Biological psychiatry
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Biological psychiatry · Nov 2004
Comparative StudyCerebrospinal fluid beta-amyloid1-42 and tau in control subjects at risk for Alzheimer's disease: the effect of APOE epsilon4 allele.
Cerebrospinal fluid (CSF) measures of beta-amyloid(1-42) and tau are linked with the known neuropathology of Alzheimer's disease (AD). Numerous lines of evidence have also suggested that individuals with at least one APOE epsilon4 allele on chromosome 19 are at increased risk of developing AD. We tested these CSF markers in groups of subjects with AD and healthy older control subjects, using the absence or presence of the APOE epsilon4 allele as a predictive variable in the search for possible prognostic biomarkers of AD. ⋯ The association of APOE epsilon4 allele and lower, more AD-like levels of CSF beta-amyloid(1-42) in older control subjects is consistent with previous studies showing possible neuroimaging and cognitive abnormalities with epsilon4 carriers and suggests that CSF beta-amyloid(1-42) decreases might represent an early biomarker of AD. Longitudinal follow-up is of course required to verify whether this biomarker is indeed predictive of clinical conversion to AD.
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Biological psychiatry · Nov 2004
ReviewNew approaches for exploring anatomical and functional connectivity in the human brain.
Information processing in the primate brain is based on the complementary principles of modular and distributed information processing. The former emphasizes the specialization of functions within different brain areas. ⋯ Here, we highlight recent advances in neuroimaging methodology that have made it possible to investigate the anatomical architecture of networks in the living human brain with diffusion tensor imaging (DTI). We also highlight recent thinking on the ways in which functional imaging can be used to characterize information transmission across networks in the human brain (functional and effective connectivity).