Variations in action potential threshold and temporal coding
Hi,
For what I read, the objective of the paper is in fact to study the neural code using methods that study the membrane threshold changes (as you said). They mention both rate and temporal code in the introduction and they do give more emphasis to the temporal coding because it explains better the irregularities of the neuronal transmission.
They did find some correlations between changes in the threshold, which influences the iniciation of the action potential, and the timing and rate of the firing or the firing pattern. That means that the firing pattern influences the iniciation of the action potential even if in an indirect way (which is by influencing the membrane threshold). Saying that the pattern of firing is important it means that the timing is also important, instead of only the rate the firing. Because this is the major difference between both neural codes theory, it does support more the temporal code.