Role of stress in cognitive impairments in psychiatric disorders

Stress is a major contributory factor in many psychiatric disorders including depression, anxiety, addiction and schizophrenia. Little is currently known about how stress modifies brain function to contribute to the symptoms seen in these diseases and one area of particular interest in the impact of stress on cognitive function. Just as stress is a common contributory factor in psychiatric disorders, cognitive impairments are common features of many psychiatric disorders and contribute to the suffering associated with these diseases. The aim of this work is to investigate how stress impacts on cognitive function associated with different domains e.g. attention, impulse control, learning and memory. The work may also consider the effects of stress on emotional behaviour and the relationship between emotion and cognition. This work is particularly relevant to the study of depression where patient and healthy volunteer studies have recently provided evidence that negative emotional processing may play an important role in the development and perpetuation of depression.
The proposed project will investigate how stress impacts on cognitive function across different domains. Using manipulations designed to induce stress and specific rodent behavioural models, such as the 5-choice serial reaction time task, working memory and decision-making tasks, these studies will investigate the impairments in cognition and executive functions induced by increased stress. Acute stress studies will use different biological relevant stressors such as psychosocial stress or physiological stress. Chronic stress studies will look at effects involving early life adversity and adaptive changes in the stress system as well as exposure to chronic mild stressors. For all these studies, translational validity will be key to the choice of stressor and behavioural test used.
To understand more about the impact of stress on cognition, complementary studies will examine how stress induced adaptive changes in different brain areas relate to current knowledge about the neural and neurochemical mechanisms which underpin optimal cognitive function. Areas of particular interest are the noradrenergic and serotonergic systems. This aspect of the project may focus on one or more of these systems and use molecular and pharmacological approaches to investigate how these transmitters contribute to stress-induced cognitive impairments. These studies may include using viral-mediated gene transfer to target specific neurochemical populations as well as optogenetic techniques to a high level of neuronal and temporal specificity.