title: To attack, or not to attack? The role of serotonin transporter genotype in the display of maternal aggression.
abstract: Aggressive behavior in males has been intensively investigated regarding the influence of the brain serotonergic system. Despite some inconsistencies, a general conclusion is that low levels of serotonin (5-HT) are associated with high levels of male aggression. The role of the serotonergic system for female aggression is less well researched. Female mice rarely show intraspecific aggressive behavior, except during lactation, when they may exhibit intense aggression towards intruders to protect their pups. The aim of the present study was to investigate the impact of 5-HT transporter (5-HTT) inactivation on maternal aggression in mice. Therefore, lactating homozygous and heterozygous 5-HTT knockout as well as wildtype mice were confronted with male intruders in their home cages. Homozygous 5-HTT knockout dams, which exhibit highest levels of extracellular 5-HT in the brain, were significantly less prone to initiate offensive aggression than wildtype controls. Moreover, they showed longer latencies to attack the intruder, attacked less often and displayed an overall lower frequency of offensive aggressive behavior patterns than wildtype dams. Heterozygous 5-HTT knockout mothers generally showed intermediate levels of aggressive behavior. Thus, our data indicate that higher extracellular including synaptic levels of 5-HT are associated with lower intensity of aggressive behavior in lactating mice, adding support to the inhibitory role of 5-HT in aggression also in females.
authors.affiliation: Department of Behavioural Biology, University of Münster, Germany; Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, Germany. RebeccaHeiming@googlemail.com
authors.forename: Rebecca S
authors.initials: RS
authors.lastname: Heiming
authors.forename: Andrea
authors.initials: A
authors.lastname: Mönning
authors.forename: Friederike
authors.initials: F
authors.lastname: Jansen
authors.forename: Vanessa
authors.initials: V
authors.lastname: Kloke
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*; D000704:Analysis of Variance; D000818:Animals; D001921:Brain / Q000378:metabolism; D005260:Female; D005838:Genotype; D008297:Male; D008425:Maternal Behavior / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D012701:Serotonin / Q000378:metabolism; D050486:Serotonin Plasma Membrane Transport Proteins / Q000172:deficiency*; D012726:Sexual Behavior, Animal / Q000502:physiology; D012919:Social Behavior; D018709:Statistics, Nonparametric
chemical_list: D050486:Serotonin Plasma Membrane Transport Proteins; D012701:Serotonin