Memory, genes, and brain imaging : relating the APOE gene to brain function and structure
Year: 2007
Type: dissertation
Study design: Observational Study
Abstract: Alzheimer´s disease (AD) is the most common form of dementia. An\nimportant goal for current AD research is to find preclinical markers of\nimpending disease. Apolipoprotein E sigma4 (APOE epsilon4) is the chief\nknown genetic risk factor for AD. A number of neuroimaging studies have\nreported structural and functional brain alterations in non-demented APOE\nepsilon4-carriers. Such results have tentatively been interpreted as\nearly signs of impending dementia, but the findings have been\ninconsistent across studies. To further address this issue, the overall\naim of this thesis was to examine asymptomatic cognitively\nwell-functioning APOE epsilon4-carriers with magnetic resonance imaging\n(MRI) techniques, together with longitudinal neuropsychological testing.\nStudy I revealed that carriers of APOE epsilon4 expressed reduced\nfunctional brain activity during incidental episodic encoding. In the\nparietal cortex, a genetic dose-effect was seen such that the activity\nreduction was more pronounced for homozygous than heterozygous APOE\nepsilon4-carriers. In addition, it was found that APOE epsilon4-carriers\nhad structural changes in white-matter tracts in the hippocampus and the\nposterior corpus callosum (Study II), and grey matter reductions in the\nhippocampus (Study III). Study IV demonstrated that the degree of\nfunctional activity in the parietal cortex predicted subsequent episodic\nmemory decline within the group of APOE epsilon4-carriers. Collectively,\nthe results suggest that a combination of genetic, neuropsychological,\nand neuroimaging strategies is beneficial in predicting AD development.
Source: Figshare
Author: Johanna Lind
Language: English
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W1591335974