When a rat smells a rat
Pheromone found to put scared rats at ease could lead to humane pest
control

Date:
June 20, 2023
Source:
University of Tokyo
Summary:
Some animals release chemical pheromones which can trigger
behavioral or hormonal changes in other animals. It is known
that calm rats can reduce the fear of nearby rats, but the exact
mechanism was unknown. Researchers have found the pheromone
responsible and demonstrated its effect both on lab rats and rats
in the human environment. Their findings could lead to a new kind
of humane pest control.


Facebook Twitter Pinterest LinkedIN Email

==========================================================================
FULL STORY ==========================================================================
Some animals release chemical pheromones which can trigger behavioral or hormonal changes in other animals. It is known that calm rats can reduce
the fear of nearby rats, but the exact mechanism was unknown. Researchers, including those from the University of Tokyo, have found the pheromone responsible and demonstrated its effect both on lab rats and rats in
the human environment. Their findings could lead to a new kind of humane
pest control.

Associate Professor Yasushi Kiyokawa from the University of Tokyo's
Laboratory of Veterinary Ethology and his colleagues are big fans of
rats. They find them fascinating to study, partly due to their relatively
high intelligence which, in some ways, even allows them to stand in for
humans in certain studies on social interactions.

"I believe that by studying the social lives of rats, we might actually
uncover something about human social interactions as well," said
Kiyokawa. "That is one of the motivations behind our latest research
topic, which explores in more details than ever before, an observed
phenomenon where rats can affect the emotional state of others around
them." It has been known for some time that, within the same species,
rats which are in a relaxed state can imbue a similar state in nearby
rats. Essentially, they can calm each other down without any direct interaction. This is due to pheromones, biological compounds in the air, released from the relaxed rat and received by the scared rat, altering
their state. But the nature of the pheromones involved was unknown
until now.

"To isolate the pheromones involved in this intra-species calming
phenomenon, we needed to be careful about how we tried to collect them,"
said Kiyokawa. "If we stressed out the rat too much, it would likely
affect what pheromones it released. So, we had to be creative and come
up with a way to collect pheromones from a relaxed rat. We did this
by putting a calm rat to sleep and used water to absorb pheromones from
its neck." The main pheromone the team found released by relaxed rats was 2-methylbutyric acid (2-MB), which is incidentally found in the aromas of cheese and wine. They first determined this was what they were seeking by making sure it did indeed reduce the fear in other lab rats. Then they
laced one of two identical small chambers with 2-MB to see if the rats
would show any preference toward either, which they did. This directly
showed that rats felt comfortable to sniff the pheromone. Given the
striking effect it seemed to have, the team also wanted to see if it
would work on wild rats in urban environments.

"We tested at two different locations to see if wild rats would
respond to 2- MB," said Kiyokawa. "They responded similarly to
our lab rats. Synthetic 2-MB reduced their fear of novel things, or
neophobia. This is important because it's neophobia in urban rats that
makes producing effective traps so difficult." Based on their results,
the team believe that 2-MB could be used to create a form of humane pest control. It could be used to lure urban rats into nonlethal traps and
also keep them calm while they're being transported out of the urban environment.

* RELATED_TOPICS
o Plants_&_Animals
# Animals # Mammals # Rodents # New_Species #
Invasive_Species # Wild_Animals # Nature #
Behavioral_Science
* RELATED_TERMS
o Brown_Rat o Pest_(animal) o Pheromone o Tuatara o Mouse o
Animal_rights o Calorie_restricted_diet o Lemming

========================================================================== Story Source: Materials provided by University_of_Tokyo. Note: Content
may be edited for style and length.


========================================================================== Journal Reference:
1. Yasushi Kiyokawa, Shigeyuki Tamogami, Masato Ootaki, Evelyn Kahl,
Dana
Mayer, Markus Fendt, Satoru Nagaoka, Tsutomu Tanikawa, Yukari
Takeuchi.

An appeasing pheromone ameliorates fear responses in the brown
rat (Rattus norvegicus). iScience, 2023; 107081 DOI: 10.1016/
j.isci.2023.107081 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2023/06/230620113813.htm

--- up 1 year, 16 weeks, 1 day, 10 hours, 50 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)