P2Y(1) purinergic receptors in sensory neurons: Contribution to touch-induced impulse generation

Somatic sensation requires the conversion of physical stimuli into the depolarization of distal nerve endings. A single cRNA derived from sensory neurons renders Xenopus laevis oocytes mechanosensitive and is found to encode a P2Y(1) purinergic receptor. P2Y(1) mRNA is concentrated in large-fiber dorsal root ganglion neurons. In contrast, P2X(3) mRNA is localized to small-fiber sensory neurons and produces less mechanosensitivity in oocytes. The frequency of touch-induced action potentials from frog sensory nerve fibers is increased by the presence of P2 receptor agonists at the peripheral nerve ending and is decreased by the presence of P2 antagonists, P2X-selective agents do not have these effects. The release of ATP into the extracellular space and the activation of peripheral P2Y(1) receptors appear to participate in the generation of sensory action potentials by light touch.