An appeasing pheromone ameliorates fear responses in the brown rat (Rattus norvegicus)

Yasushi Kiyokawa; Shigeyuki Tamogami; Masato Ootaki; Evelyn Kahl; Dana Mayer; Markus Fendt; Satoru Nagaoka; Tsutomu Tanikawa; Yukari Takeuchi

doi:10.1016/j.isci.2023.107081

An appeasing pheromone ameliorates fear responses in the brown rat (Rattus norvegicus)

iScience. 2023 Jun 9;26(7):107081. doi: 10.1016/j.isci.2023.107081. eCollection 2023 Jul 21.

Authors

Yasushi Kiyokawa¹, Shigeyuki Tamogami¹, Masato Ootaki¹, Evelyn Kahl², Dana Mayer², Markus Fendt², Satoru Nagaoka³, Tsutomu Tanikawa⁴, Yukari Takeuchi¹

Affiliations

¹ Laboratory of Veterinary Ethology, the University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan.
² Institute for Pharmacology and Toxicology & Center for Behavioral Brain Sciences, Otto-von-Guericke University Magdeburg, D-39120 Magdeburg, Germany.
³ Daimaru Compound Chemical Co., Ltd, Nagano 381-1222, Japan.
⁴ Technical Research Laboratory, Ikari Shodoku Co., Ltd, Chiba 275-0024, Japan.

Abstract

The brown rat (Rattus norvegicus) is one of the major animals both in the laboratory and in urban centers. Brown rats communicate various types of information using pheromones, the chemicals that mediate intra-species communication in minute amounts. Therefore, analyses of pheromones would further our understanding of the mode of life of rats. We show that a minute amount of 2-methylbutyric acid (2-MB) released from the neck region can ameliorate fear responses both in laboratory rats and in wild brown rats. Based on these findings, we conclude that 2-MB is an appeasing pheromone in the brown rat. A better understanding of rats themselves would allow us to perform more effective ecologically based research on social skills and pest management campaigns with low animal welfare impacts, which might contribute to furthering the advancement of science and improving public health.

Keywords: Biological sciences; Rodent behavior; zoology.