title: Fear-like behavioral responses in mice in different odorant environments: Trigeminal versus olfactory mediation under low doses.
abstract: Odors can have repulsive effects on rodents based on two complementary adaptive behaviors: the avoidance of predator odors (potentially dangerous) and the avoidance of trigeminal stimulants (potentially noxious). The present study aimed to compare the behavioral effects on mice of odors according to their trigeminal properties and ecological significance. We used three different odors: 2,4,5-trimethylthiazoline (TMT: a fox feces odor frequently used to elicit fear-induced behaviors), toluene (a strong stimulant of the trigeminal system) and phenyl ethyl alcohol (PEA: a selective stimulant of the olfactory system). First, we checked preference and avoidance behaviors in mice with and without anosmia towards these odors to ensure their olfactory/trigeminal properties. Secondly, we used a standard test (open-field and elevated plus-maze) to assess the behaviors of mice when exposed to these odors. The results show that the anosmic and control mice both avoided TMT and toluene odors. In the open-field and the elevated plus-maze, mice exhibited "anxious" behaviors when exposed to TMT. Conversely, exposure to PEA induced "anxiolytic" effects confirmed by low blood corticosterone levels resulting from completion of the elevated plus-maze. Compared with TMT exposure, toluene exposure induced moderate "anxious" effects.
authors.affiliation: Laboratoire de Neurosciences, Université de Franche-Comté, 2 Place Leclerc, Besancon Cedex, France. emmanuel.galliot2@univ-fcomte.fr
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Galliot
authors.forename: Lucie
authors.initials: L
authors.lastname: Laurent
authors.forename: Romain
authors.initials: R
authors.lastname: Hacquemand
authors.forename: Gregory
authors.initials: G
authors.lastname: Pourié
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Millot
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001007:Anxiety / Q000139:chemically induced*; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology*; D003345:Corticosterone / Q000097:blood*; D005260:Female; D051379:Mice / Q000523:psychology; D009812:Odorants; D000857:Olfaction Disorders / Q000139:chemically induced; D055696:Olfactory Perception / Q000502:physiology*; D010626:Phenylethyl Alcohol / Q000494:pharmacology; D013844:Thiazoles / Q000494:pharmacology*; D014050:Toluene / Q000494:pharmacology; D012668:Trigeminal Ganglion / Q000502:physiology*
chemical_list: D013844:Thiazoles; C424603:2,4,5-trimethylthiazole; D014050:Toluene; D010626:Phenylethyl Alcohol; D003345:Corticosterone