In many animal species, individuals have different personalities. For example, some individuals are consistently more daring than others.
"But in biology we still do not fully understand what is behind people or animals posing different personalities. In humans, people with different levels of brain signals such as serotonin or dopamine tend to behave differently. we do not know whether variations in these signal substances can explain personality differences to other species and whether signal substances cause observed differences or whether both behavioral differences and substance signal levels depend on another underlying factor, "says Robin Abbey-Lee, post PhD, Department of Physics, Chemistry and Biology, IFM, one of the researchers who led the study.
He gave drugs to people's crickets
Researchers therefore wanted to actively change levels of serotonin and dopamine signaling agents to investigate this, and used crickets for the study. They did it by giving them drugs that affect serotonin and dopamine systems and use them to treat people who suffer from depression or Parkinson's disease. Because the serotonin and dopamine systems of the different animals are similar to the others, the researchers expected the drugs to affect the crickets.
In this study, we wanted to gain an important knowledge gap by experimentally changing the levels of these signal substances and seeing whether this could lead to a change in behavior in cysts, "says Hanne Løvlie, a university assistant at the MFI, who studied the study.
Then he measured the cricket behavior
The researchers measured three different behaviors in cysts.
I measured the way the active crickets were in a familiar environment. This corresponds to how much a person moves into his own home. We have also investigated the exploratory behavior of cricket in a new environment, similar to how a person can behave in a visit to a new city. Finally, I studied how the crickets behaved in a battlefield to measure the aggression of individuals, says Robin Abbey-Lee.
Researchers have found that changing serotonin levels has made crickets less active and less aggressive. Modified dopamine levels, on the other hand, have not been associated with behavioral changes in cysts.
This indicates that serotonin has a clearer role in these behaviors, says Hanne Løvlie.
The findings increase our understanding of why animals have personality. They also raise the question of how drugs that leak in nature through wastewater affect wildlife.
"Experimental Manipulation of Monoamine Levels Changes Personality in Creepers", Abbey-Lee RN, Uhrig EJ, Garnham L, Lundgren K, Child S, LøvlieH, (2018), Scientific Reports published online November 1, 2018