Lab Rats: Rat imagination

This NFT depicts photos of a rat deciding on whether the light on the right is on or off. In the lower left, the light is off and the rat is investigating a metal cover placed to the left of the light. In the lower right, the light is occluded by the metal cover. This rat imagines the light is on and that it just can't be seen because it's occluded, and therefore decides to press a lever to get some food. The two images above are of the dentate gyrus, a part of the hippocampus which is a brain structure involved in memory. The brown staining in the upper right image indicates this brain system is active when the rat is imagining the light is present. No brown staining in the upper left image indicates that the rat is not in the process of imagining the light is on (it can tell that the light is off). The dark bands are the cell layers, with the individual cells visible from the various staining techniques used to visualize them.