TY - JOUR A1 - Meyer, Neele A1 - Richter, S. Helene A1 - Schreiber, Rebecca S. A1 - Kloke, Vanessa A1 - Kaiser, Sylvia A1 - Lesch, Klaus-Peter A1 - Sachser, Norbert T1 - The Unexpected Effects of Beneficial and Adverse Social Experiences during Adolescence on Anxiety and Aggression and Their Modulation by Genotype JF - Frontiers in Behavioral Neuroscience N2 - Anxiety and aggression are part of the behavioral repertoire of humans and animals. However, in their exaggerated form both can become maladaptive and result in psychiatric disorders. On the one hand, genetic predisposition has been shown to play a crucial modulatory role in anxiety and aggression. On the other hand, social experiences have been implicated in the modulation of these traits. However, so far, mainly experiences in early life phases have been considered crucial for shaping anxiety-like and aggressive behavior, while the phase of adolescence has largely been neglected. Therefore, the aim of the present study was to elucidate how levels of anxiety-like and aggressive behavior are shaped by social experiences during adolescence and serotonin transporter (5-HTT) genotype. For this purpose, male mice of a 5-HTT knockout mouse model including all three genotypes (wildtype, heterozygous and homozygous 5-HTT knockout mice) were either exposed to an adverse social situation or a beneficial social environment during adolescence. This was accomplished in a custom-made cage system where mice experiencing the adverse environment were repeatedly introduced to the territory of a dominant opponent but had the possibility to escape to a refuge cage. Mice encountering beneficial social conditions had free access to a female mating partner. Afterwards, anxiety-like and aggressive behavior was assessed in a battery of tests. Surprisingly, unfavorable conditions during adolescence led to a decrease in anxiety-like behavior and an increase in exploratory locomotion. Additionally, aggressive behavior was augmented in animals that experienced social adversity. Concerning genotype, homozygous 5-HTT knockout mice were more anxious and less aggressive than heterozygous 5-HTT knockout and wildtype mice. In summary, adolescence is clearly an important phase in which anxiety-like and aggressive behavior can be shaped. Furthermore, it seems that having to cope with challenge during adolescence instead of experiencing throughout beneficial social conditions leads to reduced levels of anxiety-like behavior. KW - adolescence KW - aggressiveness KW - serotonin transporter KW - coping with challenge KW - adversity KW - anxiety-like behavior KW - social experience KW - 5-HTT knockout mice Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-165090 VL - 10 IS - 97 ER - TY - JOUR A1 - Kloke, Vanessa A1 - Schreiber, Rebecca S. A1 - Bodden, Carina A1 - Möllers, Julian A1 - Ruhmann, Hanna A1 - Kaiser, Sylvia A1 - Lesch, Klaus-Peter A1 - Sachser, Norbert A1 - Lewejohann, Lars T1 - Hope for the Best or Prepare for the Worst? Towards a Spatial Cognitive Bias Test for Mice JF - PLOS ONE N2 - Cognitive bias, the altered information processing resulting from the background emotional state of an individual, has been suggested as a promising new indicator of animal emotion. Comparable to anxious or depressed humans, animals in a putatively negative emotional state are more likely to judge an ambiguous stimulus as if it predicts a negative event, than those in positive states. The present study aimed to establish a cognitive bias test for mice based on a spatial judgment task and to apply it in a pilot study to serotonin transporter (5-HTT) knockout mice, a well-established mouse model for the study of anxiety- and depression-related behavior. In a first step, we validated that our setup can assess different expectations about the outcome of an ambiguous stimulus: mice having learned to expect something positive within a maze differed significantly in their behavior towards an unfamiliar location than animals having learned to expect something negative. In a second step, the use of spatial location as a discriminatory stimulus was confirmed by showing that mice interpret an ambiguous stimulus depending on its spatial location, with a position exactly midway between a positive and a negative reference point provoking the highest level of ambiguity. Finally, the anxiety- and depression-like phenotype of the 5-HTT knockout mouse model manifested - comparable to human conditions - in a trend for a negatively distorted interpretation of ambiguous information, albeit this effect was not statistically significant. The results suggest that the present cognitive bias test provides a useful basis to study the emotional state in mice, which may not only increase the translational value of animal models in the study of human affective disorders, but which is also a central objective of animal welfare research. KW - emotional information KW - serotonin transporter gene KW - attentional bias KW - laboratory environment KW - animal behavior KW - promoter region KW - deficient mice KW - affective state KW - knockout mice KW - judgement bias Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-115569 VL - 9 IS - 8 ER - TY - JOUR A1 - Bodden, Carina A1 - Richter, S. Helene A1 - Schreiber, Rebecca S. A1 - Kloke, Vanessa A1 - Gerß, Joachim A1 - Palme, Rupert A1 - Lesch, Klaus-Peter A1 - Lewejohann, Lars A1 - Kaiser, Sylvia A1 - Sachser, Norbert T1 - Benefits of adversity?! How life history affects the behavioral profile of mice varying in serotonin transporter genotype JF - Frontiers in Behavioral Neuroscience N2 - 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-HIT) 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. KW - anxiety-like behavior KW - maternal care KW - dangerous world KW - animal behavior KW - match-mismatch KW - chronic social stress KW - elevated plus-maze KW - 5-HTT KW - life history KW - predictive adaptive response hypothesis KW - developmental plasticity KW - knockout mice KW - environmental enrichment KW - allostatic load Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-143723 VL - 9 IS - 47 ER -