The role of pre-exposure to novel food tastes in activity-based conditioned taste avoidance

Rats were given differential exposure to three distinct and novel foods. One of these foods was exposed for 7 days; another for 2 days, and the last was not exposed. Next, half of the rats received six daily sessions in which a compound of the three flavors was followed by opportunities to run in wheels. The other rats received the food compound but without wheel running. On the next day, all rats were given a choice among the three food flavors presented concurrently in separate dishes. When the compound food had been followed by wheel running, rats ate little of the food given no pre-exposure, more of the food given 2 days of pre-exposure, and considerably more of the food given 7 days of pre-exposure. In comparison, rats who did not receive an opportunity to run ate equal and moderate amounts of the three foods. The results suggest that pre-exposure to a food’s taste produces latent inhibition that interferes with conditioned taste avoidance produced by pairing a taste (CS) with wheel running (US).