Anxiety Disorders: Leonardo ED

Leonardo ED, Hen R. · Department of Psychiatry, Columbia University, New York, NY, USA. · Neuropsychopharmacology. · Pubmed #17851538 links to  free full text

Abstract: There is increasing recognition that many psychiatric disorders including anxiety disorders are neurodevelopmental in their origins. Here, we review and integrate data from human studies and from animal models that point to a critical period during which neural circuits that mediate anxiety develop. We then postulate that this highly plastic critical period is a time of heightened responsiveness that is particularly susceptible to adverse events. We discuss these concepts in the context the current heightened interest in gene by environment interactions in psychiatric illness emphasizing the importance of the temporal relationship between gene action and environmental milieu.

Leonardo ED, Hen R. · Center for Neurobiology and Behavior, Columbia University, New York, New York 10032, USA. · Annu Rev Psychol. · Pubmed #16318591 No free full text.

Abstract: The study of the genetics of complex behaviors has evolved dramatically from the days of the nature versus nurture debates that dominated much of the past century. Here we discuss advances in our understanding of the genetics of affective and anxiety disorders. In particular, we highlight our growing understanding of specific gene-environment interactions that occur during critical periods in development, setting the stage for later behavioral phenotypes. We review the recent literature in the field, focusing on recent advances in our understanding of the role of the serotonin system in establishing normal anxiety levels during development. We emphasize the importance of understanding the effect of genetic variation at the level of functional circuits and provide examples from the literature of how such an approach has been exploited to study novel genetic endpoints, including genetically based variation in response to medication, a potentially valuable phenotype that has not received much attention to date.

David DJ, Samuels BA, Rainer Q, Wang JW, Marsteller D, Mendez I, Drew M, Craig DA, Guiard BP, Guilloux JP, Artymyshyn RP, Gardier AM, Gerald C, Antonijevic IA, Leonardo ED, Hen R. · Université Paris-Sud EA 3544, Faculté de Pharmacie, Châtenay-Malabry Cedex F-92296, France. · Neuron. · Pubmed #19477151 No free full text.

Abstract: Understanding the physiopathology of affective disorders and their treatment relies on the availability of experimental models that accurately mimic aspects of the disease. Here we describe a mouse model of an anxiety/depressive-like state induced by chronic corticosterone treatment. Furthermore, chronic antidepressant treatment reversed the behavioral dysfunctions and the inhibition of hippocampal neurogenesis induced by corticosterone treatment. In corticosterone-treated mice where hippocampal neurogenesis is abolished by X-irradiation, the efficacy of fluoxetine is blocked in some, but not all, behavioral paradigms, suggesting both neurogenesis-dependent and -independent mechanisms of antidepressant action. Finally, we identified a number of candidate genes, the expression of which is decreased by chronic corticosterone and normalized by chronic fluoxetine treatment selectively in the hypothalamus. Importantly, mice deficient in one of these genes, beta-arrestin 2, displayed a reduced response to fluoxetine in multiple tasks, suggesting that beta-arrestin signaling is necessary for the antidepressant effects of fluoxetine.