Taste aversion to sugars by the gerbil

Some conditioned taste aversion experiments were undertaken to determine how the gerbil responds to disaccharides, monosaccharides and polyols. We observed the following: animals taught an aversion to 0.1 M sucrose generalized the avoidance to most sugars, the exception being galactitol; animals taught to avoid 0.01 M hydrochloric acid generalized the avoidance towards lactose, cellobiose, maltitol, methyl α- d-galactopyranoside, methyl α- d-mannopyranoside, methyl β- d-glucopyranoside, and glycerol; animals taught to avoid 0.001 M quinine·HCl generalized the avoidance towards methyl α- d-glucopyranoside, methyl β- d-glucopyranoside, glycerol, ethylene glycol and erythritol. In no case did animals taught to avoid 0.1 M sodium chloride avoid any of the sugars. Moreover, it was observed that the gerbil's behavior with most reducing sugars was different than with equivalent methyl glycosides. For example, animals that were taught to avoid sucrose generalized the avoidance towards reducing sugars, such as, d-galactose, d-glucose, and d-mannose. However, the methyl glycosides, such as methyl α- d-glucopyranoside, methyl β- d-glucopyranoside, methyl α- d-galactopyranoside and methyl α- d-mannopyranoside, in addition to being avoided by animals taught to avoid sucrose, were also avoided by animals taught to avoid quinine·HCl or hydrochloric acid. In addition, we have observed that the control animals consumed differing amounts of sugars and have concluded, therefore, that the sugars were not equally pleasant despite our attempt to use concentrations which produced equally intense neural responses in the gerbil's chorda tympani nerve.