One of the main problems of contemporary bioinformatics consists in revealing physical-chemical nature of neural signal generation, as well as some principles of information transmission from neural cell to muscular one. It may be seen as a necessary step to understanding molecular mechanisms of neural system activity.
Neural cells transmit informations by signals that represent electric currents generated by neuron surface membrane. These currents arise due to transferring charges which belong to the ions of sodium, potassium, calcium and chloride. The information transmission process in neuromuscular synapses may be divided into two basic phases: (a) a mediator release from nervous endings caused by neural impulse, and (b) a mediator interaction with postsynaptic membrane that implies the miniature end-plate potentials (MEPP).
The hypothesis on a quantum secretion nature underlyes modern views on the mediator release mechanism. Under normal conditions a spontaneous release of bubbles charged with mediator into synaptic fissure takes place. These bubbles are seen as quanta containing intermolecular portions of about acetylcholine molecules. Here the Ca2+ ions which enter into nervous endings during the action potential are the activators of release system. Then some mediator quanta attain the postsynaptic membranes surface that leads to local depolarization registered as membrane potential. In the course of depolarization caused by action potential diffusion across the nerons the quanta release is rapidly increased, and the degree of depolarization in postsynaptic membrane grows. These changes in membrane potential are registered as MEPP values. While attaining a critical value MEPP is transformed into regenerative depolarization process in postsynaptic membrane which is registered as an upward phase of action potential. Nevertheless, due to holinesterathic influences, the acetylcholine destruction takes place. It leads to restoring membrane potential on its initial level. As an alternative to quantum-vesicular hypothesis, a possibility to release acetylcholine via specific canals of presynaptic membrane is discussed.
The work is submitted to the II Scientific International Conference «Higher vocational education. Modern aspects of international cooperation», Israel, May 1-7, 2009, came to the editorial office on 19.03.2009.