@article{SchaeferSignoretGenestvonCollenbergetal.2020,
  author    = {Schaefer, Natascha and Signoret-Genest, J{\´e}r{\´e}my and von Collenberg, Cora R. and Wachter, Britta and Deckert, J{\"u}rgen and Tovote, Philip and Blum, Robert and Villmann, Carmen},
  title     = {Anxiety and Startle Phenotypes in Glrb Spastic and Glra1 Spasmodic Mouse Mutants},
  series = {Frontiers in Molecular Neuroscience},
  volume    = {13},
  journal   = {Frontiers in Molecular Neuroscience},
  number    = {152},
  issn      = {1662-5099},
  doi       = {10.3389/fnmol.2020.00152},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-210041},
  year      = {2020},
  abstract  = {A GWAS study recently demonstrated single nucleotide polymorphisms (SNPs) in the human GLRB gene of individuals with a prevalence for agoraphobia. GLRB encodes the glycine receptor (GlyRs) β subunit. The identified SNPs are localized within the gene flanking regions (3′ and 5′ UTRs) and intronic regions. It was suggested that these nucleotide polymorphisms modify GlyRs expression and phenotypic behavior in humans contributing to an anxiety phenotype as a mild form of hyperekplexia. Hyperekplexia is a human neuromotor disorder with massive startle phenotypes due to mutations in genes encoding GlyRs subunits. GLRA1 mutations have been more commonly observed than GLRB mutations. If an anxiety phenotype contributes to the hyperekplexia disease pattern has not been investigated yet. Here, we compared two mouse models harboring either a mutation in the murine Glra1 or Glrb gene with regard to anxiety and startle phenotypes. Homozygous spasmodic animals carrying a Glra1 point mutation (alanine 52 to serine) displayed abnormally enhanced startle responses. Moreover, spasmodic mice exhibited significant changes in fear-related behaviors (freezing, rearing and time spent on back) analyzed during the startle paradigm, even in a neutral context. Spastic mice exhibit reduced expression levels of the full-length GlyRs β subunit due to aberrant splicing of the Glrb gene. Heterozygous animals appear normal without an obvious behavioral phenotype and thus might reflect the human situation analyzed in the GWAS study on agoraphobia and startle. In contrast to spasmodic mice, heterozygous spastic animals revealed no startle phenotype in a neutral as well as a conditioning context. Other mechanisms such as a modulatory function of the GlyRs β subunit within glycinergic circuits in neuronal networks important for fear and fear-related behavior may exist. Possibly, in human additional changes in fear and fear-related circuits either due to gene-gene interactions e.g., with GLRA1 genes or epigenetic factors are necessary to create the agoraphobia and in particular the startle phenotype.},
  language  = {en}
}
@article{PfeifferGoetzXiangetal.2013,
  author    = {Pfeiffer, Verena and G{\"o}tz, Rudolf and Xiang, Chaomei and Camarero, Guadelupe and Braun, Attila and Zhang, Yina and Blum, Robert and Heinsen, Helmut and Nieswandt, Bernhard and Rapp, Ulf R.},
  title     = {Ablation of BRaf Impairs Neuronal Differentiation in the Postnatal Hippocampus and Cerebellum},
  series = {PLoS ONE},
  volume    = {8},
  journal   = {PLoS ONE},
  number    = {3},
  doi       = {10.1371/journal.pone.0058259},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130304},
  pages     = {e58259},
  year      = {2013},
  abstract  = {This study focuses on the role of the kinase BRaf in postnatal brain development. Mice expressing truncated, non-functional BRaf in neural stem cell-derived brain tissue demonstrate alterations in the cerebellum, with decreased sizes and fuzzy borders of the glomeruli in the granule cell layer. In addition we observed reduced numbers and misplaced ectopic Purkinje cells that showed an altered structure of their dendritic arborizations in the hippocampus, while the overall cornus ammonis architecture appeared to be unchanged. In male mice lacking BRaf in the hippocampus the size of the granule cell layer was normal at postnatal day 12 (P12) but diminished at P21, as compared to control littermates. This defect was caused by a reduced ability of dentate gyrus progenitor cells to differentiate into NeuN positive granule cell neurons. In vitro cell culture of P0/P1 hippocampal cells revealed that BRaf deficient cells were impaired in their ability to form microtubule-associated protein 2 positive neurons. Together with the alterations in behaviour, such as autoaggression and loss of balance fitness, these observations indicate that in the absence of BRaf all neuronal cellular structures develop, but neuronal circuits in the cerebellum and hippocampus are partially disturbed besides impaired neuronal generation in both structures.},
  language  = {en}
}