Theses and Dissertations
This collection includes both ASU Theses and Dissertations, submitted by graduate students, and the Barrett, Honors College theses submitted by undergraduate students.
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Description
Monoamine neurotransmitters (e.g., serotonin, norepinephrine, and dopamine) are powerful modulators of mood and cognitive function in health and disease. We have been investigating the modulation of monoamine clearance in select brain regions via organic cation transporters (OCTs), a family of nonselective monoamine transporters. OCTs are thought to complement the actions of selective monoamine transporters in the brain by helping to clear monoamines from the extracellular space; thus, assisting to terminate the monoamine signal. Of particular interest, stress hormones (corticosterone; CORT) inhibit OCT3-mediated transport of monoamine, to putatively lead to prolonged monoamine signaling. It has been demonstrated that stress levels of CORT block OCT3 transport in the rat hypothalamus, an effect that likely underlies the rapid, stress-induced increase in local monoamines. We examined the effect of chronic variable stress (CVS) on the development of mood disorders and OCT3 expression in limbic and hypothalamic regions of the rat brain. Animals subjected to CVS (14-days with random stressor exposure two times/day) showed reduced body weight gain, indicating that CVS was perceived as stressful. However, behavioral tests of anxiety and depressive-like behaviors in rats showed no group differences. Although there were no behavioral effects of stress, molecular analysis revealed that there were stress-related changes in OCT3 protein expression. In situ hybridization data confirmed that OCT3 mRNA is expressed in the hippocampus, amygdala, and hypothalamus. Analysis of Western blot data by two-way ANOVA revealed a significant treatment effect on OCT3 protein levels, with a significant decrease in OCT3 protein in the amygdala and hippocampus in CVS rats, compared to controls. These data suggest an important role for CORT sensitive OCT3 in the reduction of monoamine clearance during stress.
ContributorsBoyll, Piper Savannah (Author) / Orchinik, Miles (Thesis director) / Conrad, Cheryl (Committee member) / Talboom, Joshua (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
The stress response facilitates our ability to deal effectively with threatening situations, but exposure to severe or chronic stressors can lead to undesirable neural, physiological, and behavioral outcomes. Chronic stress is associated with structural changes in the rat hippocampus, with corresponding deficits in learning and memory. Recent studies have uncovered an inherent neuroplasticity that allows the hippocampus to recover from these stress-induced neural changes. Underlying mechanisms likely involve several different cellular and molecular pathways. In order to gain a more comprehensive understanding of these pathways, we investigated differences in protein expression throughout the timeline of chronic stress and recovery. Male Sprague-Dawley rats were randomly assigned to chronic restraint stress for 6hr/d/10d or 6hr/d/21d, stress for 6hr/d/21d followed by a recovery period of no stress for 10 or 21 days, or a control group. The proteome from the hippocampus of these rats was sequenced using liquid chromatography tandem mass spectrometry (LC-MS/MS) and analyzed. We hypothesized that chronic stress alters interneuronal signaling in the hippocampus by enhancing or attenuating the expression of proteins responsible for synaptic plasticity (functional) and neuronal structure (morphology). So far we have found that structural proteins, such as alpha-internexin, homer protein homolog 3, neurofilament light, and vimentin were significantly altered by chronic stress and recovery. In contrast, proteins necessary for or associated with myelination such as 2',3'-cyclic-nucleotide 3'-phosphodiesterase, myelin-associated glycoprotein, myelin basic protein S, and myelin proteolipid protein were significantly downregulated by chronic stress. Collectively, these results will provide a resource for further investigations into the mechanisms of the brain's recovery from chronic stress.
