Ultra-high field functional brainstem imaging of nuclei responsible for blood pressure control

Brisbane Convention & Exhibition Centre 

Muscle sympathetic nerve activity (MSNA) is composed of bursts of action potentials generated by muscle vasoconstrictor neurones that supply arterioles in skeletal muscles. MSNA is tightly coupled to the cardiac cycle via the arterial baroreflex, and by controlling blood flow to muscle, contributes importantly to the beat-to-beat regulation of blood pressure through variations in arteriolar diameter. MSNA originates within a nucleus of the brainstem - the rostral ventrolateral medulla (RVLM). Using MSNA-coupled functional MRI (fMRI) (Macefield, 2010) - in which we record MSNA and perform fMRI simultaneously, we can exploit the higher spatial resolution and signal-to-noise found at ultra-high field 7 Tesla. We aim to functionally identify the brainstem nuclei responsible for generating sympathetic drive using high-resolution 7T fMRI coupled with direct recordings of MSNA