Non-metric multidimensional scaling (NMDS), assessing the pairwise similarities of projection patterns among cases. Cases are identified by the area of tracer injection. Multiple cases with injection of tracer in the same area are identified by the number in parenthesis after each case. Since NMDS configurations are invariant to rotation, the coordinate axes provide a scale of relative similarity, but do not prescribe specific dimensions, and are left unlabeled. (A)ipsilateral cases; (B)contralateral cases. Similarity was defined as the correlation of relative retrograde projection patterns resulting from the injections. The two main projection systems apparent in the diagram consist of predominantly mediodorsal areas (to the left), and basoventral areas (to the right) for both ipsilateral (A) and contralateral (B) projections.