Helge Rootwelt

Learn More
The apolipoprotein (APOE) ε4 allele is a strong genetic risk factor for Alzheimer's disease (AD). Intrinsic fluctuations of brain activity measured by fMRI during rest may be sensitive to AD-related neuropathology. In particular, functional connectivity of the default-mode network (DMN) has gained recent attention as a possible biomarker of disease(More)
OBJECTIVES APOE is related to cholesterol transport and clearance and brain white matter (WM) properties involving myelin, of which cholesterol is a major component. Diffusion tensor imaging enables in vivo investigations of brain WM, and could increase our understanding of the pathways leading to Alzheimer disease. The main objective was to investigate the(More)
Effects of APOE genotype on age-related slopes of cortical thinning was estimated by measuring the thickness of the cerebral cortex on a point-by-point basis across the cortical mantle in 96 healthy non-demented volunteers aged 48-75 years. Fifty nine were APOE epsilon 4- (no epsilon 4 allele) and 37 were epsilon 4+ (1 or 2 epsilon 4 alleles). The genotype(More)
The present study seeks to identify effects of a common genetic polymorphism in the human nicotinic alpha4beta2 receptor on components of the cognitive event-related potentials in auditory and visual modalities. The same sense thymine-to-cytosine polymorphism (c.1629T-C; Ser543Ser) was shown to preferentially modulate early components in both modalities.(More)
In the present study, we investigated age-related changes in interactions between efficiency of neuronal repair mechanisms and efficiency of cholinergic neurotransmission in the context of attentional orienting. In addition, we explored white matter volume changes as possible neuronal underpinnings. A sample of 230 healthy middle-aged (53-64 years) and(More)
PURPOSE To study whether apolipoprotein E (APOE) genotypes are associated with risk for developing cataract and age-related macular degeneration (AMD). METHODS A sample of 88 healthy adults (50-75 years) genotyped for polymorphisms of APOE underwent an eye examination which included visual acuity (VA) testing, slit-lamp cataract evaluation, optical(More)
OBJECTIVES Recently, it was shown in vitro that the polymorphic enzyme cytochrome P450 (CYP) 2D6 mediates O-demethylation of diltiazem. The aim of this study was to compare the pharmacokinetics of diltiazem and its major metabolites in healthy human volunteers representing different CYP2D6 genotypes. METHODS Norwegians of Caucasian origin were screened(More)
Cholinergic influences on attention are well documented and recent evidence indicates that genetic variation in the alpha4beta2 nicotinic receptor affects attentional networks of the brain. Several behavioral and electrophysiological studies have shown that a common polymorphism in the CHRNA4 gene (rs1044396) affects aspects of visual and auditory(More)
BACKGROUND Pharmacological studies suggest that cholinergic neurotransmission mediates increases in attentional effort in response to high processing load during attention demanding tasks [1]. METHODOLOGY/PRINCIPAL FINDINGS In the present study we tested whether individual variation in CHRNA4, a gene coding for a subcomponent in α4β2 nicotinic receptors(More)
PURPOSE To investigate whether CHRNA4 and APOE genotypes influence retinal nerve fibre layer (RNFL) thickness at the optic disc, intraocular pressure (IOP) and the development of exfoliation syndrome (XFS). METHODS A sample of 88 healthy adults (aged 50-75 years) genotyped for polymorphisms of APOE and CHRNA4 underwent an eye examination including(More)