A fresh view of the zona incerta: From circuit complexity to disease pathogenesis

The zona incerta (ZI) is a diencephalic nucleus that houses neurochemically diverse neuronal populations. It serves as a critical integrative hub because of its bidirectional connectivity with multiple central nervous system regions. Emerging evidence highlights its essential roles in sensorimotor integration, affective processing, and behavioral regulation, thus positioning ZI neuromodulation as a key focus in systems neuroscience. Despite progress in characterizing its cytoarchitecture, molecular profiles, and network connectivity, a systematic understanding of the functional topography of ZI is yet to be achieved. This review utilizes current knowledge across three domains: 1) multimodal sensory processing, 2) emotional valence encoding, and 3) behavioral regulation and proposes an integrative framework to advance translational investigations of ZI-mediated neurophysiological mechanisms.