Student research project
Supervisors: Professor Vaughan Macefield
This project builds on our work on trying to understand how the brain controls blood pressure in health and disease. We use metal microelectrodes inserted into human peripheral nerves to record the bursts of sympathetic nerve activity, which originate in the brain, and try to modulate this activity by electrically stimulating the brain.
The sympathetic branch of the autonomic nervous system plays a critical role in the control of blood pressure, both through its effects on the heart and, importantly, through the beat-to-beat control of blood flow through systemic blood vessels. Arterioles in the skeletal muscles are particularly important in this regard (the muscle vascular bed has a very high volume), and an in-crease in muscle sympathetic nerve activity (MSNA) is known to occur during psychological stress. MSNA can be recorded directly via metal microelectrodes inserted percutaneously into a peripheral nerve in awake humans (microneurography), and by recording MSNA at the same time as performing functional Magnetic Resonance Imaging (fMRI) of the brain we have shown that the dorsolateral prefrontal cortex (dlPFC) is involved in the regulation of MSNA. Here we shall use transcutaneous Direct Current Stimulation (tcDCS) and transcutaneous Alternating Current Stimulation (tcACS), delivered by surface electrodes applied to forehead, to change the activity of the dlPFC, and thereby investigate how such changes in activity modulate MSNA and blood pressure. We have already shown that this modulates MSNA in healthy people with normal blood pressure, but do not know how it affects both MSNA and blood pressure in individuals with hypertension.
This project is suitable for an Honours or Masters student.