The comparative mammalian collections at UW and MSU contain over 275 mammal brains that were serially sectioned, stained with fiber and cell stains, mounted on glass slides, and made ready for microscopic study. The species in the collections were chosen to be representative of a broad spectrum of mammalian orders and families (see Purpose).

The comparative collection consist of over half a million stained sections, which includes a complete section series for each brain (see Methods).

For most specimens we also have acrylic casts and molds of each brain, as well as photographs of the intact brains. For each brain in the comparative collections, the sections are stained in alternate series: even-numbered sections are stained to show cell bodies and nuclear formations, and odd-numbered sections are stained to show myelinated axons, tracts and fiber pathways.

For the majority of the specimens, whenever possible, there are documented sources, histories, brain and body weights and measures, and in some cases movies and body photos of the animals. In addition to the large holdings of sectioned brains, an additional 200 or more specimens still reside in celloidin, and await further processing.

The human brain collections in the Yakovlev-Haleem slide library at the National Museum of Health and Medicine (NMHM) contains over 900 normal and pathological human brains, that were stained for myelinated fibers and cell bodies. There are over 250,000 large 5" x 7" slides of these human brain sections.

The value of the collections, based upon current costs of preparing stained sections on slides, together with all documentation and materials for all the brains in the collectons would be tens of millions of dollars.

This electronic document is designed to provide browsers with an overview of the contents and quality of the slide material in these collections. We intend to include tutorials about how the brains of mammals are constructed, how they function and how they have developed, during evolution, as well as during ontogeny.

Viewers will be able to "download" images and text for their own educational purposes. We hope to encourage the research and educational use of the collections.

Also, we provide, by means of e-mail and "response forms", an interactive forum for anyone interested in learning about how and why brains differ in different mammals.