Resting State Interoception Network Integrates Multi-Organ Representations Via Peripheral Neural Pathways

Motivation: The brain senses and regulates internal organs through interoception, but the specific network involved, its organ representations and neural origins remain unclear. Goal(s): We aim to map the interoception network in the rat brain using resting-state fMRI, evaluate its interactions with other networks, determine how it represents bodily signals, and assess its functional dependence on vagal nerves. Approach: We used seed-based correlations to map the network and assessed how bodily signals influenced its activity with the vagus nerve intact or resected. Results: The identified interoception network engaged actively with other networks, represented multiple organs in overlapping regions, and depended on the vagal pathway. Impact: We report that the resting brain actively processes interoceptive signals and forms overlapping representations of the heart, lungs, and gut through peripheral neural pathways. Our findings challenge the notion that bodily physiological fluctuations are vascular artifacts to fMRI.