Temporal properties of the rewarding and aversive effects of amphetamine in rats.

To associate amphetamine with a location and a flavor, rats were given amphetamine injections and then confined for 20 min in one side of a shuttlebox with access to a flavored solution; on control trials with saline injections, they were confined for 20 min on the opposite side with a different flavor. Three groups of rats were placed in the shuttlebox either 5 min, 120 min, or 240 min after the injections. In subsequent choice tests, the 5 min and 120 min groups preferred the side and avoided the flavor associated with amphetamine; the 240 min group was indifferent between the sides and the flavors.