When I arrived at the NIH, having had a little bit of experience with nerve-muscle synapses, I began working with a wonderful person named Norman Robbins, who was very principled. He was a Harvard graduate, who had worked with excellent trophic factor people at Harvard and at Rockefeller, and we fit right in. He was a skilled experimentalist, and we began working on the rat and mouse neuromuscular junction. We published several papers together.
We didn't want to denervate muscle, so we wanted to study use and disuse. I worked out a technique for immobilizing one hind limb of the mouse and the rat, so they couldn't stand on it. We documented the disuse by indwelling EMG, electromyograph electrodes, which I had developed and which we recorded through leads brought out to the spine. And documented profound disuse and showed that there was a change in the distribution of acetylcholine receptors. There was a spread of ACh sensitivity and we showed that this could be affected by the activity of the nerve-muscle synapse, so it was independent of denervation, which also led to a spread of activity. It's that observation, I think, though there were several others, which made me focus on use and disuse, the nerve-muscle synapse and acetylcholine receptors – which became the focus of my research for at least the next 20 years.