P2X purinoceptors and sensory transmission.

The involvement of P2X purinoreceptors (P2X receptors) in somatosensory transmission is herein reviewed with a focus on those receptors that are expressed on sensory neurons to elucidate their roles in the initiation of sensory excitation from primary afferent neurons, in modulating synaptic transmission at the first sensory synapses formed between primary afferent central terminals and dorsal horn neurons, in directly mediating sensory synaptic transmission to the spinal cord dorsal horn, and in modulating synaptic transmission among spinal cord dorsal horn neurons. Research on P2X receptors has indicated that these receptors play a significant role in both physiological and pathological pain states. As a result, P2X receptors may serve as therapeutic targets for the treatment of pathological pain conditions associated with nerve injury, tissue inflammation, cancer, and other diseases.