constant/variable question thanks in advance!

[allsmiles66]

This is a pretty basic question but I really need help with this! Thanks in advance!

 

 

When an action potential invades a presynaptic terminal, it opens Ca2+ channels in the terminal membrane and this allows Ca2+ to flow from the extracellular medium surrounding the presynaptic terminal into the terminal. The resulting increase in Ca2+ within the terminal is actually what causes the relaase of neurotransmitter from the terminal during synaptic transmission. Supporting this model of the sequence of events that occurs during synaptic transmission, experimental data has shown that if the experimenter lowers the extracellular concentration of Ca2+ from 2mM to 1 mM to 0.5 mM the amplitude of the EPSP elicited by electrical stimulation of the presynaptic axon and recorded from the postsynaptic cell becomes progressively smaller.

 

a) Describe the 2 main variables present in this experiment.

b) What changes do these variables undergo during the course of this experiment?

c) Name 3 constants present during this experiment.