Modulation of mice anxiety in response to cat odor as a consequence of predators diet

The effectiveness of predator odours as repellents was assessed, and the be havioral antipredatory responses were characterized. Mice had free access t o an unfamiliar runway containing different olfactory stimuli: modelling cl ay, or feces of a cat subjected either to a vegetarian or a carnivorous die t. The first experiment revealed various indices of a spontaneous behaviora l pattern that included exploratory activity, different kinds of emotionali ty, and a range of active or passive defensive reactions until the appearan ce of absence of risk assessment strictly related to presence or absence of anxiety. These reactions differ with larger responses to feces resulting f rom a carnivorous as opposed to vegetarian diets. In the second experiment, chlordiazepoxide (0, 2.5, 5, or 7.5 mg/kg) had a dose-related anxiolytic e ffect on exploration in mice of both vegetarian and carnivorous groups but could not totally reverse the strong anxiogenic effect of carnivorous stimu lus on defensive mechanisms. These differences are related to the nature of the mammalian cues. This paradigm may be a fear-motivated model of animal anxiety. (C) 1998 Elsevier Science Inc.