Investigating Dopaminergic Influences on Brain-State Switching and Its Relation to Human Behaviour through Translational Neuroimaging(2/2)

The brain can be thought of as a set of specialized subsystems that cohere together into a constantly shifting dynamic network. Recent work has highlighted how dynamic network properties, as revealed through different neuroimaging techniques, are related to individual differences in behaviour. Most starkly, changes to brain networks have been found in psychiatric conditions, such as schizophrenia or bipolar disorder, that are typified by severe behavioural symptoms. Although a lot of works has been done looking at these networks, very little has looked at the neurochemical mechanisms involved in their modulation. This project aims to investigate how dopamine, a neuromodulator, influences dynamic transitions between brain states. It will further aim to relate this modulation to behaviour, focusing on individual temperament in terms of engagement with the environment. A translational approach will be adopted, starting with an MRI experiment in humans that will obtain indirect measures of brain activity and dopamine function and quantify how the activity dynamics are mediated by the latter. Complementary experiments will then be conducted in rodents to provide direct measurement equivalents for the necessarily indirect measures used in the human study. Animal MRI will be used for these, along with pharmacological manipulation of dopaminergic activity and direct electrophysiological measures of neural activity.