Cytoarchitectonic mapping of the human amygdala, hippocampal region and entorhinal cortex: intersubject variability and probability maps

Abstract

Probabilistic maps of neocortical areas and subcortical fiber tracts, warped to a common reference brain, have been published using microscopic architectonic parcellations in ten human postmortem brains. The maps have been successfully applied as topographical references for the anatomical localization of activations observed in functional imaging studies. Here, for the first time, we present stereotaxic, probabilistic maps of the hippocampus, the amygdala and the entorhinal cortex and some of their subdivisions. Cytoarchitectonic mapping was performed in serial, cell-body stained histological sections. The positions and the extent of cytoarchitectonically defined structures were traced in digitized histological sections, 3-D reconstructed and warped to the reference space of the MNI single subject brain using both linear and non-linear elastic tools of alignment. The probability maps and volumes of all structures were calculated. The precise localization of the borders of the mapped regions cannot be predicted consistently by macroanatomical landmarks. Many borders, e.g. between the subiculum and entorhinal cortex, subiculum and Cornu ammonis, and amygdala and hippocampus, do not match sulcal landmarks such as the bottom of a sulcus. Only microscopic observation enables the precise localization of the borders of these brain regions. The superposition of the cytoarchitectonic maps in the common spatial reference system shows a considerably lower degree of intersubject variability in size and position of the allocortical structures and nuclei than the previously delineated neocortical areas. For the first time, the present observations provide cytoarchitectonically verified maps of the human amygdala, hippocampus and entorhinal cortex, which take into account the stereotaxic position of the brain structures as well as intersubject variability. We believe that these maps are efficient tools for the precise microstructural localization of fMRI, PET and anatomical MR data, both in healthy and pathologically altered brains.

Correlates of intellectual ability with morphology of the hippocampus and amygdala in healthy adults

“…Finally, higher IQ was strongly associated with bilateral inward deformations in the surface contour of the anterior hippocampus (Figs. 3 and 4), which we attribute to locally reduced volumes, possibly within the dentate gyrus and cornu ammonis, which constitute most of the volume of the anterior hippocampus (Amunts et al, 2005;Duvernoy, 1988).…”

Structural and functional neuroplasticity in human learning of spatial routes

“…2a extended from − 42 to − 4 mm in the anterior-posterior dimension adding confidence to the finding of a left hippocampal MD decreases with route learning. Comparison of the cluster with the Jülich histological atlas (Amunts et al, 2005;Eickhoff et al, 2007) indicated that this region included portions of the dentate gyrus and the cornu ammonis. In addition, its relatively posterior location is consistent with the hippocampal area found to increase in volume with experience in driving a London taxi cab (Maguire et al, 2000).…”

The anterior medial temporal lobes: Their role in food intake and body weight regulation

“…External food sensitivity, i.e. a personality trait associated with overeating and obesity, 3 predicts how the amygdala responds to appetizing food pictures [118]. Additionally, self-directedness (i.e., the ability to set and pursue meaningful goals, which is typically reported as altered in eating disorders, e.g., [158]) is negatively correlated with the amygdala response to appetizing food pictures [48].…”

“…Although not without issues (see e.g., [41]), BMI is currently the most commonly used measure in obesity research. 3 This personality trait can be assessed by the Dutch Eating Behavior Questionnaire [170].…”