ContributorsKachemov, Marketta Marilyn (Author) / Orchinik, Miles (Thesis director) / Pirrotte, Patrick (Committee member) / Conrad, Cheryl (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
The goal of my study is to test the overarching hypothesis that art therapy is effective because it targets emotional dysregulation that often accompanies significant health stressors. By reducing the salience of illness-related stressors, art therapy may improve overall mood and recovery, particularly in patients with cancer. After consulting the primary literature and review papers to develop psychological and neural mechanisms at work in art therapy, I created a hypothetical experimental procedure to test these hypotheses to explain why art therapy is helpful to patients with chronic illness. Studies found that art therapy stimulates activity of multiple brain regions involved in memory retrieval and the arousal of emotions. I hypothesize that patients with chronic illness have a reduced capacity for emotion regulation, or difficulty recognizing, expressing or altering illness-related emotions (Gross & Barrett, 2011). Further I hypothesize that art therapy improves mood and therapeutic outcomes by acting on the emotion-processing regions of the limbic system, and thereby facilitating the healthy expression of emotion, emotional processing, and reappraisal. More mechanistically, I propose art therapy reduces the perception or salience of stressors by reducing amygdala activity leading to decreased activation of the hypothalamic-pituitary-adrenal (HPA) axis. The art therapy literature and my hypothesis about its mechanisms of action became the basis of my proposed study. To assess the effectiveness of art therapy in alleviating symptoms of chronic disease, I am specifically targeting patients with cancer who exhibit a lack of emotional regulation. Saliva is collected 3 times a week on the day of intervention: morning after waking, afternoon, and evening. Stress levels are tested using one-hour art therapy sessions over the course of 3 months. The Perceived Stress Scale (PSS) assesses an individual's perceived stress and feelings in past and present situations, for the control and intervention group. To measure improvement in overall mood, 10 one-hour art sessions are performed on patients over 10 weeks. A one-hour discussion analyzing the participants' artwork follows each art session. The Spielberger State-Trait Anxiety Inventory (STAI) assesses overall mood for the intervention and control groups. I created rationale and predictions based on the intended results of each experiment.
ContributorsAluri, Bineetha C. (Author) / Orchinik, Miles (Thesis director) / Davis, Mary (Committee member) / Essary, Alison (Committee member) / School of Life Sciences (Contributor) / School for the Science of Health Care Delivery (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
The aim of this study was to determine whether IUD administration, with and without the presence of Levo, and with and without the presence of the ovaries, impacts cognition in a rat model. Rats received either Sham or Ovariectomy (Ovx) surgery (removal of the ovaries), plus either no IUD, a Blank IUD (without Levo), or a Levo-releasing IUD (Levo IUD), enabling us to evaluate the effects of Ovx and the effects of IUD administration on cognition. Two weeks after surgery, all treatment groups were tested on the water radial arm maze, Morris water maze, and visible platform task to evaluate cognition. At sacrifice, upon investigation of the uteri, it was determined that some of the IUDs were no longer present in animals from these groups: Sham\u2014Blank IUD, Ovx\u2014Blank IUD, and Sham\u2014Levo IUD. Results from the remaining three groups showed that compared to Sham animals with no IUDs, Ovx animals with no IUDs had marginally impaired working memory performance, and that Ovx animals with Levo IUDs as compared to Ovx animals with no IUDs had marginally enhanced memory performance, not specific to a particular memory type. Results also showed that Ovx animals with Levo IUDs had qualitatively more cells in their vaginal smears and increased uterine horn weight compared to Ovx animals with no IUDs, suggesting local stimulation of the Levo IUDs to the uterine horns. Overall, these results provide alternative evidence to the hypothesis that the Levo IUD administers Levo in solely a localized manner, and suggests that the possibility for the Levo IUD to affect reproductive cyclicity in ovary-intact animals is not rejected. The potential for the Levo IUD to exert effects on cognition suggests that either the hormone does in fact systemically circulate, or that the Levo IUD administration affects cognition by altering an as yet undetermined hormonal or other feedback between the uterus and the brain.
