Project 12

Serotonin regulation of the human stress response.

Improved understanding of the body’s response to stress is critical in establishing the abnormalities that occur in clinical anxiety. We have developed a model using a single breath of 35% CO2 that activates the hypothalamic-pituitary adrenal (HPA) axis and produces autonomic and behavioural arousal, thus modelling a stress response. This technique enables us to study stress responses in volunteers in a safe and reliable way. We propose to employ this method in combination with the dietary procedure of tryptophan depletion (TD) that temporarily reduces brain serotonin levels to study the serotonin system, which is thought to have a key role in influencing the acute stress response.