Odor exposure-induced changes in c-Fos expression of CAMKII neurons. (Top) Representative photomicrograph with CAMKII (brown) and c-Fos (blue/black) labeling in low butyric acid (left) and ferret odor-exposed (right) rats. Exposure to ferret odor increased the percentage of CAMKII-positive neurons with c-Fos in the BLA (Bottom, A), CEA (Bottom, B), and MEA (Bottom, C) compared to control, low and/or high butyric acid-exposure. ***P<0.01, **P<0.01, *P<0.05 (N=5-13). Scale bar represents approximately 50 microns. The white arrow points to a single-labeled CAMKII neuron, the black arrow points to a single-labeled c-Fos neuron, and the dashed black arrow points to a double-labeled CAMKII/c-Fos neuron.