Predator odor as an unconditioned fear stimulus in rats: elicitation of freezing by trimethylthiazoline, a component of fox feces.
Four experiments tested whether an odor from a rat predator can unconditionally elicit a fear response in rats. In a large chamber, rats displayed fear-related behaviors to trimethylthiazoline (TMT, a volatile compound isolated from fox feces), including avoidance and immobility, while showing less exploratory behavior. In a smaller chamber, TMT induced a species-typical fear response, freezing, whereas other odors did not. In addition, TMT systematically elicited more freezing as the amount of TMT increased. Moreover, there was no within-sessions or between-sessions habituation of freezing to TMT, nor did TMT promote contextual conditioning. The results indicate that the predator odor, TMT, can induce a fear-related behavioral response in rats that is controllable and quantifiable, suggesting that TMT-induced freezing may be a useful paradigm for a neurobehavioral system analysis of ecologically relevant, unconditioned fear.
Wallace
K J
KJ
Department of Psychology, University of Delaware, Newark 19716, USA.
Rosen
J B
JB
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology; D020148:Butyric Acid / Q000494:pharmacology; D003213:Conditioning, Psychological / Q000502:physiology*; D005239:Fear / Q000187:drug effects*; D005243:Feces; D006633:Histamine Antagonists / Q000494:pharmacology; D008297:Male; D009812:Odorants; D000439:Pentanols / Q000494:pharmacology; D011235:Predatory Behavior / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013844:Thiazoles / Q000494:pharmacology*; D013997:Time Factors
D006633:Histamine Antagonists; D000439:Pentanols; D013844:Thiazoles; D020148:Butyric Acid; C020377:isoamyl acetate