The downloadable atlas is comprised of a collection of MRI, blockface imaging, and Nissl-stained volumes, together with a volume of anatomic delineations and a set of 3D surfaces. Volumes range from a spatial resolution of approximately 100 x 100 x 100 µm3 (128 x 256 x 128 voxels, 4.2 Mb uncompressed) for a low-resolution grayscale MRI volume to 3 x 50 x 3 µm3 (3840 x 330 x 3072 voxels, 11.6 Gb uncompressed) for a high-resolution full-color Nissl-stained volume.

Diffusion-weighted uMRI images were acquired over several hours in a high-field magnet. Diffusion-weighted volumes show a great deal of anatomical detail and good contrast between gray and white matter. Blockface imaging is a colorimetric imaging modality free of many of the spatial artifacts that affect serially stained sections: shatter, tears, bubbles, and other mechanical distortions. High-resolution color images of the blockface are acquired as it is sectioned, relying on the inherent contrast of white and gray matter to discriminate anatomical boundaries. Nissl-stained sections provide a wealth of information about cortical lamination and the topography of subcortical nuclei. Other volumes are available for download through the database.

Anatomic delineations serve to help orient the user with graphical representations highlighting important anatomical detail and providing a standard description and nomenclature of the region of interest. The delineations are represented as a set of 3D surfaces in the same space as the data volumes, and they can be visualized and sectioned arbitrarily in the MAP Atlas Viewer.