Chronic visceral pain is a major challenge for both patients and health providers. Although the central sensitization of the brain is thought to play an important role in the development of visceral pain, the detailed neural circuits remain largely unknown. Using a well-established chronic visceral hypersensitivity model induced by neonatal maternal deprivation (NMD) in male mice, we identified a distinct pathway whereby the claustrum (CL) glutamatergic neuron projecting to the anterior cingulate cortex (ACC) is critical for visceral pain but not for CFA-evoked inflammatory pain. By a combination of in vivo circuit-dissecting extracellular electrophysiological approaches and visceral pain related electromyographic recordings, we demonstrated that optogenetic inhibition of CL glutamatergic activity suppressed the ACC neural activity and visceral hypersensitivity of NMD mice whereas selective activation of CL glutamatergic activity enhanced the ACC neural activity and evoked visceral pain of control mice. Fu...