Conditioned flavor preference and aversion: Role of the lateral hypothalamus

Food-restricted rats with ibotenic acid lesions of the lateral hypothalamus (LH) and sham controls were trained to associate flavored solutions with p ositive or negative postingestive consequences. The LH rats learned to pref er a flavor that was paired with concurrent intragastric infusions of malto dextrin. Unlike controls, the LH rats failed to learn a preference for a fl avor paired with delayed maltodextrin infusions and showed an attenuated pr eference for a flavor paired with concurrent fat infusions. The LH rats did not differ from controls in learning to avoid flavors paired with concurre nt or delayed infusions of lithium chloride. These data indicate that the L H is not essential for all types of flavor-postingestive consequence condit ioning but is critical for learning to associate flavors with delayed nutri ent feedback.