Human pharmaceuticals change cricket personality

Human pharmaceuticals change cricket personality
Researchers at Linköping University, Sweden, have found that human drugs can alter cricket behaviour. Credit: Linköping University

Crickets that are exposed to human drugs that alter serotonin levels in the brain are less active and less aggressive than crickets that have had no drug exposure, according to a new study led by researchers from Linköping University. The findings have been published in Scientific Reports.

Individuals in many show different personality types. Some individuals are, for example, consistently bolder than others.

"However, in biology, we still do not fully understand what causes people or animals to show differences in personality. In humans, people with different levels of brain chemicals, such as and dopamine, often behave differently. However, we do not know if these chemicals can also explain personality differences in other species, and if the chemicals cause the observed differences or if both the differences in behavior and levels are caused by another underlying factor," says Robin Abbey-Lee, postdoctoral researcher at the Department of Physics, Chemistry and Biology, IFM, and lead author of the study.

The researchers, therefore, set out to experimentally change the levels of the brain chemicals serotonin and dopamine in the crickets. They did that by giving the crickets human pharmaceuticals that are known to act on the serotonin and dopamine systems and are used to treat depression and Parkinson disease, respectively. Because dopamine and serotonin systems are similar across species, these chemicals were predicted to also affect behavior.

"In this study we wanted to address an important gap in our knowledge by experimentally altering these brain chemicals and seeing if we could get a resulting behavioral change," says Hanne Løvlie, associate professor at IFM, and senior author.

Researchers at Linköping University, Sweden, set out to experimentally change the levels of the brain chemicals serotonin and dopamine in crickets. They gave the crickets human pharmaceuticals that are known to act on the serotonin and dopamine systems. Because dopamine and serotonin systems are similar across species, these chemicals were predicted to also affect cricket behavior. Credit: Linköping University

The researchers measured three different behaviors.

"First, we measured the activity of crickets in a familiar environment. This is similar to how much a person moves around their own home. Second, we measured the exploration behavior of a cricket in a new environment, similar to how a human might behave on a trip to a new city. Finally, we measured cricket fighting behavior to determine how aggressive individuals were," says Robin Abbey-Lee.

What the researchers found was that changing the made crickets less active and less aggressive. But changing the dopamine levels of crickets did not change their .

"This suggests that serotonin has a clearer underlying role in these behaviors," says Hanne Løvlie.

The findings add to our understanding of why animals have personality. They also raise the issue of how pharmaceuticals leaking into nature through waste water may affect animals.


Explore further

Chemicals in brain that make honeybees more likely to sting discovered

More information: Robin N. Abbey-Lee et al, Experimental manipulation of monoamine levels alters personality in crickets, Scientific Reports (2018). DOI: 10.1038/s41598-018-34519-z
Journal information: Scientific Reports

Citation: Human pharmaceuticals change cricket personality (2018, November 19) retrieved 16 June 2019 from https://phys.org/news/2018-11-human-pharmaceuticals-cricket-personality.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
7 shares

Feedback to editors

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more