Psychology Commons^™

Characterizing The Cognitive And Emotional Effects Of Delta-9-Tetrahydrocannabinol In Distinct Hippocampal Sub-Regions, Dinat Khan

Electronic Thesis and Dissertation Repository

The objective of this study is to determine the potential differential effects of THC in the DH or VH sub-regions, as well as the upstream effects on PFC neuronal activity and oscillations. Rodents used for electrophysiology were infused with THC or vehicle in the DH or VH regions, combined with PFC recordings. Additionally, a battery of behavioural paradigms was performed. Deficits in short-term memory when THC was infused into both regions was observed, however working memory was impaired with VH infusions only. This could be due to THC-induced dysregulation in the PFC, as beta oscillations were significantly decreased selectively in …

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 …

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

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

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 …

Exploring The Neural Basis Of Top-Down Guided Action In Macaque Monkeys, Jessica M. Phillips

Electronic Thesis and Dissertation Repository

To thoroughly characterize any brain mechanism requires an appropriate animal model for invasive studies. An invaluable model system used toward a comprehension of cognitive neurophysiology is the macaque monkey. It is important to delineate similarities and limitations for this model in relation to the human brain and cognition. In this thesis, we have thus conducted three experiments to investigate putative generalizations between monkeys and humans regarding the neural processes associated with top-down action control in monkeys.

Our daily behaviour is largely comprised of automatic routine actions. The frequent repetition of certain behaviours in response to particular contexts can give rise …

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 …