14 November 2018

Why do animals differ in personality? Researchers at LiU used human drugs that alter two brain chemicals, serotonin and dopamine, to see if these drugs would change the behavior of animals. Take a closer look at the crickets used in the study, in the video below.

Individuals in many animal species show different personality types. Some individuals are for example consistently bolder than others.Robin Abbey-Lee, postdoktor (stillbild från video).Robin Abbey-Lee, postdoctoral researcher (photo from video).

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 serotonin and dopamine, often behave differently. However, we do not know if these chemicals can explain personality differences also in other species, and if the chemicals are causing the observed differences or if both the differences in behavior and chemical 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 dopamine and serotonin systems and are used to treat Parkinson disease and depression, respectively.Hanne Løvlie Photo credit Anna Nilsen

In this study we wanted to really 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.

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

“This suggest that serotonin has a clearer underlying role in these behaviors”, says Hanne Løvlie.

These results both improve our understanding of why animals have personality, and also raise the issue of how increasing levels of pharmaceuticals leaking into nature through our waste water may affect animals.

The study is published in Scientific Reports.

The article:Experimental manipulation of monoamine levels alters personality in crickets”, Robin N Abbey-Lee, Emily J Uhrig, Laura Garnham, Kristoffer Lundgren, Sarah Child and Hanne Løvlie, (2018), Scientific Reports, published online 1 November 2018, doi: 10.1038/s41598-018-34519-z

Video about the research

Why do animals differ in personality?

Are differences in personality linked to brain chemicals, such as serotonin and dopamine? Researchers at LiU used human drugs to see if they would change the behaviour of crickets.

Contact

Per Jensen with a chicken in his hands.

Pioneer with animals’ best interests at heart

What do animals do? What do they think? Do they have feelings? These are questions that have fascinated people through the ages and represent a field of research of their own. In ethology, Linköping professor Per Jensen is one of the leading figures.

two chickens.

How young chickens play can indicate how they feel

Researchers have for the first time mapped the development of play in young chickens. The results show that the young chickens spend lots of time playing in different ways – just like puppies and kittens.

red junglefowl chick looking at mealworm through transparent plastic tube.

Impulsivity is influenced by early experiences and gene expression

Differences in impulsivity between individuals are linked to both experience and gene expression, according to a study on the ancestor of domestic chickens, the red junglefowl.

Research on animal behaviour

Latest news from LiU

Sheet of glass with droplet.

Next-generation sustainable electronics are doped with air

Researchers at LiU have developed a new method where organic semiconductors can become more conductive with the help of air as a dopant. The study is a significant step towards future sustainable organic semiconductors.

physicians in a clinica setting.

Healthcare interpreters important for heart attack aftercare

After a heart attack, foreign-born people are less likely to attend a relapse-preventing Heart School than native-born patients. But with access to a professional interpreter, participation increases, according to a new study.

Battery om fingertip.

Eco-friendly and affordable battery for low-income countries

A battery made from zinc and lignin that can be used over 8000 times. This has been developed by researchers at LiU with a vision to provide a cheap and sustainable battery solution for countries where access to electricity is limited.