Figure 1.

Training and testing of mice in social transmission of food preference paradigms. Behavioral procedures were conducted over a 5 day period. In the 3 days preceding training and testing, mice were submitted to a restricted feeding regime in which they were allowed free access to food in a fixed 2 h period each day. The food provided in this period was the normal daily diet in powdered form rather than the pellets to which they were accustomed. Access to drinking water was unrestricted during the restricted feeding regime. In days 2 and 3 of this regime the animals spent 30 min of the feeding period individually in the test arena (a 33 × 33 × 25 cm high white plastic container). In this period of habituation to the test environment, ∼2 g of the powdered food was provided in a feed cup—a plastic cylinder (4 cm diameter × 5 cm high) fixed in the center of a plastic dish (6 cm diameter × 2 cm high) to catch any spillage (Figure 1). On day 4, Demonstrator mice were “loaded” by being given unrestricted access to either a flavored food or the normal food, both in powdered form. Observer mice were anesthetized, and exposed to the training odor by one of two procedures; either (1) carried on the breath of an anesthetized demonstrator, or (2) introduced to the anesthetic gas with or without CS₂. On day 5, mice were given a 30 min simultaneous choice test to determine their food preference. Mice which consumed none of either food in the preference test were excluded from further analysis.