(a)
(b)
Figure 3: Hilar c-fos+ cells after exposure to novel objects. (a, 1) A section through the ventral hippocampus is shown. There are few c-fos+ cells in the hilus of a control mouse. Calibrations: 75 μm (main image, left) and 50 μm (inset, right). HIL: hilus; GCL: granule cell layer; CA3: area CA3 pyramidal cell layer. (a, 2) In a mouse exposed to novel objects as described in Figure 1, there were many c-fos+ cells in the hilus (arrows). Same calibrations as (a, 1). (b, 1) A dorsal section shows little c-fos+ hilar cells in the control. (b, 2) Numerous hilar c-fos+ cells are present in the dorsal section of a mouse exposed to novel objects (arrows; as described in Figure 1). Calibrations: 75 μm (main image, left) and 60 μm (inset, right).