[Quasielectrostatic manipulation of a single neuron: trace phenomena and comparison with intracellular excitation]

The investigation of quasielectrostatic impact (QESI) on the electrical activity of an isolated neuron of the mollusc brain was continued under conditions of continuous (20 min to 2 hours) and repeated applications. It was shown that the repeated application of QESI changes the level of electrical activity of the neurons. For different cells the repeated application of QESI produces an increase as well as a decrease of the neurons activity, while the thresholds of the frequency modulation of the spontaneously active and the excitation of the "silent" cells become lower. These changes remain valid after QESI is stopped. The trace events shown on the level of an isolated neuron prove the importance of the properties of a single cell, rather than the intercellular interactions. The transmembrane current thresholds for FM of activity of the cells produced by QESI was compared with the currents for intracellular stimulation. It was shown that the QESI thresholds are lower being different cells (2 divided by 12) times less. The specificity of QESI important for explanation of ephatic connection mechanism is discussed.