Figure 14. Diagrammatic representation of a parasagittal view of the rat brain illustrating the VIP chemistry of the hippocampal formation. Blow-up insert shows that VIP neurons (blue) are small, polymorphic interneurons found in many layers. VIP binding (red) is shown, with the intensity of the color representing the density of VIP binding. Afferent neurons from the septum and diagonal band are shown in grey.