I have noticed when first coming on in the morning that there comes a point when a good stretch kicks things into overdrive. I know there are receptors where the muscle attaches to bone that are stimulated and I assumed that was what I was experiencing. But the article below indicates that physical tensioning systems within the neuron itself are necessary for functioning, even within the brain itself. It makes me wonder, too, about the phenomenon of "wasting" when one is confined to bed.

"ScienceDaily (Aug. 24, 2009) — Every time a neuron sends a signal – to move a muscle or form a memory, for example – tiny membrane-bound compartments, called vesicles, dump neurotransmitters into the synapse between the cells. Researchers report that this process, which is fundamental to the workings of the nervous system, relies on a simple mechanical reality: Tension in the axon of the presynaptic neuron is required.

Without this tension, the researchers found, the vesicles that must haul their chemical cargo to the synapse for neuronal signaling would instead disperse.

The new findings appear this week in the Proceedings of the National Academy of Sciences."

http://www.sciencedaily.com/releases...0720190556.htm