ContributorsStrouse, Isabel Martha (Author) / Bimonte-Nelson, Heather (Thesis director) / Glenberg, Arthur (Committee member) / Sirianni, Rachael (Committee member) / Conrad, Cheryl (Committee member) / School of Life Sciences (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2018-12
Description
This paper explores the idea of xenophilia and the circumstances under which it may occur. Xenophilia is the preference for an outgroup member over an ingroup member. This preference does not have to be amicable, and in fact can be exploitative under certain circumstances. Previous research indicates that xenophobia is much more common, but a few researchers have found support for the existence of xenophilia. To experimentally test the circumstances under which xenophilia might occur, I conducted a survey-based experiment on Amazon’s Mechanical Turk. This consisted of directed visualizations that manipulated participant goal (self-protection vs. mate acquisition) and the resources offered by both a fictitious outgroup and the hometown ingroup, followed by measures of ingroup/outgroup preference. I hypothesized that when the resource offered by the group addressed the participants’ goal, they would prefer the group with the “matched” resource—even if it was the outgroup providing that resource. My hypothesis was not supported, as the univariate analysis of variance for preference for the outgroup was not significant, F (2, 423) = .723, p = .486. This may have occurred because the goal manipulations were not strong enough to counteract the strong natural preference for ingroup members.
ContributorsDrury, Margaret E. (Author) / Neuberg, Steven (Thesis director) / Davis, Mary (Committee member) / Kenrick, Douglas (Committee member) / Department of Psychology (Contributor) / School of Life Sciences (Contributor) / School of Social and Behavioral Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
A handheld metal cricket noisemaker known as a "clicker" is often used in dog training to teach dogs new behaviors; however, evidence for the superior efficacy of clickers as opposed to providing solely primary reinforcement or other secondary reinforcers in the acquisition of novel behavior in dogs is almost entirely anecdotal. We sought to determine under what circumstances a clicker may result in acquisition of a novel behavior to a higher level when compared to other potential reinforcement methods. In Experiment 1, three groups of 30 dogs each were trained to emit a novel sit and stay behavior with either the delivery of food alone, a verbal marker with food, or a clicker and food. The group that received only a primary reinforcer reached a significantly higher criterion of training than the group trained with a verbal secondary reinforcer. Performance of the group experiencing a clicker secondary reinforcer was intermediate between the other two groups, but not significantly different from either. In Experiment 2, three different groups of 25 dogs each were shaped to emit a nose targeting behavior and then perform that behavior at increasing distances from the experimenter using the same three methods of positive reinforcement used in Experiment 1. No statistically significant differences between the groups were found. Overall, the findings suggest that both clickers and other forms of positive reinforcement can be used successfully in training a dog to perform a novel behavior.
ContributorsGilchrist, Rachel (Author) / Wynne, Clive (Thesis director) / Conrad, Cheryl (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
Estradiol (E2) and Levonorgestrel (Levo) are two hormones commonly used in hormone therapy (HT) to decrease symptoms associated with menopause. Both of these hormones have been shown to have beneficial effects on cognition when given alone in a rodent model of menopause. However, it is unknown whether these hormones, when taken in combination, are beneficial or harmful to cognition. This is a critically important question given that these hormones are most often given in combination versus separately. This thesis is composed of two studies examining the cognitive effects of E2 and Levo using a rat model of surgical menopause. Study 1 assessed how the dose of E2 treatment in rats impacted cognitive performance, and found that low dose E2 enhanced working memory performance. Next, based on the results from Study 1, Study 2 used low dose E2 in combination with different doses of Levo to examine the cognitive effects of several E2 to Levo ratio combinations. The results from Study 2 demonstrated that the combination of low dose E2 with a high dose of Levo at a 1:2 ratio impaired cognition, and that the ratio currently used in HT, 3:1, may also negatively impact cognition. Indeed, there was a dose response effect indicating that working and reference memory performance was incrementally impaired as Levo dose increased. The findings in this thesis suggest that the E2 plus Levo combination is likely not neutral for cognitive function, and prompts further evaluation in menopausal women, as well as drug discovery research to optimize HT using highly controlled preclinical models.
