Final answer:
The size of a MEPP can be estimated by using quantal analysis on the distribution of EPP amplitudes under low extracellular calcium. This involves creating a histogram of EPP amplitudes and identifying the MEPP as the difference between the steps in the histogram or by dividing the average EPP amplitude by the most probable quantal content.
Step-by-step explanation:
To estimate the size of the miniature endplate potential (MEPP) given the distribution of endplate potential (EPP) amplitudes under low extracellular calcium, one can utilize the quantal analysis method. MEPPs are the postsynaptic potentials generated by the release of a single synaptic vesicle containing neurotransmitters. In low calcium conditions, the probability of neurotransmitter release decreases, leading to a higher occurrence of MEPPs and a lower frequency of multiple vesicle releases.
Quantal analysis involves counting the number of miniature potentials, assuming that the EPP is composed of multiple, discrete units, or quanta, the size of which is equal to the MEPP. By creating a histogram of the EPP amplitudes, one can see a step-like distribution. The size of the MEPP can be estimated by calculating the difference in amplitude between these steps or by dividing the average EPP amplitude by the most probable number of quanta released.