Preference for corn oil in olfactory-blocked mice in the conditioned placepreference test and the two-bottle choice test

We studied the effects of olfactory stimuli on preference for corn oil in m ice. In the conditioned place preference test, voluntary intake of 100% cor n oil by both olfactory normal and ZnSO4-induced olfactory-blocked (anosmic ) mice resulted in their place preference for the corn oil-related box. In the olfactory normal mice, place preference was also observed by voluntary intake of linoleic acid as well as of corn oil. In the two-bottle choice te st, normal mice showed significant preference for test fluids that containe d corn oil at all concentrations (1 - 10%) tested relative to vehicle alone . However, the lower concentrations (1 and 3%) of corn oil were not preferr ed in the anosmic mice. These results suggested that stimuli other than olf action contributed to the rewarding effects of corn oil, but at lower conce ntrations olfactory stimuli might act as a signal for the oil. (C) 2001 Els evier Science. All rights reserved.