Innovations in brain imaging cast new light on the fundamentals of autonomic function, improve how autonomic disorders are detected and characterised, and provide a blueprint to apply advanced graphical modelling in other areas.
The autonomic nervous system is a complex network that regulates the body’s response to external changes in the environment. Without conscious control, it transmits information between the brain and the body to regulate the heart, lungs, gut, blood vessels, sweat glands and sexual organs. The complexity of this process, is rarely captured by current techniques used to model the workings of the brain.
In a new study published in Cortex, the operation of the autonomic system is revealed in greater detail than what was previously thought possible.
Adam Farmer and Qasim Aziz from Queen Mary University of London, joined researchers from University College London and Kings College. The team combined several types of brain imaging with heart rate data drawn from a large group of people, to produce a multidimensional, generative network. They discovered this was capable of illuminating the brain’s autonomic nervous system more finely than current methods dominant in the field.
Researchers were also able to distinguish between sympathetic and parasympathetic systems, not possible with conventional mapping. The imaging revealed ‘autonomic connectome’ that illustrated many areas of the brain working together to regulate the autonomic nervous system, including in sensation, motion, visual processing, cognition and social reflection.
Maps produced in this ground-breaking study not only confirm the far-reaching roles of the autonomic nervous system, but also identify where the autonomic nervous system can be disrupted from disease. For example, disruptions in the brain may occur secondary to neurodegenerative disease; or autonomic roles in metabolism and the gut can be disrupted by diabetes.
Lead Researcher Dr James Ruffle from University College London, commented: “By better understanding how the autonomic nervous system is regulated within the brain, this allows us to better characterise its dysregulation within the brain from disease. Moreover, these maps within the brain can then be used to monitor effects of treatments that aim to remediate any disruption to the autonomic nervous system.”
These newfound capabilities to model the brain as a complex network, open up new possibilities to better understand the autonomic system’s function in health and disease. Neuroimaging via a multidimensional, generative network can be applied to other debilitating disorders, including brain tumours, stroke and multiple sclerosis, and provide a vital step in identifying new methods of patient treatments.
Research Paper: ‘The autonomic brain: Multi-dimensional generative hierarchical modelling of the autonomic connectome.’ James K. Ruffle, Harpreet Hyare, Matthew A. Howard, Adam D. Farmer, A. Vania Apkarian, Steven C.R. Williams, Qasim Aziz, and Parashkev Nachev. Cortex, 143, pp.164-179. 2021.