InsulaBodyLoop · The Insula-Body Loop for Neural Control of Gut Physiology

The brain and body are in a continuous dialog. Our brains constantly receive sensory information from within our body, as well as from the external environment, and then use it to regulate bodily function. Brain-body communication is essential for our physical and mental health, yet little is known about how it is achieved at the neurobiological level. A large corpus of work implicates the insular cortex as a central node in the brain's interoceptive network. Current models suggest that insular cortex integrates internal and external sensory information to regulate bodily physiology. Yet direct experimental evidence has been scarce. I propose a research program that focuses on the insular cortex as part of a dynamic loop with the gastrointestinal system, which regulates peripheral metabolic function and feeding behaviour. Two fundamental questions form the core of this proposal: (1) How do the sight, smell, and taste of a savoury dish, or a sweet dessert, enable our brains to predict the post-ingestive nutrients they will supply? (2) How are these predictions relayed to our body to pre-emptively prepare it for consumption, e.g., by inducing salivation and insulin release? To answer these questions we need to understand both cortical predictive computations, as well as peripheral physiology. I therefore propose to build on my expertise and use an inter-disciplinary approach, combining cutting-edge neuroscience and computational methods with recordings and optogenetic control of peripheral physiology. This will reveal: (1) how insular cortex represents internal sensations, (2) how insular cortex forms associations between internal and external sensory information, and (3) how these associations are relayed to the body to maintain homeostasis. This study will provide a conceptual and methodological foundation for future elucidation of how different internal sensory modalities act together within the brain-body loop to maintain our physical and emotional health.