title: LRRTM1-deficient mice show a rare phenotype of avoiding small enclosures--a tentative mouse model for claustrophobia-like behaviour.
abstract: The LRRTM family proteins have been shown to act as synaptogenic cell adhesion molecules via interaction with presynaptic neurexins and are associated with neuropsychiatric disorders. LRRTM1-knockout mice have subtle morphological deficits in excitatory hippocampal synapses and were suggested to have impaired cognitive function. Here we report that LRRTM1-knockout mice exhibit an extraordinary phenotype of avoiding small enclosures. In the light-dark box, the knockout mice escape to dark through a standard opening as quickly as wild-type littermates but avoid escaping through a small doorway. While all wild-type mice spontaneously enter a small tube, most knockout mice do not. This apparent aversion to enter narrow space may explain other abnormalities such as increased time in open arms in the elevated plus maze and less visits through a tunnel in the IntelliCage. Moreover, LRRTM1-knockout mice show increased social interaction, reduced nest building and MK801-induced locomotion, and slower swim speed but normal water maze learning. Since LRRTM1 is predominantly expressed in thalamus, hippocampus and limbic cortex, specific synaptic defects in those areas presumably cause these behavioural abnormalities.
authors.affiliation: Neuroscience Center, University of Helsinki, Finland.|Department of Biosciences, University of Helsinki, Finland.
authors.forename: V
authors.initials: V
authors.lastname: Voikar
authors.affiliation: Neuroscience Center, University of Helsinki, Finland.|Department of Biosciences, University of Helsinki, Finland.
authors.forename: N
authors.initials: N
authors.lastname: Kulesskaya
authors.affiliation: Neuroscience Center, University of Helsinki, Finland.
authors.forename: T
authors.initials: T
authors.lastname: Laakso
authors.affiliation: Cellular Neuroscience, Neurodegeneration, and Repair Program, and Departments of Neurology and Neurobiology, Yale School of Medicine, New Haven, CT, USA.
authors.forename: J
authors.initials: J
authors.lastname: Lauren
authors.affiliation: Cellular Neuroscience, Neurodegeneration, and Repair Program, and Departments of Neurology and Neurobiology, Yale School of Medicine, New Haven, CT, USA.
authors.forename: S M
authors.initials: SM
authors.lastname: Strittmatter
authors.affiliation: Neuroscience Center, University of Helsinki, Finland.|Institute of Biomedicine, University of Helsinki, Finland.
authors.forename: M S
authors.initials: MS
authors.lastname: Airaksinen
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D004195:Disease Models, Animal; D018782:Maze Learning / Q000502:physiology; D008565:Membrane Proteins; D051379:Mice; D018345:Mice, Knockout; D009043:Motor Activity / Q000502:physiology*; D009419:Nerve Tissue Proteins; D019006:Neural Cell Adhesion Molecules / Q000235:genetics* / Q000378:metabolism; D010641:Phenotype; D010698:Phobic Disorders / Q000235:genetics* / Q000378:metabolism; D012919:Social Behavior; D013550:Swimming / Q000502:physiology
chemical_list: C561490:LRRTM1 protein, mouse; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D019006:Neural Cell Adhesion Molecules