Dissecting axes of autonomic control in humans: Insights from neuroimaging

The combination of functional brain imaging with measurement of peripheral autonomic responses in humans can provide insight into the embodiment of mental processes and the integration of cognition and emotion with changes in somatic physiology. Initial studies in healthy people and patents validate inferences from more detailed animal experiments regarding the organization of central autonomic control. In particular these have illustrated the coupling of behaviour with sympathetic arousal. Over the last two decades, the growth of emotional neuroscience alongside advances in functional brain imaging has fuelled investigations of relationships between perception, feeling states, somatic and autonomic bodily reactions. These studies have driven a more mechanistic understanding of brain systems through which bodily state is regulated and modified to support adaptive behaviour. In parallel, they have enabled the application of human neuroimaging to autonomic neuroscience. Specific methodological challenges are posed by combining physiological recordings with neuroimaging techniques, particularly functional magnetic resonance brain imaging, which are nevertheless addressable. Using such methods, the neural correlates of dynamic autonomic control has been systematically examined in studies of healthy individuals and patients with specific autonomic dysfunction (including autonomic failure, autonomic (neurally) mediated syncope and the postural tachycardia syndrome). These studies reveal antagonistic interaction of systems underpinning autonomic cardiovascular control (involving mid and subgenual cingulate cortices) and partial organ-specificity of other axes of autonomic response. Current and anticipated technical advances, including the integration of autonomically-focused microneurography and neural stimulation with advanced neuroimaging, will continue to provide detailed insight into dynamics of autonomic control. Translating these insights into clinical benefits remains a priority.