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Full-Text Articles in Medicine and Health Sciences

Mri Investigations Of Metabolic And Structural Brain Changes In Alzheimer’S Disease And Vitamin D Deprivation, Dickson Wong Sep 2019

Mri Investigations Of Metabolic And Structural Brain Changes In Alzheimer’S Disease And Vitamin D Deprivation, Dickson Wong

Electronic Thesis and Dissertation Repository

Alzheimer's disease (AD) is a neurodegenerative disorder of the brain that presents as progressive impairment across several cognitive domains. The biological mechanisms underlying the development of AD remain unclear, with amyloid-beta plaques, neurofibrillary tangles, calcium dysregulation, and oxidative stress all contributing to neurodegeneration in AD. Vitamin D (VitD) deficiency, a common condition in the elderly, may modulate these mechanisms and complicate the AD process. Due to this complicated pathogenesis, the diagnosis of AD requires subjective clinical judgement, staging of AD is challenging, and it remains difficult to predict when and who will progress to AD. The purpose of this thesis …


Identifying Neuroimaging And Genetic Correlates Of Delusions And Hallucinations In Alzheimer’S Disease, Juweiriya Ahmed May 2019

Identifying Neuroimaging And Genetic Correlates Of Delusions And Hallucinations In Alzheimer’S Disease, Juweiriya Ahmed

Electronic Thesis and Dissertation Repository

The co-occurrence of psychotic symptoms and Alzheimer’s disease (AD) is a devastating phenotype that affects around 50% of individuals with AD. We hypothesized that distinct interactions between brain structures and genetic variants in dopaminergic, cholinergic and glutamatergic neurotransmitter systems may be associated with the presence of hallucinations and delusions in AD. Using the Alzheimer’s Disease Neuroimaging Initiative, we identified participants that presented with symptoms of delusions, hallucinations, or both symptoms. PLS-CA was used to identify differences in patterns of interactions between 15 single nucleotide polymorphisms and 82 neuroanatomical regions of interest between AD patients endorsing symptoms of delusions, hallucinations, and …


Cerebral Lactate Metabolism And Memory: Implications For Alzheimer's Disease, Richard Andrew Harris Apr 2017

Cerebral Lactate Metabolism And Memory: Implications For Alzheimer's Disease, Richard Andrew Harris

Electronic Thesis and Dissertation Repository

Alzheimer’s disease (AD) is a neurodegenerative disease characterized by amyloid plaques that are comprised of aggregated amyloid-beta peptides. These toxic proteins promote mitochondrial dysfunction and neuronal cell death. A shift in metabolism away from oxidative phosphorylation and toward aerobic glycolysis, with the concomitant production of lactate, affords neurons a survival advantage against amyloid-beta toxicity. Recent evidence now suggests that aerobic glycolysis in the brain plays a critical role in supporting synaptic plasticity, learning, and memory. However, the role of aerobic glycolysis and lactate metabolism in AD-mediated cognitive decline is unknown. My objective was to test the hypotheses that aerobic glycolysis …


Behavioural Inflexibility And White Matter Inflammation In An Aged Happ Rat With Subcortical Stroke, Aaron M. Regis Dec 2016

Behavioural Inflexibility And White Matter Inflammation In An Aged Happ Rat With Subcortical Stroke, Aaron M. Regis

Electronic Thesis and Dissertation Repository

The interactions between Alzheimer’s disease (AD) and ischemic stroke pathology are of key interest in the development of post-stroke cognitive decline. While clinical and experimental studies have suggested an interaction, the mechanisms whereby these conditions interact to worsen cognition haven’t been fully revealed. This study aimed to combine rodent models of AD and stroke in an aged rat and assess the behavioural and histological outcomes. An injection of endothelin-1 (ET-1), a potent vasoconstrictor into the basal ganglia of a rat with human amyloid precursor protein (hAPP) overexpression (F344Tg) was followed up 3 months later to assess behavioural flexibility, memory and …


An Investigation Into The Combined Effects Of Β-Amyloid Toxicity And Cerebral Ischemia On The Pathological Expression Of Gangliosides., Jeffrey D. Hepburn Oct 2012

An Investigation Into The Combined Effects Of Β-Amyloid Toxicity And Cerebral Ischemia On The Pathological Expression Of Gangliosides., Jeffrey D. Hepburn

Electronic Thesis and Dissertation Repository

Identifying mechanisms underlying the synergistic pathological interaction between stroke and Alzheimer’s disease (AD) can effectively guide future therapeutic strategies for these highly co-morbid conditions. Aberrant ganglioside expression marked by the pathological accumulation of ganglioside GM3 is common to stroke and AD, yet it is unclear whether GM3 is synergistically enhanced in a comorbid model, or if GM3 is a viable therapeutic target. Adult male Wistar rats received a unilateral ischemic striatal infarct via endothelin-1 (ET-1) injection alone or in combination with bilateral intracerebroventricular injection of the β-Amyloid 25-35 peptide (Aβ) to induce generalized Aβ toxicity (Aβ/ET-1). Animals were sacrificed after …