Responses to sympathomimetics in rat sensory neurones after nerve transection.

Noradrenaline activation of sensory somata that project in damaged peripheral nerves has been postulated to underlie sympathetically-mediated pain. Intracellular recordings from some neurones with myelinated axons in acutely isolated rat dorsal root ganglia showed small prolonged depolarizations to brief applications of 0.1-5 mM noradrenaline whether or not the spinal nerve had been transected.