Abstract
The neural circuits that transmit the sense of pain and how pain is encoded by these circuits are still poorly understood.Mechanical allodynia is a prominent form of chronic pain characterized by painful responses to innocuous touch that develops as a consequence of nerve damage and inflammation. Here, we show that alterations to the normal log-normal distribution of neuronal activity and structure of neural correlations between neurons in the dorsal column nuclei (DCN) constitute a signature feature of mechanical allodynia, with the transmission of "allodynic" light touch information to the thalamus by somatostatin-positive projection neurons in the DCN being essential for its expression and development. Our findings are consistent with neural activity in the DCN encoding a reference landscape of tactile percepts that animals use to differentiate innocuous touch from potentially noxious mechanical stimuli.