title: Lsamp is implicated in the regulation of emotional and social behavior by use of alternative promoters in the brain.
abstract: Limbic system-associated membrane protein (LSAMP) is a neural cell adhesion molecule involved in neurite formation and outgrowth. The purpose of the present study was to characterize the distribution of alternatively transcribed Lsamp isoforms in the mouse brain and its implications on the regulation of behavior. Limbic system-associated membrane protein 1b transcript was visualized by using a mouse strain expressing beta-galactosidase under the control of Lsamp 1b promoter. The distribution of Lsamp 1a transcript and summarized expression of the Lsamp transcripts was investigated by non-radioactive in situ RNA hybridization analysis. Cross-validation was performed by using radioactive in situ hybridization with oligonucleotide probes. Quantitative RT-PCR was used to study correlations between the expression of Lsamp isoforms and behavioral parameters. The expression pattern of two promoters differs remarkably from the developmental initiation at embryonic day 12.5. Limbic system-associated membrane protein 1a promoter is active in "classic" limbic structures where the hippocampus and amygdaloid area display the highest expression. Promoter 1b is mostly active in the thalamic sensory nuclei and cortical sensory areas, but also in areas that regulate stress and arousal. Higher levels of Lsamp 1a transcript had significant correlations with all of the measures indicating higher trait anxiety in the elevated plus-maze test. Limbic system-associated membrane protein transcript levels in the hippocampus and ventral striatum correlated with behavioral parameters in the social interaction test. The data are in line with decreased anxiety and alterations in social behavior in Lsamp-deficient mice. We propose that Lsamp is involved in emotional and social operating systems by complex regulation of two alternative promoters.
authors.affiliation: Department of Physiology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, 50411, Estonia, maphilips@gmail.com.
authors.forename: Mari-Anne
authors.initials: MA
authors.lastname: Philips
authors.forename: Kersti
authors.initials: K
authors.lastname: Lilleväli
authors.forename: Indrek
authors.initials: I
authors.lastname: Heinla
authors.forename: Hendrik
authors.initials: H
authors.lastname: Luuk
authors.forename: Christian Ansgar
authors.initials: CA
authors.lastname: Hundahl
authors.forename: Karina
authors.initials: K
authors.lastname: Kongi
authors.forename: Taavi
authors.initials: T
authors.lastname: Vanaveski
authors.forename: Triin
authors.initials: T
authors.lastname: Tekko
authors.forename: Jürgen
authors.initials: J
authors.lastname: Innos
authors.forename: Eero
authors.initials: E
authors.lastname: Vasar
mesh_terms: D000367:Age Factors; D000818:Animals; D001007:Anxiety / Q000378:metabolism; D001921:Brain / Q000196:embryology / Q000378:metabolism*; D015816:Cell Adhesion Molecules, Neuronal / Q000378:metabolism*; D004644:Emotions / Q000502:physiology*; D058851:GPI-Linked Proteins / Q000378:metabolism; D008032:Limbic System / Q000196:embryology / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D011401:Promoter Regions, Genetic; D020033:Protein Isoforms / Q000378:metabolism; D012919:Social Behavior
chemical_list: D015816:Cell Adhesion Molecules, Neuronal; D058851:GPI-Linked Proteins; D020033:Protein Isoforms; C095362:limbic system-associated membrane protein