@article{StraubeReifRichteretal.2014,
  author    = {Straube, B. and Reif, A. and Richter, J. and Lueken, U. and Weber, H. and Arolt, V. and Jansen, A. and Zwanzger, P. and Domschke, K. and Pauli, P. and Konrad, C. and Gerlach, A. L. and Lang, T. and Fydrich, T. and Alpers, G. W. and Stroehle, A. and Wittmann, A. and Pfleiderer, B. and Wittchen, H.-U. and Hamm, A. and Deckert, J. and Kircher, T.},
  title     = {The functional - 1019C/G HTR1A polymorphism and mechanisms of fear},
  series = {Translational Psychiatry},
  volume    = {4},
  journal   = {Translational Psychiatry},
  issn      = {2158-3188},
  doi       = {10.1038/tp.2014.130},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-114369},
  pages     = {e490},
  year      = {2014},
  abstract  = {Serotonin receptor 1A gene (HTR1A) knockout mice show pronounced defensive behaviour and increased fear conditioning to ambiguous conditioned stimuli. Such behaviour is a hallmark of pathological human anxiety, as observed in panic disorder with agoraphobia (PD/AG). Thus, variations in HTR1A might contribute to neurophysiological differences within subgroups of PD/AG patients. Here, we tested this hypothesis by combining genetic with behavioural techniques and neuroimaging. In a clinical multicentre trial, patients with PD/AG received 12 sessions of manualized cognitive-behavioural therapy (CBT) and were genotyped for HTR1A rs6295. In four subsamples of this multicentre trial, exposure behaviour (n = 185), defensive reactivity measured using a behavioural avoidance test (BAT; before CBT: n = 245; after CBT: n = 171) and functional magnetic resonance imaging (fMRI) data during fear conditioning were acquired before and after CBT (n = 39). HTR1A risk genotype (GG) carriers more often escaped during the BAT before treatment. Exploratory fMRI results suggest increased activation of the amygdala in response to threat as well as safety cues before and after treatment in GG carriers. Furthermore, GG carriers demonstrated reduced effects of CBT on differential conditioning in regions including the bilateral insulae and the anterior cingulate cortex. Finally, risk genotype carriers demonstrated reduced self-initiated exposure behaviour to aversive situations. This study demonstrates the effect of HTR1A variation on defensive behaviour, amygdala activity, CBT-induced neural plasticity and normalization of defence behaviour in PD/AG. Our results, therefore, translate evidence from animal studies to humans and suggest a central role for HTR1A in differentiating subgroups of patients with anxiety disorders.},
  language  = {en}
}
@article{SchrautJakobWeidneretal.2014,
  author    = {Schraut, K. G. and Jakob, S. B. and Weidner, M. T. and Schmitt, A. G. and Scholz, C. J. and Strekalova, T. and El Hajj, N. and Eijssen, L. M. T. and Domschke, K. and Reif, A. and Haaf, T. and Ortega, G. and Steinbusch, H. W. M. and Lesch, K. P. and Van den Hove, D. L.},
  title     = {Prenatal stress-induced programming of genome-wide promoter DNA methylation in 5-HTT-deficient mice},
  series = {Translational Psychiatry},
  volume    = {4},
  journal   = {Translational Psychiatry},
  doi       = {10.1038/tp.2014.107},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-119199},
  pages     = {e473},
  year      = {2014},
  abstract  = {The serotonin transporter gene (5-HTT/SLC6A4)-linked polymorphic region has been suggested to have a modulatory role in mediating effects of early-life stress exposure on psychopathology rendering carriers of the low-expression short (s)-variant more vulnerable to environmental adversity in later life. The underlying molecular mechanisms of this gene-by-environment interaction are not well understood, but epigenetic regulation including differential DNA methylation has been postulated to have a critical role. Recently, we used a maternal restraint stress paradigm of prenatal stress (PS) in 5-HTT-deficient mice and showed that the effects on behavior and gene expression were particularly marked in the hippocampus of female 5-Htt+/- offspring. Here, we examined to which extent these effects are mediated by differential methylation of DNA. For this purpose, we performed a genome-wide hippocampal DNA methylation screening using methylated-DNA immunoprecipitation (MeDIP) on Affymetrix GeneChip Mouse Promoter 1.0 R arrays. Using hippocampal DNA from the same mice as assessed before enabled us to correlate gene-specific DNA methylation, mRNA expression and behavior. We found that 5-Htt genotype, PS and their interaction differentially affected the DNA methylation signature of numerous genes, a subset of which showed overlap with the expression profiles of the corresponding transcripts. For example, a differentially methylated region in the gene encoding myelin basic protein (Mbp) was associated with its expression in a 5-Htt-, PS- and 5-Htt × PS-dependent manner. Subsequent fine-mapping of this Mbp locus linked the methylation status of two specific CpG sites to Mbp expression and anxiety-related behavior. In conclusion, hippocampal DNA methylation patterns and expression profiles of female prenatally stressed 5-Htt+/- mice suggest that distinct molecular mechanisms, some of which are promoter methylation-dependent, contribute to the behavioral effects of the 5-Htt genotype, PS exposure and their interaction.},
  language  = {en}
}