Analysis of neuroanatomical differences in mice with genetically modified serotonin transporters assessed by structural magnetic resonance imaging / J. ELLEGOOD in Molecular Autism, 9 (2018)  

Public ISBD [article]  inMolecular Autism > 9 (2018) . - 24p. Titre : Analysis of neuroanatomical differences in mice with genetically modified serotonin transporters assessed by structural magnetic resonance imaging Type de document : Texte imprimé et/ou numérique Auteurs : J. ELLEGOOD, Auteur ; Y. YEE, Auteur ; T. M. KERR, Auteur ; C. L. MULLER, Auteur ; R. D. BLAKELY, Auteur ; R. M. HENKELMAN, Auteur ; J. VEENSTRA-VANDERWEELE, Auteur ; J. P. LERCH, Auteur Article en page(s) : 24p. Langues : Anglais (eng) Mots-clés : Animals  Brain/diagnostic imaging/metabolism  Female  Magnetic Resonance Imaging  Male  Mice  Mice, Inbred C57BL  Mutation  Neurons/metabolism  Serotonin/metabolism  Serotonin Plasma Membrane Transport Proteins/genetics/metabolism  5-ht  5htt  Brain  Dorsal raphe  Magnetic resonance imaging  Neurodevelopment  Serotonin  Slc6a4 Index. décimale : PER Périodiques Résumé : Background: The serotonin (5-HT) system has long been implicated in autism spectrum disorder (ASD) as indicated by elevated whole blood and platelet 5-HT, altered platelet and brain receptor and transporter binding, and genetic linkage and association findings. Based upon work in genetically modified mice, 5-HT is known to influence several aspects of brain development, but systematic neuroimaging studies have not previously been reported. In particular, the 5-HT transporter (serotonin transporter, SERT; 5-HTT) gene, Slc6a4, has been extensively studied. Methods: Using a 7-T MRI and deformation-based morphometry, we assessed neuroanatomical differences in an Slc6a4 knockout mouse on a C57BL/6 genetic background, along with an Slc6a4 Ala56 knockin mouse on two different genetic backgrounds (129S and C57BL/6). Results: Individually (same sex, same background, same genotype), the only differences found were in the female Slc6a4 knockout mouse; all the others had no significant differences. However, an analysis of variance across the whole study sample revealed a significant effect of Slc6a4 on the amygdala, thalamus, dorsal raphe nucleus, and lateral and frontal cortices. Conclusions: This work shows that an increase or decrease in SERT function has a significant effect on the neuroanatomy in 5-HT relevant regions, particularly the raphe nuclei. Notably, the Slc6a4 Ala56 knockin alone appears to have an insignificant, but suggestive, effect compared to the KO, which is consistent with Slc6a4 function. Despite the small number of 5-HT neurons and their localization to the brainstem, it is clear that 5-HT plays an important role in neuroanatomical organization. En ligne : https://dx.doi.org/10.1186/s13229-018-0210-z Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=371 [article] Analysis of neuroanatomical differences in mice with genetically modified serotonin transporters assessed by structural magnetic resonance imaging [Texte imprimé et/ou numérique] / J. ELLEGOOD, Auteur ; Y. YEE, Auteur ; T. M. KERR, Auteur ; C. L. MULLER, Auteur ; R. D. BLAKELY, Auteur ; R. M. HENKELMAN, Auteur ; J. VEENSTRA-VANDERWEELE, Auteur ; J. P. LERCH, Auteur . - 24p. Langues : Anglais (eng) in Molecular Autism > 9 (2018) . - 24p. Mots-clés : Animals  Brain/diagnostic imaging/metabolism  Female  Magnetic Resonance Imaging  Male  Mice  Mice, Inbred C57BL  Mutation  Neurons/metabolism  Serotonin/metabolism  Serotonin Plasma Membrane Transport Proteins/genetics/metabolism  5-ht  5htt  Brain  Dorsal raphe  Magnetic resonance imaging  Neurodevelopment  Serotonin  Slc6a4 Index. décimale : PER Périodiques Résumé : Background: The serotonin (5-HT) system has long been implicated in autism spectrum disorder (ASD) as indicated by elevated whole blood and platelet 5-HT, altered platelet and brain receptor and transporter binding, and genetic linkage and association findings. Based upon work in genetically modified mice, 5-HT is known to influence several aspects of brain development, but systematic neuroimaging studies have not previously been reported. In particular, the 5-HT transporter (serotonin transporter, SERT; 5-HTT) gene, Slc6a4, has been extensively studied. Methods: Using a 7-T MRI and deformation-based morphometry, we assessed neuroanatomical differences in an Slc6a4 knockout mouse on a C57BL/6 genetic background, along with an Slc6a4 Ala56 knockin mouse on two different genetic backgrounds (129S and C57BL/6). Results: Individually (same sex, same background, same genotype), the only differences found were in the female Slc6a4 knockout mouse; all the others had no significant differences. However, an analysis of variance across the whole study sample revealed a significant effect of Slc6a4 on the amygdala, thalamus, dorsal raphe nucleus, and lateral and frontal cortices. Conclusions: This work shows that an increase or decrease in SERT function has a significant effect on the neuroanatomy in 5-HT relevant regions, particularly the raphe nuclei. Notably, the Slc6a4 Ala56 knockin alone appears to have an insignificant, but suggestive, effect compared to the KO, which is consistent with Slc6a4 function. Despite the small number of 5-HT neurons and their localization to the brainstem, it is clear that 5-HT plays an important role in neuroanatomical organization. En ligne : https://dx.doi.org/10.1186/s13229-018-0210-z Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=371

