There are two main somatosensory pathways in the spinal cord that relay sensory signals from the periphery to brain. The dorsal column (DC)-medial lemniscus pathway transmits innocuous tactile information, while the spinothalamic tract (STT) conveys noxious signals, including pain and temperature14. As there is compelling evidence that innocuous or noxious stimulation influences the mesolimbic DA system2, 15, the spinal ascending pathways, such as DC and STT, likely play a role in linking the peripheral sensory system to reward circuits. In addition, the lateral habenula (LHb), a key epithalamic structure interconnecting sensory inputs to mesolimbic DA systems, has been reported to be critically involved in processing of peripheral sensory inputs and reward16–18.