The encoding of interoceptive-based predictions by the paraventricular nucleus of the thalamus D2R+ neurons

Interoceptive predictions are internal models that guide behavior by anticipating physiological needs based on past experiences and environmental cues. The paraventricular nucleus of the thalamus (PVT), which receives both interoceptive and exteroceptive inputs, is well-positioned to integrate these signals. Using fiber photometry and bulk calcium imaging in mice performing a reward-based linear maze task, we found that dopamine receptor 2-expressing PVT neurons (PVT^D2R+) are engaged in behaviors leading to physiologically relevant outcomes, with their activity highly dependent on the interoceptive state of the mice and the expected outcome. Furthermore, we show that the chronic inhibition of PVT^D2R+ neurons impairs the long-term performance of interoceptive-guided motivated behavior. Collectively, these findings identify PVT^D2R+ neurons as critical integrators of internal states, external cues, and experiential factors, all of which contribute to interoceptive predictions that facilitate adaptive, goal-directed behavior.