miniature end-plate potential
Also written as: mEPP — miniature end-plate potential
Small spontaneous depolarizations at the neuromuscular junction caused by single vesicle release.
Full Definition
Miniature end-plate potentials (mEPPs) are small, spontaneous depolarizations recorded at the neuromuscular junction that result from the spontaneous release of single synaptic vesicles containing acetylcholine. Each mEPP represents the postsynaptic response to the contents of one vesicle, providing insight into the quantal nature of neurotransmitter release. mEPPs occur randomly in the absence of nerve stimulation and have relatively uniform amplitudes, reflecting the consistent amount of neurotransmitter in each vesicle. Analysis of mEPP frequency and amplitude is used to study presynaptic function and neuromuscular disorders. The study of mEPPs was fundamental to understanding synaptic transmission mechanisms.
Usage
Usage note: Specific to neuromuscular junction; distinguish from miniature EPSPs in central synapses.
In Context
- "The frequency of mEPPs increased following treatment with the cholinesterase inhibitor." — Pharmacological study
- "Analysis of mEPP amplitude distribution revealed changes in vesicular acetylcholine content." — Neuromuscular research