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Since the retina shares its embryological origin with the central nervous system, optical coherence tomography (OCT), an imaging technique frequently employed in ophthalmology to analyze the macula and intraretinal layer thicknesses and volumes, has recently become increasingly important in psychiatric research. We examined 34 autistic and 31 neurotypical adults (NT) using OCT. Autistic adults had reduced overall macular and outer nuclear layer (ONL) thickness and volume compared to NT. Both macular and ONL thickness showed significant inverse associations with the severity of autistic symptoms measured with the Social Responsiveness Scale 2 (SRS-2). Longitudinal studies across different age groups are required to clarify whether retinal changes may represent a possible trait marker.
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Fear acquisition and extinction are crucial mechanisms in the etiology and maintenance of anxiety disorders. Moreover, they might play a pivotal role in conveying the influence of genetic and environmental factors on the development of a (more or less) stronger proneness for, or resilience against psychopathology. There are only few insights in the neurobiology of genetically and environmentally based individual differences in fear learning and extinction. In this functional magnetic resonance imaging study, 74 healthy subjects were investigated. These were invited according to 5-HTTLPR/rs25531 (S+ vs. L(A)L(A); triallelic classification) and TPH2 (G(-703)T) (T+ vs. T-) genotype. The aim was to investigate the influence of genetic factors and traumatic life events on skin conductance responses (SCRs) and neural responses (amygdala, insula, dorsal anterior cingulate cortex (dACC) and ventromedial prefrontal cortex (vmPFC)) during acquisition and extinction learning in a differential fear conditioning paradigm. Fear acquisition was characterized by stronger late conditioned and unconditioned responses in the right insula in 5-HTTLPR S-allele carriers. During extinction traumatic life events were associated with reduced amygdala activation in S-allele carriers vs. non-carriers. Beyond that, T-allele carriers of the TPH2 (G(-703)T) polymorphism with a higher number of traumatic life events showed enhanced responsiveness in the amygdala during acquisition and in the vmPFC during extinction learning compared with non-carriers. Finally, a combined effect of the two polymorphisms with higher responses in S- and T-allele carriers was found in the dACC during extinction. The results indicate an increased expression of conditioned, but also unconditioned fear responses in the insula in 5-HTTLPR S-allele carriers. A combined effect of the two polymorphisms on dACC activation during extinction might be associated with prolonged fear expression. Gene-by-environment interactions in amygdala and vmPFC activation may reflect a neural endophenotype translating genetic and adverse environmental influences into vulnerability for or resilience against developing affective psychopathology.
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Individuals are different 'chronotypes' with early 'larks' and late 'owls' forming the limits of a normal distribution in the population. We recently described that late chronotypes who suffer from a conflict between internal and external time ('social jetlag') suffer from more mental distress and are more likely to smoke than early chronotypes (Wittmann, Dinich, Merrow, and Roenneberg, 2006 . Social jetlag: mis-alignment of biological and social time. Chronobiology International, 23:497-509.). We performed a detailed analysis of the same database collected in 2002 comprising 134 daily smokers and 366 nonsmokers, scrutinizing the relationships between chronotype, smoking, and alcohol consumption as well as psychological well-being using a multiple mediation analysis. On average, smokers tend to be later chronotypes, report more sleep-associated psychosomatic symptoms, are more depressed, less balanced, and less vigilant. The mediation analysis suggests that only those late chronotypes who smoke and those who drink more suffer from increased psychological distress. We suggest that 'chronotype' is introduced as an additional factor in substance use, that is, when considering motives for smoking and drinking.
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Thema
- Phenotype
- Adolescent (1)
- Adult (3)
- Affect/drug effects (1)
- Aged (1)
- Aged, 80 and over (1)
- Alcohol Drinking/*psychology (1)
- Alleles (1)
- ASD (1)
- *Autism Spectrum Disorder (1)
- Autism spectrum disorder (1)
- *Autistic Disorder (1)
- Brain Mapping/methods (1)
- Brain/pathology/physiology (1)
- *Circadian Rhythm/drug effects (1)
- Conditioning, Psychological/physiology (1)
- Environment (1)
- Ethanol/pharmacology (1)
- Extinction, Psychological/physiology (1)
- *Fear (1)
- Female (2)
- Genetic Predisposition to Disease (1)
- Genotype (1)
- Humans (3)
- Magnetic Resonance Imaging/methods (1)
- Male (2)
- Middle Aged (1)
- Models, Genetic (1)
- Models, Psychological (1)
- Nicotine/pharmacology (1)
- OCT (1)
- Optical coherence tomography (1)
- *Polymorphism, Genetic (1)
- Retina (1)
- Retina/diagnostic imaging (1)
- Serotonin/*metabolism (1)
- Skin/pathology (1)
- Sleep/*drug effects (1)
- Smoking/*psychology (1)
- Stress, Psychological/*psychology (1)
- Wakefulness (1)
- Wounds and Injuries (1)