BIASTRESS · Neural mechanisms of cognitive bias and its role in the triggering of the stress response in zebrafish

Neural mechanisms of cognitive bias and its role in the triggering of the stress response in zebrafish

Stress has long been a major concern among researchers interested in health and welfare. Most of their work has considered stress from either a biological or an environmental perspective, focusing on the activation of the physiological systems involved in the stress process or the role of stressful life events in specific diseases. While interesting, if we are to fully understand the effects of stress on health, we must also take into account a psychological perspective that considers an individual’s perception (i.e. subjective) of stress. In this way, the involvement of appraisal in the activation of the stress response opens up the potential for evaluation biases (i.e., some individuals will consistently evaluate ambiguous stimuli as negative - pessimistic, and others as positive - optimistic). This is a relevant aspect, since assessing the stress resilience of optimistic and pessimistic phenotypes may be crucial for the study of stress-related disorders (SRD) (e.g., anxiety and depression), which will be extremely useful for developing ways to mitigate the effects of chronic stress. Moreover, this project has the potential to also be helpful in the field of antidepressant drug research, since pessimistic and optimistic individuals may diverge in their response to antidepressants. In this scenario, the overall aim of this project is to unravel the neural mechanisms of cognitive bias and its role in the triggering of the stress response as well as whether these personality traits are meaningfully linked to resilience to SRD, using zebrafish (Danio rerio) as a model. In line with the ongoing development of scientific knowledge and methodologies, zebrafish has become increasingly valuable as a translational research model, and is now contributing to hundreds of studies on human disease mechanisms worldwide, ranging from neurological and psychiatric disorders to stress-associated diseases. The specific objectives that were designed to achieve the project goal are: Objective 1: To develop a behavioural assay for testing cognitive bias in zebrafish, and to characterise the behavioural and neuroendocrine profiles of “optimistic” versus “pessimistic” individuals. Objective 2: To assess whether cognitive bias (i.e. pessimistic bias) is mediating inter-individual variations in susceptibility to the detrimental effects of stress. Objective 3: To use the available GAL4-UAS enhancer trapped lines in zebrafish to study the loss of function (i.e. genetic inactivation) of specific neural circuits involved in the cognitive appraisal of stressors.

Data: CORDIS, © European Union