title: The winner and loser effect, serotonin transporter genotype, and the display of offensive aggression.
abstract: Aggressive behaviour results from a complex interplay between genetic and environmental factors. Key modulators of aggression include the serotonergic system on the molecular level and experience in prior aggressive contests as an environmental factor. The aim of this study was to elucidate the effects of fighting experience on the display of offensive aggressive behaviour in adult male mice varying in serotonin transporter (5-HTT) genotype. 5-HTT +/+, 5-HTT +/- and 5-HTT -/- mice were given either a winning or a losing experience on each of three consecutive days and were subsequently observed for their offensive aggressive behaviour as residents against a docile intruder from the C3H strain in a resident-intruder paradigm. The main findings were: There was no significant difference between the amount of offensive aggressive behaviour displayed by the genotypes. Winners showed more engagement with the intruder, attacked him faster and exhibited overall higher aggression scores than losers. There was no significant genotype × social experience interaction: winning and losing had a similar effect on offensive aggressive behaviour in all three 5-HTT genotypes. We conclude that social experience in terms of having been a winner or having been a loser rather than the 5-HTT genotype determines the behaviour towards a docile intruder.
authors.affiliation: Department of Behavioural Biology, University of Münster, Badestr. 13, 48149 Münster, Germany. vanessa.kloke@uni-muenster.de
authors.forename: Vanessa
authors.initials: V
authors.lastname: Kloke
authors.forename: Friederike
authors.initials: F
authors.lastname: Jansen
authors.forename: Rebecca S
authors.initials: RS
authors.lastname: Heiming
authors.forename: Rupert
authors.initials: R
authors.lastname: Palme
authors.forename: Klaus-Peter
authors.initials: KP
authors.lastname: Lesch
authors.forename: Norbert
authors.initials: N
authors.lastname: Sachser
mesh_terms: D000374:Aggression / Q000502:physiology*; D000818:Animals; D003345:Corticosterone / Q000378:metabolism; D005838:Genotype; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D018345:Mice, Knockout; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics* / Q000502:physiology*; D012919:Social Behavior; D013739:Testosterone / Q000097:blood
chemical_list: D050486:Serotonin Plasma Membrane Transport Proteins; D013739:Testosterone; D003345:Corticosterone