Grant: Project Grant

Steroid hormones are very powerful, and they have widespread and profound effects on human health and behaviour. Steroid hormones are critical for the brain to develop and function normally, and they also play important roles in psychiatric and neurological diseases. The brain is generally considered a recipient of blood-borne steroids from peripheral organs, such as the gonads and adrenal glands, but the brain can also locally synthesize its own steroids (neurosteroids). My recent studies discovered that a key circuit within the brain, the mesocorticolimbic dopamine system, locally synthesizes testosterone and contains receptors for testosterone. This circuit regulates higher order cognition and executive function, including decision making and behavioural flexibility. This project aims to understand how neurosteroids affect the mesocorticolimbic system, dopamine signaling, and executive function. In particular, the research will use cutting-edge techniques to map neurosteroids in this circuit and will use pharmacological and genetic tools to dissect the roles of gonadal and neural steroids in executive function. This project will improve our understanding of how steroid hormones act on the brain, including the prefrontal cortex, to impact higher order cognitive processes. Such knowledge will help in the design of novel hormone treatments for psychiatric and neurological diseases, including those that are characterized by deficits in executive function.