Role of olfaction in the formation of preference for high-fat foods in mice.

Male albino mice were given access to both high- and low-fat food mixtures in the home cage for 4 days. Mice were then divided into three groups and given a choice test in which all groups demonstrated a significant preference for the high-fat food mixture. One group was then bilaterally olfactory nerve sectioned. Seven days following surgery, all groups were given a second choice test. Olfactory nerve-sectioned mice (while anosmic) showed no preference, whereas high-fat food preference in the two control groups strengthened. However, high-fat food preference returned to recovered nerve-sectioned mice by 21 days postsurgery. It appears that preference for many high-fat foods in mice requires olfaction. This is in good agreement with earlier work that reported the loss of the novel food effect in olfactory nerve-sectioned mice while anosmic, and points to an important role for olfaction in the formation of preference for many high-fat foods.