, demonstrating a critical role for ARs in mating-induced stress attenuation. Further, sexually experienced males displayed higher AR expression in the MPOA, as evident from immunohistochemical analysis and western immunoblots. Moreover, dual immunolabeling revealed that AR-ir preoptic cells co-localize with GABA, indicating a potential inhibitory role for androgen-mediated actions in the MPOA. Lastly, to better understand how activity in the MPOA affects functioning in the PVN, a circuit level of analysis was employed. Here, the retrograde neuronal tracer, Fluorgold (FG) was microinfused into the PVN and afferents to the PVN from the MPOA were examined. Retrograde tracing confirmed that PVN afferents emanate from the MPOA. Further, retrograde tracing combined with immunolabeling revealed that a dense population of AR-ir cells in the MPOA express FG, and thus project to the PVN. In addition, a subpopulation of mating-induced c-Fos-ir cells were also co-labeled with FG, indicating that mating stimulates PVN afferents from the MPOA. Collectively, these data demonstrate that repeated mating suppresses stress-responses of the PVN, in part by AR-mediated actions in the MPOA. Further, repeated mating results in higher AR density in the MPOA and the majority of AR-containing preoptic cells project to the PVN. In addition, since AR-containing cells in the MPOA are GABAergic, this may be one means by which repeated mating enhances the inhibitory effects of androgens in the MPOA, perhaps in androgen-sensitive projections to the PVN. These data demonstrate that repeated mating imparts neurobiological and physiological alterations in stress responses systems and an androgen-mediated mechanism in the MPOA regulates mating-induced stress buffering in the PVN. / A Dissertation submitted to the Department of Psychology in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Fall Semester, 2013. / November 5, 2013. / Androgen, Anxiety, Mating, Medial Preoptic Area, Stress / Includes bibliographical references. / Elaine Hull, Professor Directing Dissertation; Thomas Keller, University Representative; Carlos Bolaños, Committee Member; Mohamed Kabbaj, Committee Member; Michael Kaschak, Committee Member.
372

Dopamine Regulation of Paternal Behavior

Unknown Date (has links)
In this Dissertation, we investigate the regulatory role of dopamine (DA) in the nucleus accumbus (NAcc) in male parental care using the socially monogamous and bi-parental prairie vole (Microtus ochrogaster) model. In Chapter 1, along with introducing this animal model, we reviewed several neural mechanisms that have been implicated with social behaviors, such as pair-bonding and parental behavior. Chapter 2 examined the effects of pair-bonding on paternal behaviors. We found that pair-bonded males, in comparison to sexually naïve males, showed higher levels of overall paternal care and pup licking/grooming behavior, and these were associated with DA changes in the NAcc. In Chapter 3, we studied how the NAcc responds to pup exposure/interaction in terms of DA release. We saw that pup exposure/interaction evoked a transient increase of extracellular DA in the NAcc, and this was accompanied by temporal changes in paternal behavior subtypes. In Chapter 4, we pharmacologically manipulated DA receptors in the NAcc, and examined the subsequent effects on paternal behaviors. We demonstrated that NAcc DA receptors regulate paternal care in a receptor- and behavior-specific manner. Finally, in Chapter 5, we provided a summary of our findings and a discussion of their implications, as well as future directions in the study of DA regulation on paternal behavior. / A Dissertation submitted to the Department of Psychology in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Spring Semester, 2014. / March 20, 2014. / Dopamine, Nucleus Accumbens, Pair-Bonding, Paternal Behavior, Prairie Vole / Includes bibliographical references. / Zuoxin Wang, Professor Directing Dissertation; Yanchang Wang, University Representative; Elaine Hull, Committee Member; Michael Meredith, Committee Member; Barbara Licht, Committee Member.
373

Increasing Adherence in Aging Interventions Using Action Video Games by Adding a Social Component: Investigating the Interaction Between Game Type and Multiplayer Game-Play

