Such an operation did not lead to any significant disturbances in the normal life of animals at rest and under constant environmental conditions. However, such animals lost the ability to quickly adapt and died from insignificant stressful influences. The behavior of the operated animals with a distant peripheral sympathetic nervous system reminded me of the behavior of elderly people. This similarity was expressed in a low threshold of a stress response to what seemed to be the most insignificant, both external and internal influences, manifested in humans in inadequately strong and unreasonable feelings, fears and worries.
This strengthened me in the consciousness that I was on the right track. I became interested in the fine structure of the ANS and the structural features of the neurons of this metabolic regulation system, looking for weak links that could make it the most vulnerable component of the aging mechanism of the body. The success of the search was largely predetermined by my “bioenergetic” past in science [6]. Since then, I have viewed all significant aging events through the prism of bioenergetics.
Such weak links were quickly discovered – incredibly extended processes of pseudo-unipolar neurons, in which a single axon leaves the cell body, splitting into two branches: a long one towards the sense organ and a short one towards the central nervous system, as well as slow and energy-consuming processes of axonal transport over long distances of tens of centimeters, which determines the slow process of their regeneration.
The volume of cytoplasm located in the extended processes of such neurons is hundreds of times greater than the volume of cytoplasm in the body of the neuron, in which the nucleus and the Golgi apparatus are localized, supplying the processes with all the necessary “building materials” for their growth and regeneration due to slow axonal vesicular transport, the speed which is much less than the blood flow velocity. The speed of vesicular transport in the axon reaches 20–50 cm / day, and the blood flow rate is in the range from 0.03 cm / sec in the capillaries to 40 cm / sec in the aorta.
Thus, the rate of vesicular axonal transport of mitochondria and enzymes accumulated in the Golgi apparatus and is 50–70000 times less than the rate of transport of nutrients by the circulatory system. This difference predetermines the limiting stage of the regeneration process of axons damaged in one way or another, which is from 2 to 5 mm per day. I came to the conclusion, that it is the energetics of these unique neurons that can be a limiting factor in their effective work and the regeneration of their offshoots. And since the energetics of a neuron is based on oxidative phosphorylation, I came to the preliminary conclusion that only oxygen can be the initial limiting factor in the work of these unique neurons. Later it turned out that the weakest point of these neurons are the terminal areas of axons farthest from the cell nucleus and from the Golgi apparatus, on which receptors are localized and which are capable of regeneration after physiological degeneration.