Figure 2.

Standard blocking procedure for extracting the midbrain. With the brain pinned to the custom-made slicing box through the frontal lobe and the cerebellum, a coronal slice was made caudal of the cerebellum to remove the spinal cord (A), while a second coronal slice was made through the center of the temporal lobes to remove the rostral half of the brain (B). A frontal view of the cortex being peeled away from the midbrain is shown in (C), followed by removal of the cerebellum (labeled Ce in D) using a small razor. Finally, with the left midbrain pinned down, a mid-sagittal cut was made to extract the right midbrain (E). Red dots on the right inferior colliculus show where the dyed shanks entered through its surface during the in vivo portion of the experiment.