title: Alarm pheromone increases defensive and risk assessment behaviors in male rats.
abstract: Previously, we reported that alarm pheromone released from the perianal region of male rats aggravated stress-induced hyperthermia and increased Fos expression in the vomeronasal pathway and stress-related nuclei in pheromone-recipient rats. However, the alarm property of this pheromone in terms of behavior modification is still unclear. We recently found that this alarm pheromone could be trapped in water. Based on this finding, we developed an experimental paradigm to assess the effect of alarm pheromone on recipient behavior. Male Wistar rats were acclimatized for 5 min to an open field, where two pieces of filter paper soaked with 750 microl of either pheromone-containing water or vehicle water were attached to the wall. Then, a small "hiding box" was placed in one corner of the field and the behavioral responses of the subject rat were recorded for 10 subsequent minutes. Exposure to alarm pheromone significantly increased defensive and risk assessment behaviors and decreased exploratory and grooming behaviors compared to the vehicle control group, indicating the alarm property of the pheromone. In addition, the comparison with previous results suggests that the alarm pheromone released from the perianal region of the male rat increases anxiety in recipients, rather than evoking a stereotyped autonomic response.
authors.affiliation: Laboratory of Veterinary Ethology, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan. kiyokawa-ns@umin.ac.jp
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Kiyokawa
authors.forename: Michito
authors.initials: M
authors.lastname: Shimozuru
authors.forename: Takefumi
authors.initials: T
authors.lastname: Kikusui
authors.forename: Yukari
authors.initials: Y
authors.lastname: Takeuchi
authors.forename: Yuji
authors.initials: Y
authors.lastname: Mori
mesh_terms: D000374:Aggression / Q000187:drug effects*; D000818:Animals; D001007:Anxiety / Q000139:chemically induced / Q000523:psychology; D003627:Data Interpretation, Statistical; D005106:Exploratory Behavior / Q000187:drug effects; D006120:Grooming / Q000187:drug effects; D007124:Immunoenzyme Techniques; D008297:Male; D010675:Pheromones / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012309:Risk-Taking
chemical_list: D010675:Pheromones