Showing papers by "Iris E. C. Sommer published in 2009"

The Relationship of DNA Methylation with Age, Gender and Genotype in Twins and Healthy Controls

Abstract: Cytosine-5 methylation within CpG dinucleotides is a potentially important mechanism of epigenetic influence on human traits and disease. In addition to influences of age and gender, genetic control of DNA methylation levels has recently been described. We used whole blood genomic DNA in a twin set (23 MZ twin-pairs and 23 DZ twin-pairs, N = 92) as well as healthy controls (N = 96) to investigate heritability and relationship with age and gender of selected DNA methylation profiles using readily commercially available GoldenGate bead array technology. Despite the inability to detect meaningful methylation differences in the majority of CpG loci due to tissue type and locus selection issues, we found replicable significant associations of DNA methylation with age and gender. We identified associations of genetically heritable single nucleotide polymorphisms with large differences in DNA methylation levels near the polymorphism (cis effects) as well as associations with much smaller differences in DNA methylation levels elsewhere in the human genome (trans effects). Our results demonstrate the feasibility of array-based approaches in studies of DNA methylation and highlight the vast differences between individual loci. The identification of CpG loci of which DNA methylation levels are under genetic control or are related to age or gender will facilitate further studies into the role of DNA methylation and disease.

Language production in the non-dominant hemisphere as a potential source of auditory verbal hallucinations

Abstract: Sir, in his comment, Dr Craig (2009 a ) raises an interesting hypothesis. He poses that an important aspect of auditory verbal hallucinations, namely the experience of the alien or non-self origin, results from an imbalance between the anterior cingulated gyrus and the anterior insula in the right hemisphere. This non-self aspect of auditory verbal hallucinations is an important and characteristic factor inducing patients to attribute the voices they experience to an external source, be it humans, spirits or demons. This attribution to a non-self source increases fear and delusional belief and greatly contributes to psychopathology (Garcia-Montes et al ., 2004; Engh et al ., 2009). Understanding the neurobiology of the non-self aspect would therefore be helpful in elucidating the pathophysiology of auditory verbal hallucinations and perhaps, as Craig stated, have consequences for future therapy. The lack of activity in the right anterior cingulated cortex during the experience of auditory verbal hallucinations was correctly observed by Craig. In fact, post hoc region of interest (ROI) analysis of this area demonstrated no significant activation, neither in the left nor in the right anterior cingulated gyrus, although there was bilateral activity in the middle cingulated region and the superior frontal gyri during auditory verbal hallucinations. In contrast, the verbal fluency task induced robust activity in the bilateral anterior cingulated area (left more than right) in the same subjects. We agree with Craig that the striking absence of anterior cingulated activity during auditory verbal hallucinations may reflect the lack of conscious control the patients had over these experiences. Craig makes another suggestion, namely that the prominent activity in the right insula during auditory verbal hallucinations may represent the ‘feeling’ or ‘awareness’ of …

Language Lateralization and Psychosis

Abstract: List of contributors Preface Part I. Asymmetry, Handedness and Language Lateralization: 1. Molecular mechanisms establishing consistent left-right asymmetry during vertebrate embryogenesis Sherry Aw and Michael Levin 2. Cerebral lateralization in animal species Onur Gunturkun 3. The history and geography of human handedness I. C. McManus 4. The association between hand preference and language lateralization Bianca Stubbe-Drager and Stefan Knecht 5. The genetic basis of lateralization Marian Annett 6. Language lateralization and handedness in twins an argument against a genetic basis? Iris E. C. Sommer and Rene S. Kahn 7. Sex differences in handedness and language lateralization Iris E. C. Sommer and Rene S. Kahn Part II. Language Lateralization and Psychosis: 8. Hand-preference and population schizotypy Metten Somers, Iris E. C. Sommer and Rene S. Kahn 9. Functional imaging studies on language lateralization in schizophrenia patients Annick Razafimandimby, Olivier Maiza and Sonia Dollfus 10. The role of the right hemisphere for language in schizophrenia Alexander Rapp 11. Auditory verbal hallucinations and language lateralization Kelly Diederen and Iris E. C. Sommer 12. Language lateralization in patients with Formal Thought Disorder Carin Whitney and Tilo Kircher 13. LRRTM1: a maternally suppressed genetic effect on handedness and schizophrenia Clyde Francks.

Network analysis of positional candidate genes of schizophrenia highlights myelin-related pathways

Abstract: Network analysis of positional candidate genes of schizophrenia highlights myelin-related pathways

Comprar Language Lateralization and Psychosis | Iris E. C. Sommer | 9780521882842 | Cambridge University Press

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