Interoceptive processing in the nucleus of the solitary tract

The interoceptive nervous system continuously monitors the status of visceral organs to synthesize internal perceptions and regulate behavioral and physiological responses. The nucleus of the solitary tract (NTS) in the brainstem serves as a central interoceptive hub and the initial site where sensory information from internal organs is processed in the brain. Here we review the neurobiological underpinnings of interoceptive processing in the NTS, focusing on recent progress enabled by modern genetic and optical tools for neural circuit dissection and neuronal recordings. Sensory information from internal organs is organized into a topographic map within the NTS, computed locally, modulated by descending inputs from higher brain regions, and distributed to downstream targets via projection neurons to control behavior and physiology. We present a sensory processing perspective on interoceptive coding within this brain structure.