Odor identification (OI) tests are increasingly used clinically as biomarkers for Alzheimer's disease and schizophrenia. The aim of this study was to directly compare the neuronal correlates to identified odors vs. nonidentified odors. Seventeen females with normal olfactory function underwent a functional magnetic resonance imaging (fMRI) experiment with postscanning assessment of spontaneous ...

BACKGROUND Structural brain changes have often been found in major depressive disorder (MDD), and it is thought that hypothalamic-pituitary-adrenal (HPA) axis hyperactivity may explain this relation. We investigated the association of MDD and history of depression with hippocampal and entorhinal cortex volumes and whether HPA axis activity explained this association. METHODS In 636 participan...

BACKGROUND AND PURPOSE High resolution 7T MRI is increasingly used to investigate hippocampal subfields in vivo, but most studies rely on manual segmentation which is labor intensive. We aimed to evaluate an automated technique to segment hippocampal subfields and the entorhinal cortex at 7T MRI. MATERIALS AND METHODS The cornu ammonis (CA)1, CA2, CA3, dentate gyrus, subiculum, and entorhinal...

OBJECTIVE Recent evidence indicates that the apolipoprotein E (ApoE) epsilon4 allele is a risk factor for developing Alzheimer's disease. It has also been proposed that it is associated with increased counts of amyloid plaques and neurofibrillary tangles that in turn are neuropathological hallmarks initially appearing in the medial temporal lobe structures in Alzheimer's disease. In this study,...

Available evidence suggests there is functional differentiation among hippocampal and parahippocampal subregions and along the dorsoventral (septotemporal) axis of the hippocampus. The aim of this study was to characterize and compare the efferent and afferent connections of perirhinal areas 35 and 36, postrhinal cortex, and the lateral and medial entorhinal areas (LEA and MEA) with dorsal and ...

In Alzheimer`s disease (AD), regional heterogeneity of ?-amyloid burden and microglial activation individual patients is a well-known phenomenon. Recently, we described high incidence inter-individual in terms asymmetry plaque mouse models AD as assessed by positron-emission-tomography (PET). We now investigate the associations between amyloid burden, activation, impaired spatial learning perfo...

Background Previous studies have shown that Aß-amyloid (Aß) likely promotes tau to spread beyond the medial temporal lobe. However, Aß levels necessary for in neocortex is still unclear. Method 466 participants underwent imaging with [18F]MK6420 and [18F]NAV4694 (Fig. 1). scans were quantified on Centiloid (CL) scale a cut-off of 25CL abnormal (A+). Tau three regions interest (ROI) (mesial (Me)...

We carried out a study of the expression patterns of seven developmental regulatory genes (Lef1, Lhx2, Lhx9, Lhx5, Lmo3, Lmo4, and Prox1), in combination with topological position, to identify the medial pallial derivatives, define its major subdivisions, and compare them between mouse and chicken. In both species, the medial pallium is defined as a pallial sector adjacent to the cortical hem a...

The grid cells of the rat medial entorhinal cortex (MEC) show an increased firing frequency when the position of the animal correlates with multiple regions of the environment that are arranged in regular triangular grids. Here, we describe an artificial neural network based on a twisted torus topology, which allows for the generation of regular triangular grids. The association of the activity...