@article{KlokeSchreiberBoddenetal.2014,
  author    = {Kloke, Vanessa and Schreiber, Rebecca S. and Bodden, Carina and M{\"o}llers, Julian and Ruhmann, Hanna and Kaiser, Sylvia and Lesch, Klaus-Peter and Sachser, Norbert and Lewejohann, Lars},
  title     = {Hope for the Best or Prepare for the Worst? Towards a Spatial Cognitive Bias Test for Mice},
  series = {PLOS ONE},
  volume    = {9},
  journal   = {PLOS ONE},
  number    = {8},
  doi       = {10.1371/journal.pone.0105431},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-115569},
  pages     = {e105431},
  year      = {2014},
  abstract  = {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.},
  language  = {en}
}
@article{AraragiMlinarBaccinietal.2013,
  author    = {Araragi, Naozumi and Mlinar, Boris and Baccini, Gilda and Gutknecht, Lise and Lesch, Klaus-Peter and Corradetti, Renato},
  title     = {Conservation of 5-HT1A receptor-mediated autoinhibition of serotonin (5-HT) neurons in mice with altered 5-HT homeostasis},
  series = {Frontiers in Neuropharmacology},
  journal   = {Frontiers in Neuropharmacology},
  doi       = {10.3389/fphar.2013.00097},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97098},
  year      = {2013},
  abstract  = {Firing activity of serotonin (5-HT) neurons in the dorsal raphe nucleus (DRN) is controlled by inhibitory somatodendritic 5-HT1A autoreceptors. This autoinhibitory mechanism is implicated in the etiology of disorders of emotion regulation, such as anxiety disorders and depression, as well as in the mechanism of antidepressant action. Here, we investigated how persistent alterations in brain 5-HT availability affect autoinhibition in two genetically modified mouse models lacking critical mediators of serotonergic transmission: 5-HT transporter knockout (Sert-/-) and tryptophan hydroxylase-2 knockout (Tph2-/-) mice. The degree of autoinhibition was assessed by loose-seal cell-attached recording in DRN slices. First, application of the 5-HT1A-selective agonist R(+)-8-hydroxy-2-(di-n-propylamino)tetralin showed mild sensitization and marked desensitization of 5-HT1A receptors in Tph2-/- mice and Sert-/- mice, respectively. While 5-HT neurons from Tph2-/- mice did not display autoinhibition in response to L-tryptophan, autoinhibition of these neurons was unaltered in Sert-/- mice despite marked desensitization of their 5-HT1A autoreceptors. When the Tph2-dependent 5-HT synthesis step was bypassed by application of 5-hydroxy-L-tryptophan (5-HTP), neurons from both Tph2-/- and Sert-/- mice decreased their firing rates at significantly lower concentrations of 5-HTP compared to wildtype controls. Our findings demonstrate that, as opposed to the prevalent view, sensitivity of somatodendritic 5-HT1A receptors does not predict the magnitude of 5-HT neuron autoinhibition. Changes in 5-HT1A receptor sensitivity may rather be seen as an adaptive mechanism to keep autoinhibition functioning in response to extremely altered levels of extracellular 5-HT resulting from targeted inactivation of mediators of serotonergic signaling.},
  language  = {en}
}
@article{RiveroReifSanjuanetal.2010,
  author    = {Rivero, Olga and Reif, Andreas and Sanjuan, Julio and Molto, Maria D. and Kittel-Schneider, Sarah and Najera, Carmen and Toepner, Theresia and Lesch, Klaus-Peter},
  title     = {Impact of the AHI1 Gene on the Vulnerability to Schizophrenia: A Case-Control Association Study},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-68501},
  year      = {2010},
  abstract  = {Background: The Abelson helper integration-1 (AHI1) gene is required for both cerebellar and cortical development in humans. While the accelerated evolution of AHI1 in the human lineage indicates a role in cognitive (dys)function, a linkage scan in large pedigrees identified AHI1 as a positional candidate for schizophrenia. To further investigate the contribution of AHI1 to the susceptibility of schizophrenia, we evaluated the effect of AHI1 variation on the vulnerability to psychosis in two samples from Spain and Germany. Methodology/Principal Findings: 29 single-nucleotide polymorphisms (SNPs) located in a genomic region including the AHI1 gene were genotyped in two samples from Spain (280 patients with psychotic disorders; 348 controls) and Germany (247 patients with schizophrenic disorders; 360 controls). Allelic, genotypic and haplotype frequencies were compared between cases and controls in both samples separately, as well as in the combined sample. The effect of genotype on several psychopathological measures (BPRS, KGV, PANSS) assessed in a Spanish subsample was also evaluated. We found several significant associations in the Spanish sample. Particularly, rs7750586 and rs911507, both located upstream of the AHI1 coding region, were found to be associated with schizophrenia in the analysis of genotypic (p = 0.0033, and 0.031,respectively) and allelic frequencies (p = 0.001 in both cases). Moreover, several other risk and protective haplotypes were detected (0.006,p,0.036). Joint analysis also supported the association of rs7750586 and rs911507 with the risk for schizophrenia. The analysis of clinical measures also revealed an effect on symptom severity (minimum P value = 0.0037). Conclusions/Significance: Our data support, in agreement with previous reports, an effect of AHI1 variation on the susceptibility to schizophrenia in central and southern European populations.},
  subject      = {Schizophrenie},
  language  = {en}
}