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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
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 …
Connectomic Analysis Of Substantia Nigra Pars Compacta And Ventral Tegmental Area Projections To The Striatum And Cortex, Nicholas Handfield-Jones
Connectomic Analysis Of Substantia Nigra Pars Compacta And Ventral Tegmental Area Projections To The Striatum And Cortex, Nicholas Handfield-Jones
Electronic Thesis and Dissertation Repository
We investigated the connectivity of dopamine (DA) neurons emerging from the substantia nigra pars compacta (SNc) and ventral tegmental area (VTA) and targeting the dorsal striatum (DS), ventral striatum (VS), and prefrontal cortex (PFC). We used diffusion magnetic resonance imaging (dMRI) probabilistic tractography on human connectome project MRI data. We found that unlike conventional descriptions of DA pathways (i.e., nigrostriatal, mesolimbic, mesocortical), connectivity from both SNc and VTA each targeted DS, VS, and PFC. We also found that from the DS, VS, and PFC, a greater proportion of connections targeted the SNc as compared to the VTA. These findings suggest …