Neurobiological Correlates of Decision-Making in Framing Conditions

Human decision-making is a complex process, of which the neurobiological correlates are not well understood. Several theories have been proposed, among others Prospect theory which assumes a different evaluation of gains and losses of the same value. De Martino et al. tested the influence of the “framing effect” on decision-making and we aimed to replicate their study as some of the findings remained unclear. A general tendency to act in accordance with the frame was shown in a behavioural study. In order to uncover the underlying neural correlates, participants performed the same task in an fMRI scanner. Even though the amygdala could not be linked to framing, increased activity in the ACC when making frame-incongruent decisions was established. This can be related to acting in a more rational manner. Furthermore, activity in the cerebellum was increased when making a choice, indicating the involvement of this brain area in decision-making under uncertainty

Association of Lung Inflammatory Cells with Small Airways Function and Exhaled Breath Markers in Smokers – Is There a Specific Role for Mast Cells?

BACKGROUND:Smoking is associated with a mixed inflammatory infiltrate in the airways. We evaluated whether airway inflammation in smokers is related to lung function parameters and inflammatory markers in exhaled breath. METHODS:Thirty-seven smokers undergoing lung resection for primary lung cancer were assessed pre-operatively by lung function testing including single-breath-nitrogen washout test (sb-N2-test), measurement of fractional exhaled nitric oxide (FeNO) and pH/8-isoprostane in exhaled breath condensate (EBC). Lung tissue sections containing cancer-free large (LA) and small airways (SA) were stained for inflammatory cells. Mucosal (MCT) respectively connective tissue mast cells (MCTC) and interleukin-17A (IL-17A) expression by mast cells was analysed using a double-staining protocol. RESULTS:The median number of neutrophils, macrophages and mast cells infiltrating the lamina propria and adventitia of SA was higher than in LA. Both MCTC and MCT were higher in the lamina propria of SA compared to LA (MCTC: 49 vs. 27.4 cells/mm2; MCT: 162.5 vs. 35.4 cells/mm2; P<0.005 for both instances). IL-17A expression was predominantly detected in MCTC of LA. Significant correlations were found for the slope of phase III % pred. of the sb-N2-test (rs= -0.39), for the FEV1% pred. (rs= 0.37) and for FEV1/FVC ratio (rs=0.38) with MCT in SA (P<0.05 for all instances). 8-isoprostane concentration correlated with the mast cells in the SA (rs=0.44), there was no correlation for pH or FeNO with cellular distribution in SA. CONCLUSIONS:Neutrophils, macrophages and mast cells are more prominent in the SA indicating that these cells are involved in the development of small airway dysfunction in smokers. Among these cell types, the best correlation was found for mast cells with lung function parameters and inflammatory markers in exhaled breath. Furthermore, the observed predominant expression of IL-17A in mast cells warrants further investigation to elucidate their role in smoking-induced lung injury, despite the lack of correlation with lung function and exhaled breath parameters