@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{vonCollenbergSchmittRuelickeetal.2019,
  author    = {von Collenberg, Cora R. and Schmitt, Dominique and R{\"u}licke, Thomas and Sendtner, Michael and Blum, Robert and Buchner, Erich},
  title     = {An essential role of the mouse synapse-associated protein Syap1 in circuits for spontaneous motor activity and rotarod balance},
  series = {Biology Open},
  volume    = {8},
  journal   = {Biology Open},
  doi       = {10.1242/bio.042366},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-201986},
  pages     = {bio042366},
  year      = {2019},
  abstract  = {Synapse-associated protein 1 (Syap1) is the mammalian homologue of synapse-associated protein of 47 kDa (Sap47) in Drosophila. Genetic deletion of Sap47 leads to deficiencies in short-term plasticity and associative memory processing in flies. In mice, Syap1 is prominently expressed in the nervous system, but its function is still unclear. We have generated Syap1 knockout mice and tested motor behaviour and memory. These mice are viable and fertile but display distinct deficiencies in motor behaviour. Locomotor activity specifically appears to be reduced in early phases when voluntary movement is initiated. On the rotarod, a more demanding motor test involving control by sensory feedback, Syap1-deficient mice dramatically fail to adapt to accelerated speed or to a change in rotation direction. Syap1 is highly expressed in cerebellar Purkinje cells and cerebellar nuclei. Thus, this distinct motor phenotype could be due to a so-far unknown function of Syap1 in cerebellar sensorimotor control. The observed motor defects are highly specific since other tests in the modified SHIRPA exam, as well as cognitive tasks like novel object recognition, Pavlovian fear conditioning, anxiety-like behaviour in open field dark-light transition and elevated plus maze do not appear to be affected in Syap1 knockout mice.},
  language  = {en}
}
@article{LueningschroerBinottiDombertetal.2017,
  author    = {L{\"u}ningschr{\"o}r, Patrick and Binotti, Beyenech and Dombert, Benjamin and Heimann, Peter and Perez-Lara, Angel and Slotta, Carsten and Thau-Habermann, Nadine and von Collenberg, Cora R. and Karl, Franziska and Damme, Markus and Horowitz, Arie and Maystadt, Isabelle and F{\"u}chtbauer, Annette and F{\"u}chtbauer, Ernst-Martin and Jablonka, Sibylle and Blum, Robert and {\"U}{\c{c}}eyler, Nurcan and Petri, Susanne and Kaltschmidt, Barbara and Jahn, Reinhard and Kaltschmidt, Christian and Sendtner, Michael},
  title     = {Plekhg5-regulated autophagy of synaptic vesicles reveals a pathogenic mechanism in motoneuron disease},
  series = {Nature Communications},
  volume    = {8},
  journal   = {Nature Communications},
  number    = {678},
  doi       = {10.1038/s41467-017-00689-z},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170048},
  year      = {2017},
  abstract  = {Autophagy-mediated degradation of synaptic components maintains synaptic homeostasis but also constitutes a mechanism of neurodegeneration. It is unclear how autophagy of synaptic vesicles and components of presynaptic active zones is regulated. Here, we show that Pleckstrin homology containing family member 5 (Plekhg5) modulates autophagy of synaptic vesicles in axon terminals of motoneurons via its function as a guanine exchange factor for Rab26, a small GTPase that specifically directs synaptic vesicles to preautophagosomal structures. Plekhg5 gene inactivation in mice results in a late-onset motoneuron disease, characterized by degeneration of axon terminals. Plekhg5-depleted cultured motoneurons show defective axon growth and impaired autophagy of synaptic vesicles, which can be rescued by constitutively active Rab26. These findings define a mechanism for regulating autophagy in neurons that specifically targets synaptic vesicles. Disruption of this mechanism may contribute to the pathophysiology of several forms of motoneuron disease.},
  language  = {en}
}