Rat Brain Comparative Anatomy. The C29 model shows a rat brain in approximate 6-fold enlargement. Sectioned medially, it can be disassembled into two halves. The right half of the model shows the structures of the cerebrum, cerebellum and brain stem, each of which is color-coded for didactic purposes (cerebrum = pink, cerebellum = blue, brain stem = yellow), both externally and in the median section. The left half of the model is largely transparent, thus revealing a view of the colored left lateral ventricle and hippocampus, which can also be seen in the median section. For purposes of comparison, a natural cast of a rat brain and a didactic, small-scale illustration of a human brain in median section are shown on the base, with the same color coding used for the various regions.