P2X RECEPTORS IN AUTONOMIC AND SENSORY NEURONS

ATP-gated ion channels (P2X receptors) are ubiquitously present in aut onomic and sensory neurons as well as in smooth muscle; they mediate f ast excitatory synaptic transmission at sympathetic neuromuscular junc tions, at some neuro-neuronal synapses and may be involved in the gene ration and transmission of primary afferent information. Five subtypes of native P2X receptors can be distinguished by their kinetics and th eir agonist and antagonist profile. Six distinct P2X receptors have be en cloned; all are present in sensory neurons and most are present in autonomic neurons; homomeric or heteromeric forms of these cloned rece ptors reproduce the five phenotypes observed in native cells. (C) 1996 Academic Press Ltd