The brain is ordinarily divided into three parts: forebrain, midbrain, and hindbrain. These are in turn subdivided into smaller and smaller divisions down to about 350 primary structures in the macaque. In NeuroNames, the names for all of the parts are organized into a hierarchy with "BRAIN" at the top, and primary structures at the bottom. Some primary structures are as many as 10 levels deep.

Try finding the location of substantia nigra in the hierarchy. (It may be useful to print these instructions.)

1. Click in the control bar below.

2. Click in the sidebar.

3. Scroll to the name of the structure, substantia nigra.

4. Click substantia nigra.

5. Click Show in Relation to Hierarchy .

Listed below it are its two substructures: pars compacta and pars reticulata. To see the superstructure to which the substantia nigra belongs, click the arrow pointing to the left , i.e., up the hierarchy. By repeatedly clicking the arrows pointing up the hierarchy, you will find that substantia nigra is part of the midbrain and the midbrain is part of the brain. Likewise, at any level, you can click arrows pointing to the right to see substructures. If you wish to view the whole hierarchy in a condensed, but less navigable, format, click .