Browsing by Subject "Social Behavior"

Now showing 1 - 3 of 3
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    Characteristics of Bipolar I patients grouped by externalizing disorders
    (Elsevier, 2015-06-01) Swaminathan, Shanker; Koller, Daniel L.; Foroud, Tatiana; Edenberg, Howard J.; Xuei, Xiaoling; Niculescu, Alexander B.; Bipolar Genome Study (BiGS) Consortium; Nurnberger, John I.; Department of Psychiatry, IU School of Medicine
    BACKGROUND: Bipolar disorder co-occurs with a number of disorders with externalizing features. The aim of this study is to determine whether Bipolar I (BPI) subjects with comorbid externalizing disorders and a subgroup with externalizing symptoms prior to age 15 have different clinical features than those without externalizing disorders and whether these could be attributed to specific genetic variations. METHODS: A large cohort (N=2505) of Bipolar I subjects was analyzed. Course of illness parameters were compared between an Externalizing Group, an Early-Onset Subgroup and a Non-Externalizing Group in the Discovery sample (N=1268). Findings were validated using an independent set of 1237 BPI subjects (Validation sample). Genetic analyses were carried out. RESULTS: Subjects in the Externalizing Group (and Early-Onset Subgroup) tended to have a more severe clinical course, even in areas specifically related to mood disorder such as cycling frequency and rapid mood switching. Regression analysis showed that the differences are not completely explainable by substance use. Genetic analyses identified nominally associated SNPs; calcium channel genes were not enriched in the gene variants identified. LIMITATIONS: Validation in independent samples is needed to confirm the genetic findings in the present study. CONCLUSIONS: Our findings support the presence of an externalizing disorder subphenotype within BPI with greater severity of mood disorder and possible specific genetic features.
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    Nuance and behavioral cogency: How the Visible Burrow System inspired the Stress-Alternatives Model and conceptualization of the continuum of anxiety
    (Elsevier, 2015-07-01) Robertson, James M.; Prince, Melissa A.; Achua, Justin K.; Carpenter, Russ E.; Arendt, David H.; Smith, Justin P.; Summers, Torrie L.; Summers, Tangi R.; Summers, Cliff H.; Department of Psychiatry, IU School of Medicine
    By creating the Visible Burrow System (VBS) Bob Blanchard found a way to study the interaction of genetics, physiology, environment, and adaptive significance in a model with broad validity. The VBS changed the way we think about anxiety and affective disorders by allowing the mechanisms which control them to be observed in a dynamic setting. Critically, Blanchard used the VBS and other models to show how behavioral systems like defense are dependent upon context and behavioral elements unique to the individual. Inspired by the VBS, we developed a Stress Alternatives Model (SAM) to further explore the multifaceted dynamics of the stress response with a dichotomous choice condition. Like the VBS, the SAM is a naturalistic model built upon risk assessment and defensive behavior, but with a choice of response: escape or submission to a large conspecific aggressor. The anxiety of novelty during the first escape must be weighed against fear of the aggressor, and a decision must be made. Both outcomes are adaptively significant, evidenced by a 50/50 split in outcome across several study systems. By manipulating the variables of the SAM, we show that a gradient of anxiety exists that spans the contextual settings of escaping an open field, escaping from aggression, and submitting to aggression. These findings correspond with increasing levels of corticosterone and increasing levels of NPS and BDNF in the central amygdala as the context changes.Whereas some anxiolytics were able to reduce the latency to escape for some animals, only with the potent anxiolytic drug antalarmin (CRF1R-blocker) and the anxiogenic drug yohimbine (α2 antagonist) were we able to reverse the outcome for a substantial proportion of individuals. Our findings promote a novel method for modeling anxiety, offering a distinction between low-and-high levels, and accounting for individual variability. The translational value of the VBS is immeasurable, and it guided us and many other researchers to seek potential clinical solutions through a deeper understanding of regional neurochemistry and gene expression in concert with an ecological behavioral model.
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    Social learning and amygdala disruptions in Nf1 mice are rescued by blocking p21-activated kinase
    (Nature Publishing Group, 2014-11) Molosh, Andrei I.; Johnson, Philip L.; Spence, John P.; Arendt, David; Federici, Lauren M.; Bernabe, Cristian; Janasik, Steven P.; Segu, Zaneer M.; Khanna, Rajesh; Goswami, Chirayu; Zhu, Weiguo; Park, Su-Jung; Li, Lang; Mechref, Yehia S.; Clapp, D. Wade; Shekhar, Anantha; Department of Psychiatry, IU School of Medicine
    Children with Neurofibromatosis type 1 (NF1) are increasingly recognized to have high prevalence of social difficulties and autism spectrum disorders (ASD). We demonstrated selective social learning deficit in mice with deletion of a single Nf1 gene (Nf1+/−), along with greater activation of mitogen activated protein kinase pathway in neurons from amygdala and frontal cortex, structures relevant to social behaviors. The Nf1+/− mice showed aberrant amygdala glutamate/GABA neurotransmission