Disparity between formation of conditioned flavor aversions and neophobia during grooming in rats and mice.

Mice (Mus musculus) allowed to groom a paste containing saccharin from their fur before injection with lithium chloride displayed a saccharin aversion in subsequent drinking preference tests. No attenuation of neophobia was observed in mice grooming saccharin because the animals failed to display a neophobia towards saccharin in drinking tests. Rattus norvegicus displayed neophobia towards saccharin in two- and single-bottle drinking tests but this neophobia was not attenuated by grooming experience with the saccharin paste. Rats apparently learn that if a taste is hazardous in the grooming context it is also likely hazardous in an appetitive context. Learned safety in grooming, however, does not generalize into the appetitive context. The results support the view that neophobia and learned taste aversion depend upon different mechanisms.