The effect of calcium ions on the binomial statistic parameters which control acetylcholine release at synapses in striated muscle.
A study has been made of the effects of changing [Ca]O and [Mg]O on the binomial statistic parameters p and n which control the average quantal content (m) of the synaptic potential due to acetylcholine release. 2. When [Ca]O was varied in the range 0-1 to 1-0 mM, p increased as the first power of [Ca]O whereas n increased as the third power of [Ca]O. 3. Increasing [Mg]O depressed both p and n, however variations of [Ca]O in the presence of high [Mg]O did not significantly change the power relationship between either p and [Ca]O or between n and [Ca]O. 4. The facilitated increase in m during a short train was due to an increase in n, whereas the post-tetanic increase in m during a tetanus was due to an increase in p. These results are considered in terms of the role of Ca ions in facilitation and post-tetanic potentiation.
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D004558:Electric Stimulation; D004594:Electrophysiology; D066298:In Vitro Techniques; D008274:Magnesium / Q000494:pharmacology; D009132:Muscles / Q000187:drug effects; D009469:Neuromuscular Junction / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D013223:Statistics as Topic; D013569:Synapses / Q000187:drug effects / Q000502:physiology*
D008274:Magnesium; D000109:Acetylcholine; D002118:Calcium