Effects of a social stimulus on gene expression in a mouse model of fragile X syndrome / T. D. ROGERS in Molecular Autism, 8 (2017)  

Public ISBD [article]  inMolecular Autism > 8 (2017) . - 30p. Titre : Effects of a social stimulus on gene expression in a mouse model of fragile X syndrome Type de document : Texte imprimé et/ou numérique Auteurs : T. D. ROGERS, Auteur ; A. M. J. ANACKER, Auteur ; T. M. KERR, Auteur ; C. G. FORSBERG, Auteur ; J. WANG, Auteur ; B. ZHANG, Auteur ; J. VEENSTRA-VANDERWEELE, Auteur Article en page(s) : 30p. Langues : Anglais (eng) Mots-clés : Amygdala  Autism spectrum disorder  Fragile X syndrome  Prefrontal cortex  RNA sequencing  Social behavior Index. décimale : PER Périodiques Résumé : BACKGROUND: People with fragile X syndrome (FXS) often have deficits in social behavior, and a substantial portion meet criteria for autism spectrum disorder. Though the genetic cause of FXS is known to be due to the silencing of FMR1, and the Fmr1 null mouse model representing this lesion has been extensively studied, the contributions of this gene and its protein product, FMRP, to social behavior are not well understood. METHODS: Fmr1 null mice and wildtype littermates were exposed to a social or non-social stimulus. In one experiment, subjects were assessed for expression of the inducible transcription factor c-Fos in response to the stimulus, to detect brain regions with social-specific activity. In a separate experiment, tissue was taken from those brain regions showing differential activity, and RNA sequencing was performed. RESULTS: Immunohistochemistry revealed a significantly greater number of c-Fos-positive cells in the lateral amygdala and medial amygdala in the brains of mice exposed to a social stimulus, compared to a non-social stimulus. In the prelimbic cortex, there was no significant effect of social stimulus; although the number of c-Fos-positive cells was lower in the social condition compared to the non-social condition, and negatively correlated with c-Fos in the amygdala. RNA sequencing revealed differentially expressed genes enriched for molecules known to interact with FMRP and also for autism-related genes identified in the Simons Foundation Autism Research Initiative gene database. Ingenuity Pathway Analysis detected enrichment of differentially expressed genes in networks and pathways related to neuronal development, intracellular signaling, and inflammatory response. CONCLUSIONS: Using the Fmr1 null mouse model of fragile X syndrome, we have identified brain regions, gene networks, and molecular pathways responsive to a social stimulus. These findings, and future experiments following up on the role of specific gene networks, may shed light on the neural mechanisms underlying dysregulated social behaviors in fragile X syndrome and more broadly. En ligne : http://dx.doi.org/10.1186/s13229-017-0148-6 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=330 [article] Effects of a social stimulus on gene expression in a mouse model of fragile X syndrome [Texte imprimé et/ou numérique] / T. D. ROGERS, Auteur ; A. M. J. ANACKER, Auteur ; T. M. KERR, Auteur ; C. G. FORSBERG, Auteur ; J. WANG, Auteur ; B. ZHANG, Auteur ; J. VEENSTRA-VANDERWEELE, Auteur . - 30p. Langues : Anglais (eng) in Molecular Autism > 8 (2017) . - 30p. Mots-clés : Amygdala  Autism spectrum disorder  Fragile X syndrome  Prefrontal cortex  RNA sequencing  Social behavior Index. décimale : PER Périodiques Résumé : BACKGROUND: People with fragile X syndrome (FXS) often have deficits in social behavior, and a substantial portion meet criteria for autism spectrum disorder. Though the genetic cause of FXS is known to be due to the silencing of FMR1, and the Fmr1 null mouse model representing this lesion has been extensively studied, the contributions of this gene and its protein product, FMRP, to social behavior are not well understood. METHODS: Fmr1 null mice and wildtype littermates were exposed to a social or non-social stimulus. In one experiment, subjects were assessed for expression of the inducible transcription factor c-Fos in response to the stimulus, to detect brain regions with social-specific activity. In a separate experiment, tissue was taken from those brain regions showing differential activity, and RNA sequencing was performed. RESULTS: Immunohistochemistry revealed a significantly greater number of c-Fos-positive cells in the lateral amygdala and medial amygdala in the brains of mice exposed to a social stimulus, compared to a non-social stimulus. In the prelimbic cortex, there was no significant effect of social stimulus; although the number of c-Fos-positive cells was lower in the social condition compared to the non-social condition, and negatively correlated with c-Fos in the amygdala. RNA sequencing revealed differentially expressed genes enriched for molecules known to interact with FMRP and also for autism-related genes identified in the Simons Foundation Autism Research Initiative gene database. Ingenuity Pathway Analysis detected enrichment of differentially expressed genes in networks and pathways related to neuronal development, intracellular signaling, and inflammatory response. CONCLUSIONS: Using the Fmr1 null mouse model of fragile X syndrome, we have identified brain regions, gene networks, and molecular pathways responsive to a social stimulus. These findings, and future experiments following up on the role of specific gene networks, may shed light on the neural mechanisms underlying dysregulated social behaviors in fragile X syndrome and more broadly. En ligne : http://dx.doi.org/10.1186/s13229-017-0148-6 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=330

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