P2X3 receptors are transducers of sensory signals

Peripheral stimuli are transduced by specific receptors expressed by sensory neurons and are further processed in the dorsal horn of spinal cord before to be transmitted to the brain. While relative few receptor subtypes mediate the initial depolarisation of sensory neurons, an impressive number of molecules and ion channels integrate these inputs into coded signals. Soluble mediators and ambient conditions further shape these processes, potentially triggering peripheral and central sensitisation, or sensory downregulation. Extracellular ATP is a major signaling molecule that acts via purinergic receptors and is a powerful modulator of cell communication as well as a neurotransmitter at peripheral/central synapses. In particular, ATP-mediated signals are transduced by P2X3 receptors expressed mainly by peripheral sensory neurons. Recent evidence suggests that P2X3 receptor function not only induces neuron depolarisation and firing with consequent neurotransmitter release, but it also triggers intracellular molecular changes that amplify purinergic signaling with important consequences.