@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{LuekenKuhnYangetal.2017,
  author    = {Lueken, U and Kuhn, M and Yang, Y and Straube, B and Kircher, T and Wittchen, H-U and Pfleiderer, B and Arolt, V and Wittmann, A and Str{\"o}hle, A and Weber, H and Reif, A and Domschke, K and Deckert, J and Lonsdorf, TB},
  title     = {Modulation of defensive reactivity by GLRB allelic variation: converging evidence from an intermediate phenotype approach},
  series = {Translational Psychiatry},
  volume    = {7},
  journal   = {Translational Psychiatry},
  number    = {e1227},
  doi       = {10.1038/tp.2017.186},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-182381},
  year      = {2017},
  abstract  = {Representing a phylogenetically old and very basic mechanism of inhibitory neurotransmission, glycine receptors have been implicated in the modulation of behavioral components underlying defensive responding toward threat. As one of the first findings being confirmed by genome-wide association studies for the phenotype of panic disorder and agoraphobia, allelic variation in a gene coding for the glycine receptor beta subunit (GLRB) has recently been associated with increased neural fear network activation and enhanced acoustic startle reflexes. On the basis of two independent healthy control samples, we here aimed to further explore the functional significance of the GLRB genotype (rs7688285) by employing an intermediate phenotype approach. We focused on the phenotype of defensive system reactivity across the levels of brain function, structure, and physiology. Converging evidence across both samples was found for increased neurofunctional activation in the (anterior) insular cortex in GLRB risk allele carriers and altered fear conditioning as a function of genotype. The robustness of GLRB effects is demonstrated by consistent findings across different experimental fear conditioning paradigms and recording sites. Altogether, findings provide translational evidence for glycine neurotransmission as a modulator of the brain's evolutionary old dynamic defensive system and provide further support for a strong, biologically plausible candidate intermediate phenotype of defensive reactivity. As such, glycine-dependent neurotransmission may open up new avenues for mechanistic research on the etiopathogenesis of fear and anxiety disorders.},
  language  = {en}
}