PH CHANGES DURING EXCITATION OF NERVE

Rhythmic excitation of frog, crab, and squid nerves is known to cause an acidification of environment medium. Its extent depends on excitation rhythm and proportions of extracellular sodium, potassium and hydrogen ions. It can also be modified by addition of agents, which inhibit the metabolic processes in the nerve or modify the sodium and potassium ion transport. With the use of microspectrofluorometry the pH-dynamics in the nerve at rest and during rhythmic excitation was investigated. Rhythmic excitation results in increase of hydrogen ion concentration in the nerve fibres. Metabolic and ion channel inhibitors affect intracellular pH changes. The results obtained suggest a different role of H+ at excitation and deprotonation of axolemma. The removal of hydrogen ions out of the Na channels has been suggested as the most probable explanation for the above observations.