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Start Over Subject Psychophysiology Thesis Degree Master of Science (M.Sc.) Thesis Degree Discipline Neuroscience

  • 1. Exploring the Neuroplastic and Antidepressant-Like Effects of Erythropoietin

    Resource Type:
    Thesis
    Creator:
    Constable, Jonathan Robert M.
    Abstract:
    A growing body of evidence implies that depression may arise in part through a deregulation of neuroplasticity, and novel antidepressants have shown therapeutic potential by exerting neurogenic and neuroplastic effects. The hematopoietic cytokine erythropoietin (EPO) has shown antidepressant potential with an ability to regulate neuroplastic and cognitive-behavioral outcomes. This research sought to further the knowledge of the antidepressant potential of EPO through cellular and behavioral outcomes. In Exp 1, effects of 2 week EPO administration on chronically stressed rodents (an animal model of depression) was observed by the forced swim test (FST) and doublecortin immunohistochemistry for immature granule cells. In Exp. 2, whether acute EPO administration has the potential to synergize with an SSRI was analyzed using the FST. This research showed no effect of EPO on cellular or behavioral outcomes, suggesting a necessity for further studies of this paradigm utilizing alternative models or methods to those used here.
    Thesis Degree:
    Master of Science (M.Sc.)
    Thesis Degree Discipline:
    Neuroscience
    Date Created:
    2015

  • 2. Role of Genetics and Social Connectedness on Resilience: A Comparison Between Varsity Athletes and Non-Athletes

    Resource Type:
    Thesis
    Creator:
    Coates, Samantha
    Abstract:
    Resilience generally refers to an individual’s ability to overcome illness or to cope with trauma or adversity. There appears to be great variability in this regard, possibly being attributable to life events, social designations, personality traits and genetic factors. The present study was to examined the relationship between early life trauma, social connectedness and psychological well-being and to investigate the role of a NPY polymorphism (rs16147) among varsity athletes. Carleton University varsity athletes and non-varsity athlete students (N= 284) completed questionnaires and provided saliva samples for genotyping. It was found that there was a relationship between early life trauma and diminished psychological well-being which was mediated by social connectedness, which was then further moderated by NPY genotypes and athletic condition. These findings suggest that among individuals that had experienced trauma, the GG genotype might be linked to resilience and higher levels of well-being, in a highly social environmental.
    Thesis Degree:
    Master of Science (M.Sc.)
    Thesis Degree Discipline:
    Neuroscience
    Date Created:
    2016

  • 3. Cognitive, Experiential and Genetic Contribution to Depressive Symptoms in Male and Female Students with a History of Concussion

    Resource Type:
    Thesis
    Creator:
    Dixon, Kaylyn Ann
    Abstract:
    Concussions are generally accompanied by a variety of somatic, cognitive and affective symptoms, including depressive-like symptoms. Although for most individuals, the affective symptoms are relatively transient, for others these symptoms can persist for extended periods of time. The purpose of the present study was to examine several cognitive, genetic, and experiential factors which might be associated with depressive pathology among males and females with and without a history of concussion. Male and female university students with a history of concussions and a control group of “never-concussed” individuals completed the Wisconsin Card Sorting Task to assess executive function as well as several questionnaires assessing cognitive vulnerabilities to depression, early life adversity, and depressive symptomatology. Participants also provided a saliva sample for DNA analysis. The present findings provide further insight into several factors that might contribute to vulnerability to long-lasting depressive pathology following a concussion and the significance of gender.
    Thesis Degree:
    Master of Science (M.Sc.)
    Thesis Degree Discipline:
    Neuroscience
    Date Created:
    2016

  • 4. Stranger Danger! The Role of Ghrelin in Modulation of Social Behavior

    Resource Type:
    Thesis
    Creator:
    Park, Su-Bin
    Abstract:
    Ghrelin, a gut-derived peptide, is associated with feeding, energy balance, reward and the stress response. Among many of its functions, the role of ghrelin in anxiety has been particularly controversial. Here, we demonstrated that increasing ghrelin receptor activity (particularly in the VTA) in mice has anxiolytic effects in tests involving stimuli with positive incentive value (i.e. palatable food or social opportunity). A role for ghrelin in social anxiety is intriguing because social anxiety is a common symptom of depression. Thus, we explored the possibility whether treatment with ghrelin agonist GHRP6 alone of in combination with SSRI citalopram could prevent and/or alleviate stress-induced social anxiety. We found that peripheral GHRP6 treatment was not sufficient to prevent/treat stress-induced social anxiety. Interestingly, post stress GHRP6 and GHRP6+citalopram treatment reduced weight gain, a common side effect of antidepressant treatment. Thus, our finding that GHRP6 can reduce these metabolic side effects has potential therapeutic potential.
    Thesis Degree:
    Master of Science (M.Sc.)
    Thesis Degree Discipline:
    Neuroscience
    Date Created:
    2017

