Saccharin's aversive taste in rats: evidence and implications.

In most biobehavioral research using rats as subjects, saccharin is viewed as a "sugar substitute"--sweet, palatable, and conveniently lacking in calories. This characterization has merit: Saccharin seems to share some sensory, affective, and motivating properties with sugars. This paper focuses on saccharin's lesser known, aversive properties. Evidence of saccharin's distinctive taste in rats is reviewed, followed by discussion of several modulating variables. Procedures that influence rats' responses to saccharin and their measurement are summarized, and the argument is advanced that saccharin can be used to study the relationship of taste and ingestion to learning, stress, and emotional processes in rats and humans.