title: Benefits of adversity?! How life history affects the behavioral profile of mice varying in serotonin transporter genotype.
abstract: Behavioral profiles are influenced by both positive and negative experiences as well as the genetic disposition. Traditionally, accumulating adversity over lifetime is considered to predict increased anxiety-like behavior ("allostatic load"). The alternative "mismatch hypothesis" suggests increased levels of anxiety if the early environment differs from the later-life environment. Thus, there is a need for a whole-life history approach to gain a deeper understanding of how behavioral profiles are shaped. The aim of this study was to elucidate the effects of life history on the behavioral profile of mice varying in serotonin transporter (5-HTT) genotype, an established mouse model of increased anxiety-like behavior. For this purpose, mice grew up under either adverse or beneficial conditions during early phases of life. In adulthood, they were further subdivided so as to face a situation that either matched or mismatched the condition experienced so far, resulting in four different life histories. Subsequently, mice were tested for their anxiety-like and exploratory behavior. The main results were: (1) Life history profoundly modulated the behavioral profile. Surprisingly, mice that experienced early beneficial and later escapable adverse conditions showed less anxiety-like and more exploratory behavior compared to mice of other life histories. (2) Genotype significantly influenced the behavioral profile, with homozygous 5-HTT knockout mice displaying highest levels of anxiety-like and lowest levels of exploratory behavior. Our findings concerning life history indicate that the absence of adversity does not necessarily cause lower levels of anxiety than accumulating adversity. Rather, some adversity may be beneficial, particularly when following positive events. Altogether, we conclude that for an understanding of behavioral profiles, it is not sufficient to look at experiences during single phases of life, but the whole life history has to be considered.
authors.affiliation: Department of Behavioural Biology, University of Muenster Muenster, Germany ; Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Muenster Muenster, Germany.
authors.forename: Carina
authors.initials: C
authors.lastname: Bodden
authors.affiliation: Department of Behavioural Biology, University of Muenster Muenster, Germany.
authors.forename: S Helene
authors.initials: SH
authors.lastname: Richter
authors.affiliation: Department of Behavioural Biology, University of Muenster Muenster, Germany ; Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Muenster Muenster, Germany.
authors.forename: Rebecca S
authors.initials: RS
authors.lastname: Schreiber
authors.affiliation: Department of Behavioural Biology, University of Muenster Muenster, Germany ; Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Muenster Muenster, Germany.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Kloke
authors.affiliation: Institute of Biostatistics and Clinical Research, University of Muenster Muenster, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Gerß
authors.affiliation: Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Austria.
authors.forename: Rupert
authors.initials: R
authors.lastname: Palme
authors.affiliation: Division of Molecular Psychiatry, Laboratory of Translational Neuroscience, Department of Psychiatry, Psychosomatics, and Psychotherapy, University of Wuerzburg Wuerzburg, Germany.
authors.forename: Klaus-Peter
authors.initials: KP
authors.lastname: Lesch
authors.affiliation: Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Muenster Muenster, Germany ; Department of Behavioral Biology, University of Osnabrueck Germany.
authors.forename: Lars
authors.initials: L
authors.lastname: Lewejohann
authors.affiliation: Department of Behavioural Biology, University of Muenster Muenster, Germany ; Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Muenster Muenster, Germany.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Kaiser
authors.affiliation: Department of Behavioural Biology, University of Muenster Muenster, Germany ; Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Muenster Muenster, Germany.
authors.forename: Norbert
authors.initials: N
authors.lastname: Sachser
keywords: 5-HTT; anxiety-like behavior; life history; match-mismatch; predictive adaptive response hypothesis