ContributorsBerns-Leone, Claire Elizabeth (Co-author) / Prakapenka, Alesia (Co-author) / Pena, Veronica (Co-author) / Northup-Smith, Steven (Co-author) / Melikian, Ryan (Co-author) / Ladwig, Ducileia (Co-author) / Patel, Shruti (Co-author) / Croft, Corissa (Co-author) / Bimonte-Nelson, Heather (Thesis director) / Glenberg, Arthur (Committee member) / Conrad, Cheryl (Committee member) / School of Life Sciences (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
Cardiovascular disease is the leading cause of death in the United States, and classic risk factors only predict half of the variance of cases. In this study, parental overprotection and temperamental negative affectivity both significantly correlated with blood pressure and heart rate, which suggests the importance of examining early life factors when determining one's risk for CVD.
ContributorsCarter, Steven Cross (Author) / Luecken, Linda (Thesis director) / Presson, Clark (Committee member) / Davis, Mary (Committee member) / Barrett, The Honors College (Contributor) / Department of Psychology (Contributor) / School of Life Sciences (Contributor)
Created2013-05
Description
This paper provides a multidisciplinary analysis of the relationship between beauty and addiction, with a focus on the emerging field of neuroaesthetics. Neuroaesthetics investigates the neural mechanisms that underlie aesthetic experiences and how the brain cognitively processes beauty. Since there is a biological foundation of this report, I will predominantly discuss neuroanatomy, neurological studies, and the overlap in neural circuitry between beauty and addiction. In addition, I will discuss the philosophical roots of beauty, as well as the environmental elements involved. Chapter 1 begins by explaining the history of beauty and its importance. I discuss the main constituents of beauty and differentiate between key terms involved in the beauty experience. In order to understand the link between beauty and addiction, it is essential to have a knowledgeable background on what beauty is. Next, I discuss the neurobiology of addiction. The main component of this chapter involves the mesolimbic and mesocortical reward pathways. I also describe neuroanatomical terms involved in addiction. The last chapter considers the implications of neuroaesthetics in various studies, which primarily involve the use of fMRIs. I discuss the sensory evaluations of beauty and the brain regions involved in the beauty experience. From this, I found that the experience of beauty activates these main brain regions: PFC, amygdala, striatum, NAcc, cingulate, VTA, and most remarkably, field A1 of the mOFC. By combining the neurological studies with studies of aesthetics, I reached the conclusion that there is an overlap in the neural pathways during the experience of beauty and during addiction. Although it is necessary for further research to be conducted to properly declare this, I discovered that the pursuit of beauty can lead to addictive behaviors, as the reward centers of the brain are activated by aesthetic experiences.
ContributorsFarrell, Natalie (Author) / de Alcantara, Christiane Fontinha (Thesis director) / Conrad, Cheryl (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / Department of Marketing (Contributor)
Created2023-05
Description
Hand-coding systems of measuring facial expressions were developed to study and analyze human emotions, but they are time-intensive and thus seldom used. As technology has advanced, new computer software programs, such as Affectiva, were developed to code facial expressions automatically using artificial intelligence and machine learning. Since this technology is still new, Affectiva and its validity remain understudied, and no psychological research has been conducted to compare Affectiva computer coding and hand coding of children’s emotions. The purpose of this study was to compare hand and computer coding of children’s expressions of emotion during a videotaped parent-child interaction. The study answered the following questions: 1) Do hand and computer coding agree?; and 2) Are hand and computer coding in higher agreement for some emotions than others? The sample included 25 pairs of twins from the Arizona Twin Project. Facial expressions were coded from videotape by a trained and reliable human coder and using the software Affectiva. The results showed that hand and computer coded emotion were in agreement for positive, but not negative emotions. Changing the context of the interaction to elicit more negative emotion, and using the same indicators of each emotion in computer and hand coding are suggested to improve the comparison of computer and hand coding.
ContributorsKwok, Connie (Author) / Lemery-Chalfant, Kathryn (Thesis director) / Davis, Mary (Committee member) / Miadich, Samantha (Committee member) / Department of Psychology (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05