caa a22 4500 463254465 CHVBK 20180405153350.0 cr unu---uuuuu 170326e20070501xx s 000 0 eng 10.1007/s10571-006-9130-0 doi (NATIONALLICENCE)springer-10.1007/s10571-006-9130-0 Depressing Effects of Caffeine at Crayfish Neuromuscular Synapses I. Dosage Response and Ca++ Gradient Effects [Elektronische Daten] [Kristin Judd, Elizabeth Shugert, Samuel Vélez] The response of crayfish synaptic terminals to drugs began to be studied to characterize the terminal's physiological characteristics. Caffeine, the first drug to be studied, was selected to enhance synaptic transmission because of its ability to increase calcium release from internal stores. 1. The largest excitor neuron to the superficial flexor muscle system of Procambarus clarkii was stimulated at 10Hz while recording junction potentials from several lateral muscle fibers. 2. Caffeine unexpectedly decreased synaptic transmission in this system in a dosage-dependent manner. The depressing effect of caffeine was observed at 5mM caffeine and junction potentials disappeared completely at 50mM. Washing the preparation in fresh control Ringers did not restore the amplitudes of the junction potentials. 3. Changes in extracellular calcium concentrations delayed or depressed the caffeine effect depending on the calcium gradient across the membrane or the caffeine dosage. The data suggest that calcium is involved in caffeine's response in this system in a way yet to be determined. Springer Science+Business Media, LLC, 2007 crayfish nationallicence neuromuscular junction nationallicence junction potentials (JPs) nationallicence caffeine nationallicence calcium nationallicence Judd Kristin Department of Biological Sciences, Dartmouth College, 03755, Hanover, New Hampshire, Germany aut Shugert Elizabeth Department of Biological Sciences, Dartmouth College, 03755, Hanover, New Hampshire, Germany aut Vélez Samuel Department of Biological Sciences, Dartmouth College, 03755, Hanover, New Hampshire, Germany aut Cellular and Molecular Neurobiology Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 27/3(2007-05-01), 367-380 0272-4340 27:3<367 2007 27 10571 https://doi.org/10.1007/s10571-006-9130-0 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10571-006-9130-0 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Judd Kristin Department of Biological Sciences, Dartmouth College, 03755, Hanover, New Hampshire, Germany aut NATIONALLICENCE 700 1- Shugert Elizabeth Department of Biological Sciences, Dartmouth College, 03755, Hanover, New Hampshire, Germany aut NATIONALLICENCE 700 1- Vélez Samuel Department of Biological Sciences, Dartmouth College, 03755, Hanover, New Hampshire, Germany aut NATIONALLICENCE 773 0- Cellular and Molecular Neurobiology Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 27/3(2007-05-01), 367-380 0272-4340 27:3<367 2007 27 10571 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer