The insular cortex (Ins) of rodents is a central hub for integrating visceral, autonomic, and exteroceptive information. Foundational tract-tracing studies showed that the posterior Ins receives dense thalamic inputs conveying chemosensory, viscerosensory, and somatosensory signals, and projects extensively to amygdalar and brainstem regions as well as to a specific posterior lateral hypothalamic nucleus involved in autonomic control. Early electrophysiological and lesion studies demonstrated essential roles in cardiovascular regulation, gastric motility, and visceral pain perception, establishing the Ins as a key node in homeostatic control, integrating exteroceptive contexts with bodily state signals to guide behavior.