Chronically Decerebrate Rats Demonstrate Satiation But Not Bait Shyness

Taste substances applied to the oral cavity result in either ingestion or rejection, each with a characteristic muscular response pattern. These responses are the same in decerebrate and intact rats; the caudal brainstem appears to be the neural substrate of ingestion and rejection responses. The experiment determined whether decerebrates can alter these discriminative responses as a function of food deprivation or toxicosis. Food-deprived decerebrate rats, like intact ones, ingested a taste substance they had rejected when sated. However, these same decerebrates, in contrast to controls, neither rejected nor decreased ingestive reactions to a novel taste after that taste had been repeatedly paired with lithium chloride-induced illness. Although the forebrain may be important for integrating ingestion, some aspects of this control seem to be represented in caudal brain areas.