Stationary and non-stationary occurrences of miniature end plate potentials are well described as stationary and non-stationary Poisson processes in the mollusc Navanax inermis.
Protractor muscles in the gastropod mollusc Navanax inermis exhibit typical spontaneous miniature end plate potentials with mean amplitude 1.71 +/- 1.19 (standard deviation) mV. The evoked end plate potential is quantized, with a quantum equal to the miniature end plate potential amplitude. When their rate is stationary, occurrence of miniature end plate potentials is a random, Poisson process. When non-stationary, spontaneous miniature end plate potential occurrence is a non-stationary Poisson process, a Poisson process with the mean frequency changing with time. This extends the random Poisson model for miniature end plate potentials to the frequently observed non-stationary occurrence. Reported deviations from a Poisson process can sometimes be accounted for by the non-stationary Poisson process and more complex models, such as clustered release, are not always needed.
Cappell
M S
MS
Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461.
Spray
D C
DC
Bennett
M V
MV
D000200:Action Potentials; D000818:Animals; D008974:Mollusca / Q000502:physiology*; D009045:Motor Endplate / Q000502:physiology*; D009046:Motor Neurons / Q000502:physiology*; D009132:Muscles / Q000502:physiology*; D009469:Neuromuscular Junction / Q000502:physiology*