Organization, fine structure, and stereotaxic maps of the human Bed nucleus of the Stria terminalis.

The human Bed nucleus of the Stria terminalis is a basal forebrain structure and a key player in stress response and anxiety perception. It is a heterogenous structure and consists of distinct subdivisions. However, subdivisions are not visible in routine MR imaging due to low contrast and small size, which makes the exact assignment and identification in images of the living brain difficult or even impossible. Here, we mapped the Bed nucleus in serial, cell body-stained sections of 10 human brains in its full extent, resulting in 1130 annotations. Four subdivisions, a central, dorsal, medial, and a posterior part were identified. Texture analysis was applied to further characterize the subdivisions. Two sets of maps were generated: (1) Probabilistic cytoarchitectonic maps of the Bed nucleus in MNI space, which consider interindividual variability among the brains; (2) Ultra-high-resolution maps of the four subdivisions in the BigBrain 3D histology dataset, to capture complex shape and topology at microscopical level. The maps are openly available, to serve as anatomical reference to neuroimaging studies in healthy subjects and patients and inform modeling and simulation.