Two papers by George Collier are reviewed and replications and extensions of these data are presented. The first paper by Collier and Bolles (1968) reported the total caloric intake of rats during sucrose versus water preference tests. In addition, a paired comparison was made with each of a wide range of sucrose solutions. The latter experiment resulted in a re-thinking of "preference" in that it showed that although rats drank more of a middle range concentration, they always consumed more of the higher concentrations in paired comparison tests. Many other behavioral studies have confirmed that the rat's attraction to the taste of sucrose is a direct function of sucrose concentration. The second paper by Collier and Novell (1967) reported that saccharin was similar to sucrose in that intake increased and then decreased as concentration increased, although in direct choice tests, higher concentrations were preferred to lower ones except in one case. Subsequent studies using a wider range of saccharin concentrations and a variety of test measures revealed, however, that saccharin preference and acceptance decreases substantially as concentration exceeds 0.4% (19.5 mM). Furthermore, saccharin versus sucrose choice tests indicate that optimal saccharin solutions (0.2-0.4%) are "isopreferred" to only dilute sucrose solutions (2-4%). Thus, at best, saccharin is only a weak surrogate for sugar.
Copyright 2002 Elsevier Science Ltd.