Purines As Transmitter Molecules: Electrophysiological Studies On Purinergic Signalling In Different Cell Systems

Elisabetta Coppi Purines as Transmitter Molecules Electrophysiological Studies on Purinergic Signalling in Different Cell Systems Firenze University Press 2008 Purines as Transmitter Molecules: Electrophysiological Studies on Purinergic Signalling in Different Cell Systems / Elisabetta Coppi. – Firenze : Firenze University Press, 2008. (Premio FUP. Tesi di dottorato ; 1) http://digital.casalini.it/9788884539052 ISBN 978-88-8453-904-5 (print) ISBN 978-88-8453-905-2 (online) Progetto grafico di Alberto Pizarro Fernández © 2008 Firenze University Press Università degli Studi di Firenze Firenze University Press Borgo Albizi, 28 50122 Firenze, Italy http://www.fupress.com/ Printed in Italy A Marco, per la sua pazienza Contents Abbreviations Introduction 1. Historical overview 2. Synthesis, release and catabolism of ATP 2.1 Vesicular release of ATP 2.2 Anion channel-mediated release of ATP 2.3 Connexin hemichannel-mediated ATP release 3. Synthesis, release and catabolism of adenosine. 3.1 Adenosine release 3.2 Synthesis of adenosine at extracellular level XI 1 1 2 3 4 4 6 7 8 Purinergic receptors 1. P1 receptors 2. Pharmacology of P1 receptors 3. Distribution of P1 receptors. 3.1 Central Nervous System (CNS) 4. P2 receptors 5. P2X receptors 6. Pharmacology of P2X receptors 6.1 Agonists 6.2 Antagonists 7. P2Y receptors 8. Pharmacology of P2Y receptors. 8.1 Agonists 8.2 Antagonists 9. Distribution of P2 receptors 9.1 Neuronal localization of P2X receptors 9.2 Neuronal localization of P2Y receptors 9 9 10 11 12 13 14 18 18 19 20 22 22 23 24 26 27 Effects of extracellular purines 1. Role of P1 receptors  1.1 P1 receptors and neurotransmission. 1.1 P1 receptors and cerebral ischemia 2. Anoxic depolarization 29 29 30 32 35 Elisabetta Coppi, Purines as Transmitter Molecules: Electrophysiological Studies on Purinergic Signalling in Different Cell Systems, ISBN 978-88-8453-904-5 (print), ISBN 978-88-8453-905-2 (online) © 2008 Firenze University Press 3. Role of P2 receptors 3.1 P2 receptors and neurotransmission 3.2 P2 receptors and cerebral ischemia 3.3 P2 receptors and trophic effects 38 39 43 44 Aim of the study 46 Materials and methods 1. Extracellular recordings 1.1 Acute rat hippocampal slices preparation. 1.2 Experimental procedure 1.3 Protocols used 1.4 OGD conditions 2. Patch clamp recordings 3. Cell cultures 4. Solutions 5. Patch pipettes fabrication 6. Experimental procedures. 7. Voltage clamp protocols 8. Current clamp experiments. 9. Measurement of ATP release from hMSCs 10. Chemicals 11. Statistical analysis 47 47 47 47 48 48 49 50 51 51 52 53 54 55 55 61 RESULTS. Section 1 ROLE OF PURINES IN CA1 HIPPOCAMPAL NEUROTRANSMISSION UNDER NORMOXIC CONDITIONS AND DURING OGD. EXTRACELLULAR RECORDINGS FROM RAT HIPPOCAMPAL SLICES Chapter 1 Role of A3 adenosine receptors during OGD 1. Historical background 2. Results 2.1 Experiments were performed on a total of 219 slices taken from 133 rats 3. Discussion 3.1 Role of adenosine receptor antagonists in depression and disruption of CA1 hippocampal excitatory synaptic transmission during in vitro ischemia.  3.2 Therapeutic implications for the protective role of adenosine A3 receptor antagonists during prolonged ischemic conditions.  3.3 Role of adenosine receptor agonists in depression and disruption of CA1 hippocampal excitatory synaptic transmission during in vitro ischemia.  3.5 Conclusions 65 65 66 66 78 78 81 82 83 Chapter 2 Role of P2 purinergic receptors on hippocampal CA1 neurotransmission under normoxic conditions and during OGD 1. Historical background 2. Results 2.1 Effects of ATP on CA1 hippocampal neurotransmission 2.2 Effects o