Age-differences in odor preference following an odor-illness pairing

Abstract

An ambient maple odor was paired with illness in rats ranging in age from weaning to old age. The animals then were tested for an aversion to a maple-odored solution. The results indicated no aversion to the odored solution at any age level and, hence, support previous research indicating that odor is a weak cue for illness. However, both young-adult and old-age rats made ill after drinking water in the absence of odor preferred the maple-odored solution to plain water. This finding suggests that, whereas odor may be a weak cue for illness in adult rats, it may be an effective safety signal. In contrast, weanling rats made ill in the presence of the odor preferred the odored solution. This paradoxical preference was explained in terms of olfactory imprinting and the effect punishment has on imprinted responses.