The influence of dopamine on personality in the Mediterranean field cricket (Gryllus bimaculatus)

Abstract: For some behavior there are consistent differences between individuals within a population, which is called animal personality. Across species, ranging from insects to mammals, personality has been described along behavioral gradients like activity, exploration, boldness and aggression. Monoamines such as dopamine have been shown to be essential for modulating animal behavior and could therefore be important also in explaining variation in animal personality. Supporting this, the dopaminergic system affect activity (in Confused flour beetles), and aggression (in Mediterranean field crickets). However, the causality and effect of dopamine on these behaviors, and also other behavioral traits used to describe personality is currently less explored. This study experimentally investigated how increased level of dopamine affects activity, boldness, exploration and aggression in Mediterranean field crickets (Gryllus bimaculatus). I show that dopamine manipulation had no effects on measured behavior. These results indicate that increased dopamine levels do not affect the scored personality traits in Mediterranean field crickets. The causality and generality of the relationship between dopamine and behavior used to score variation in personality is thus not clear in this species.