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Effects of physiologic alterations on binomial transmitter release at magnesium‐depressed neuromuscular junctions.
Author(s) -
Branisteanu D D,
Miyamoto M D,
Volle R L
Publication year - 1976
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.1976.sp011218
Subject(s) - transmitter , amplitude , magnesium , neuromuscular transmission , poisson distribution , statistics , negative binomial distribution , neuromuscular junction , chemistry , mathematics , physics , biophysics , telecommunications , medicine , biology , anesthesia , neuroscience , computer science , quantum mechanics , channel (broadcasting) , organic chemistry
1. Transmitter release from Mg2+‐treated frog neuromuscular junctions can be described by binomial statistics. Good agreement between the observed amplitude‐frequency distribution of e.p.p.s. and that predicted by binomial statistics is observed with relatively low concentrations of Mg2+. Conversely, good agreement is found with Poisson predictions when higher concentrations of Mg2+ are used to depress transmission. 2. Binomial analysis at these junctions shows that Mg2+ reduces quantal content (m), the probability of release (p) and to a lesser extent the available stores of transmitter (n). Raising Ca2+ causes an increase in n and p and a small but significant increase in n. K+ increases m and p but not n. 3. During 'frequency‐facilitation' (1‐6 Hz), e.p.p.s., m and n are increased but p is unaffected. 4. It is concluded that binomial statistics can be used to estimate the quantal parameters of transmitter release and that these parameters can be identified as discrete entities.