Figure Q3-4 Documents the Quantal Release of Neurotransmitter

Essay

Figure Q3-4 documents the quantal release of neurotransmitter. Figure Q3-4
A. The investigators stimulated the nerve in low-Ca²⁺ and high-Mg²⁺ saline so that they had many failures with nerve stimulation. Why was the presence of failures so important?
B. In the top trace, there were three motor nerve stimulations that occurred at the arrow. Why is the flat trace flat and, based on what we know now, what is the reason that the other two traces are multiples of each other?
C. The investigators compared the evoked EPPs in low Ca²⁺/high Mg²⁺ saline to spontaneous EPPs (mEPP). What did they find (see figures on the right) and what did they conclude?
D. Based on the findings in this figure, what did they conclude about transmitter release in an evoked EPP in normal saline?