A simple method of olfactory discrimination of urines for the Mongolian gerbil, Meriones unguiculatus

Olfactory discrimination in gerbils can be reliably assessed by measuring changes in rearing toward an odor. After the frequency of rearing stabilizes during a non-odor period, the introduction of a urinary odor through a ceiling aperture quickly produced an increase in rearing frequency and duration. Rearing then habituated during the odor presentation period but recurred at high levels if a new urinary odor was introduced. This pattern of rearing was robust enough to allow for the testing of three urinary odors during a single 24-min test period. Preliminary work suggests that the procedure is equally sensitive with different odors, can be adapted for use with other rodents, and may provide additional information about differential investigation of urinary odors. The simplicity, reliability, and brevity of this method makes it a potentially important tool for olfactory research.