The biological mechanisms underlying inter-individual differences in human stress reactivity remain poorly understood. We aimed to identify the molecular underpinning of aberrant neural stress... Show moreThe biological mechanisms underlying inter-individual differences in human stress reactivity remain poorly understood. We aimed to identify the molecular underpinning of aberrant neural stress sensitivity in individuals at risk for schizophrenia. Linking mRNA expression data from the Allen Human Brain Atlas to task-based fMRI revealed 201 differentially expressed genes in cortex-specific brain regions differentially activated by stress in individuals with low (healthy siblings of schizophrenia patients) or high (healthy controls) stress sensitivity. These genes are associated with stress-related psychiatric disorders (e.g. schizophrenia and anxiety) and include markers for specific neuronal populations (e.g. ADCYAP1, GABRB1, SSTR1, and TNFRSF12A), neurotransmitter receptors (e.g. GRIN3A, SSTR1, GABRB1, and HTR1E), and signaling factors that interact with the corticosteroid receptor and hypothalamic-pituitary-adrenal axis (e.g. ADCYAP1, IGSF11, and PKIA). Overall, the identified genes potentially underlie altered stress reactivity in individuals at risk for schizophrenia and other psychiatric disorders and play a role in mounting an adaptive stress response in at-risk individuals, making them potentially druggable targets for stress-related diseases. Show less
This thesis studies the normal developmental pattern of social evaluative fears from childhood to adolescence. We have investigated age differences in self-reported social fears and physical... Show moreThis thesis studies the normal developmental pattern of social evaluative fears from childhood to adolescence. We have investigated age differences in self-reported social fears and physical responses during a public speaking task. In addition, youth's perceptions of speaking in public were studied through a short interview. Finally, two aspects of adolescent development are highlighted, namely resistance to peer influence and self-restraint, in the two concluding chapters. The main finding of the thesis is that social evaluative fears seem to increase with age. However, future research needs to develop more developmentally sensitive measures and further investigate the underlying processes of this increase. Show less
