Integration of oral habituation and gastric signals in decerebrate rat pups.

During a series of oral infusions of a sweet solution, the ingestive responses of young rat pups habituate; pups stop responding to the infusions even when their stomachs are empty and the infused diet is nonnutritive. The rate of this oral habituation is enhanced by the addition of gastric fill signals, even in decerebrate pups. In intact but not in decerebrate pups, prior deprivation gates out the influence of gastric fill on habituation. This oral habituation system, responsive to multiple ingestion-related signals, may serve as the elemental process that integrates physiological state with ongoing behavior to control ingestion.