So, it was really a throwback, this early science. Even to my undergrads over many years. I had majored in mathematics at Colgate and had a very good course in partial differential equations. One of the key questions, which was commented on by ignorant reviewers, was these cells are not real, they're all artifact, they're tissue culture artifacts. I felt it was important to study the membrane properly of muscle and nerve.
It was about the time when Wilfred Rall at the NIH and Phil Nelson [and three other authors] had published a series of papers in the Journal of Neurophysiology on motor neurons, showing that these highly branched neurons could be reduced mathematically to the single cylinders, and they could estimate the membrane properties. I decided to do a similar but different project with the branched myotubes. And we analyzed the input resistance, the membrane capacitance, as well as the membrane potential of myotubes at different stages of development, whether they were single cylinders or branched cylinders.
That analysis showed that the membrane resistivity, which was derived from these differential equations, was very comparable to adult mature muscle, so this was not tissue culture artifact, but it was real muscle with intact membranes. That gave me a great deal of satisfaction because it combined the partial differential equation with a very important and relevant developmental issue. I think that settled, in my mind at least, the notion that we were not dealing with leaky cells, artifacts.