title: The effects of calcium and magnesium on statistical release parameters at the crayfish neuromuscular junction.
abstract: 1. Transmitter release at excitatory neuromuscular junctions of crayfish muscle was studied at low temperature by recording synaptic potentials with extracellular micro-electrodes.2. Increasing the Ca concentration in the bathing solution produced an increase in the average number of quanta released per nerve stimulus (m). Increasing the Mg concentration resulted in a decrease in m.3. Statistical analysis of fluctuations in the quantal release from trial to trial, assuming binomial statistics, indicated that both the changes in m were due to changes in the average quantal release probability (p).
mesh_terms: D000818:Animals; D003400:Astacoidea; D002118:Calcium / Q000494:pharmacology*; D003864:Depression, Chemical; D004594:Electrophysiology; D066298:In Vitro Techniques; D008274:Magnesium / Q000494:pharmacology*; D008839:Microelectrodes; D009469:Neuromuscular Junction / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D018377:Neurotransmitter Agents / Q000378:metabolism; D011336:Probability; D012636:Secretory Rate / Q000187:drug effects; D013268:Stimulation, Chemical; D013569:Synapses / Q000502:physiology; D009435:Synaptic Transmission
chemical_list: D018377:Neurotransmitter Agents; D008274:Magnesium; D002118:Calcium