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Full-Text Articles in Neuroscience and Neurobiology

Putting 'Dopamine Overdose' To The Test: A Psychopharmacological Investigation In Parkinson's Disease And Healthy Volunteers, Andrew Vo Jan 2020

Putting 'Dopamine Overdose' To The Test: A Psychopharmacological Investigation In Parkinson's Disease And Healthy Volunteers, Andrew Vo

Electronic Thesis and Dissertation Repository

Dopaminergic therapy prescribed to address motor symptoms in Parkinson’s disease (PD) is done at the expense of some cognition functions. It has been hypothesized that whether a given function is improved or impaired by medication depends on the baseline dopamine levels within underlying brain regions. Areas most affected by PD and severely dopamine depleted are predicted to benefit from dopaminergic therapy. Regions with less dopamine deficiency are predicted to worsen from excessive dopamine stimulation. This theoretical framework is known as the dopamine overdose hypothesis. The central aim of this thesis was to critically test the straightforward predictions put forward by …


In Search Of Psychiatric Kinds: Natural Kinds And Natural Classification In Psychiatry, Nicholas Slothouber Oct 2019

In Search Of Psychiatric Kinds: Natural Kinds And Natural Classification In Psychiatry, Nicholas Slothouber

Electronic Thesis and Dissertation Repository

In recent years both philosophers and scientists have asked whether or not our current kinds of mental disorder—e.g., schizophrenia, depression, bipolar disorder—are natural kinds; and, moreover, whether or not the search for natural kinds of mental disorder is a realistic desideratum for psychiatry. In this dissertation I clarify the sense in which a kind can be said to be “natural” or “real” and argue that, despite a few notable exceptions, kinds of mental disorder cannot be considered natural kinds. Furthermore, I contend that psychopathological phenomena do not cluster together into kinds in the way that paradigmatic natural kinds (e.g., chemical …


Investigating How Neural Entrainment Relates To Beat Perception By Disentangling The Stimulus-Driven Response, Aaron Wc Gibbings Jul 2019

Investigating How Neural Entrainment Relates To Beat Perception By Disentangling The Stimulus-Driven Response, Aaron Wc Gibbings

Electronic Thesis and Dissertation Repository

Beat perception – the ability to perceive a steady pulse in music – is nearly ubiquitous in humans, but the neural mechanisms underlying this ability are unknown. A growing number of electroencephalography (EEG) studies suggest that beat perception is related to neural entrainment, a phenomenon in which cyclic changes in the excitability of populations of neurons synchronize with a rhythmic stimulus. However, the relationship between acoustically-driven and entrainment-driven neural activity is unclear. This thesis presents EEG research that extends our understanding neural entrainment is related to beat perception by characterizing, equating, and finally removing the stimulus-driven response in the neural …


The Neural Mechanisms Underlying The Perception And Production Of Learned Vocalizations In Songbirds, Shannon Katie Mischler Oct 2017

The Neural Mechanisms Underlying The Perception And Production Of Learned Vocalizations In Songbirds, Shannon Katie Mischler

Electronic Thesis and Dissertation Repository

Songbirds produce a wide array of vocalizations, including song, and learned and innate calls. Songs and calls can be functionally defined. Songs are typically used to attract potential mates and defend one’s territory, whereas calls are used for everything else, such as advertising the presence of a predator, or location of a food source, and maintaining contact with members of one’s flock. The purpose of this thesis was to better understand the neural mechanisms underlying call production and perception in two songbird species; the black-capped chickadee (Poecile atricapillus) and the zebra finch (Taeniopygia guttata). My objectives …


A Diffusion Tensor Imaging Study Of Motor Fibre Path Integrity And Overt Responsiveness In Disorders Of Consciousness, Clara A. Stafford Aug 2017

A Diffusion Tensor Imaging Study Of Motor Fibre Path Integrity And Overt Responsiveness In Disorders Of Consciousness, Clara A. Stafford

Electronic Thesis and Dissertation Repository

This study investigated the relationship between motor thalamo-cortico-cerebellar fibre path integrity and overt responsiveness in patients with disorders of consciousness (DOC). Additionally, we investigated the potential of imaging these motor tracts at ultra-high fields. Study I and II aimed to map the white matter connections of motor execution fibres in DOC patients. Our results showed significant reductions in motor fibre path integrity across DOC diagnostic categories. Study III and IV aimed to develop a 7T MRI Diffusion Tensor Imaging (DTI) sequence. We optimized this sequence to image motor fibre paths in DOC patients. We concluded that, in healthy controls, probabilistic …


The Influence Of Estrogen On Sex Differences In Chemotherapy-Induced Nausea And Vomiting (Cinv), Danna L. Zevy Apr 2017

The Influence Of Estrogen On Sex Differences In Chemotherapy-Induced Nausea And Vomiting (Cinv), Danna L. Zevy

Electronic Thesis and Dissertation Repository

Chemotherapy-induced nausea and vomiting (CINV) is one of the most distressing events that affects the quality of life of cancer patients. Evidence suggests that females are more susceptible to CINV than males, but the mechanism remains unknown. The current thesis examined whether higher levels of circulating estrogens in females contributes to this sex difference. CINV was analyzed in a pediatric oncology population, where it was revealed female patients demonstrate increased delayed CINV relative to male patients, in the post-pubertal age group. CINV was also studied by examining the influence of the estrous cycle on anticipatory nausea (AN) in rats. This …


Neural And Behavioural Responses To Rewards And Losses In Early Development: A Functional Magnetic Resonance Imaging Study, Niki Hosseini-Kamkar Sep 2015

Neural And Behavioural Responses To Rewards And Losses In Early Development: A Functional Magnetic Resonance Imaging Study, Niki Hosseini-Kamkar

Electronic Thesis and Dissertation Repository

Functional magnetic resonance imaging (fMRI) was used to investigate the neural and behavioural correlates of learning from rewards and losses in children. Greater blood-oxygen-level dependent (BOLD) responses in the ventral striatum (VS) and the ventromedial prefrontal cortex (VMPFC) were found when participants received rewards compared to when they missed out on an opportunity to receive rewards. In contrast, greater BOLD responses in the anterior insula (AI) and the anterior cingulate cortex (ACC) were found when participants received losses compared to when they avoided losing. The BOLD response to rewards in the VS and VMPFC correlated positively with the tendency to …


Associations Between Hypothalamic-Pituitary-Adrenal Axis System Gene Variants And Cortisol Reactivity In Preschoolers: Main Effects And Gene-Environment Interactions, Haroon I. Sheikh Jun 2014

Associations Between Hypothalamic-Pituitary-Adrenal Axis System Gene Variants And Cortisol Reactivity In Preschoolers: Main Effects And Gene-Environment Interactions, Haroon I. Sheikh

Electronic Thesis and Dissertation Repository

Exposure to stressful events during early development has consistently been shown to produce long lasting effects on the hypothalamic-pituitary-adrenal (HPA) axis, which may increase vulnerability to mood and anxiety disorders. Recently reported genetic association studies indicate that these disorders may be influenced, in part, by gene-environment interactions (GxE) involving polymorphisms within the corticotrophin-releasing hormone and monoaminergic system genes. However, little is known about how genetic variants and life stress work to shape children’s neuroendocrine reactivity and emerging symptoms. Therefore, the aim of this thesis is to examine main effects of candidate genes and GxE on the neuroendocrine stress response and …


Fmri Reveals The Neural Correlates Of Real And Pantomimed Tool Use In Humans, Joseph Umberto Paciocco Aug 2012

Fmri Reveals The Neural Correlates Of Real And Pantomimed Tool Use In Humans, Joseph Umberto Paciocco

Electronic Thesis and Dissertation Repository

Although functional magnetic resonance imaging (fMRI) can be used to study the neural mechanisms underlying greatly expanded cognitive functions in humans like tool use, surprisingly little fMRI research has been done on actual tool use. In fact, due to technical constraints, most fMRI studies have used pantomimed actions as a proxy for real use. However, human neuropsychology patients who are impaired at pantomiming often improve when handling a tool suggesting potential neural differences. We used fMRI to record brain activation while 13 right-handed participants performed one of two tasks, real or pantomime tool use with one of two tools, a …