Unknown Date (has links)
Video game interventions have shown promise for both younger (e.g., Powers et al., 2013) and older populations (e.g., Basak, Boot, Voss, & Kramer, 2008) in improving various cognitive abilities. A recent video game intervention study with older adults (Boot et al., 2013) observed a disparity in adherence between the action video game and the brain-training game groups. The current study sought to increase adherence in future video game intervention studies in this population by investigating older adult video game preferences for game type (competitive or cooperative), as well as playing alone or with a partner. Data from 50 older participants who were randomly assigned to play a cooperative action game (Lego Star Wars: The Complete Saga) or a competitive action game (Mario Kart DS) either alone, or with their spouse or partner is reported. The a priori hypothesis that older adults would play a cooperative game longer than a competitive game was not upheld (F(1, 42) = 0.193, p = 0.663, Partial η2 = .005), and the hypothesis that older adults would report enjoying a cooperative game more than a competitive game was found to be significant opposite the hypothesized direction (F(1, 42) = 9.439, p < 0.004, Partial η2 = 0.187). Playing either game with their spouse/partner was not found to produce any significant difference over playing their game alone in average session enjoyment rating (F(1, 42) = 0.399, p = 0.531, η2 = 0.010), or total time played (F(1, 42) = 2.816, p = 0.101, Partial η2 = 0.064). Recommendations for future gaming intervention studies in older populations are discussed. / A Thesis submitted to the Department of Psychology in partial fulfillment of the requirements for the degree of Master of Arts. / Fall Semester, 2013. / August 20, 2013. / Adherence, Aging, Aging Interventions, Video Games / Includes bibliographical references. / Neil Charness, Professor Directing Thesis; Walter R. Boot, Committee Member; Valerie Shute, Committee Member; Natalie Sachs-Ericsson, Committee Member.
374

Neurobiological Sequelae of Emotional and Physical Stress during Adolescence in Male Mice

Unknown Date (has links)
Early life experiences play a major role in adult onset psychopathology. Childhood maltreatment, whether physical or emotional, is linked to mental illness and behavioral malfunctioning. Individuals who are emotionally, physically, or sexually abused as children have a higher prevalence of major depression, drug abuse, and suicide. Most current animal models are unable to tease apart the potentially distinct effects of emotional versus physical stress, and they focus mainly on stress effects in pre-weanling or adult animals and often overlook adolescence, a critical developmental period. Therefore, the following set of experiments was designed to examine the life-long effects of physical (PS) and emotional (ES) stress using a novel model of stress during adolescence. In this study, adolescent male C57BL/6J mice were divided into three groups: those experiencing social defeat, those forced to witness the social defeat, and no stress controls. Briefly, the home cage of a male CD-1 retired breeder mouse was separated by a Plexiglas divider into two adjacent compartments. An adolescent male C57BL/6J mouse was introduced into the compartment territorialized by the CD-1 mouse where it was repeatedly overpowered (PS), demonstrating escape-like behaviors, vocalizations, and submissive posturing, while a second adolescent male C57BL/6J mouse witnessed (ES) this interaction from the adjacent compartment. Here it is demonstrated that 10 days of PS or ES exposure during adolescence (PD 35-44) induces long-lasting deficits in a battery of behavioral assays designed to assess changes in mood in adulthood. Specifically, exposure to PS or ES increases anxiety- and depression-like behaviors as measured by the elevated plus maze and forced swim test. Interestingly, mice exposed to PS and ES also displayed social avoidance in the social interaction test. Molecular analyses yielded reduced expression of the scaffolding protein shank3 within the ventral tegmental area (VTA), a brain region highly implicated in responses to stress and the etiology of mood disorders, in both ES- and PS-exposed mice. Overexpressing shank3 within the VTA was sufficient to restore control levels of social interaction in both PS- and ES-exposed mice. Together, these data indicate that experiencing traumatic stress, whether physical or emotional, is a potent stressor in adolescent mice capable of inducing life-long behavioral dysregulation, and changes in shank3 expression may mediate some of these effects. / A Dissertation submitted to the Department of Psychology in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Fall Semester, 2013. / October 11, 2013. / Adolescence, Anxiety, Depression, Emotional Stress / Includes bibliographical references. / Carlos A. Bolaños-Guzmán, Professor Directing Dissertation; Branko Stefanovic, University Representative; Zuoxin Wang, Committee Member; Mohamed Kabbaj, Committee Member; Jesse Cougle, Committee Member.
375

Measuring Self-Regulation Depletion and Depletion's Effect on the Consumption of an Alcohol Palcebo

