DOES ORAL EXPERIENCE TERMINATE INGESTION

Using data from studies of ingestive behavior in developing rat pups w e demonstrate how oral experience can contribute to the termination of ingestion. In rat pups, repeated oral stimulation with sweet solution s causes a decline in oral responsiveness. The diminished responsivene ss is specific to the flavor of the stimulus experienced orally and ca n persist for several hours. We suggest that this experience-based dec rement in responsiveness is best considered ''oral habituation'' and t hat oral habituation largely accounts for the onset of satiety. Post-i ngestive feedback signals may have their influence through the oral ha bituation process or act in the context of oral habituation. Oral habi tuation is also shown to depend on the pattern of stimulus presentatio n, a phenomenon that adds considerable complexity to assessing the con tributions of oral experience to satiety. The concept of oral habituat ion may be useful in understanding the immediate control of ingestion and the moment-to-moment expression of ingestive behavior in adult ani mals.