Cortical and subcortical components involved in the sympathetic control of blood pressure in humans

Abstract

The neural control of blood pressure by the brain is brought about via the autonomic nervous system, with a major determinant of blood pressure being blood flow through the muscle vascular bed. By performing functional magnetic resonance imaging (fMRI) of the brain at the same time as recording muscle sympathetic nerve activity (MSNA), via a microelectrode inserted into a peripheral nerve, we have identified areas of the brain involved in the generation of MSNA and hence established key components of the human sympathetic connectome and their roles in the control of blood pressure. In addition to the critical roles of specific medullary nuclei, including the rostral ventrolateral medulla (RVLM), in the baroreflex-mediated control of MSNA, we have identified cortical areas—dorsolateral prefrontal cortex, precuneus and insula—that are coupled to RVLM via the hypothalamus and midbrain periaqueductal gray (PAG), emphasizing the importance of areas above the brainstem in the regulation of blood pressure.