Unknown Date (has links)
The depletion of self-regulation may lead to poorer impulse control and an inability to control actions that may be detrimental to one's livelihood, such as drinking and driving. To date, few studies have examined the impact of self-regulation depletion on drinking. This study aimed to replicate and expand on a study conducted by Muraven et al. (2002), which found that a self-regulation depleted group consumed more alcohol than a control group. However, the current study used an alcohol placebo (as opposed to alcohol itself) to eliminate the confound of alcohol affecting self-regulation. Additionally, electrocardiogram and skin conductance response data were used in an attempt to explore measuring self-regulation depletion physiologically, as few studies have attempted to measure self-regulation in this way. One hundred and eight college students completed a battery of behavioral tests and self-report questionnaires to determine whether the depletion group consumed more of the alcohol placebo than the control group. Participants' physiological responses were also measured to determine whether the depletion of self-regulation could be measured physiologically. Results indicated that both trait self-regulation (β=.04, p=.78) and the depletion of self-regulation (β=-.05, p=.68) had no effect on the consumption of the alcohol placebo. The findings also suggest that individuals in a high self-regulatory depleting activity had increased heart rate (HR; t(104) = 2.43, p = .02) and skin conductance responses (SCR; t(93.42) = 8.31, p< .01). The findings that trait-self-regulation and the depletion of self-regulation had no effect on the consumption of the alcohol placebo were contrary to the hypothesis. They may indicate that self-regulation plays no role in the consumption of alcohol; however, as the study contained limitations, such as the size of the placebo beverage and the inclusion age of the participants, the results must be interpreted with caution. Furthermore, the finding of increased physiological responses to a high self-regulatory depleting activity may be an initial step in developing a psychophysiological measurement of self-regulation depletion. / A Thesis submitted to the Department of Psychology in partial fulfillment of the requirements for the degree of Master of Science. / Spring Semester, 2014. / February 25, 2014. / Alcohol, Depletion, Self-Regulation, Self-Regulation Depletion / Includes bibliographical references. / Jeanette Taylor, Professor Directing Thesis; Ashby Plant, Committee Member; Joyce Carbonell, Committee Member.
376

Want to Stand Out or Blend in?: Cultural Differences in Meeting the Need to Belong

Unknown Date (has links)
The present investigation tested the hypothesis that people with individualistic cultural orientation favor an experience of standing out, whereas those with collectivistic cultural orientation prefer an experience of blending in as a means to meet the need to belong. In Study 1, more often than Koreans, Americans recalled an incident of standing out when they were asked to think about an experience of social acceptance. In contrast, Koreans recalled an experience of blending in more than did Americans. In Study 2, highly independent participants favored a situation in which the self stands out. Those who were highly interdependent, however, preferred a situation in which the self blends into others. In Study 3, regardless of cultural orientations, rejected participants deviated from the cultural defaults more than those in the neutral control condition. Taken together, individualists differed from collectivists in preference for standing out versus blending in as a means to cultivate the sense of social acceptance. However, following recall of intense experience of social exclusion, the cultural differences decreased or even trended toward the opposite direction to those in the neutral condition. / A Dissertation submitted to the Department of Psychology in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Summer Semester, 2014. / July 2, 2014. / Includes bibliographical references. / Roy F. Baumeister, Professor Directing Dissertation; Daekwan Kim, University Representative; Neil Charness, Committee Member; E. Ashby Plant, Committee Member; James K. McNulty, Committee Member.
377

Neurcognitive Function and Dementia in Early versus Late-Onset Depression: Relation to the Glucocorticoid Cascade and Prodrome Hypotheses of Depression and Dementia

Unknown Date (has links)
Depression is associated with subsequent dementia in older adults, and two distinct, but not mutually exclusive, hypotheses have been suggested to account for this relationship. The "glucocorticoid cascade hypothesis" posits depression over the lifespan damages the brain, particularly the hippocampus, increasing risk of Alzheimer's disease (AD). The "prodrome hypothesis" suggests vascular episodes affect underlying neurological processing, giving rise to both late-life, prodromal depressive symptoms and cognitive deficits. Evidence to date does not conclusively support one hypothesis over another. We examined age of depression onset among a sample of clinically depressed patients age 60 and older to better understand the mechanisms of this association. We predicted early-onset depression (EOD; / A Dissertation submitted to the Department of Psychology in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Summer Semester, 2014. / December 4, 2013. / Includes bibliographical references. / Natalie Sachs-Ericsson, Professor Directing Dissertation; Jean Munn, University Representative; Jeanette Taylor, Committee Member; Joyce Carbonell, Committee Member; Mary Gerend, Committee Member; Walter Boot, Committee Member.
378

Effects of Interpretation Bias Modification on Tolerance of Uncertainty and Compulsive Checking Symptom Presentation