  • 5. Investigating the Associations Between Brain Network Functional Connectivity and Health-Related Quality of Life Following a Pediatric Concussion

    Resource Type:
    Thesis
    Creator:
    Healey, Katherine
    Abstract:
    Concussions negatively affect adolescent health-related quality of life (HRQoL) for months post-injury. Functional connectivity (FC) within and between the default mode network (DMN), central executive network (CEN), and salience network (SN) has shown alterations post-concussion. The present study explored whether FC differs between concussion and orthopedic injury (OI) groups aged 10-18 and if associations exist between FC and HRQoL 4-weeks post-concussion. Resting-state functional MRI (rs-fMRI) and HRQoL measurements were completed 4-weeks post-injury. One-way ANCOVA analyses were conducted between groups with network FC. Multivariate linear regressions assessed associations between connectivity and HRQoL. A total of 55/72 concussion and 27/30 OI participants were included. FC was increased within the CEN and SN, between the DMN-SN and CEN-SN, and decreased between the DMN-CEN in the concussion group. No significant associations were found between HRQoL and FC. Differential connectivity patterns exist 4-weeks following pediatric concussion, however, they are not associated with HRQoL.
    Thesis Degree:
    Master of Science (M.Sc.)
    Thesis Degree Discipline:
    Neuroscience
    Date Created:
    2021

  • 6. Examining Neuroendocrine and Inflammatory Biomarker Profiles to Characterize PTSD Subtypes and Symptom Profiles.

    Resource Type:
    Thesis
    Creator:
    Jarkas, Dana Abdulaziz
    Abstract:
    Post-traumatic stress disorder (PTSD) is a multifaceted mental health disorder characterized by diverse clinical and biological profiles. Participants in the current study comprised individuals with PTSD who had military experience and healthy controls. All participants completed questionnaires assessing mental health symptoms and provided saliva and blood samples for cortisol and inflammatory marker determination. The dissociative PTSD group displayed the highest symptom severity, reflecting a high degree of comorbidity, in addition to elevated traumatic life encounters, including experiences of childhood abuse. Individuals with dissociative PTSD had elevated nighttime cortisol, whereas the non-dissociative PTSD group did not differ from controls, while both PTSD groups showed elevated cortisol awakening response. Inflammatory levels were associated with clinical symptomatology and childhood traumatic experiences. This suggests that PTSD subtypes may be differentiated on a clinical and neurobiological level. Further delineation of the biological underpinnings of these subtypes can inform personalized treatment strategies for individuals with PTSD.
    Thesis Degree:
    Master of Science (M.Sc.)
    Thesis Degree Discipline:
    Neuroscience
    Date Created:
    2022

  • 7. Sex Differences in the Antidepressant Effects of Ketamine

    Resource Type:
    Thesis
    Creator:
    Myers, Mysa Arrey
    Abstract:
    Major depressive disorder (MDD) is a disabling mental disorder characterized by negative mood and suicidality. The NMDA antagonist ketamine has been found to reduce depressive symptoms and suicidal thoughts in patients unresponsive to first-line antidepressants, but ketamine’s mechanism of action remains unclear. More women are diagnosed with MDD than men and present with greater suicidal ideation, but it is unclear if there are sex-dependent responses to ketamine. It was recently determined that activating mRNA translation via phosphorylation of the eukaryotic initiation factor 4E binding proteins (4E-BPs) is a crucial mechanism of ketamine’s antidepressant effect in non-stressed male mice. The aim is to understand if stressed females also engage this mechanism following ketamine treatment. After investigating whether 4E-BP1 and 4E-BP2 are relevant to ketamine’s antidepressant mechanisms of action in female mice, the present study’s findings are inconclusive, as ketamine had no effect on several chronic variable stress-induced behaviors in tested mice.
    Thesis Degree:
    Master of Science (M.Sc.)
    Thesis Degree Discipline:
    Neuroscience
    Date Created:
    2023