Nucleotides and their receptors in the nervous system, Leipzig, Germany, August 1-2, 1998

Abstract

This symposium was organized by P. Illes (Univ. Leipzig, Germany), A. Reichenbach (Paul-Flechsig Institute for Brain Research, Leipzig, Germany) and H. Zimmermann (Univ. Frankfurt/Main, Germany). More than 150 experts on purinergic transmission met at a historical building of the University of Leipzig in the center of the town. The symposium consisted of 32 twenty-minute-long lectures by invited speakers from eleven countries. In addition, 50 posters were presented in two poster sessions. After an informal gathering of speakers, participants and guests on Friday evening, the official scientific program of the conference began on Saturday by the opening addresses of T. Butz (Univ. Leipzig) and P. Illes. The first session was chaired by E. A. Barnard (Royal Free Hospital School of Medicine, London, UK) and G. Burnstock (from the same institution). The first speaker of this session was one of the chairmen, G. Burnstock. He gave an outstanding lecture on the current status of purinergic signalling in the nervous system. He reviewed the history of purinergic transmission, from the early 1970s until now. The “purinergic nerve” hypothesis was proposed in 1972, with evidence to suggest that ATP is a neurotransmitter in some non-adrenergic, non-cholinergic nerves. Later it became evident that ATP is a cotransmitter with classical transmitters in autonomic and sensory-motor nerves. In 1978, receptors to purines were shown to belong to two main subtypes: P1 purinoceptors, which are selective for adenosine, and P2 purinoceptors, which are selective for ATP and ADP. Subsequently, subtypes of P1 purinoceptors: A1, A2a, A2b, and A3 were identified. Burnstock and colleagues proposed the subclassification of P2 purinoceptors into P2X and P2Y receptors. Further investigations revealed that the P2X receptors, which are ligand-gated cation channels, can be subclassified to at least seven subtypes, while the P2Y receptor family (G protein-coupled receptors) consists of at least 10 subtypes. G. Burnstock mentioned some new aspects of the purinergic research field at the end of his excellent presentation. P2X and P2Y receptors are present on sensory nerves, and might play an important role in mechanoception and nociception. There is rapidly expanding interest in purinergic signalling in the brain and spinal cord. The plasticity of purinergic cotransmission has a remarkable role in some pathophysiological conditions (e.g., interstitial cystitis, outflow obstruction of the bladder, hypertension). Apart from “fast” purinergic signalling in the nervous system, nucleotides play long-term (trophic) roles in development and degeneration.