Unknown Date (has links)
Research suggests that intolerance of uncertainty (IU) may be a maintaining factor for obsessive-compulsive disorder (OCD). Cognitive models contend that information-processing biases play an etiological role in anxiety. One such bias can occur at the stage of information-processing when stimulus information is interpreted and evaluated, with anxious individuals being more likely to display a threatening interpretation. Interpretation bias modifications (IBMs) seek to alter automatic interpretations and have been shown to lead to reductions in symptoms for anxious populations. IBM as a potential treatment modality may also be more efficiently utilized by addressing transdiagnostic, cognitive factors. The present study investigated the utility of a novel IBM in addressing threatening interpretations of ambiguous situations. Further, the present study proposed that in reducing threatening interpretations of ambiguous situations, the IBM would affect performance during an in vivo checking task as well as symptoms related to IU when uncertainty was induced. A student sample with elevated checking symptoms (N = 64) was recruited. Following completion of a questionnaire battery assessing OC symptoms and IU, participants were randomly assigned to a single-session of positive interpretation training (reducing threat-related biases) or a control training group. Afterwards, bias for interpreting uncertain situations as threatening or safe was measured. Subsequently, participants engaged in a behavioral stove-checking task, during which anxiety and urge to check were measured as well as an uncertainty induction during which state IU and current anxiety were measured. Results indicated that participants in the positive interpretation training condition demonstrated a lower bias in interpreting these situations as threatening, relative to the control condition. The positive training condition led to lower peak anxiety during the checking task and lower current anxiety during the uncertainty induction relative to the control condition. Further, these effects were fully mediated by differences in threat-related interpretation bias. These findings provide initial support for the utility of IBM in addressing symptoms of compulsive checking and IU. / A Thesis submitted to the Department of Psychology in partial fulfillment of the requirements for the degree of Master of Science. / Summer Semester, 2014. / April 15, 2014. / Anxiety, Compulsive checking, Interpretation bias modification, Intolerance of uncertainty / Includes bibliographical references. / Jesse R. Cougle, Professor Directing Thesis; E. Ashby Plant, Committee Member; Norman B. Schmidt, Committee Member.
379

Development and Evaluation of a Computerized Intervention for Low Distress Tolerance and Its Effect on Performance on a Neutralization Task

Unknown Date (has links)
A growing body of research has linked high distress intolerance (DI) to obsessions, but not other OCD symptom domains. However, existing research is correlational and experimental studies are needed before causal determinations can be made. Further, there is little research on domain-general DI interventions. To address these gaps in the literature, a brief, computerized intervention aimed at reducing DI was developed and evaluated relative to a waitlist control in a sample with high DI (N=53). The effects of this intervention on obsession-relevant phenomena were also assessed. Results revealed greater reductions in DI across self-report and behavioral measures in the intervention condition relative to the waitlist condition, as well as lower in-vivo urges to neutralize an intrusive thought; however, anxious reactivity to the intrusion and neutralization behavior were not affected. Further, reductions in DI mediated the effect of the intervention on neutralization urges. These results provide important evidence for the causal role of DI in obsessional phenomena, specifically in urges to neutralize intrusions, findings consistent with negative reinforcement models of DI. Further, results revealed that DI can be reduced with a brief, computerized intervention, which has important treatment and dissemination implications. / A Thesis submitted to the Department of Psychology in partial fulfillment of the requirements for the degree of Master of Science. / Summer Semester, 2014. / June 9, 2014. / Includes bibliographical references. / Jesse R. Cougle, Professor Directing Thesis; Norman B. Schmidt, Committee Member; Ashby E. Plant, Committee Member.
380

The Efficacy of a Mental Health Court in Reducing Recidivism for Individuals with Severe and Persistent Mental Illness and Comorbid Substance Use Disorders

Unknown Date (has links)
The current study examined the efficacy of a specialized mental health court in reducing recidivism for severely mentally ill defendants with comorbid substance use disorders. There is a wealth of research supporting the efficacy of mental health courts in reducing recidivism for those with severe mental illness; however, the benefit of these courts for individuals with severe mental illness and comorbid substance use disorders has received limited empirical attention. A court database of defendants (n=514) who were enrolled in a traditional adversarial court or a specialized mental health court was examined in this study. Recidivism was assessed across different outcome variables: frequency, severity, and length of time to reoffend. When compared to participants in traditional adversarial court, enrollment in mental health court was associated with a greater length of time to rearrest and a reduction in the number of participants who were rearrested. Group differences between those with and without comorbid substance use disorders who were enrolled in the mental health court were not found across recidivism outcome metrics. Limitations and future directions for research are discussed. / A Dissertation submitted to the Department of Psychology in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Summer Semester, 2014. / June 26, 2014. / Mental Health Court, Serious Mental Illness, Substance Use / Includes bibliographical references. / Joyce Carbonell, Professor Directing Dissertation; Marc Gertz, University Representative; Jeanette Taylor, Committee Member; Jesse Cougle, Committee Member.

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