caa a22 4500 463254449 CHVBK 20180405153350.0 cr unu---uuuuu 170326e20070501xx s 000 0 eng 10.1007/s10571-006-9131-z doi (NATIONALLICENCE)springer-10.1007/s10571-006-9131-z Depressing Effect of Caffeine at Crayfish Neuromuscular Synapses II. Initial Search for Possible Sites of Action [Elektronische Daten] II. Initial Search for Possible Sites of Action [Kathryn Celenza, Elizabeth Shugert, Samuel Vélez] Caffeine's unexpected depression of synaptic transmission in the superficial flexor muscle system (SFM) of Procambarus clarkii was studied by looking at three known sites of action of this drug: via adenosine and ryanodine receptors and inhibition of phosphodiesterase. 1. JPs did not change in size when exposed to physiological concentrations of adenosine, suggesting that the SFM system lacks presynaptic adenosine receptors. 2. JPs slightly increased in size in the presence of a phosphodiesterase inhibitor, the opposite response to that obtained with caffeine, suggesting that caffeine is not acting via this pathway. 3. A calcium ionophore immediately enhanced synaptic transmission in the SFM system but when given in combination with caffeine the enhancement is reduced and declines over time. 4. Serotonin enhanced synaptic transmission in the SFM system, but when given in combination with caffeine this enhancement was not observed. 5. These caffeine effects are interpreted in terms of alterations to the calcium homeostatic mechanisms of the terminals. Springer Science+Business Media, LLC, 2007 caffeine nationallicence adenosine nationallicence phosphodiesterase inhibitor nationallicence calcium ionophore nationallicence serotonin nationallicence Celenza Kathryn Department of Biological Sciences, Dartmouth College, 03755, Hanover, New Hampshire, USA aut Shugert Elizabeth Department of Biological Sciences, Dartmouth College, 03755, Hanover, New Hampshire, USA aut Vélez Samuel Department of Biological Sciences, Dartmouth College, 03755, Hanover, New Hampshire, USA aut Cellular and Molecular Neurobiology Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 27/3(2007-05-01), 381-393 0272-4340 27:3<381 2007 27 10571 https://doi.org/10.1007/s10571-006-9131-z text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10571-006-9131-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Celenza Kathryn Department of Biological Sciences, Dartmouth College, 03755, Hanover, New Hampshire, USA aut NATIONALLICENCE 700 1- Shugert Elizabeth Department of Biological Sciences, Dartmouth College, 03755, Hanover, New Hampshire, USA aut NATIONALLICENCE 700 1- Vélez Samuel Department of Biological Sciences, Dartmouth College, 03755, Hanover, New Hampshire, USA aut NATIONALLICENCE 773 0- Cellular and Molecular Neurobiology Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 27/3(2007-05-01), 381-393 0272-4340 27:3<381 2007 27 10571 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer