Plos One
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Safe from harm: learned, instructed, and symbolic generalization pathways of human threat-avoidance.
Avoidance of threatening or unpleasant events is usually an adaptive behavioural strategy. Sometimes, however, avoidance can become chronic and lead to impaired daily functioning. Excessive threat-avoidance is a central diagnostic feature of anxiety disorders, yet little is known about whether avoidance acquired in the absence of a direct history of conditioning with a fearful event differs from directly learned avoidance. ⋯ Three groups were then tested with a learned CS+ and CS- (learned group), instructed CS+ (instructed group), and generalized CS+ (derived group) presentations. Results showed similar levels of avoidance behaviour and threat-belief ratings about the likelihood of shock across each of the three pathways despite the different mechanisms by which they were acquired. Findings have implications for understanding the aetiology of clinical avoidance in anxiety.
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Learning induced changes in protein acetylation, mediated by histone acetyl transferases (HATs), and the antagonistic histone deacetylases (HDACs) play a critical role in memory formation. The status of histone acetylation affects the interaction between the transcription-complex and DNA and thus regulates transcription-dependent processes required for long-term memory (LTM). While the majority of studies report on the role of elevated acetylation in memory facilitation, we address the impact of both, increased and decreased acetylation on formation of appetitive olfactory memory in honeybees. ⋯ Reducing acetylation levels by blocking HAT activity after strong training leads to a suppression of transcription-dependent LTM. The memory suppression is also observed in case of weak training, which does not require transcription processes. Thus, our findings demonstrate that acetylation-mediated processes act as bidirectional regulators of memory formation that facilitate or suppress memory independent of its transcription-requirement.
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Cigarette smoke is the main risk factor for emphysema, which is a key pathology in chronic obstructive pulmonary disease (COPD). Low attenuation areas (LAA) in computed tomography (CT) images reflect emphysema, and the cumulative size distribution of LAA clusters follows a power law characterized by the exponent D. This property of LAA clusters can be explained by model simulation, where mechanical force breaks alveolar walls causing local heterogeneous lung tissue destruction. However, a longitudinal CT study has not investigated whether continuous smoking causes the spatially heterogeneous progression of emphysema. ⋯ Susceptibility to parenchymal destruction induced by continuous smoking is not uniform over the lung, but might be higher in local regions of relatively advanced emphysema. These could result in the spatially heterogeneous progression of emphysema in current smokers.
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Amateur choral singing is a common pastime and worthy of study, possibly conferring benefits to health and social behaviour. Participants might be expected to possess musical ability and share some behavioural characteristics. Polymorphisms in genes concerned with serotonergic neurotransmission are associated with both behaviour and musical aptitude. ⋯ Our null findings with respect to RS3, RS1 and AVR, polymorphisms associated with musical ability by other authors, suggest that choir membership may depend partly on factors other than musical ability. In a related musical project involving one participating choir, a new 40-part unaccompanied choral work, "Allele", was composed and broadcast on national radio. In the piece, each singer's part incorporated their personal RS3 genotype.
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Autophagy is a major degradative process responsible for the disposal of cytoplasmic proteins and dysfunctional organelles via the lysosomal pathway. During the autophagic process, cells form double-membraned vesicles called autophagosomes that sequester disposable materials in the cytoplasm and finally fuse with lysosomes. In the present study, we investigated the inhibition of autophagy by a synthesized compound, MHY1485, in a culture system by using Ac2F rat hepatocytes. ⋯ In conclusion, MHY1485 has an inhibitory effect on the autophagic process by inhibition of fusion between autophagosomes and lysosomes leading to the accumulation of LC3II protein and enlarged autophagosomes. MHY1485 also induces mTOR activity, providing a possibility for another regulatory mechanism of autophagy by the MHY compound. The significance of this study is the finding of a novel inhibitor of autophagy with an mTOR activating effect.